Capivasertib in combination with enzalutamide for metastatic castration resistant prostate cancer after docetaxel and abiraterone: Results from the randomized phase II RE-AKT trial

BACKGROUND

PTEN loss and aberrations in PI3K/AKT signaling kinases associate with poorer response to abiraterone acetate (AA) in metastatic castration-resistant prostate cancer (mCRPC). In this study, we assessed antitumor activity of the AKT inhibitor capivasertib combined with enzalutamide in mCRPC with prior progression on AA and docetaxel.

METHODS

This double-blind, placebo-controlled, randomized phase 2 trial, recruited men ≥ 18 years with progressing mCRPC and performance status 0-2 from 15 UK centers. Randomized participants (1:1) received enzalutamide (160 mg orally, once daily) with capivasertib (400 mg)/ placebo orally, twice daily on an intermittent (4 days on, 3 days off) schedule. Primary endpoint was composite response rate (RR): RECIST 1.1 objective response, ≥ 50 % PSA decrease from baseline, or circulating tumor cell count conversion (from ≥ 5 at baseline to < 5 cells/7.5 mL). Subgroup analyses by PTENIHC status were pre-planned.

RESULTS

Overall, 100 participants were randomized (50:50); 95 were evaluable for primary endpoint (47:48); median follow-up was 43 months. RR were 9/47 (19.1 %) enzalutamide/capivasertib and 9/48 (18.8 %) enzalutamide/placebo (absolute difference 0.4 % 90 %CI -12.8 to 13.6, p = 0.58), with similar results in the PTENIHC loss subgroup. Irrespective of treatment, OS was significantly worse for PTENIHC loss (10.1 months [95 %CI: 4.6-13.9] vs 14.8 months [95 %CI: 10.8-18]; p = 0.02). Most common treatment-emergent grade ≥ 3 adverse events for the combination were diarrhea (13 % vs 2 %) and fatigue (10 % vs 6 %).

CONCLUSIONS

Combined capivasertib/enzalutamide was well tolerated but didn't significantly improve outcomes from abiraterone pre-treated mCRPC.

Systemic anticancer therapy for urothelial carcinoma: UK oncologists' perspective

Urothelial carcinoma (UC) is a common cancer associated with a poor prognosis in patients with advanced disease. Platinum-based chemotherapy has remained the cornerstone of systemic anticancer treatment for many years, and recent developments in the treatment landscape have improved outcomes. In this review, we provide an overview of systemic treatment for UC, including clinical data supporting the current standard of care at each point in the treatment pathway and author interpretations from a UK perspective. Neoadjuvant cisplatin-based chemotherapy is recommended for eligible patients with muscle-invasive bladder cancer and is preferable to adjuvant treatment. For first-line treatment of advanced UC, platinum-eligible patients should receive cisplatin- or carboplatin-based chemotherapy, followed by avelumab maintenance in those without disease progression. Among patients unable to receive platinum-based chemotherapy, immune checkpoint inhibitor (ICI) treatment is an option for those with programmed death ligand 1 (PD-L1)-positive tumours. Second-line or later treatment options depend on prior treatment, and enfortumab vedotin is preferred after prior ICI and chemotherapy, although availability varies between countries. Additional options include rechallenge with platinum-based chemotherapy, an ICI, or non-platinum-based chemotherapy. Areas of uncertainty include the optimal number of first-line chemotherapy cycles for advanced UC and the value of PD-L1 testing for UC.

First-line talazoparib with enzalutamide in HRR-deficient metastatic castration-resistant prostate cancer: the phase 3 TALAPRO-2 trial

Preclinical evidence has suggested an interplay between the androgen receptor, which largely drives the growth of prostate cancer cells, and poly(ADP-ribose) polymerase. This association provides a rationale for their co-inhibition for the treatment of metastatic castration-resistant prostate cancer (mCRPC), an area of unmet medical need. The phase 3 TALAPRO-2 study investigated combining the poly(ADP-ribose) polymerase inhibitor talazoparib with enzalutamide versus enzalutamide alone as first-line treatment of mCRPC. Patients were prospectively assessed for tumor alterations in DNA damage response genes involved in homologous recombination repair (HRR). Two cohorts were enrolled sequentially: an all-comers cohort that was enrolled first (cohort 1; N = 805 (169 were HRR-deficient)), followed by an HRR-deficient-only cohort (cohort 2; N = 230). We present results from the alpha-controlled primary analysis for the combined HRR-deficient population (N = 399). Patients were randomized in a 1:1 ratio to talazoparib or placebo, plus enzalutamide. The primary endpoint, radiographic progression-free survival, was met (median not reached at the time of the analysis for the talazoparib group versus 13.8 months for the placebo group; hazard ratio, 0.45; 95% confidence interval, 0.33 to 0.61; P < 0.0001). Data for overall survival, a key secondary endpoint, are immature but favor talazoparib (hazard ratio, 0.69; 95% confidence interval, 0.46 to 1.03; P = 0.07). Common adverse events in the talazoparib group were anemia, fatigue and neutropenia. Combining talazoparib with enzalutamide significantly improved radiographic progression-free survival in patients with mCRPC harboring HRR gene alterations, supporting talazoparib plus enzalutamide as a potential first-line treatment for these patients. ClinicalTrials.gov Identifier: NCT03395197 .

Quantitative imaging of three-dimensional fiber orientation in the human brain via two illumination angles using polarization-sensitive optical coherence tomography

The accurate measurement of three-dimensional (3D) fiber orientation in the brain is crucial for reconstructing fiber pathways and studying their involvement in neurological diseases. Optical imaging methods such as polarization-sensitive optical coherence tomography (PS-OCT) provide important tools to directly quantify fiber orientation at micrometer resolution. However, brain imaging based on the optic axis by PS-OCT so far has been limited to two-dimensional in-plane orientation, preventing the comprehensive study of connectivity in 3D. In this work, we present a novel method to obtain the 3D fiber orientation in full angular space with only two illumination angles. We measure the optic axis orientation and the apparent birefringence by PS-OCT from a normal and a 15 deg tilted illumination, and then apply a computational method yielding the 3D optic axis orientation and true birefringence. We verify that our method accurately recovers a large range of through-plane orientations from -85 deg to 85 deg with a high angular precision. We further present 3D fiber orientation maps of entire coronal sections of human cerebrum and brainstem with 10 μm in-plane resolution, revealing unprecedented details of fiber configurations. We envision that further development of our method will open a promising avenue towards large-scale 3D fiber axis mapping in the human brain and other complex fibrous tissues at microscopic level.

Talazoparib plus enzalutamide in men with first-line metastatic castration-resistant prostate cancer (TALAPRO-2): a randomised, placebo-controlled, phase 3 trial

BACKGROUND

Co-inhibition of poly(ADP-ribose) polymerase (PARP) and androgen receptor activity might result in antitumour efficacy irrespective of alterations in DNA damage repair genes involved in homologous recombination repair (HRR). We aimed to compare the efficacy and safety of talazoparib (a PARP inhibitor) plus enzalutamide (an androgen receptor blocker) versus enzalutamide alone in patients with metastatic castration-resistant prostate cancer (mCRPC).

METHODS

TALAPRO-2 is a randomised, double-blind, phase 3 trial of talazoparib plus enzalutamide versus placebo plus enzalutamide as first-line therapy in men (age ≥18 years [≥20 years in Japan]) with asymptomatic or mildly symptomatic mCRPC receiving ongoing androgen deprivation therapy. Patients were enrolled from 223 hospitals, cancer centres, and medical centres in 26 countries in North America, Europe, Israel, South America, South Africa, and the Asia-Pacific region. Patients were prospectively assessed for HRR gene alterations in tumour tissue and randomly assigned (1:1) to talazoparib 0·5 mg or placebo, plus enzalutamide 160 mg, administered orally once daily. Randomisation was stratified by HRR gene alteration status (deficient vs non-deficient or unknown) and previous treatment with life-prolonging therapy (docetaxel or abiraterone, or both: yes vs no) in the castration-sensitive setting. The sponsor, patients, and investigators were masked to talazoparib or placebo, while enzalutamide was open-label. The primary endpoint was radiographic progression-free survival (rPFS) by blinded independent central review, evaluated in the intention-to-treat population. Safety was evaluated in all patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov (NCT03395197) and is ongoing.

FINDINGS

Between Jan 7, 2019, and Sept 17, 2020, 805 patients were enrolled and randomly assigned (402 to the talazoparib group and 403 to the placebo group). Median follow-up for rPFS was 24·9 months (IQR 21·9-30·2) for the talazoparib group and 24·6 months (14·4-30·2) for the placebo group. At the planned primary analysis, median rPFS was not reached (95% CI 27·5 months-not reached) for talazoparib plus enzalutamide and 21·9 months (16·6-25·1) for placebo plus enzalutamide (hazard ratio 0·63; 95% CI 0·51-0·78; p<0·0001). In the talazoparib group, the most common treatment-emergent adverse events were anaemia, neutropenia, and fatigue; the most common grade 3-4 event was anaemia (185 [46%] of 398 patients), which improved after dose reduction, and only 33 (8%) of 398 patients discontinued talazoparib due to anaemia. Treatment-related deaths occurred in no patients in the talazoparib group and two patients (<1%) in the placebo group.

INTERPRETATION

Talazoparib plus enzalutamide resulted in clinically meaningful and statistically significant improvement in rPFS versus standard of care enzalutamide as first-line treatment for patients with mCRPC. Final overall survival data and additional long-term safety follow-up will further clarify the clinical benefit of the treatment combination in patients with and without tumour HRR gene alterations.

FUNDING

Pfizer.

Results from a Phase 1b/2 Study of Ibrutinib Combination Therapy in Advanced Urothelial Carcinoma

Ibrutinib is a first-in-class Bruton's tyrosine kinase inhibitor approved for the treatment of various B-cell malignancies and chronic graft-versus-host disease. We evaluated the safety and efficacy of ibrutinib, alone or combined with standard-of-care regimens, in adults with advanced urothelial carcinoma (UC). Once-daily ibrutinib was administered orally at 840 mg (single-agent or with paclitaxel) or at 560 mg (with pembrolizumab). Phase 1b determined the recommended phase 2 dose (RP2D) of ibrutinib, and phase 2 assessed progression-free survival (PFS), overall response rate (ORR), and safety. Thirty-five, eighteen, and fifty-nine patients received ibrutinib, ibrutinib plus pembrolizumab, and ibrutinib plus paclitaxel at the RP2D, respectively. Safety profiles were consistent with those of the individual agents. The best-confirmed ORRs were 7% (two partial responses) with single-agent ibrutinib and 36% (five partial responses) with ibrutinib plus pembrolizumab. Median PFS was 4.1 months (range, 1.0-37.4+) with ibrutinib plus paclitaxel. The best-confirmed ORR was 26% (two complete responses). In previously treated patients with UC, ORR was higher with ibrutinib plus pembrolizumab than with either agent alone (historical data in the intent-to-treat population). ORR with ibrutinib plus paclitaxel was greater than historical values for single-agent paclitaxel or ibrutinib. These data warrant further evaluation of ibrutinib combinations in UC.

Abiraterone acetate plus prednisolone with or without enzalutamide for patients with metastatic prostate cancer starting androgen deprivation therapy: final results from two randomised phase 3 trials of the STAMPEDE platform protocol

BACKGROUND

Abiraterone acetate plus prednisolone (herein referred to as abiraterone) or enzalutamide added at the start of androgen deprivation therapy improves outcomes for patients with metastatic prostate cancer. Here, we aimed to evaluate long-term outcomes and test whether combining enzalutamide with abiraterone and androgen deprivation therapy improves survival.

METHODS

We analysed two open-label, randomised, controlled, phase 3 trials of the STAMPEDE platform protocol, with no overlapping controls, conducted at 117 sites in the UK and Switzerland. Eligible patients (no age restriction) had metastatic, histologically-confirmed prostate adenocarcinoma; a WHO performance status of 0-2; and adequate haematological, renal, and liver function. Patients were randomly assigned (1:1) using a computerised algorithm and a minimisation technique to either standard of care (androgen deprivation therapy; docetaxel 75 mg/m² intravenously for six cycles with prednisolone 10 mg orally once per day allowed from Dec 17, 2015) or standard of care plus abiraterone acetate 1000 mg and prednisolone 5 mg (in the abiraterone trial) orally or abiraterone acetate and prednisolone plus enzalutamide 160 mg orally once a day (in the abiraterone and enzalutamide trial). Patients were stratified by centre, age, WHO performance status, type of androgen deprivation therapy, use of aspirin or non-steroidal anti-inflammatory drugs, pelvic nodal status, planned radiotherapy, and planned docetaxel use. The primary outcome was overall survival assessed in the intention-to-treat population. Safety was assessed in all patients who started treatment. A fixed-effects meta-analysis of individual patient data was used to compare differences in survival between the two trials. STAMPEDE is registered with ClinicalTrials.gov (NCT00268476) and ISRCTN (ISRCTN78818544).

