Tolerability of Olaparib Combined with Abiraterone in Patients with Metastatic Castration-resistant Prostate Cancer: Further Results from the Phase 3 PROpel Trial

BACKGROUND

The PROpel study (NCT03732820) demonstrated a statistically significant progression-free survival benefit with olaparib plus abiraterone versus placebo plus abiraterone in the first-line metastatic castration-resistant prostate cancer (mCRPC) setting, irrespective of homologous recombination repair mutation status.

OBJECTIVE

We report additional safety analyses from PROpel to increase clinical understanding of the adverse-event (AE) profiles of olaparib plus abiraterone versus placebo plus abiraterone.

DESIGN, SETTING, AND PARTICIPANTS

A randomised (1:1), double-blind, placebo-controlled trial was conducted at 126 centres in 17 countries (October 2018-January 2020). Patients had mCRPC and no prior systemic mCRPC treatment.

INTERVENTION

Olaparib (300 mg bid) or placebo with abiraterone (1000 mg od) plus prednisone/prednisolone (5 mg bid).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The data cut-off date was July 30, 2021. Safety was assessed by AE reporting (Common Terminology Criteria for Adverse Events v4.03) and analysed descriptively.

RESULTS AND LIMITATIONS

The most common AEs (all grades) for olaparib plus abiraterone versus placebo plus abiraterone were anaemia (46.0% vs 16.4%), nausea (28.1% vs 12.6%), and fatigue (27.9% vs 18.9%). Grade ≥3 anaemia occurred in 15.1% versus 3.3% of patients in the olaparib plus abiraterone versus placebo plus abiraterone arm. The incidences of the most common AEs for olaparib plus abiraterone peaked early, within 2 mo, and were managed typically by dose modifications or standard medical practice. Overall, 13.8% versus 7.8% of patients discontinued treatment with olaparib plus abiraterone versus placebo plus abiraterone because of an AE; 3.8% versus 0.8% of patients discontinued because of anaemia. More venous thromboembolism events were observed in the olaparib plus abiraterone arm (any grade, 7.3%; grade ≥3, 6.8%) than in the placebo plus abiraterone arm (any grade, 3.3%; grade ≥3, 2.0%), most commonly pulmonary embolism (6.5% vs 1.8% for olaparib plus abiraterone vs placebo plus abiraterone).

CONCLUSIONS

Olaparib plus abiraterone has a manageable and predictable safety profile.

PATIENT SUMMARY

The PROpel trial showed that in patients who had not received any previous treatment for metastatic castration-resistant prostate cancer, olaparib combined with abiraterone was more effective in delaying progression of the disease than abiraterone alone. Most side effects caused by combining olaparib with abiraterone could be managed with supportive care methods, by pausing olaparib administration for a short period of time and/or by reducing the dose of olaparib.

Prognostic Value of the Modeled Prostate-Specific Antigen KELIM Confirmation in Metastatic Castration-Resistant Prostate Cancer Treated With Taxanes in FIRSTANA

PURPOSE

In a previous exploratory study, modeled early longitudinal prostate-specific antigen (PSA) kinetics observed within the 100-first treatment days with androgen deprivation therapy with or without docetaxel was associated with progression-free survival (PFS) and overall survival (OS) in patients with prostate cancer with rising PSA levels after primary local therapy. This prognostic value had to be confirmed in different settings. The objectives were to assess PSA kinetics modeling in patients with metastatic castration-resistant prostate cancer (mCRPC) treated with chemotherapy in FIRSTANA trial and to investigate modeled PSA kinetic parameters prognostic/predictive value.

MATERIALS AND METHODS

FIRSTANA phase III trial (ClinicalTrials.gov identifier: NCT01308567) assessed whether cabazitaxel is superior to docetaxel in terms of PFS/OS in patients with chemotherapy-naïve mCRPC. PSA longitudinal kinetics was assessed using the previous kinetic-pharmacodynamics model. Patient modeled ELIMination rate constant K (PSA.KELIM) was used to categorize favorable/unfavorable PSA declines (standardized PSA.KELIM < or ≥ 1.0 days-1) and further correlated with PFS/OS.

RESULTS

In total, 1,050 of 1,168 enrolled patients were assessable for PSA.KELIM estimation. The median PSA.KELIM was 0.02 days-1. In univariate analyses, PSA.KELIM exhibited a significant prognostic value regarding survival: unfavorable versus favorable PSA.KELIM; median PFS, 3.6 months (95% CI, 3.0 to 4.2) versus 4.7 months (95% CI, 3.9 to 5.2), P = .002; median OS, 17.4 months (95% CI, 14.8 to 19.3) versus 28.4 months (95% CI, 26.7 to 31.6), P < .001. In multivariate analyses, PSA.KELIM was significant for PFS (hazard ratio [HR], 0.79 [95% CI, 0.67 to 0.93], P = .005) and OS (HR, 0.51 [95% CI, 0.44 to 0.60], P < .001), together with baseline radiological tumor progression and PSA doubling time. PSA.KELIM predictive value was not significant across treatment arms.

CONCLUSION

This external validation study confirmed previous results about modeled PSA longitudinal kinetics prognostic value regarding PFS/OS in patients with mCRPC treated with taxanes. PSA.KELIM could be used to identify a subpopulation with poor prognosis, who may benefit from treatment intensification.

Efficacy and safety of cabozantinib rechallenge in metastatic renal cell carcinoma: A retrospective multicentric study

BACKGROUND

Despite metastatic renal cell carcinoma (mRCC) expanded treatment options, disease progression ultimately occurs for most patients. Rechallenge may be a compelling strategy in a refractory setting. Cabozantinib is the standard of care in first and later lines of therapy, but its activity in rechallenge is unknown.

METHODS

This retrospective study assessed the efficacy and safety of cabozantinib rechallenge, as defined by a second exposure after an interval of ≥3 months without treatment or ≥1 other treatment line, in patients with mRCC. The primary endpoint was median progression-free survival (PFS) at rechallenge. Secondary endpoints included overall survival, objective response rate, and safety at rechallenge.

RESULTS

We included 51 mRCC patients who received cabozantinib in a rechallenge setting between 2017 and 2022. Median age at diagnosis was 54 years, 78% were male, 90% had clear cell mRCC, and 92% had prior nephrectomy. 15 patients (29%) were rechallenged after a pause in treatment, whereas 36 (70.6%) had ≥1 other treatment lines between first cabozantinib exposure (CABO-1) and rechallenge (CABO-2). Median PFS was 15.1 months (mo, 95% Confidence interval 11.2-22.1) at CABO-1 and 14.4mo (95%CI 9.8-NR) at CABO-2. Median overall survival was 67.6mo for CABO-1 (95% CI 52.2-NR) and 27.4mo for CABO-2 (95%CI 17.2-NR); objective response rate was 70.6% for CABO-1 and 60% for CABO-2. CABO-2 PFS was higher for patients with CABO-1 PFS > 12 months, and for those who discontinued CABO-1 because of toxicity, without statistical significance. There were no unexpected adverse events.

CONCLUSIONS

Cabozantinib rechallenge is a feasible treatment option with potential clinical benefit for mRCC patients.

Biological Biomarkers of Response and Resistance to Immune Checkpoint Inhibitors in Renal Cell Carcinoma

Renal cell carcinoma (RCC) represents around 2% of cancer-related deaths worldwide per year. RCC is an immunogenic malignancy, and treatment of metastatic RCC (mRCC) has greatly improved since the advent of the new immunotherapy agents, including immune checkpoint inhibitors (ICIs). However, it should be stressed that a large proportion of patients does not respond to these therapies. There is thus an urgent need to identify predictive biomarkers of efficacy or resistance associated with ICIs or ICI/Tyrosine kinase inhibitor (TKI) combinations; this is a major challenge to achieve precision medicine for mRCC in routine practice. To identify potential biomarkers, it is necessary to improve our knowledge on the biology of immune checkpoints. A lot of efforts have been made over the last decade in the field of immuno-oncology. We summarize here the main data obtained in this field when considering mRCC. As for clinical biomarkers, clinician and scientific experts of the domain are facing difficulties in identifying such molecular entities, probably due to the complexity of immuno-oncology and the constant adaptation of tumor cells to their changing environment.

A PK-PD model linking biomarker dynamics to progression-free survival in patients treated with everolimus and sorafenib combination therapy, EVESOR phase I trial

PURPOSE

The objective was to develop a pharmacokinetic-pharmacodynamic (PK-PD) model linking everolimus and sorafenib exposure with biomarker dynamics and progression-free survival (PFS) based on data from EVESOR trial in patients with solid tumors treated with everolimus and sorafenib combination therapy and to simulate alternative dosing schedules for sorafenib.