FINDINGS

Between Nov 15, 2011, and Jan 17, 2014, 1003 patients were randomly assigned to standard of care (n=502) or standard of care plus abiraterone (n=501) in the abiraterone trial. Between July 29, 2014, and March 31, 2016, 916 patients were randomly assigned to standard of care (n=454) or standard of care plus abiraterone and enzalutamide (n=462) in the abiraterone and enzalutamide trial. Median follow-up was 96 months (IQR 86-107) in the abiraterone trial and 72 months (61-74) in the abiraterone and enzalutamide trial. In the abiraterone trial, median overall survival was 76·6 months (95% CI 67·8-86·9) in the abiraterone group versus 45·7 months (41·6-52·0) in the standard of care group (hazard ratio [HR] 0·62 [95% CI 0·53-0·73]; p<0·0001). In the abiraterone and enzalutamide trial, median overall survival was 73·1 months (61·9-81·3) in the abiraterone and enzalutamide group versus 51·8 months (45·3-59·0) in the standard of care group (HR 0·65 [0·55-0·77]; p<0·0001). We found no difference in the treatment effect between these two trials (interaction HR 1·05 [0·83-1·32]; p_interaction=0·71) or between-trial heterogeneity (I² p=0·70). In the first 5 years of treatment, grade 3-5 toxic effects were higher when abiraterone was added to standard of care (271 [54%] of 498 vs 192 [38%] of 502 with standard of care) and the highest toxic effects were seen when abiraterone and enzalutamide were added to standard of care (302 [68%] of 445 vs 204 [45%] of 454 with standard of care). Cardiac causes were the most common cause of death due to adverse events (five [1%] with standard of care plus abiraterone and enzalutamide [two attributed to treatment] and one (<1%) with standard of care in the abiraterone trial).

INTERPRETATION

Enzalutamide and abiraterone should not be combined for patients with prostate cancer starting long-term androgen deprivation therapy. Clinically important improvements in survival from addition of abiraterone to androgen deprivation therapy are maintained for longer than 7 years.

FUNDING

Cancer Research UK, UK Medical Research Council, Swiss Group for Clinical Cancer Research, Janssen, and Astellas.

Predictive value of C reactive protein (CRP) in patients with metastatic renal cell carcinoma (mRCC) treated with pembrolizumab (pembro) and axitinib (axi)

716

Background: CRP, a biomarker of systemic inflammation, has been shown to have prognostic value in numerous tumour types, including mRCC. The combination of the immune check inhibitor (ICI), pembro, and vascular endothelial growth factor receptor tyrosine kinase inhibitor (VEGFR-TKI) axi is one of several internationally approved combination ICI/VEGFR-TKI treatment options. We evaluated the predictive value of biomarkers of systemic inflammation in a real-world cohort of patients with mRCC treated with pembro and axi. Methods: Retrospective data of patients treated with pembro and axi were collected from a regional electronic database from two large cancer centres. Inflammatory biomarkers from routine blood tests (including haemoglobin, neutrophil count, platelets, albumin and CRP) prior to starting treatment were recorded. The IMDC score and modified Glasgow Prognostic Score (combining albumin and CRP) were calculated. The primary end point, progression free survival (PFS), was defined as the time between initiation of treatment and clinical or radiographical progression or death, or censorship. Overall survival, defined as the time between initiation of treatment and death, or censorship was also calculated. Univariate and multivariate analyses were undertaken using Cox Regression model and the relationship between different markers and PFS was assessed using Kaplan-Meier curves. Results: Data were available for 93 patients. 74 pts (80%) had clear cell histology, 19 pts (20%) had non-clear cell and 11 pts (12%) had sarcomatoid component. 46 patients had previous nephrectomy. 15 (16%), 46 (50%) and 32 (34%) pts respectively were classified as favourable, intermediate, and poor risk group as per IMDC score. Median PFS was 10.7 (IQR 4.6-not reached) months after a minimum 12.5 months follow-up. Baseline CRP was recorded in 77 (83%) patients, reflecting current routine clinical guidelines. On univariate analysis, neutrophils (≤7.5x109/L/>7.5x109/L) (p=0.044), platelets (≤400 x109/L/>400x109/L) (p=0.043), CRP (≤10mg/L/>10mg/L) (p=0.001), mGPS (0/1/2) (p=0.004) and IMDC risk group (low/intermediate/poor) (p=0.038) were predictive of PFS. On multivariate analyses only CRP was associated with PFS (HR2.78 (95% CI, 1.42-5.44) (p=0.003). At a 1-year landmark PFS was 62% (CRP ≤10mg/L) v 29% (CRP >10mg/L) (p=0.002). CRP also predicted OS ((HR4.50 (95% CI, 1.58-12.8) (p=0.005)) with 1-year OS 85% (CRP ≤10mg/L) v 59% (CRP >10mg/L) (p=0.002). Conclusions: CRP, a biomarker of systemic inflammation, predicts survival in mRCC patients undergoing combined ICI/VEGF-TKI therapy. Our findings support comparable studies in the mRCC population and routine recording of CRP in patients with mRCC. We advocate further work to validate utilisation of CRP as a prognostic biomarker for mRCC in clinical practice.

First-in-class oral innate immune activator BXCL701 combined with pembrolizumab in patients with metastatic, castration-resistant prostate cancer (mCRPC) of small cell neuroendocrine (SCNC) phenotype: Phase 2a final results

176

Background: BXCL701 (talabostat), oral small molecule inhibitor of dipeptidyl peptidases (DPP)—primarily DPP8/9 & DPP4—triggers inflammasome to alert and prime immune cells, leading to induction of IL-18 & IL-1ß, bridging innate & adaptive immunity. BXCL701 is evaluated in a Phase 2 study in combination with pembrolizumab, in mCRPC patients with SCNC phenotype. SCNC is highly proliferative and aggressive with limited duration of response to platinum-based chemotherapy. Here are reported the results of the Phase 2a after enrollment of 32 patients for the SCNC cohort. The final results will be presented at the Symposium. Methods: Phase 2a patients with any SCNC histopathological features, either de novo or treatment-emergent including mixed SCNC, required to have progression by PCWG3 on ≥1 prior line of cytotoxic chemotherapy (patients who either have refused chemotherapy or are considered unsuitable for chemotherapy also permitted entry with prior approval by sponsor). Patients receive pembrolizumab (200 mg IV q3week) + BXCL701 0.2 mg BID on days 1-7 with step-up to 0.3 mg BID on days 8-14, and 0.3 mg BID on days 1-14 of subsequent cycles. Primary endpoint is Composite Response, either objective response by RECIST 1.1 or PSA50 or CTC count conversion from ≥5/7.5 mL to <5/7.5 mL from baseline. Study uses a Simon 2-stage minimax design with 15 evaluable patients in stage 1 and 13 in stage 2. Baseline markers and changes in relevant immune effector cells also evaluated. Results: As of 10/11/2022, 32 patients have been accrued, 27 of which are evaluable. 16 patients (59%) are treatment-emergent SCNC and 11 (41%) are de novo SCNC. 19 patients (70%) received prior platinum chemotherapy. BXCL701 in combination with pembrolizumab continues to demonstrate acceptable tolerability without evidence of increased immune-related AEs compared to historic controls with checkpoint inhibitors. Adverse Events consistent with cytokine activation were observed (hypotension, fever, fatigue). In the previously reported 15 evaluable SCNC patients, 5 were composite responders, including 4 RECIST responders with a median duration of response of 39 weeks (range 9-45 weeks). 2/5 responders still actively receiving treatment and median duration of follow up is 48.3 weeks (range 1.9-88 weeks). All responders are MSS and/or low TMB. Enrollment is ongoing and 9 patients are actively receiving treatment at abstract submission. Final data for 28 evaluable patients will be presented at the Symposium. Conclusions: Oral BXCL701 in combination with pembrolizumab demonstrates encouraging anti-tumor activity with durability of response in late-line, refractory mCRPC SCNC for which there is currently no standard of care. BXCL701 BID dosing continues to demonstrate an acceptable safety profile. Clinical trial information: NCT03910660 .

Phase 1/2a study of AZD5305, a novel poly(adenosine diphosphate ribose) polymerase (PARP) 1-selective inhibitor in combination with new hormonal agents (NHAs) in patients (pts) with metastatic prostate cancer (mPC)

TPS296

Background: AZD5305 is a potent and selective oral PARP inhibitor (PARPi) that specifically targets and traps PARP1, in contrast to approved PARPis which target both PARP1 and PARP2. Preclinical data suggest that PARP1 inhibition confers antiproliferative effects, while PARP2 inhibition is a major driver of hematological toxicity. Thus, AZD5305 may have an improved therapeutic index with less toxicity. The Phase 3 PROpel study showed that first-line olaparib plus abiraterone (abi) significantly improved radiographic progression-free survival (rPFS) over abi alone in pts with metastatic castration-resistant prostate cancer (mCRPC) enrolled irrespective of homologous recombination repair (HRR) gene mutations (Clarke et al, NEJM Evidence 2022). There is a need for better understanding of the benefit of adding PARPi to NHA and the potential synergy between them in early treatment of mPC. The PETRANHA study (NCT05367440) is evaluating the combination of AZD5305 with physician’s choice of NHA including abi, darolutamide, and enzalutamide, in pts with mPC. Methods: This is a multi-arm, open-label, nonrandomized dose-escalation phase study. Key eligibility criteria include age ≥18 years, histologically confirmed mPC (mCRPC or metastatic castration-sensitive prostate cancer [mCSPC], suitability for NHA treatment, ECOG PS 0–1, and life expectancy ≥16 wks. HRR gene mutation status is assessed at screening by testing blood, tumor or circulating tumor (ct) DNA; however, an identified mutation is not required for study entry. Key exclusion criteria for pts with mCRPC include previous PARPi, platinum chemotherapy, or targeted radioligand therapy. For pts with mCSPC, key exclusion criteria are the same, plus previous NHA or docetaxel in the mCSPC setting. Treatment continues until disease progression, starting an alternative anticancer therapy, or unacceptable toxicity. The primary objectives are to assess the safety and tolerability of AZD5305 in combination with NHAs, in terms of adverse events (AEs), serious AEs, and dose-limiting toxicities. Key secondary objectives include characterization of pharmacokinetics, changes in tumor size and prostate-specific antigen level, and assessment of preliminary antitumor activity by objective response rate, rPFS, and time to and duration of response by RECIST v1.1 and Prostate Cancer Clinical Trials Working Group 3 criteria. Exploratory endpoints include evaluating the role of predictive biomarkers including longitudinal assessment of ct cells and ctDNA, prostate-specific membrane antigen positron emission tomography (PET) and fluorodeoxyglucose PET. Enrollment began on June 23, 2022, in Melbourne, Australia; additional sites are planned in Australia, USA, and Europe. Clinical trial information: NCT05367440 .

Real-world survival outcomes of patients (pts) treated with 6-weekly pembrolizumab 400mg (pem6w) plus axitinib (axi) for advanced renal cell carcinoma (aRCC)

645

Background: The Keynote 426 trial demonstrated 3-weekly pembrolizumab 200mg (pem3w) plus axi twice daily is effective in aRCC. We previously reported real-world experience of pem6w + axi demonstrating a comparable safety profile to pem3w + axi reported in Keynote 426, with the added benefit of less frequent hospital visits. Here we present updated results on progression free survival (PFS) and landmark analyses of overall survival (OS) at 6, 9 and 12-months. Methods: Electronic medical records of pts on pem6w + axi between 1st May 2020 & 1st June 2021 in two large cancer centres in Scotland were analysed retrospectively for pts’ characteristics, efficacy and treatment related adverse events (TRAE). A data cut-off of 1st June 2022 was applied. Results: A total of 93 pts were identified (baseline demographics previously reported). 74 pts (80%) had clear cell histology, 19 pts (20%) had non-clear cell and 11 pts (12%) had sarcomatoid component. Approximately half had previous nephrectomy (46 pts). 15 (16%), 46 (50%) and 32 (34%) pts respectively were classified as favourable, intermediate, and poor risk group as per international metastatic renal cell carcinoma database consortium (IMDC) criteria. The median follow-up was 13 months (inter-quartile range [IQR] 8-17). At data cut off, 59 (63%) had progressed or died, with median PFS of 10.7 (IQR: 4.6-not reached) months. At landmark time-points of 6, 9 and 12 months 63 (68%), 50 (54%) and 42 (45%) of pts were progression free (Table). The median OS was not reached and follow up continues. At landmark time-points of 6, 9 and 12 months 88 (95%), 69 (74%) and 65 (70%) of pts were alive (Table). Clinician assessed radiological response was evaluable in 87 pts. Overall response rate (ORR), including partial response and complete response, was noted in 51 pts (59%). Clinical benefit rate including pts with ORR and stable disease was seen in 74 pts (85%). 82 pts (88%) had any grade and 28 pts (30%) had grade 3/4 TRAE. Any grade immune related AE (irAE) occurred in 62 pts (67%) and grade 3/4 in 19 pts (20%); g3/4 transaminitis (10%), colitis (8%), nephritis (2%) and skin (2%). Any grade AE due to axi occurred in 69 (74%) and grade 3/4 AE in 14 pts (15%). 25pts (27%) on Pem and 19pts (20%) on axi discontinued treatment due to TRAE. Conclusions: Our real-world experience demonstrates that pem6w + axi appears to have comparable efficacy and safety profile to pem3w + axi reported in Keynote 426 study. [Table: see text]

TALAPRO-2: Phase 3 study of talazoparib (TALA) + enzalutamide (ENZA) versus placebo (PBO) + ENZA as first-line (1L) treatment in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC)

LBA17

Background: TALAPRO-2 (NCT03395197) is the first phase 3 study to combine the poly(ADP-ribose) polymerase inhibitor TALA with the androgen receptor inhibitor ENZA. Pts unselected for genetic alterations in DNA damage repair pathways, directly or indirectly involved with homologous recombination repair (HRR), received either TALA + ENZA or PBO + ENZA as 1L treatment for mCRPC. Methods: Pts randomized 1:1 to TALA 0.5 mg or PBO (all pts received ENZA 160 mg daily) were stratified by prior abiraterone or docetaxel for castration-sensitive PC and HRR gene alteration status. Key eligibility criteria: mildly or asymptomatic mCRPC with disease progression at study entry, ECOG PS ≤1, ongoing androgen deprivation therapy, no prior life-prolonging therapy for CRPC. Primary endpoint: imaging-based progression-free survival (ibPFS) by BICR per RECIST 1.1 and PCWG3. Results: 402 pts were randomized to receive TALA + ENZA and 403 PBO + ENZA. Of these 805 pts, enrollment was informed by tumor tissue for 804 (99.9%), by tumor tissue and blood for 114 (14.2%), and by blood only for 1 (0.1%). Median ibPFS by BICR was significantly improved in the TALA + ENZA vs PBO + ENZA arm (not reached vs 21.9 months, respectively; HR, 0.63; 95% CI, 0.51–0.78; P< 0.001). ibPFS was significantly improved in HRR-deficient (HR, 0.46; 95% CI, 0.30–0.70; P< 0.001), HRR-non-deficient or unknown (HR, 0.70; 95% CI, 0.54–0.89; P= 0.004), and HRR-non-deficient pts by tumor tissue testing (HR, 0.66; 95% CI, 0.49–0.91; P= 0.009) in the TALA + ENZA vs PBO + ENZA arm. Overall survival data are immature; 30.6% (TALA) and 32.0% (PBO) pts had died; HR (0.89 [95% CI, 0.69–1.14; P= 0.35]) favored the TALA + ENZA arm. Objective response rates, PSA response ≥50%, and time to PSA progression and use of subsequent cytotoxic chemotherapy and antineoplastic therapy significantly favored the TALA + ENZA vs PBO + ENZA arm. In pts, 71.9% (TALA + ENZA) and 40.6% (PBO + ENZA) had grade 3-4 treatment-emergent adverse events (TEAEs). The most common grade ≥3 TEAEs were anemia, low neutrophil, and low platelet counts (TALA + ENZA), and hypertension, anemia, and fatigue (PBO + ENZA). TEAEs led to discontinuation of TALA in 19.1% of pts (vs PBO in 12.2%). Discontinuation rates of ENZA were 10.8% in the TALA + ENZA vs 11.0% in PBO + ENZA arm. Median time to definitive clinically meaningful deterioration in global health status/quality of life (GHS/QoL) was significantly longer with TALA + ENZA vs PBO + ENZA (30.8 vs 25.0 months, respectively; HR, 0.78; 95% CI, 0.62–0.99; P= 0.04). Conclusions: TALA + ENZA demonstrated statistically significant and clinically meaningful improvement in ibPFS over standard of care ENZA as 1L treatment in pts with mCRPC regardless of HRR status, while delaying time to worsening in GHS/QoL. There were no new safety signals; toxicity was generally manageable. Clinical trial information: NCT03395197 .

Clinical testing of transcriptome-wide expression profiles in high-risk localized and metastatic prostate cancer starting androgen deprivation therapy: an ancillary study of the STAMPEDE abiraterone Phase 3 trial

Metastatic and high-risk localized prostate cancer respond to hormone therapy but outcomes vary. Following a pre-specified statistical plan, we used Cox models adjusted for clinical variables to test associations with survival of multi-gene expression-based classifiers from 781 patients randomized to androgen deprivation with or without abiraterone in the STAMPEDE trial. Decipher score was strongly prognostic (p<2×10-5) and identified clinically-relevant differences in absolute benefit, especially for localized cancers. In metastatic disease, classifiers of proliferation, PTEN or TP53 loss and treatment-persistent cells were prognostic. In localized disease, androgen receptor activity was protective whilst interferon signaling (that strongly associated with tumor lymphocyte infiltration) was detrimental. Post-Operative Radiation-Therapy Outcomes Score was prognostic in localized but not metastatic disease (interaction p=0.0001) suggesting the impact of tumor biology on clinical outcome is context-dependent on metastatic state. Transcriptome-wide testing has clinical utility for advanced prostate cancer and identified worse outcomes for localized cancers with tumor-promoting inflammation.

A Randomized, Double-Blind, Biomarker-Selected, Phase II Clinical Trial of Maintenance Poly ADP-Ribose Polymerase Inhibition With Rucaparib Following Chemotherapy for Metastatic Urothelial Carcinoma

PURPOSE

A DNA repair deficiency (DRD) phenotype exists within a subset of metastatic urothelial carcinomas (mUC) predicting benefit from platinum-based chemotherapy. We tested switch maintenance therapy with the poly ADP-ribose polymerase inhibitor rucaparib, following chemotherapy, for DRD biomarker-positive mUC.

METHODS

DRD biomarker-positive mUC patients, within 10 weeks of chemotherapy, and without cancer progression, were randomly assigned (1:1) to maintenance rucaparib 600 mg twice a day orally, or placebo, until disease progression. The primary end point was progression-free survival (PFS). Statistical analysis targeted a hazard ratio of 0.5 with a 20% one-sided α for this signal-seeking trial. PFS (RECIST 1.1) was compared between trial arms, by intention to treat, within a Cox model.

RESULTS

Out of 248 patients, 74 (29.8%) were DRD biomarker-positive and 40 were randomly assigned. A total of 12 (60%) and 20 (100%) PFS events occurred in the rucaparib and placebo arms, respectively (median follow-up was 94.6 weeks in those still alive). Median PFS was 35.3 weeks (80% CI, 11.7 to 35.6) with rucaparib and 15.1 weeks (80% CI, 11.9 to 22.6) with placebo (hazard ratio, 0.53; 80% CI, 0.30 to 0.92; one-sided P = .07). In the safety population (n = 39) treatment-related adverse events were mostly low grade. Patients received a median duration of 10 rucaparib or six placebo cycles on treatment. Treatment-related adverse events (all grades) of fatigue (63.2% v 30.0%), nausea (36.8% v 5.0%), rash (21.1% v 0%), and raised alanine aminotransferase (57.9% v 10%) were more common with rucaparib.

CONCLUSION

Maintenance rucaparib, following platinum-based chemotherapy, extended PFS in DRD biomarker-selected patients with mUC and was tolerable. Further investigation of poly ADP-ribose polymerase inhibition in selected patients with mUC is warranted.

Overall Survival Update for Patients with Metastatic Castration-resistant Prostate Cancer Treated with Capivasertib and Docetaxel in the Phase 2 ProCAID Clinical Trial

The PI3K/AKT/PTEN pathway is frequently deregulated in metastatic castration-resistant prostate cancer (mCRPC). ProCAID was a phase 2 trial assessing addition of the AKT1/2/3 inhibitor capivasertib to docetaxel for patients with mCRPC. We previously reported that capivasertib did not extend a composite progression-free survival primary endpoint but did significantly improve the secondary endpoint of overall survival (OS). Here we present OS data after 66% of events had occurred in the intent-to-treat population (n = 150). Median OS was 25.3 mo for capivasertib plus docetaxel versus 20.3 mo for placebo plus docetaxel (hazard ratio [HR] 0.70, 95% confidence interval [CI] 0.47-1.05; nominal p = 0.09). Receipt of subsequent life-extending treatments was balanced between the treatment arms. The OS benefit associated with capivasertib was maintained in a subset of patients previously treated with abiraterone and/or enzalutamide (median OS 25.0 vs 17.6 mo; HR 0.57, 95% CI 0.36-0.91; nominal p = 0.02) but not in abiraterone/enzalutamide-naïve patients (median OS 31.1 mo vs not reached; HR 1.43, 95% CI 0.63-3.23). We conclude that OS may be extended by addition of capivasertib to docetaxel. Exploratory analysis revealed that the OS benefit was maintained in a subset of patients previously exposed to androgen receptor-targeted agents, which should be evaluated in prospective trials. PATIENT SUMMARY: The ProCAID study examined whether adding the AKT inhibitor drug capivasertib to docetaxel chemotherapy improves outcomes for patients with advanced prostate cancer. Initial analysis of the ProCAID results suggested that capivasertib improved overall survival benefit. This follow-up analysis suggests that capivasertib addition may be particularly beneficial for patients whose cancer was previously treated with drugs that target the androgen receptor.

A Phase II study of neoadjuvant axitinib for reducing the extent of venous tumour thrombus in clear cell renal cell cancer with venous invasion (NAXIVA)

BACKGROUND

Surgery for renal cell carcinoma (RCC) with venous tumour thrombus (VTT) extension into the renal vein (RV) and/or inferior vena cava (IVC) has high peri-surgical morbidity/mortality. NAXIVA assessed the response of VTT to axitinib, a potent tyrosine kinase inhibitor.

METHODS

NAXIVA was a single-arm, multi-centre, Phase 2 study. In total, 20 patients with resectable clear cell RCC and VTT received upto 8 weeks of pre-surgical axitinib. The primary endpoint was percentage of evaluable patients with VTT improvement by Mayo level on MRI. Secondary endpoints were percentage change in surgical approach and VTT length, response rate (RECISTv1.1) and surgical morbidity.

RESULTS

In all, 35% (7/20) patients with VTT had a reduction in Mayo level with axitinib: 37.5% (6/16) with IVC VTT and 25% (1/4) with RV-only VTT. No patients had an increase in Mayo level. In total, 75% (15/20) of patients had a reduction in VTT length. Overall, 41.2% (7/17) of patients who underwent surgery had less invasive surgery than originally planned. Non-responders exhibited lower baseline microvessel density (CD31), higher Ki67 and exhausted or regulatory T-cell phenotype.

CONCLUSIONS

NAXIVA provides the first Level II evidence that axitinib downstages VTT in a significant proportion of patients leading to reduction in the extent of surgery.

CLINICAL TRIAL REGISTRATION

NCT03494816.

Cancer Trial Impact: Understanding Implementation of the Short Course Oncology Treatment (SCOT) Trial Findings in colorectal cancer at a National Level

AIMS

The Short Course Oncology Treatment (SCOT) trial indicated that 3 months of adjuvant doublet chemotherapy was non-inferior to 6 months of treatment for patients with colorectal cancer, with considerably less toxicity. The SCOT trial results were disseminated in June 2017. The aim of this study was to understand if SCOT trial findings were implemented in Scotland.

MATERIALS AND METHODS

A retrospective analysis was carried out on a dataset derived from a source population of 5.4 million people. Eligible patients were those with stage II or III colorectal cancer who received adjuvant chemotherapy. Logistic regression was applied to understand the extent of practice change to a 3-month adjuvant chemotherapy duration after the SCOT trial results were disseminated. Interrupted time series analysis was used to visualise differences in prescribing trends before and after June 2017 for the overall cohort, and by SCOT trial eligibility.

RESULTS

In total, 2310 patients were included in the study; 1957 and 353 treated pre- and post-June 2017, respectively. The median treatment duration decreased from 21 weeks (interquartile range 14-24) prior to June 2017 to 12 weeks (interquartile range 12-21 weeks) after June 2017 (P < 0.001). The proportion of patients receiving over 3 months of adjuvant treatment decreased from 75% to 42% (P < 0.001). This change was most noticeable for patients who met the SCOT trial eligibility criteria, and specifically for those with low-risk stage III disease and those treated with capecitabine and oxaliplatin (CAPOX). Although practice change occurred in all locations, there were differences between regions that could be explained by pre-SCOT trial prescribing trends.

DISCUSSION

A significant change in chemotherapy prescribing occurred after dissemination of the SCOT trial results. National, real-world data can be used to capture the extent of implementation of clinical trial results. In this case, implementation was aligned with clinical trial subgroup findings. This type of analysis could be conducted to evaluate the impact of other clinical trials.

Docetaxel for Nonmetastatic Prostate Cancer: Long-Term Survival Outcomes in the STAMPEDE Randomized Controlled Trial

BACKGROUND

STAMPEDE previously reported adding upfront docetaxel improved overall survival for prostate cancer patients starting long-term androgen deprivation therapy. We report long-term results for non-metastatic patients using, as primary outcome, metastatic progression-free survival (mPFS), an externally demonstrated surrogate for overall survival.