PATIENTS AND METHODS

Everolimus (5-10 mg once daily, qd) and sorafenib (200-400 mg twice daily, bid) were administered according to four different dosing schedules in 43 solid tumor patients. Rich PK and PD sampling for serum angiogenesis biomarkers was performed. Baseline activation of RAS/RAF/ERK (MAPK) pathway was assessed by quantification of mRNA specific gene panel in tumor biopsies. The PK-PD modeling was performed using NONMEM^® software.

RESULTS

An indirect response PK-PD model linking sorafenib plasma exposure with soluble vascular endothelial growth factor receptor 2 (sVEGFR2) dynamics was developed. Progression-free survival (PFS) was described by a parametric time-to-event model. Higher decreases in sVEGFR2 at day 21 and higher baseline activation of MAPK pathway were associated with longer PFS (p = 0.002 and p = 0.007, respectively). The simulated schedule sorafenib 200 mg bid 5 days-on/2 days-off + continuous everolimus 5 mg qd was associated with median PFS of 4.3 months (95% CI 1.6-14.4), whereas the median PFS in the EVESOR trial was 3.6 months (95% CI 2.7-4.2, n = 43).

CONCLUSION

Sorafenib 200 mg bid 5 days-on/2 days-off + everolimus 5 mg qd continuous was selected for an additional arm of EVESOR trial to evaluate whether this simulated schedule is associated with higher clinical benefit.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01932177.

Clinical results of the EVESOR trial, a multiparameter phase I trial of everolimus and sorafenib combination in solid tumors

PURPOSE

Everolimus (EVE) and sorafenib (SOR) combination was associated with synergistic activity in preclinical models. However, previous clinical studies were hampered by cumulative toxicities when both were given continuously. The academic EVESOR trial (NCT01932177) was designed to assess alternative doses and intermittent dosing schedules of EVE and SOR combination therapy to improve the benefit-risk ratio for patients with solid tumors.

METHODS

EVESOR is a multiparameter dose-escalation phase I trial investigating different doses and dosing schedules, with the final objective of generating data for modeling and simulation. Patients were allocated into continuous (A and B) or intermittent (C and D) schedules to determine the recommended phase II dose (RP2D). The clinical outcomes are presented here.

RESULTS

Forty-three patients were included from 2013 to 2019. Most of them had gynecological (25.6%), cholangiocarcinomas (23.2%), colorectal (14.0%), and breast cancers (11.6%). Dose-escalation up to EVE 10 mg QD and SOR 400 mg BID was possible on intermittent schedules. Five dose-limiting toxicities were observed, and dose reductions were required in 39.5% patients, stabilizing at EVE 5 mg and SOR 200 mg BID for 58.1% of them. The overall response rate was 6.3%, and disease control rate was 75.0%. The median progression-free survival (PFS) was 3.6 months. The longest median PFS were observed in cholangiocarcinomas (9.9 months), and gynecological adenocarcinomas (9.2 months).

CONCLUSION

Intermittent arms were associated with improved efficacy/toxicity profiles; and EVE 5 mg QD and SOR 200 mg BID was defined a clinically feasible dose. Strong signs of efficacy were found in cholangiocarcinomas and gynecologic carcinomas.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01932177.

Intra-individual dose escalation of abiraterone (ABI) according to its plasma exposure in patients (pts) with progressive metastatic castration-resistant prostate cancer (mRCPC): Results of the OPTIMABI trial

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Background: Abiraterone acetate (ABI) improves survival in mCRPC. In a previous observational study, worse PSA response and shorter progression-free survival (PFS) were associated with mean ABI plasma through concentration (ABI Cmin) < 8.5 ng/mL within the first three months (ms) of treatment (Carton E et al. Eur J Cancer 2017). The OPTIMABI study, a multicenter non-randomized study (NCT 03458247), aimed to investigate whether a dose escalation of ABI improve PFS in underexposed progressive mCRPC pts. Methods: In step 1, pts with docetaxel-naive progressive mCRPC received ABI at the standard dose of 1000 mg/d + Prednisone 10 mg/d. Mean ABI Cmin was calculated from three monthly dosages. Pts experiencing progression within the first 6 ms and for whom mean ABI Cmin was < 8.5 ng/mL were included in step 2 and received 1000 mg twice daily (2000 mg/d) of ABI. ABI Cmin was assessed every month. The primary endpoint was the non-progression rate at 12 weeks in step 2. Identification of risk factors of 6 ms-PFS was done using Cox regression analysis. Results: From 06/2018 to 09/2021, 81 of 93 pts (median age: 72 yrs) included in step 1 were evaluable for statistical analysis. The median ABI Cmin was 10.0 (IQR: 4.5-15. 0) ng/mL over the first three ms. Inter-individual variability was 59%. The 6 ms-PFS was 68% (IC 95%: 56% - 80%) with no statistical difference between pts with mean ABI Cmin ≥ or < 8.5 ng/mL (log-rank test, p= 0.24). In multivariate analysis, liver metastasis (Hazard ratio, HR = 5.95, CI95% = 1.22–28.92; p=0.027) and creatinine clearance < 60 mL/min (HR = 3.51, CI95% = 1.12–10.99; p=0.031) were independently associated with 6 ms-PFS. Among 21 pts (25.9%), with mean ABI Cmin < 8.5 ng/mL, 8 pts (38.1%) experienced tumor progression within the first 6 ms; four of them could be included in step 2. None of them fulfilled the primary endpoint despite a significant increase in plasma ABI Cmin (p <0.036 by paired t-test). Conclusions: Despite high inter-individual variability of mean ABI Cmin, the OPTIMABI study does not support the strategy of intra-individual dose escalation according to plasma concentration of ABI in mCRPC. Underexposure to ABI (ABI Cmin < 8.5 ng/mL) was not statistically associated with shorter PFS. Clinical trial information: NCT03458247 .

Overall survival (OS) and efficacy results of second-line treatment in patients (pts) with metastatic clear cell renal cell carcinoma (mRCC) treated in the randomized phase II BIONIKK trial

607

Background: To date, no biomarker of efficacy of nivolumab+/-ipilimumab (N+/-I) or anti-VEGFR TKI has been prospectively validated in mRCC. The BIONIKK trial showed promising objective response rate (ORR) and progression-free survival (PFS) with these treatments in first line (L1) after selection by tumour molecular group. We report OS and efficacy results of the second-line (L2) treatment. Methods: BIONIKK is a French multicentre non-comparative phase II trial, randomising 199 mRCC pts to receive N (58), NI (101) or TKI (40) in L1 according to four molecular groups (ccrcc1-4). ORR and PFS were already reported. With an additional follow-up of ≥20 months, we report OS from randomization and from the start of L2, as well as ORR and PFS with a TKI in L2 by molecular group. Results: With a median follow-up of 42.1 months (40.5-45.2), 86 (43%) patients died: 27/58 (46.5%), 39/101 (39%) and 20/40 (50%) in the N, NI, and TKI arm, respectively. Median OS were 43.4 months (95%CI=31.4-NR) with N, 52.7 months (95%CI=46-NR) with NI and 38.1 months (95%CI=33.2-NR) with TKI (table). 175 (88%) patients discontinued first-line treatment, including 20 deaths, and 129 (74%) received a L2, 38/58 (65.5%), 64/101 (63%), and 27/40 (67.5%) after N, NI and TKI, respectively. The most frequent L2 received after N+/-I was a TKI in 96/102 (94%) pts, including cabozantinib in 49, sunitinib/pazopanib in 32, axitinib in 13, and lenvatinib in 2. N was the most frequent L2 after TKI, 20/27 (74%). ORR with TKI in L2 was 28.5% (10/35) after N, 39% (24/61) after NI and 80% (4/5) after TKI, with marked benefit in ccrcc2 pts (table). The mPFS with TKI in L2 was 8.2 (95%CI=6.9-19.3) after N, 11.4 (95%CI= 8.9-16.8) after NI, and 12.1 (95%CI =11.4-NR) months after TKI, with a higher benefit in ccrcc2 pts (vs. ccrcc1+4, p=0.04). Conversely, ORR and mPFS with N after TKI in ccrcc2-pts were 12.5% (2/16) and 5.4 (2.6-NR) months, respectively. Median OS L2 was reported in the table. The updated ORR and PFS in L1 will presented at the Meeting, as well as PFS2 and efficacy by TKI type in L2. Conclusions: We report for the first-time OS and L2 efficacy results by molecular group in a randomized trial. Molecular selection also has an impact on treatment efficacy in L2. These results, together with those reported in L1, can inform clinicians on the best treatment sequence in L1-2. Clinical trial information: NCT02960906 . [Table: see text]

Complete Response in Metastatic Clear Cell Renal Cell Carcinoma Patients Treated with Immune-Checkpoint Inhibitors: Remission or Healing? How to Improve Patients' Outcomes?