METHODS

Standard of care (SOC) was androgen deprivation therapy with or without radical prostate radiotherapy. A total of 460 SOC and 230 SOC plus docetaxel were randomly assigned 2:1. Standard survival methods and intention to treat were used. Treatment effect estimates were summarized from adjusted Cox regression models, switching to restricted mean survival time if non-proportional hazards. mPFS (new metastases, skeletal-related events, or prostate cancer death) had 70% power (α = 0.05) for a hazard ratio (HR) of 0.70. Secondary outcome measures included overall survival, failure-free survival (FFS), and progression-free survival (PFS: mPFS, locoregional progression).

RESULTS

Median follow-up was 6.5 years with 142 mPFS events on SOC (3 year and 54% increases over previous report). There was no good evidence of an advantage to SOC plus docetaxel on mPFS (HR = 0.89, 95% confidence interval [CI] = 0.66 to 1.19; P = .43); with 5-year mPFS 82% (95% CI = 78% to 87%) SOC plus docetaxel vs 77% (95% CI = 73% to 81%) SOC. Secondary outcomes showed evidence SOC plus docetaxel improved FFS (HR = 0.70, 95% CI = 0.55 to 0.88; P = .002) and PFS (nonproportional P = .03, restricted mean survival time difference = 5.8 months, 95% CI = 0.5 to 11.2; P = .03) but no good evidence of overall survival benefit (125 SOC deaths; HR = 0.88, 95% CI = 0.64 to 1.21; P = .44). There was no evidence SOC plus docetaxel increased late toxicity: post 1 year, 29% SOC and 30% SOC plus docetaxel grade 3-5 toxicity.

CONCLUSIONS

There is robust evidence that SOC plus docetaxel improved FFS and PFS (previously shown to increase quality-adjusted life-years), without excess late toxicity, which did not translate into benefit for longer-term outcomes. This may influence patient management in individual cases.

A randomised, double blind, phase II clinical trial of maintenance cabozantinib following chemotherapy for metastatic urothelial carcinoma (mUC): Final analysis of the ATLANTIS cabozantinib comparison

LBA4505

Background: Platinum-based chemotherapy (PBC) is an active first line therapy in mUC, but duration of response is usually short. We hypothesised that switch maintenance therapy with the tyrosine kinase inhibitor cabozantinib, in patients who have derived clinical benefit from PBC, would improve outcomes for mUC. Methods: ATLANTIS is an adaptive, multi-comparison, phase II trial platform. It tests multiple maintenance therapies for mUC patients who complete 4 to 8 cycles of PBC without disease progression. Whilst some patients were selected for randomisation into alternative comparisons in the platform based on putative predictive biomarkers, those who were not selected were randomised 1:1 to commence either cabozantinib 40mg once-daily or matching placebo within 10 weeks of completing PBC until progression. The primary endpoint was progression free survival (PFS) and 114 events in 140 patients (90% power, 20% 1-sided level alpha) were required to target a hazard ratio of 0.67. Due to a change in standard of care (maintenance avelumab), this was modified to 50 events in 57 patients (72.3% power, 20% 1-sided alpha) prior to the study closing early. PFS was compared between trial arms, by intention to treat, within a Cox model incorporating baseline minimisation factors. Secondary endpoints included overall survival (OS), response rate, maximum percentage decrease in measurable disease, safety and tolerability. Results: 30 patients were randomised to cabozantinib and 31 to placebo from 25 sites (Feb 2017-March 2021). Patient characteristics (median age 69.0 years; 75.4% male; 75.4% bladder primary; 67.2% ECOG PS 0; 70.5% prior cisplatin; 36.1% visceral metastases) were balanced by treatment arm. 25 (83.3%) and 26 (83.9%) PFS events had occurred in the cabozantinib and placebo arms. Median PFS was 13.7 weeks (80% confidence interval (CI) 12.1-23.3) with cabozantinib and 15.8 weeks (80% CI 11.3-23.6) with placebo (adjusted hazard ratio 0.89 favouring cabozantinib, 80% CI 0.61-1.3, 1-sided p = 0.35). There was no difference in overall survival (hazard ratio 0.80 (0.52-1.23) p=0.25). In the safety population (n = 61) treatment related adverse events were mostly low grade. The most frequent (all grades), fatigue (56.7% vs 32.2%, p = 0.02), hypertension (43.3% vs 12.9%, p = 0.01), nausea (30% vs 19.4%, p = 0.36) and diarrhea (40.0% vs 6.5%, p < 0.01), were more common with cabozantinib. Overall, cabozantinib was tolerable with median duration of treatment of 13 28-day cycles of cabozantinib or 10 of placebo. 13 (43.%) vs 3 (9.7%) patients required dose reduction in the cabozantinib and placebo arms respectively. Conclusions: Though tolerable, cabozantinib did not show a significant benefit compared to placebo when used in the switch maintenance setting following platinum based chemotherapy. Clinical trial information: ISRCTN25859465.

Mitigation of SARS-CoV-2 transmission at a large public university

In Fall 2020, universities saw extensive transmission of SARS-CoV-2 among their populations, threatening health of the university and surrounding communities, and viability of in-person instruction. Here we report a case study at the University of Illinois at Urbana-Champaign, where a multimodal “SHIELD: Target, Test, and Tell” program, with other non-pharmaceutical interventions, was employed to keep classrooms and laboratories open. The program included epidemiological modeling and surveillance, fast/frequent testing using a novel low-cost and scalable saliva-based RT-qPCR assay for SARS-CoV-2 that bypasses RNA extraction, called covidSHIELD, and digital tools for communication and compliance. In Fall 2020, we performed >1,000,000 covidSHIELD tests, positivity rates remained low, we had zero COVID-19-related hospitalizations or deaths amongst our university community, and mortality in the surrounding Champaign County was reduced more than 4-fold relative to expected. This case study shows that fast/frequent testing and other interventions mitigated transmission of SARS-CoV-2 at a large public university.

Mitigation of SARS-CoV-2 transmission at a large public university

In Fall 2020, universities saw extensive transmission of SARS-CoV-2 among their populations, threatening health of the university and surrounding communities, and viability of in-person instruction. Here we report a case study at the University of Illinois at Urbana-Champaign, where a multimodal “SHIELD: Target, Test, and Tell” program, with other non-pharmaceutical interventions, was employed to keep classrooms and laboratories open. The program included epidemiological modeling and surveillance, fast/frequent testing using a novel low-cost and scalable saliva-based RT-qPCR assay for SARS-CoV-2 that bypasses RNA extraction, called covidSHIELD, and digital tools for communication and compliance. In Fall 2020, we performed >1,000,000 covidSHIELD tests, positivity rates remained low, we had zero COVID-19-related hospitalizations or deaths amongst our university community, and mortality in the surrounding Champaign County was reduced more than 4-fold relative to expected. This case study shows that fast/frequent testing and other interventions mitigated transmission of SARS-CoV-2 at a large public university.

Safely opening university campuses has been a major challenge during the COVID-19 pandemic. Here, the authors describe a program of public health measures employed at a university in the United States which, combined with other non-pharmaceutical interventions, allowed the university to stay open in fall 2020 with limited evidence of transmission.

Addition of nintedanib or placebo to neoadjuvant gemcitabine and cisplatin in locally advanced muscle-invasive bladder cancer (NEOBLADE): a double-blind, randomised, phase 2 trial

BACKGROUND

Recurrence is common after neoadjuvant chemotherapy and radical treatment for muscle-invasive bladder cancer. We investigated the effect of adding nintedanib to neoadjuvant chemotherapy on response and survival in muscle-invasive bladder cancer.

METHODS

NEOBLADE was a parallel-arm, double-blind, randomised, placebo-controlled, phase 2 trial of neoadjuvant gemcitabine and cisplatin chemotherapy with nintedanib or placebo in locally advanced muscle-invasive bladder cancer. Patients aged 18 years or older, with an Eastern Cooperative Oncology Group performance status of 0-1, were recruited from 15 hospitals in the UK. Patients were randomly assigned (1:1) to nintedanib or placebo using permuted blocks with random block sizes of two or four, stratified by centre and glomerular filtration rate. Treatments were allocated using an interactive web-based system, and patients and investigators were masked to treatment allocation throughout the study. Patients received oral nintedanib (150 mg or 200 mg twice daily for 12 weeks) or placebo, in addition to usual neoadjuvant chemotherapy with intravenous gemcitabine 1000 mg/m2 on days 1 and 8 and intravenous cisplatin 70 mg/m2 on day 1 of a 3-weekly cycle. The primary endpoint was pathological complete response rate, assessed at cystectomy or at day 8 of cyclde 3 (plus or minus 7 days) if cystectomy did not occur. Primary analyses were done in the intention-to-treat population. The trial is registered with EudraCT, 2012-004895-01, and ISRCTN, 56349930, and has completed planned recruitment.

FINDINGS

Between Dec 4, 2014, and Sept 3, 2018, 120 patients were recruited and were randomly allocated to receive nintedanib (n=57) or placebo (n=63). The median follow-up for the study was 33·5 months (IQR 14·0-44·0). Pathological complete response in the intention-to-treat population was reached in 21 (37%) of 57 patients in the nintedanib group and 20 (32%) of 63 in the placebo group (odds ratio [OR] 1·25, 70% CI 0·84-1·87; p=0·28). Grade 3 or worse toxicities were observed in 53 (93%) of 57 participants who received nintedanib and 50 (79%) of 63 patients in the placebo group (OR 1·65, 95% CI 0·74-3·65; p=0·24). The most common grade 3 or worse adverse events were thromboembolic events (17 [30%] of 57 patients in the nintedanib group vs 13 [21%] of 63 patients in the placebo group [OR 1·63, 95% CI 0·71-3·76; p=0·29]) and decreased neutrophil count (22 [39%] in the nintedanib group vs seven [11%] in the placebo group [5·03, 1·95-13·00; p=0·0006]). 45 treatment-related serious adverse events occurred in the nintedanib group and 43 occurred in the placebo group. One treatment-related death occurred in the placebo group, which was due to myocardial infarction.

INTERPRETATION

The addition of nintedanib to chemotherapy was safe but did not improve the rate of pathological complete response in muscle-invasive bladder cancer.

FUNDING

Boehringer Ingelheim.

Quality of Life in Men With Prostate Cancer Randomly Allocated to Receive Docetaxel or Abiraterone in the STAMPEDE Trial

PURPOSE

Docetaxel and abiraterone acetate plus prednisone or prednisolone (AAP) both improve survival when commenced alongside standard of care (SOC) androgen deprivation therapy in locally advanced or metastatic hormone-sensitive prostate cancer. Thus, patient-reported quality of life (QOL) data may guide treatment choices.

METHODS

A group of patients within the STAMPEDE trial were contemporaneously enrolled with the possibility of being randomly allocated to receive either docetaxel + SOC or AAP + SOC. A mixed-model assessed QOL in those who had completed at least one QLQ-C30 + PR25 questionnaire. The primary outcome measure was difference in global-QOL (QLQ-C30 Q29&30) between patients allocated to docetaxel + SOC or AAP + SOC over the 2 years after random assignment, with a predefined criterion for clinically meaningful difference of > 4.0 points. Secondary outcome measures included longitudinal comparison of functional domains, pain, and fatigue, plus global-QOL at defined timepoints.

RESULTS

Five hundred fifteen patients (173 docetaxel + SOC and 342 AAP + SOC) were included. Baseline characteristics, proportion of missing data, and mean baseline global-QOL scores (docetaxel + SOC 77.8 and AAP + SOC 78.0) were similar. Over the 2 years following random assignment, the mean modeled global-QOL score was +3.9 points (95% CI, +0.5 to +7.2; P = .022) higher in patients allocated to AAP + SOC. Global-QOL was higher for patients allocated to AAP + SOC over the first year (+5.7 points, 95% CI, +3.0 to +8.5; P < .001), particularly at 12 (+7.0 points, 95% CI, +3.0 to +11.0; P = .001) and 24 weeks (+8.3 points, 95% CI, +4.0 to +12.6; P < .001).

CONCLUSION

Patient-reported QOL was superior for patients allocated to receive AAP + SOC, compared with docetaxel + SOC over a 2-year period, narrowly missing the predefined value for clinical significance. Patients receiving AAP + SOC reported clinically meaningful higher global-QOL scores throughout the first year following random assignment.

Healthcare Costs for Metastatic Castration-Resistant Prostate Cancer Patients Treated with Abiraterone or Enzalutamide

OBJECTIVE

The aim was to assess the real-world healthcare resource use and direct medical costs for metastatic castration-resistant prostate cancer (mCRPC) patients treated with abiraterone or enzalutamide, in whom chemotherapy is not yet indicated (pre-chemotherapy) or who had previously received docetaxel-based chemotherapy (post-chemotherapy), before commencing these medicines.