Renal-cell carcinoma (RCC) accounts for 2% of cancer diagnoses and deaths worldwide. Clear-cell RCCs represent the vast majority (85%) of kidney cancers and are considered morphologically and genetically as immunogenic tumors. Indeed, the RCC tumoral microenvironment comprises T cells and myeloid cells in an immunosuppressive state, providing an opportunity to restore their activity through immunotherapy. Standard first-line systemic treatment for metastatic patients includes immune-checkpoint inhibitors (ICIs) targeting PD1, in combination with either another ICI or with antiangiogenic targeted therapy. During the past few years, several combinations have been approved with an overall survival benefit and overall response rate that depend on the combination. Interestingly, some patients achieve prolonged complete responses, raising the question of whether these metastatic RCC patients can be cured. This review will focus on recent therapeutic advances in RCC and the clinical and biological aspects underpinning the potential for healing.

Urachal carcinoma: a large retrospective multicentric study from the French Genito-Urinary Tumor Group

Introduction

Urachal cancer (UrC) is a rare, non-urothelial malignancy. Its natural history and management are poorly understood. Although localized to the bladder dome, the most common histological subtype of UrC is adenocarcinoma. UrC develops from an embryonic remnant, and is frequently diagnosed in advanced stage with poor prognosis. The treatment is not standardized, and based only on case reports and small series. This large retrospective multicentric study was conducted by the French Genito-Urinary Tumor Group to gain a better understanding of UrC.

Material and Methods

data has been collected retrospectively on 97 patients treated at 22 French Cancer Centers between 1996 and 2020.

Results

The median follow-up was 59 months (range 44-96). The median age at diagnosis was 53 years (range 20-86), 45% were females and 23% had tobacco exposure. For patients with localized disease (Mayo I-II, n=46) and with lymph-node invasion (Mayo III, n=13) median progression-free-survival (mPFS) was 31 months (95% CI: 20-67) and 7 months (95% CI: 6-not reached (NR)), and median overall survival (mOS) was 73 months (95% CI: 57-NR) and 22 months (95% CI: 21-NR) respectively. For 45 patients with Mayo I-III had secondary metastatic progression, and 20 patients were metastatic at diagnosis. Metastatic localization was peritoneal for 54% of patients. Most patients with localized tumor were treated with partial cystectomy, with mPFS of 20 months (95% CI: 14-49), and only 12 patients received adjuvant therapy. Metastatic patients (Mayo IV) had a mOS of 23 months (95% CI: 19-33) and 69% received a platin-fluorouracil combination treatment.

Conclusion

UrC is a rare tumor of the bladder where patients are younger with a higher number of females, and a lower tobacco exposure than in standard urothelial carcinoma. For localized tumor, partial cystectomy is recommended. The mOS and mPFS were low, notably for patients with lymph node invasion. For metastatic patients the prognosis is poor and standard therapy is not well-defined. Further clinical and biological knowledge are needed.

Impact of Bone Metastases on Patients with Renal Cell Carcinoma or Melanoma Treated with Combotherapy Ipilimumab Plus Nivolumab

(1) Background: Ipilimumab plus nivolumab (combo-ICI) improves overall survival (OS) in patients with advanced renal cell carcinoma (RCC) or melanoma. The impact of bone metastases (BM) on survival outcomes of combo-ICI-treated patients is unknown. (2) Methods: This single-center retrospective observational study involved 36 combo-ICI-treated patients with advanced RCC and 35 with melanoma. Clinical and laboratory data preceding the initiation of combo-ICI were collected. Univariate and multivariate Cox proportional hazard models were used to assess the effect of BM on overall survival (OS) and progression-free survival (PFS). (3) Results: zNine RCC and 11 melanoma patients had baseline BM. In unadjusted analysis, baseline BM was associated with a poorer OS in the RCC cohort. Baseline BM did not have any impact on survival outcomes in melanoma patients. After adjustment on baseline performance status and on neutrophil-to-lymphocyte ratio (NLR), the impact of BM was no longer significant, but a NLR ≥ 3 was significantly associated with a poorer OS in the RCC cohort. (4) Conclusions: The presence of baseline BM seems to be associated with worse outcomes in RCC combo-ICI-treated patients, while its effect might not be independent from the inflammatory state (approximated by the NLR). BM seems to have no impact on the outcomes of melanoma combo-ICI-treated patients.