METHODS

A retrospective cost analysis of mCRPC patients who commenced abiraterone or enzalutamide between 2012 and 2015 was conducted. Routinely collected datasets from the largest health board in Scotland and the UK, Greater Glasgow and Clyde, were linked. They contained information on patient demographics, diagnosis, outpatient consultations, hospital admissions, treatments (abiraterone and enzalutamide), and supportive medicines. Unit costs were obtained from the Scottish Health Service Costs, Personal Social Services Research Unit, and British National Formulary. Generalised linear model-based regression was used to estimate total mean direct costs, and two-part models were used to estimate separate cost components. All models were adjusted for propensity score and key variables. Sensitivity analysis was conducted to explore the impact of hypothetical patient access scheme discounts.

RESULTS

Estimated total mean direct medical costs of treating mCRPC patients were similar, albeit with wide and overlapping confidence intervals. Across both treatments, patients who received abiraterone or enzalutamide in a pre-chemotherapy setting incurred the highest total mean direct medical costs. However, post-chemotherapy patients were associated with higher outpatient clinic visits, inpatient hospital admissions, and supportive medicines. Regarding relative contribution to the total mean direct medical cost, the treatment costs were the main contributor, followed by inpatient admissions, outpatient clinic visits, and supportive medicines.

CONCLUSION

The total mean direct medical costs were similar for abiraterone and enzalutamide patients. The costs were not driven by the choice of treatment regimen, but treatment setting (pre-chemotherapy or post-chemotherapy indications) and related healthcare resource utilisation. Future studies should focus on economic evaluations, such as cost-effectiveness analyses, using real-world data.

Mechanistic and Clinical Overview Cardiovascular Toxicity of BRAF and MEK Inhibitors: JACC: CardioOncology State-of-the-Art Review

Rapidly accelerated fibrosarcoma B-type (BRAF) and mitogen-activated extracellular signal-regulated kinase (MEK) inhibitors have revolutionized melanoma treatment. Approximately half of patients with melanoma harbor a BRAF gene mutation with subsequent dysregulation of the RAF-MEK-ERK signaling pathway. Targeting this pathway with BRAF and MEK blockade results in control of cell proliferation and, in most cases, disease control. These pathways also have cardioprotective effects and are necessary for normal vascular and cardiac physiology. BRAF and MEK inhibitors are associated with adverse cardiovascular effects including hypertension, left ventricular dysfunction, venous thromboembolism, atrial arrhythmia, and electrocardiographic QT interval prolongation. These effects may be underestimated in clinical trials. Baseline cardiovascular assessment and follow-up, including serial imaging and blood pressure assessment, are essential to balance optimal anti-cancer therapy while minimizing cardiovascular side effects. In this review, an overview of BRAF/MEK inhibitor-induced cardiovascular toxicity, the mechanisms underlying these, and strategies for surveillance, prevention, and treatment of these effects are provided.

Preferences and perceptions of patients with metastatic castration-resistant prostate cancer for treatments and biomarker testing: An international qualitative study

63

Background: Metastatic castration-resistant prostate cancer (mCRPC) is a lethal disease with significant morbidity. Poly adenosine diphosphate-ribose polymerase inhibitors (PARPi) are targeted therapeutics approved to treat mCRPC patients with genetic mutations in homologous recombination repair (HRR). However, to benefit from PARPi as a single agent, patients usually need to undergo biomarker testing to determine their mutation status. As an initial step to understand patient preferences for mCRPC treatments, this study investigated the treatment features important to mCRPC patients and their preferences for and perceptions of biomarker testing. Methods: This preliminary qualitative study included 25 men in the US, UK, Germany, Spain, and Japan with self-reported mCRPC diagnosed at least 6 months previously. Participants completed a 60-minute one-on-one interview about mCRPC treatments and disease impact. Results: Participants had a mean age of 62 years and were diagnosed with prostate cancer an average of 68 months prior. About half (52%) had metastasized > 1 year prior and more than half (56%) reported no HRR genetic mutation . The most frequently reported symptoms were pain (60%), urinary problems (56%), and fatigue (32%). Participants stated that pain impacted their sleep, daily activities, and social lives. 60% reported they shared treatment decision-making with their physician, some (24%) shared it with partners or caregivers, and others (32%) left treatment decisions up to their physician due to their lack of knowledge. Quality of life (QoL) was the most important treatment benefit reported (56%), followed by progression-free survival (PFS) (52%), overall survival (OS) (48%), and reduced pain (44%). Some participants reported their desire for prolonged survival needed to be balanced with adequate QoL. Few participants reported reduced fatigue (24%) or urinary problems (12%) as desired treatment benefits. 64% had previously undergone biomarker testing to determine mutation status. 56% of tested participants reported that their physician discussed the purpose and benefits of testing. Based on conversations with their physicians, both tested and untested participants felt that biomarker testing would inform them about heritable risk of mutation and help find new targeted treatments. Untested participants with a negative view of biomarker testing (22%) reported concerns about the need for further invasive biopsies. Conclusions: QoL followed by PFS, OS, and reduced pain were the most important benefits of treatment to participants. More than half of participants had a positive view of biomarker testing, especially if testing could lead to targeted therapies and inform about heritable risk. These results will inform the design of an international discrete choice study of biomarker testing among men with mCRPC.

Updated overall survival (OS) analysis for ProCAID: A randomized, double-blind, placebo-controlled phase II trial of capivasertib with docetaxel versus docetaxel alone in metastatic castration-sensitive prostate cancer (mCRPC)

108

Background: The AKT pathway is frequently deregulated in mCRPC. ProCAID tested addition of capivasertib, a potent selective inhibitor of all three AKT isoforms (AKT1/2/3) to docetaxel chemotherapy vs. placebo plus docetaxel for mCRPC. The primary analysis showed no difference between treatment arms for the primary endpoint of composite progression free survival (cPFS). However, OS, which was a secondary endpoint, was extended in the capivasertib plus docetaxel arm. cPFS and OS results were consistent irrespective of PI3K/AKT/PTEN pathway biomarker status (Crabb et al, J Clin Oncol 2021;39(3):190-201). Methods: An updated analysis of mature OS data was undertaken once events reached ≥65% by Cox proportional hazards model, adjusted for minimisation factors, within the intent to treat (ITT) population (n = 150). Patients (pts) and investigators remained blinded to treatment allocation. We also investigated OS outcomes within subsets based on prior androgen receptor targeted agent (ARTA) exposure to abiraterone and/or enzalutamide (abi/enza) and the balance of post-trial life extending treatment use by treatment arm. Funding: Cancer Research UK (C9317/A16029, CRUK/12/042) and AstraZeneca. Results: At this OS update, 99 pts (66.0%) had died, with 88 of these deaths (88.9%) due to prostate cancer. 5 pts (3.3%) remained on capivasertib or placebo. Median OS was 25.3 months for the capivasertib plus docetaxel arm vs. 20.3 months for placebo plus docetaxel (hazard ratio (HR) 0.70, 95% confidence interval (CI) 0.47 to 1.05; nominal p = 0.09). One, or more, subsequent life extending treatment options, including abiraterone, enzalutamide, radium-223 and cabazitaxel, were received by 99 pts (66.0%) and were balanced between treatment arms (68% capivasertib, 64% placebo). 101 pts (67.3%; 51 capivasertib, 50 placebo) had received abi/enza prior to entering ProCAID. Within this subgroup, OS benefit for capivasertib plus docetaxel (median OS 31.1 months) was maintained vs. placebo plus docetaxel (median OS 19.3 months; HR 0.57, 95% CI 0.36 to 0.91), but not in the remaining 49 pts who were naive to prior abi/enza (median OS 31.1 vs. not reached respectively; HR 1.43, 95% CI 0.63 to 3.23). These updated OS results remained consistent irrespective of biomarker status for PI3K/AKT/PTEN pathway activation. No clinically significant differences from the previously reported safety outcomes were seen with extended follow up of this trial. Conclusions: OS remains longer within the ProCAID ITT population with the addition of capivasertib to docetaxel for mCRPC. This does not appear to be explained by subsequent treatment choices. Exploratory analysis found prolonged OS with capivasertib within a subset of pts previously exposed to an ARTA which should be evaluated in prospective trials. Clinical trial information: NCT02121639.

Efficacy and safety outcomes of darolutamide in patients with nonmetastatic castration-resistant prostate cancer with comorbidities and concomitant medications from ARAMIS

256

Background: Patients (pts) with nonmetastatic castration-resistant prostate cancer (nmCRPC) are primarily older, have comorbidities, and take concomitant medications. Darolutamide (DARO), a structurally distinct and highly potent androgen receptor inhibitor, significantly reduced the risk of metastasis by ̃2 years and the risk of death by 31% versus placebo (PBO) and demonstrated favorable safety and tolerability in the phase 3 ARAMIS trial. DARO also has low potential for drug−drug interactions. This post hoc analysis of ARAMIS evaluated overall survival (OS) and safety in pts with ongoing comorbidities and concomitant medications. Methods: Pts with nmCRPC were randomized 2:1 to DARO (n=955) or PBO (n=554) while continuing androgen-deprivation therapy. At the final data cutoff (Nov 15, 2019), OS and adverse events (AEs) were evaluated in pts with a median of ≤ and >6 comorbidities or ≤ and >10 concomitant medications in the double-blind period. HRs (95% CIs) were determined from univariate analysis using Cox regression. Results: The majority of pts had ≥6 comorbidities (53%; 795/1509) or received ≥10 concomitant medications (54%; 813/1509). For pts with ≤6 and >6 comorbidities, DARO prolonged OS vs PBO (HR 0.65 and 0.73, respectively). OS benefit of DARO vs PBO was consistent for pts with metabolic, cardiovascular (CV), and other comorbid disorders (HR range: 0.39–0.88). For pts receiving ≤10 and >10 concomitant medications, OS was prolonged with DARO vs PBO (HR 0.76 and 0.66, respectively). Subgroups of pts receiving concomitant medications for gastrointestinal/metabolic disorders, CV disease, urologic disorders, and pain/inflammation achieved similar OS benefit with DARO vs PBO (HR range: 0.45–0.80). Incidence of AEs and AEs leading to treatment discontinuation with DARO was comparable to PBO across subgroups by number of comorbidities and concomitant medications (Table). Conclusions: The OS benefit and safety of DARO remained consistent with that observed in the overall ARAMIS population, even in patients with a high number of comorbidities or concomitant medications. Clinical trial information: NCT02200614. [Table: see text]

A randomized, double blind, biomarker selected, phase II clinical trial of maintenance PARP inhibition following chemotherapy for metastatic urothelial carcinoma (mUC): Final analysis of the ATLANTIS rucaparib arm

436

Background: A subset of mUC exhibits a DNA repair deficiency (DRD) phenotype predicting benefit from platinum based chemotherapy (PBC). We hypothesised that switch maintenance therapy with the PARP inhibitor rucaparib, in patients who have derived clinical benefit from PBC, would improve outcomes for patients with mUC harbouring a DRD biomarker. Methods: ATLANTIS is an adaptive, multi-comparison, phase II trial platform. It tests multiple biomarker selected maintenance therapies for mUC after 4 to 8 PBC cycles without disease progression. Biomarker allocation to the rucaparib comparison was based on ≥10% genomic loss of heterozygosity (%LOH) and/or somatic alteration in defined DRD associated genes ( ATM, BARD1, BRCA1, BRCA2, BRIP1, CDK12, CHEK2, FANCA, NBN, PALB2, RAD51, RAD51B, RAD51C, RAD51D, RAD54L) and/or germline BRCA1 or BRCA2 alteration. Biomarker positive patients were randomised (1:1) to maintenance rucaparib 600 mg BID PO, or matched placebo, within 10 weeks of completing PBC, until disease progression. The primary endpoint was progression free survival (PFS). Statistical analysis (data cut 17/Nov/2021) was pre-planned to target a hazard ratio of 0.5. We selected a 20% 1-sided alpha for this signal seeking phase II trial with 85.4% power (requiring 30 PFS events in 40 patients). PFS (RECIST 1.1) was compared between trial arms, by intention to treat, within a Cox model incorporating baseline minimisation factors. Adverse events (AE) were assessed by CTCAE v4.03. Results: 74 of 279 (26.5%) screened patients were biomarker positive. 40 were randomised within the rucaparib comparison (Dec 2017-Dec 2020). Biomarker positive status was by high %LOH in 22 (55%), DRD gene alteration in 11 (27.5%) and both in 7 (17.5%). Patient characteristics (median age 70.5; 82.5% male; 87.5% bladder primary; 52.5% ECOG PS 0; 62.5% prior cisplatin; 45% visceral metastases) were balanced by treatment arm. 12 (60%) and 20 (100%) PFS events have occurred in the rucaparib and placebo arms respectively (median duration follow up 94.6 weeks in those still alive). Median PFS was 35.3 weeks (80% confidence interval (CI) 11.7-35.6) with rucaparib and 15.1 weeks (80% CI 11.9-22.6) with placebo (hazard ratio 0.53, 80% CI 0.30-0.92, 1 sided p = 0.07). In the safety population (n = 39) treatment related adverse events were mostly low grade. Rucaparib was tolerable with a median duration of 10 rucaparib or 6 placebo cycles on treatment. The most frequent treatment related AEs (all grades) of fatigue (63.2% vs 30.0%, p = 0.03), nausea (36.9% vs 5.0%, p = 0.03) and rash (21.1% vs 0%, p = 0.04) were more common with rucaparib respectively. Conclusions: Maintenance rucaparib, following PBC, extended PFS in DRD biomarker selected patients with mUC and is tolerable. Further investigation of PARP inhibition for mUC is warranted. Clinical trial information: 25859465.

Real-world experience (RWE) of safety and efficacy of 6-weekly pembrolizumab 400mg (pem6w) plus axitinib (axi) in patients (pts) with advanced renal cell carcinoma (aRCC)

309

Background: The KEYNOTE 426 trial demonstrated pem 200mg plus axi twice daily (bd) is effective in aRCC. Pharmacokinetic modelling of pem 400 mg every six weeks demonstrated similar observed exposures to pem 200 mg every three weeks. In NHS Scotland, pem6w + axi was used during the COVID-19 pandemic to reduce hospital visits and for pts’ convenience. Here, we evaluate the RWE of pem6w + axi in aRCC. Methods: Electronic medical records of pts on pem6w + axi between 1 May 2020 & 1 Jun 2021 in two large cancer centers in Scotland were analyzed retrospectively for pts’ characteristics, treatment related adverse events (TRAE) and efficacy. Results: Total of 93 pts were identified (Table). At data cut off of 8 Sep 2021, with a median follow-up of 7 months (mo) (inter-quartile range (IQR) 5 mo; range 0-15 mo), 73 pts (78%) were alive. Clinician assessed radiological response was evaluable in 87 pts. Overall response rate (ORR) including partial response + complete response was noted in 49 pts (56%) with median time to response of 80 days (d). Clinical benefit rate including pts with ORR and stable disease was seen in 72 pts (83%). At data cut off, 24 pts (26%) had progressed with a median time to progression of 117 d (IQR: 85d). Median overall and progression free survival were not reached and follow-up continues. 81 pts (87%) had any grade and 28 pts (30%) had grade 3/4 TRAE. Immune related AE (irAE) of any grade occurred in 60 pts (65%) and grade 3/4 in 19 pts (20%). Common grade 3/4 irAE were transaminitis (10%), colitis (8%), nephritis (2%) and skin (2%). 28 (30%) and 14 pts (15%) respectively required steroids and hospitalisation for irAE with median hospital stay 6 d (range: 2-43 d). 10 pts suffered a second irAE requiring steroids and 5 pts had a second hospital stay with median hospital stay of 6 d. Any grade AE and grade 3/4 AE related to axi occurred in 67 (72%) and 14 pts (15%) respectively. Axi dose was escalated from 5mg to 7mg bd in 12 pts (13%), reduced to 3mg bd in 35 pts (38%) and 2mg bd in 10 pts (11%). 21pts (23%) on Pem and 15pts (16%) on axi discontinued treatment due to TRAE. Conclusions: Our RWE demonstrates that pem6w + axi appears to have comparable safety profile to pem 200mg + axi reported in Keynote 426 study, with the added benefits of less frequent hospital visits. Further follow up continues for efficacy in this heterogeneous pts population. Pt characteristics, total=93 (%).[Table: see text]

Abiraterone acetate and prednisolone with or without enzalutamide for high-risk non-metastatic prostate cancer: a meta-analysis of primary results from two randomised controlled phase 3 trials of the STAMPEDE platform protocol

BACKGROUND

Men with high-risk non-metastatic prostate cancer are treated with androgen-deprivation therapy (ADT) for 3 years, often combined with radiotherapy. We analysed new data from two randomised controlled phase 3 trials done in a multiarm, multistage platform protocol to assess the efficacy of adding abiraterone and prednisolone alone or with enzalutamide to ADT in this patient population.

METHODS

These open-label, phase 3 trials were done at 113 sites in the UK and Switzerland. Eligible patients (no age restrictions) had high-risk (defined as node positive or, if node negative, having at least two of the following: tumour stage T3 or T4, Gleason sum score of 8-10, and prostate-specific antigen [PSA] concentration ≥40 ng/mL) or relapsing with high-risk features (≤12 months of total ADT with an interval of ≥12 months without treatment and PSA concentration ≥4 ng/mL with a doubling time of <6 months, or a PSA concentration ≥20 ng/mL, or nodal relapse) non-metastatic prostate cancer, and a WHO performance status of 0-2. Local radiotherapy (as per local guidelines, 74 Gy in 37 fractions to the prostate and seminal vesicles or the equivalent using hypofractionated schedules) was mandated for node negative and encouraged for node positive disease. In both trials, patients were randomly assigned (1:1), by use of a computerised algorithm, to ADT alone (control group), which could include surgery and luteinising-hormone-releasing hormone agonists and antagonists, or with oral abiraterone acetate (1000 mg daily) and oral prednisolone (5 mg daily; combination-therapy group). In the second trial with no overlapping controls, the combination-therapy group also received enzalutamide (160 mg daily orally). ADT was given for 3 years and combination therapy for 2 years, except if local radiotherapy was omitted when treatment could be delivered until progression. In this primary analysis, we used meta-analysis methods to pool events from both trials. The primary endpoint of this meta-analysis was metastasis-free survival. Secondary endpoints were overall survival, prostate cancer-specific survival, biochemical failure-free survival, progression-free survival, and toxicity and adverse events. For 90% power and a one-sided type 1 error rate set to 1·25% to detect a target hazard ratio for improvement in metastasis-free survival of 0·75, approximately 315 metastasis-free survival events in the control groups was required. Efficacy was assessed in the intention-to-treat population and safety according to the treatment started within randomised allocation. STAMPEDE is registered with ClinicalTrials.gov, NCT00268476, and with the ISRCTN registry, ISRCTN78818544.

FINDINGS

Between Nov 15, 2011, and March 31, 2016, 1974 patients were randomly assigned to treatment. The first trial allocated 455 to the control group and 459 to combination therapy, and the second trial, which included enzalutamide, allocated 533 to the control group and 527 to combination therapy. Median age across all groups was 68 years (IQR 63-73) and median PSA 34 ng/ml (14·7-47); 774 (39%) of 1974 patients were node positive, and 1684 (85%) were planned to receive radiotherapy. With median follow-up of 72 months (60-84), there were 180 metastasis-free survival events in the combination-therapy groups and 306 in the control groups. Metastasis-free survival was significantly longer in the combination-therapy groups (median not reached, IQR not evaluable [NE]-NE) than in the control groups (not reached, 97-NE; hazard ratio [HR] 0·53, 95% CI 0·44-0·64, p<0·0001). 6-year metastasis-free survival was 82% (95% CI 79-85) in the combination-therapy group and 69% (66-72) in the control group. There was no evidence of a difference in metatasis-free survival when enzalutamide and abiraterone acetate were administered concurrently compared with abiraterone acetate alone (interaction HR 1·02, 0·70-1·50, p=0·91) and no evidence of between-trial heterogeneity (I2 p=0·90). Overall survival (median not reached [IQR NE-NE] in the combination-therapy groups vs not reached [103-NE] in the control groups; HR 0·60, 95% CI 0·48-0·73, p<0·0001), prostate cancer-specific survival (not reached [NE-NE] vs not reached [NE-NE]; 0·49, 0·37-0·65, p<0·0001), biochemical failure-free-survival (not reached [NE-NE] vs 86 months [83-NE]; 0·39, 0·33-0·47, p<0·0001), and progression-free-survival (not reached [NE-NE] vs not reached [103-NE]; 0·44, 0·36-0·54, p<0·0001) were also significantly longer in the combination-therapy groups than in the control groups. Adverse events grade 3 or higher during the first 24 months were, respectively, reported in 169 (37%) of 451 patients and 130 (29%) of 455 patients in the combination-therapy and control groups of the abiraterone trial, respectively, and 298 (58%) of 513 patients and 172 (32%) of 533 patients of the combination-therapy and control groups of the abiraterone and enzalutamide trial, respectively. The two most common events more frequent in the combination-therapy groups were hypertension (abiraterone trial: 23 (5%) in the combination-therapy group and six (1%) in control group; abiraterone and enzalutamide trial: 73 (14%) and eight (2%), respectively) and alanine transaminitis (abiraterone trial: 25 (6%) in the combination-therapy group and one (<1%) in control group; abiraterone and enzalutamide trial: 69 (13%) and four (1%), respectively). Seven grade 5 adverse events were reported: none in the control groups, three in the abiraterone acetate and prednisolone group (one event each of rectal adenocarcinoma, pulmonary haemorrhage, and a respiratory disorder), and four in the abiraterone acetate and prednisolone with enzalutamide group (two events each of septic shock and sudden death).

INTERPRETATION

Among men with high-risk non-metastatic prostate cancer, combination therapy is associated with significantly higher rates of metastasis-free survival compared with ADT alone. Abiraterone acetate with prednisolone should be considered a new standard treatment for this population.

FUNDING

Cancer Research UK, UK Medical Research Council, Swiss Group for Clinical Cancer Research, Janssen, and Astellas.

Refractive-index matching enhanced polarization sensitive optical coherence tomography quantification in human brain tissue

The importance of polarization-sensitive optical coherence tomography (PS-OCT) has been increasingly recognized in human brain imaging. Despite the recent progress of PS-OCT in revealing white matter architecture and orientation, quantification of fine-scale fiber tracts in the human brain cortex has been a challenging problem, due to a low birefringence in the gray matter. In this study, we investigated the effect of refractive index matching by 2,2'-thiodiethanol (TDE) immersion on the improvement of PS-OCT measurements in ex vivo human brain tissue. We show that we can obtain fiber orientation maps of U-fibers that underlie sulci, as well as cortical fibers in the gray matter, including radial fibers in gyri and distinct layers of fibers exhibiting laminar organization. Further analysis shows that index matching reduces the noise in axis orientation measurements by 56% and 39%, in white and gray matter, respectively. Index matching also enables precise measurements of apparent birefringence, which was underestimated in the white matter by 82% but overestimated in the gray matter by 16% prior to TDE immersion. Mathematical simulations show that the improvements are primarily attributed to the reduction in the tissue scattering coefficient, leading to an enhanced signal-to-noise ratio in deeper tissue regions, which could not be achieved by conventional noise reduction methods.

OUP accepted manuscript

Cancer is the second leading cause of death in people with chronic kidney disease (CKD) after cardiovascular disease. The incidence of CKD in patients with cancer is higher than in the non-cancer population. Across various populations, CKD is associated with an elevated risk of cancer incidence and cancer death compared with people without CKD, although the risks are cancer site-specific. Higher risk of cancer is detectable in mild CKD [estimated glomerular filtration rate (eGFR) 60-89 mL/min/1.73 m2], although this risk is more obvious if sensitive markers of kidney disease are used, such as cystatin C. Independent of eGFR, albuminuria is associated with increased risk of site-specific cancer incidence and death. Here, we explore the potential mechanisms for the increased risk of cancer observed in CKD, including patient factors (shared risks such as cardiometabolic disease, obesity, smoking, diet, lifestyle and environment), disease (genetic, inflammatory and infective) and treatment factors. In particular, we discuss the ways in which renal adverse events associated with conventional chemotherapies and newer systemic anti-cancer therapies (including targeted and immunotherapies) may contribute to worse cancer outcomes in people with CKD. Finally, we review the potential benefits of acknowledging increased risk of cancer in risk prediction tools used for the management of CKD.

Using diffusion MRI data acquired with ultra-high gradient strength to improve tractography in routine-quality data

The development of scanners with ultra-high gradient strength, spearheaded by the Human Connectome Project, has led to dramatic improvements in the spatial, angular, and diffusion resolution that is feasible for in vivo diffusion MRI acquisitions. The improved quality of the data can be exploited to achieve higher accuracy in the inference of both microstructural and macrostructural anatomy. However, such high-quality data can only be acquired on a handful of Connectom MRI scanners worldwide, while remaining prohibitive in clinical settings because of the constraints imposed by hardware and scanning time. In this study, we first update the classical protocols for tractography-based, manual annotation of major white-matter pathways, to adapt them to the much greater volume and variability of the streamlines that can be produced from today’s state-of-the-art diffusion MRI data. We then use these protocols to annotate 42 major pathways manually in data from a Connectom scanner. Finally, we show that, when we use these manually annotated pathways as training data for global probabilistic tractography with anatomical neighborhood priors, we can perform highly accurate, automated reconstruction of the same pathways in much lower-quality, more widely available diffusion MRI data. The outcomes of this work include both a new, comprehensive atlas of WM pathways from Connectom data, and an updated version of our tractography toolbox, TRActs Constrained by UnderLying Anatomy (TRACULA), which is trained on data from this atlas. Both the atlas and TRACULA are distributed publicly as part of FreeSurfer. We present the first comprehensive comparison of TRACULA to the more conventional, multi-region-of-interest approach to automated tractography, and the first demonstration of training TRACULA on high-quality, Connectom data to benefit studies that use more modest acquisition protocols.