Chemotherapy following immune checkpoint inhibitors in patients with locally advanced or metastatic urothelial carcinoma

BACKGROUND

Recent studies suggest improvements in response to salvage chemotherapy (CT) after immune checkpoint inhibitors (ICIs) in several types of cancer. Our objective was to assess the efficacy of chemotherapy re-challenge after ICI, compared with second-line chemotherapy without previous ICI in patients with locally advanced or metastatic urothelial carcinoma (la/mUC).

METHODS

In this multicentre retrospective study, we included all patients with la/mUC initiating second or third-line chemotherapy from January 2015 to June 2020. We compared patients treated with second-line chemotherapy without previous ICI (CT2) and patients treated with third-line chemotherapy after ICI (CT3). The primary end-point was objective response rate (ORR) in CT3 compared with CT2. Secondary end-points included progression-free survival (PFS) and toxicities.

RESULTS

Overall, 553 patients were included. ORRs were 31.0% (95% CI, 26.5 to 35.5) and 29.2% (95% CI, 21.9 to 36.6), respectively, in CT2 and CT3, with no statistically significant differences (P = 0.62). In subgroup analyses, no differences in ORR were observed by Bellmunt risk group, type of chemotherapy (platinum or taxanes), duration of response to first-platinum-based chemotherapy (< or ≥ 12 months) or FGFR-status. Median PFS was 4.6 months (95% CI, 3.9 to 5.1) and 4.9 months (95% CI, 4.1 to 5.5) in CT2 and CT3, respectively, and grade 3-4 hematologic toxicity occurred in 35.0% and 22.4% of patients.

CONCLUSION

This large multicentre retrospective study provides clinically relevant real-world data. Chemotherapy re-challenge after ICI in la/mUC achieves ORR and PFS comparable with those obtained in CT2 with an acceptable safety profile. These updated results offer more promising outcomes than historically reported with second-line chemotherapy data.

Embryonated Chicken Tumor Xenografts Derived from Circulating Tumor Cells as a Relevant Model to Study Metastatic Dissemination: A Proof of Concept

Simple Summary

Circulating Tumor Cells (CTCs) are heterogeneous and rare in the bloodstream, but responsible for cancer metastasis. Their in vitro or in vivo expansion remains a major challenge. The chicken Chorioallantoic Membrane (CAM) assay has proven to be a reliable alternative to the murine model, notably for tumor xenografts. We have developed a promising model of CTC-derived xenografts in the chicken CAM and demonstrated the feasibility of Next Generation Sequencing (NGS) analysis in this assay, with a genomic concordance between the in ovo tumor and the original patient’s tumor. We also evidenced metastatic dissemination from the xenograft in the chicken embryo’s distant organs. Further characterization of the in ovo tumors and metastases may provide new insights into the mechanisms of tumor dissemination. The development of a xenograft from a given patient’s CTCs, in a time frame compatible with managing the patient’s treatment, could also be a step forward towards personalized medicine.

Abstract

Patient-Derived Xenografts (PDXs) in the Chorioallantoic Membrane (CAM) are a representative model for studying human tumors. Circulating Tumor Cells (CTCs) are involved in cancer dissemination and treatment resistance mechanisms. To facilitate research and deep analysis of these few cells, significant efforts were made to expand them. We evaluated here whether the isolation of fresh CTCs from patients with metastatic cancers could provide a reliable tumor model after a CAM xenograft. We enrolled 35 patients, with breast, prostate, or lung metastatic cancers. We performed microfluidic-based CTC enrichment. After 48–72 h of culture, the CTCs were engrafted onto the CAM of embryonated chicken eggs at day 9 of embryonic development (EDD9). The tumors were resected 9 days after engraftment and histopathological, immunochemical, and genomic analyses were performed. We obtained in ovo tumors for 61% of the patients. Dedifferentiated small tumors with spindle-shaped cells were observed. The epithelial-to-mesenchymal transition of CTCs could explain this phenotype. Beyond the feasibility of NGS in this model, we have highlighted a genomic concordance between the in ovo tumor and the original patient’s tumor for constitutional polymorphism and somatic alteration in one patient. Alu DNA sequences were detected in the chicken embryo’s distant organs, supporting the idea of dedifferentiated cells with aggressive behavior. To our knowledge, we performed the first chicken CAM CTC-derived xenografts with NGS analysis and evidence of CTC dissemination in the chicken embryo.