Fermentative volatile fatty acid production and recovery from grass using a novel combination of solids separation, pervaporation, and electrodialysis technologies

A novel combination of solids screening, centrifugation, microfiltration, pervaporation, and electrodialysis were used for the targeted and exclusive recovery of volatile fatty acids (VFAs) from an 80L bioreactor. The bioreactor was continually-fed with grass waste, containing 40gL^-1 total solids, over three, seven-day, hydraulic retention times. A VFA solution with a concentration up to 4,500 mgL^-1 was recovered. VFA yields were also increased from 707 to 875 mg of VFA per gram of volatile solids by alleviating end-product inhibition. Both these accomplishments are significant step-changes in adding value to waste, and increased substrate utilisation rates will be attractive from a waste remediation perspective.

Tissue based biomarkers in non-clear cell RCC: Correlative analysis from the ASPEN clinical trial

Biomarkers are needed in patients with non-clear cell renal cell carcinomas (NC-RCC), particularly papillary renal cell carcinoma, in order to inform on initial treatment selection and identify potentially novel targets for therapy. We enrolled 108 patients in ASPEN, an international randomized open-label phase 2 trial of patients with metastatic papillary, chromophobe, or unclassified NC-RCC treated with the mTOR inhibitor everolimus (n=57) or the vascular endothelial growth factor (VEGF) receptor inhibitor sunitinib (n=51), stratified by MSKCC risk and histology. The primary endpoint was overall survival (OS) and secondary efficacy endpoints for this exploratory biomarker analysis were radiographic progression-free survival (rPFS) defined by intention-to-treat using the RECIST 1.1 criteria and radiographic response rates. Tissue biomarkers (n=78) of mTOR pathway activation (phospho-S6 and -Akt, c-kit) and VEGF pathway activation (HIF-1α, c-MET) were prospectively explored in tumor tissue by immunohistochemistry prior to treatment and associated with clinical outcomes. We found that S6 activation was more common in poor risk NC-RCC tumors and S6/Akt activation was associated with worse PFS and OS outcomes with both everolimus and sunitinib, while c-kit was commonly expressed in chromophobe tumors and associated with improved outcomes with both agents. C-MET was commonly expressed in papillary tumors and was associated with lower rates of radiographic response but did not predict PFS for either agent. In multivariable analysis, both pAkt and c-kit were statistically significant prognostic biomarkers of OS. No predictive biomarkers of treatment response were identified for clinical outcomes. Most biomarker subgroups had improved outcomes with sunitinib as compared to everolimus.

Three Versus Six Months of Adjuvant Doublet Chemotherapy for Patients With Colorectal Cancer: A Multi-Country Cost-Effectiveness and Budget Impact Analysis

BACKGROUND

The Short Course Oncology Treatment (SCOT) trial demonstrated non-inferiority, less toxicity, and cost-effectiveness from a UK perspective of 3 versus 6 months of oxaliplatin-based chemotherapy for patients with colorectal cancer. This study assessed the cost-effectiveness of shorter treatment and the budget impact of implementing trial findings from the perspectives of all countries recruited to SCOT: Australia, Denmark, New Zealand, Spain, Sweden, and the United Kingdom.

PATIENTS AND METHODS

Individual cost-utility analyses were performed from the perspective of each country. Resource, quality of life, and survival estimates from the SCOT trial (N = 6065) were used. Probabilistic sensitivity analysis and subgroup analyses were undertaken. Using undiscounted costs from these cost-utility analyses, the impact on country-specific healthcare budgets of implementing the SCOT trial findings was calculated over a 5-year period. The currency used was US dollars (US$), and 2019 was the base year. One-way and scenario sensitivity analysis addressed uncertainty within the budget impact analysis.

RESULTS

Three months of treatment were cost saving and cost-effective compared to 6 months from the perspective of all countries. The incremental net monetary benefit per patient ranged from US$8972 (Spain) to US$13,884 (Denmark). The healthcare budget impact over 5 years for the base-case scenario ranged from US$3.6 million (New Zealand) to US$61.4 million (UK) and totaled over US$150 million across all countries.

CONCLUSION

This study has widened the transferability of results from the SCOT trial, showing that shorter treatment is cost-effective from a multi-country perspective. The vast savings from implementation could fully justify the investment in conducting the SCOT trial.

Do clinical trials change practice? A longitudinal, international assessment of colorectal cancer prescribing practices

INTRODUCTION

Over half of the 1.5 million individuals globally who are diagnosed with colorectal cancer (CRC) present with stage II-III disease. Understanding clinician attitudes towards treatment for this group is paramount to contextualise real-world outcomes and plan future trials. The aim of this study was to assess clinician awareness of trials assessing the optimal duration of CRC adjuvant therapy, their attitudes towards shorter treatment and their self-reported practice.

METHODS

A survey was developed using OnlineSurveys® and distributed to clinicians in April 2019, with a follow-up survey disseminated to a subset of respondents in August 2020. Microsoft Excel® and Stata® were used for analysis.

RESULTS

265 clinicians replied to the first survey, with the majority aware of findings from the International Duration Evaluation of Adjuvant Therapy collaboration and contributory trials. Practice change was greatest for patients under 70 with low-risk stage III CRC, with most uncertainty around using 3-months of doublet chemotherapy for high-risk stage II disease. In August 2020, clinicians (n = 106) were more likely to use 3-months of FOLFOX for low-risk stage III disease and 3-months of CAPOX for stage II disease compared to April 2019. There was no indication that the COVID-19 pandemic had enduring changes on treatment decisions beyond those made in response to trial evidence.

DISCUSSION

Clinicians use a risk-stratified approach to treat CRC the adjuvant setting. Lower utilisation of doublet chemotherapy for older and stage II patients has affected the extent of trial implementation. Active dialogue regarding how trial results apply to these groups may improve consensus.

Angiokines Associated with Targeted Therapy Outcomes in Patients with Non-Clear Cell Renal Cell Carcinoma

PURPOSE

Biomarkers are needed in patients with non-clear cell renal cell carcinomas (NC-RCC) to inform treatment selection but also to identify novel therapeutic targets. We thus sought to profile circulating angiokines in the context of a randomized treatment trial of everolimus versus sunitinib.

PATIENTS AND METHODS

ASPEN (NCT01108445) was an international, randomized, open-label phase II trial of patients with metastatic papillary, chromophobe, or unclassified NC-RCC with no prior systemic therapy. Patients were randomized to everolimus or sunitinib and treated until disease progression or unacceptable toxicity. The primary endpoint was radiographic progression-free survival (PFS) defined by RECIST 1.1. Plasma angiokines were collected at baseline, cycle 3, and progression and associated with PFS and overall survival (OS).

RESULTS

We enrolled 108 patients, 51 received sunitinib and 57 everolimus; of these, 99 patients had evaluable plasma for 23 angiokines. At the final data cutoff, 94 PFS and 64 mortality events had occurred. Angiokines that were independently adversely prognostic for OS were osteopontin (OPN), TIMP-1, thrombospondin-2 (TSP-2), hepatocyte growth factor (HGF), and VCAM-1, and these were also associated with poor-risk disease. Stromal derived factor 1 (SDF-1) was associated with improved survival. OPN was also significantly associated with worse PFS. No statistically significant angiokine-treatment outcome interactions were observed for sunitinib or everolimus. Angiopoeitin-2 (Ang-2), CD-73, HER-3, HGF, IL6, OPN, PIGF, PDGF-AA, PDGF-BB, SDF-1, TGF-b1-b2, TGFb-R3, TIMP-1, TSP-2, VCAM-1, VEGF, and VEGF-R1 levels increased with progression on everolimus, while CD-73, ICAM-1, IL6, OPN, PlGF, SDF-1, TGF-b2, TGFb-R3, TIMP-1, TSP-2, VEGF, VEGF-D, and VCAM-1 increased with progression on sunitinib.

CONCLUSIONS

In patients with metastatic NC-RCC, we identified several poor prognosis angiokines and immunomodulatory chemokines during treatment with sunitinib or everolimus, particularly OPN.

Creation of the first national linked colorectal cancer dataset in Scotland: prospects for future research and a reflection on lessons learned

INTRODUCTION

Current understanding of cancer patients, their treatment pathways and outcomes relies mainly on information from clinical trials and prospective research studies representing a selected sub-set of the patient population. Whole-population analysis is necessary if we are to assess the true impact of new interventions or policy in a real-world setting. Accurate measurement of geographic variation in healthcare use and outcomes also relies on population-level data. Routine access to such data offers efficiency in research resource allocation and a basis for policy that addresses inequalities in care provision.

OBJECTIVE

Acknowledging these benefits, the objective of this project was to create a population level dataset in Scotland of patients with a diagnosis of colorectal cancer (CRC).

METHODS

This paper describes the process of creating a novel, national dataset in Scotland.

RESULTS

In total, thirty two separate healthcare administrative datasets have been linked to provide a comprehensive resource to investigate the management pathways and outcomes for patients with CRC in Scotland, as well as the costs of providing CRC treatment. This is the first time that chemotherapy prescribing and national audit datasets have been linked with the Scottish Cancer Registry on a national scale.

CONCLUSIONS

We describe how the acquired dataset can be used as a research resource and reflect on the data access challenges relating to its creation. Lessons learned from this process and the policy implications for future studies using administrative cancer data are highlighted.

Clinician Attitudes to Using Low-Dose Radiation Therapy to Treat COVID-19 Lung Disease

PURPOSE

Current treatments for coronavirus disease 2019 (COVID-19) lung disease have limited efficacy. Low-dose radiation therapy (LDRT) has received both interest and criticism as a potential treatment for this condition. In this qualitative study we explored clinicians' perspectives to identify barriers to testing LDRT in clinical trials and implementing it in clinical practice.

METHODS AND MATERIALS

Semistructured interviews were undertaken with 6 clinicians from 3 medical disciplines. Interviews were recorded, transcribed verbatim, and analyzed thematically, using a framework approach. Common themes regarding barriers to using LDRT for COVID-19 lung disease were identified from the data.

RESULTS

Three categories of barriers emerged: (1) the potential to do harm to the patient, including difficulty in predicting harm and lack of existing data to inform quantification of risks; (2) the feasibility of trialing this novel treatment strategy in the clinical setting, in particular trial design and recruitment, patient selection and buy-in from relevant clinician groups; and (3) the logistics of delivering the treatment, in particular risks of transmission to other patients and resources required for patient transfer.

CONCLUSIONS

This study identified several barriers that may impede the evaluation and subsequent implementation of LDRT as a treatment for COVID-19 lung disease, from the perspectives of clinicians in 3 relevant specialties. By documenting and articulating these concerns, we hope to enhance discussion of why these barriers exist, and enable them to be addressed in a proactive manner to facilitate research into the potential benefits of radiation treatment for patients with COVID-19 lung disease going forward.

Evaluating cancer research impact: lessons and examples from existing reviews on approaches to research impact assessment

BACKGROUND

Performing cancer research relies on substantial financial investment, and contributions in time and effort from patients. It is therefore important that this research has real life impacts which are properly evaluated. The optimal approach to cancer research impact evaluation is not clear. The aim of this study was to undertake a systematic review of review articles that describe approaches to impact assessment, and to identify examples of cancer research impact evaluation within these reviews.

METHODS

In total, 11 publication databases and the grey literature were searched to identify review articles addressing the topic of approaches to research impact assessment. Information was extracted on methods for data collection and analysis, impact categories and frameworks used for the purposes of evaluation. Empirical examples of impact assessments of cancer research were identified from these literature reviews. Approaches used in these examples were appraised, with a reflection on which methods would be suited to cancer research  impact evaluation going forward.

RESULTS

In total, 40 literature reviews were identified. Important methods to collect and analyse data for impact assessments were surveys, interviews and documentary analysis. Key categories of impact spanning the reviews were summarised, and a list of frameworks commonly used for impact assessment was generated. The Payback Framework was most often described. Fourteen examples of impact evaluation for cancer research were identified. They ranged from those assessing the impact of a national, charity-funded portfolio of cancer research to the clinical practice impact of a single trial. A set of recommendations for approaching cancer research impact assessment was generated.

CONCLUSIONS

Impact evaluation can demonstrate if and why conducting cancer research  is worthwhile. Using a mixed methods, multi-category assessment organised within a framework, will provide a robust evaluation, but the ability to perform this type of assessment may be constrained by time and resources. Whichever approach is used, easily measured, but inappropriate metrics should be avoided. Going forward, dissemination of the results of cancer research impact assessments will allow the cancer research community to learn how to conduct these evaluations.

Blind and partially sighted physiotherapy in the United Kingdom. A century of development, success and challenge. Will it still belong?

Background:In 2019 the Association of Visually Impaired Chartered Physiotherapists, originally the Association of Blind Certificated Masseurs, celebrated the centenary of its formation and becoming the first ever Specific Interest Group admitted to the Incorporated Society of Trained Masseuses which, later in the 20^th century, became the Chartered Society of Physiotherapy. These landmarks motivated the author to research for this chronological, descriptive, narrative review of the history of blind physiotherapy and its contribution to physiotherapy in the United Kingdom. Purpose:The early training and practice of massage by blind practitioners, the organizational milestones in mainstream and blind physiotherapy and the inter-relationship between the two is considered. Key developments, challenges, innovations and opportunities throughout the history are reviewed including the impact of World War 1 and contribution of blind physiotherapy to the profession. Conclusion:Significant changes in physiotherapy educational and training arrangements for blind students and changes in physiotherapy practice generally over the last four decades engender serious questions about whether blind physiotherapy will still "belong", despite the increasing aspiration within society toward acceptance of diversity and inclusion. The author challenges the profession about whether it will facilitate blind physiotherapy to continue making its valuable contribution and be included. Will it still "belong?"

NAXIVA: A phase II neoadjuvant study of axitinib for reducing extent of venous tumor thrombus in clear cell renal cell cancer (RCC) with venous invasion

275

Background: Venous tumor thrombus (VTT) extension occurs in 4-15% cases of renal cell cancer (RCC). The Mayo classification distinguishes 4 levels of VTT extension between the renal vein and supradiaphragmatic inferior vena cava (IVC). Although surgery is performed with curative intent, mortality is high (5-15%) with complications increasing with the level of the VTT. 5-year survival rates are poor; ~40-65% in non-metastatic RCC. It is hypothesised that neoadjuvant targeted therapy could downstage the VTT reducing the extent of surgery, leading to reduced surgical morbidity and mortality, and increased survival. However, level I or II evidence is lacking. NAXIVA provides the first level II evidence in this patient group, assessing the response of VTT to axitinib. Extensive translational sampling will provide in depth interrogation of VTT (using genomics, proteomics, immunophenotyping and metabolomics) to examine the role of the tumor microenvironment of VTT and response to axitinib. Methods: NAXIVA was a single arm, single agent, multi-center phase 2 feasibility study of axitinib in patients with both metastatic and non-metastatic clear cell RCC prior to nephrectomy and thrombectomy. A Simon two stage minimax design was adopted and the trial designed for adequate power to distinguish a <5% from a >25% improvement in the Mayo VTT level. 21 patients were recruited over a 24 month period between 15/Dec/2017 and 06/Jan/2020 at 5 sites across the UK. Patients were treated with 8 weeks of axitinib (starting dose 5mg bd, increasing to 10mg bd as tolerated) prior to planned surgery. The primary endpoint was the percentage of evaluable patients with an improvement in VTT according to the Mayo classification (assessed using MRI abdomen scans at screening and week 9, prior to surgery. Secondary endpoints were percentage change in surgical approach, percentage change in VTT height, response rate (by RECIST) and evaluation of surgical morbidity assessed by Clavien-Dindo classification. Results: The percentage of evaluable patients with an improvement in VTT according to the Mayo classification was 26.58% [80% CI: 15.76%, 39.74%] (6 of 21 evaluable patients). 35.29% (6 of 17 patients who progressed to surgery) had a change in surgical approach to a less invasive option. There was a median percentage reduction in VTT height of 21.49% (SD=27.60%). The response rate (by RECIST) in the evaluable population was 61.90% SD, 14.29% PR, 9.52% PD. In terms of surgical morbidity 11.76% (2 of 17 patients who progressed to surgery) experienced a Clavien-Dindo 3 or greater complication (0 CD3, 1 CD4, 1 CD5). Conclusions: NAXIVA provides unique prospective data on the feasibility of neoadjuvant axitinib administration to down stage IVC VTT and reduce the extent of surgery. Work is ongoing to establish predictors of response. Clinical trial information: NCT03494816 .

Updated outcomes of POUT: A phase III randomized trial of peri-operative chemotherapy versus surveillance in upper tract urothelial cancer (UTUC)

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Background: The POUT trial (CRUK/11/027; NCT01993979) previously reported (with median follow-up 30.3 months) that adjuvant chemotherapy improves disease free survival (DFS) for patients (pts) with histologically confirmed pT2-T4 N0-3 M0 UTUC. Here we present results of a pre-planned analysis updating the primary endpoint and reporting key secondary endpoints including overall survival. Methods: 261 pts with UTUC were enrolled following nephro-ureterectomy and randomised (1:1) to 4 cycles of gemcitabine-cisplatin (gemcitabine-carboplatin if GFR 30-49ml/min) or surveillance with subsequent chemotherapy if required. Pts had 6 monthly imaging and cystoscopy for 2 years, then annually to 5 years. Toxicity was assessed by CTCAE v4. Primary endpoint was DFS. Secondary endpoints included metastasis free survival (MFS), overall survival (OS), toxicity and patient reported quality of life (QoL). The trial closed to recruitment early on advice of the independent data monitoring committee due to evidence of efficacy. Time-to-event endpoints are analysed (intention-to-treat) by Cox proportional hazard models. Unadjusted and adjusted (by nodal status, planned chemotherapy type, microscopic margin status, pathological stage) hazard ratios (HR, < 1 favouring chemotherapy) are reported. Results: From May 2012 to Nov 2017, 261 pts were recruited (129 surveillance; 132 chemotherapy) at 56 UK centres. One participant withdrew consent for data usage and was excluded from analyses. Pts had median age 69 years (range 37-88), 28% pT2, 66% pT3; 91% pN0. To 09/09/2020, median follow up was 48.1 months (IQR: 36.0-60.1). The unadjusted/adjusted HR for DFS was 0.48 (95% CI: 0.33-0.71; p = 0.0003) / 0.50 (95%CI: 0.34-0.75; p = 0.001), and for MFS was 0.52 (95% CI: 0.35-0.77; p = 0.001) / 0.54 (95% CI: 0.36-0.81; p = 0.002). 93/260 (35.8%) pts have died (52/129 [40.3%] surveillance and 41/131 [31.3%] chemotherapy). Chemotherapy conferred a non-statistically significant 28% reduction in relative risk of death (HR = 0.72, 95% CI: 0.47-1.08; p = 0.11; adjusted HR = 0.79, 95% CI: 0.52-1.19; p = 0.26). 3 year OS was surveillance: 67% (95% CI: 58-74%; chemotherapy: 79% (71%-85%). There was no evidence of long-term toxicity associated with chemotherapy (Wilcoxon rank-sum test p-value for worst grade post-6 months = 0.32). Most common grade 2+ adverse events were hypertension (25/240 [10.4%]), lethargy (25/240 [10.4%]) and hearing loss (13/240 [5.4%]). There was no evidence of statistically or clinically relevant differences in QoL. 12 months after treatment (EORTC Q30 global health status mean difference 4.1 and 4.8 at 12 and 24 months respectively in favour of chemotherapy). Conclusions: With additional follow-up, the previously reported DFS benefit for chemotherapy was maintained with no detrimental long-term toxicity. No statistically significant improvement in OS was observed. Clinical trial information: NCT01993979.

SAPROCAN: Saracatinib (AZD0530) and docetaxel in metastatic,castrate-refractory prostate cancer (mCRPC)—A phase I/randomized phase II study by the United Kingdom National Cancer Research Institute Prostate Group

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Background: Saracatinib is an orally-available, highly selective inhibitor of Abl and Src family members. It is an ATP-competitive tyrosine kinase inhibitor. Preclinical data suggested that the combination of a Src kinase inhibitor and docetaxel is synergistic, and Src kinase activity was also implicated in the bone’s metabolic response to cancer metastases. Methods: Patients with mCRPC were initially enrolled in an open-label, dose escalation phase I trial of oral saracatinib (cohorts of 50mg, 125mg and 175mg daily) with docetaxel (75mg/m2) in a 3+3 design. Subsequent patients were randomised 1:1 between saracatinib 175mg and placebo once daily. Pharmacokinetics (PK) of docetaxel were explored in phase I to exclude significant drug-drug interaction. The primary endpoint of phase II was biochemical or radiographic progression free survival (PFS). Secondary endpoints included overall survival (OS), safety and tolerability. Changes in circulating tumour cell (CTC) counts were also measured. The phase II was designed with a 1-sided alpha of 0.2 with 90% power to detect a hazard ratio (HR) for PFS of 0.67. Results: 10 patients were enrolled in phase I and 142 in the randomised phase II. No dose limiting toxicities or PK interactions were observed and the recommended dose for phase II was 175mg saracatinib daily and 75mg/m2docetaxel every 21 days. In phase II, the HR for PFS was 1.35 (80% confidence interval (CI) 1.07 to 1.70). The HR for OS was 1.42 (1.08 – 1.81). 41/71 and 29/71 experienced treatment related toxicities of grade 3 or above in the saracatinib and placebo arms respectively. 10/19 (53%) and 14/27 (52%) evaluable patients demonstrated a reduction in CTCs from ≥5 to < 5 /7.5ml blood at 6 weeks after starting saracatinib and placebo respectively. Conclusions: Saracatinib, in combination with docetaxel, adds toxicity and not efficacy in mCRPC. This combination should not be developed further in combination with docetaxel in the treatment of mCRPC. Clinical trial information: ISRCTN22566729.

Pan-AKT Inhibitor Capivasertib With Docetaxel and Prednisolone in Metastatic Castration-Resistant Prostate Cancer: A Randomized, Placebo-Controlled Phase II Trial (ProCAID)

PURPOSE

Capivasertib is a pan-AKT inhibitor. Preclinical data indicate activity in metastatic castration-resistant prostate cancer (mCRPC) and synergism with docetaxel.

PATIENTS AND METHODS

ProCAID was a placebo controlled randomized phase II trial in mCRPC. Patients received up to ten 21-day cycles of docetaxel (75 mg/m2 intravenous, day 1) and prednisolone (5 mg twice daily, oral, day 1-21) and were randomly assigned (1:1) to oral capivasertib (320 mg twice daily, 4 days on/3 days off, from day 2 each cycle), or placebo, until disease progression. Treatment allocation used minimization factors: bone metastases; visceral metastases; investigational site; and prior abiraterone or enzalutamide. The primary objective, by intention to treat, determined if the addition of capivasertib prolonged a composite progression-free survival (cPFS) end point that included prostate-specific antigen progression events. cPFS and overall survival (OS) were also assessed by composite biomarker subgroup for PI3K/AKT/PTEN pathway activation status.

RESULTS

One hundred and fifty patients were enrolled. Median cPFS was 7.03 (95% CI, 6.28 to 8.25) and 6.70 months (95% CI, 5.52 to 7.36) with capivasertib and placebo respectively (hazard ratio [HR], 0.92; 80% CI, 0.73 to 1.16; one-sided P = .32). Median OS was 31.15 (95% CI, 20.07 to not reached) and 20.27 months (95% CI, 17.51 to 24.18), respectively (HR, 0.54; 95% CI, 0.34 to 0.88; two-sided P = .01). cPFS and OS results were consistent irrespective of PI3K/AKT/PTEN pathway activation status. Grade III-IV adverse events were equivalent between arms (62.2%). The most common adverse events of any grade deemed related to capivasertib were diarrhea, fatigue, nausea, and rash.

CONCLUSION

The addition of capivasertib to chemotherapy did not extend cPFS in mCRPC irrespective of PI3K/AKT/PTEN pathway activation status. The observed OS result (a secondary end point) will require prospective validation in future studies to address potential for bias.

Monitoring of urothelial cancer disease status after treatment by digital droplet PCR liquid biopsy assays

OBJECTIVES

Real-time monitoring of disease status would be beneficial for timely decision making in the treatment of urothelial cancer (UC), and may accelerate the evaluation of clinical trials. Use of cell free tumor DNA (cftDNA) as a biomarker in liquid biopsy is minimally invasive and its successful use has been reported in various cancer types, including UC. The objective of this study was to evaluate the use of digital droplet PCR (ddPCR)-based assays to monitor UC after treatment.

METHOD AND MATERIALS

Blood, urine and matching formalin fixed, paraffin embedded diagnostic specimens were collected from 20 patients diagnosed with stage T1 (n = 2) and T2/T3 (n = 18) disease. SNaPshot assays, Sanger sequencing and whole exome sequencing were used to identify tumor-specific mutations, and somatic mutation status was confirmed using patient-matched DNAs extracted from buffy coats and peripheral blood mononucleocytes. The ddPCR assays of the tumor-specific mutations were used to detect the fractional abundance of cftDNA in plasma and urine.

RESULTS

SNaPshot and Sanger sequencing identified point mutations in 70% of the patients that were assayable by ddPCR. Cases of remission and relapse monitored by assays for PIK3CA E542K and TP53 Y163C mutations in plasma and urine concurred with clinical observations up to 48 months from the start of chemotherapy. A new ddPCR assay for the telomerase reverse transcriptase (TERT) promoter (-124) mutation was developed. The TERT assay was able to detect mutations in cases below the limit of detection by SNaPshot. Whole exome sequencing identified a novel mutation, CNTNAP4 G727*. A ddPCR assay designed to detect this mutation was able to distinguish mutant from wild-type alleles.

CONCLUSIONS

The study demonstrated that ddPCR assays could be used to detect cftDNA in liquid biopsy monitoring of the post-therapy disease status in patients with UC. Overall, 70% of the patients in our study harbored mutations that were assayable by ddPCR.