Tolerability of abiraterone (abi) combined with olaparib (ola) in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC): Further results from the phase III PROpel trial

5019

Background: The Phase III PROpel (NCT03732820) trial demonstrated at interim analysis a statistically significant clinical benefit from combining ola + abi in the first-line (1L) mCRPC setting vs placebo (pbo) + abi. Benefit was seen irrespective of a pt’s homologous recombination repair mutation (HRRm) status; median radiographic progression-free survival (rPFS) 24.8 for ola + abi vs 16.6 months for pbo + abi (hazard ratio [HR] 0.66, 95% confidence interval [CI] 0.54–0.81; P<0.0001). The safety profile of ola + abi was shown to be consistent with that for the individual drugs. We report additional interim safety analysis from PROpel. Methods: Eligible pts were ≥18 years with mCRPC, had received no prior chemotherapy or next-generation hormonal agent treatment at mCRPC stage, and were unselected by HRRm status. Pts were randomized 1:1 to abi (1000 mg qd) plus prednisone/prednisolone with either ola (300 mg bid) or pbo. Primary endpoint was investigator-assessed rPFS. Safety was assessed in all pts receiving ≥1 dose of study treatment by adverse event (AE) reporting (CTCAE v4.03). Results: 398 pts received ola + abi and 396 pbo + abi (safety analysis set). At data cut-off (July 30, 2021), median total duration of exposure for ola was 17.5 vs 15.7 months for pbo, and for abi 18.2 months in the ola + abi arm and 15.7 in the pbo + abi arm. Anemia (n=183) was the most common AE in the ola + abi arm, and 34% of these 183 events were managed by dose interruption, 23% by dose reduction, and 8% resulted in treatment discontinuation. Anemia and pulmonary embolism (PE) were the only Grade ≥3 AEs in ≥5% of pts (anemia: ola + abi, 15.1% vs pbo + abi, 3.3%; PE: 6.5% vs 1.8%, respectively). Most PEs were detected incidentally on radiographic imaging (69.2% and 71.4% in the ola + abi and pbo + abi arms, respectively) and no pts discontinued. More pts in the ola + abi arm experienced venous thromboembolism (Table). Arterial thromboembolism and cardiac failure AEs were balanced between the treatment arms. No AE of myelodysplastic syndrome/acute myeloid leukemia was reported in either treatment arm. COVID-19 was reported more frequently with ola + abi (8.3% vs 4.5%). Conclusions: PROpel demonstrated a predictable safety profile for ola + abi given in combination to pts with 1L mCRPC unselected by HRRm status. AEs of cardiac failure and arterial thromboembolism were reported at similar frequency in both treatment arms. The majority of PEs were asymptomatic. The safety profile of abiraterone was not adversely impacted by its combination with olaparib. Clinical trial information: NCT03732820. [Table: see text]

Cabozantinib-nivolumab sequence in metastatic renal cell carcinoma: the CABIR study

Nivolumab and cabozantinib are approved agents in mRCC patients after sunitinib/pazopanib (TKI) failure. However, the optimal sequence, cabozantinib then nivolumab (CN) or nivolumab then cabozantinib (NC), is still unknown. The CABIR study aimed to identify the optimal sequence between CN and NC after frontline VEGFR‐TKI. In this multicenter retrospective study, we collected data from mRCC pts receiving CN or NC, after frontline VEGFR‐TKI. A propensity score (PrS) was calculated to manage bias selection, and sequence comparisons were carried out with a cox model on a matched sample 1:1. The primary endpoint was progression‐free survival (PFS) from the start of second line to progression in third line (PFS_2‐3). Key secondary endpoints included overall survival from second line (OS₂). Out of 139 included mRCC patients, 38 (27%) and 101 (73%) received CN and NC, respectively. Overlap in PrS allowed 1:1 matching for each CN pts, with characteristics well balanced. For both PFS_2‐3 and OS₂, NC sequence was superior to CN (PFS_2‐3: HR = 0.58 [0.34‐0.98], P = .043; OS₂: 0.66 [0.42‐1.05], P = .080). Superior PFS_2‐3 was in patients treated between 6 and 18 months with prior VEGFR‐TKI (P = .019) and was driven by a higher PFS_L3 with cabozantinib when given after nivolumab (P < .001). The CABIR study shows a prolonged PFS of the NC sequence compared to CN in mRCC after first line VEGFR‐TKI failure. The data suggest that cabozantinib may be more effective than nivolumab in the third‐line setting, possibly related to an ability of cabozantinib to overcome resistance to PD‐1 blockade.

CIMUC: Chemotherapy following Immune checkpoints inhibitors in patients with locally advanced or metastatic urothelial carcinoma (la/mUC)

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Background: Immune checkpoints inhibitors (ICIs) have recently changed therapeutic landscape of la/mUC. Recent studies suggested an improvement of response to salvage chemotherapy (CT) after ICIs in several cancer types including urothelial carcinoma. We assumed that efficacy of CT rechallenge after ICIs may be improved compared to second-line CT without previous ICIs in patients (pts) with la/mUC. Methods: CIMUC is a French multicentric retrospective study including all pts with la/mUC initiating second or third-line CT from January 1st 2015 to June 30th 2020. Two groups of pts were defined: pts in group 1 (G1) were treated with a second-line CT without previous ICIs; pts in group 2 (G2) were treated with third line CT after ICIs. Primary endpoint was objective response rate (ORR: proportion of patients with complete or partial response, according to RECIST 1.1 criteria) in G2 versus G1. Secondary endpoints were progression-free survival (PFS), defined as time from initiation of second or third-line CT to disease progression or death from any cause, and toxicities. This study is supported by the French Genito Urinary Group (GETUG). Results: 553 pts were included. Baseline characteristics of the 2 groups are summarized in the Table. ORRs were 31% (95%CI [26.5-35.5]) and 29.2% (95%CI [21.9-36.6]) respectively in G1 and G2, without statistically significant difference (p=0.617), even after adjustment for Bellmunt risk factors (p=0.3214). In subgroups analysis, no difference in ORR was observed by type of CT (platinum or taxanes), duration of response (DOR) to first-platinum-based CT (< 12 months or ≥ 12 months) and FGFR-status. We did not identify any predictive factor of OR in G2 in multivariate analysis. Median PFS were 4.6 months (95%CI [3.88; 5.06]) and 4.86 months (95%CI [4.11; 5.45]), respectively in G1 and G2. Grade 3/4 hematologic toxicity occurred in 35% and 22.4%, respectively in G1 and G2. Conclusions: While ORR was not superior in G2 versus G1, pts derive comparable benefit in a further line of treatment (G2) in terms of ORR and PFS. Despite limits inherent to any retrospective study, CIMUC represents one of the largest retrospective studies in this setting.[Table: see text]

Modeled Early Longitudinal PSA Kinetics Prognostic Value in Rising PSA Prostate Cancer Patients after Local Therapy Treated with ADT +/− Docetaxel

Background: In metastatic prostate cancer (PCa) patients, androgen-deprivation therapy (ADT) combined with chemotherapy or next-generation androgen receptor targeted agents is a new standard treatment. The objective of the present study is to assess longitudinal PSA kinetics during treatment using mathematical modeling, to identify the modeled PSA kinetic parameters able to exhibit early prognostic/predictive values. Methods: Phase III clinical trial dataset (NCT00764166) comparing ADT +/− docetaxel in 250 locally treated patients for PCa with rising PSA levels, who were at high risk of metastatic disease was assessed. A kinetic-pharmacodynamic (K-PD) model was used to fit PSA kinetics during the first 100 treatment days, to estimate the modeled PSA production rate K (KPROD) and elimination constant rate K (KELIM). The prognostic value of these parameters, considered as categorized (favorable vs. unfavorable) covariates regarding PSA progression-free survival (PSA-PFS) and overall survival (OS), was assessed using univariate/multivariate analyses. Results: Data from 177/250 patients was assessed. KELIM exhibited a significant prognostic value regarding PSA-PFS and KPROD regarding OS (univariate analysis). In the PSA-PFS final multivariate model, KELIM and the primary therapy type were significant. The OS multivariate model integrated both KPROD and baseline PSA doubling-time. Conclusion: In this first study assessing the modeled PSA kinetics prognostic value in PCa patients treated with systemic treatments, KELIM and KPROD exhibited respective prognostic values regarding PSA-PFS and OS.

Her2 Expression in Circulating Tumor Cells Is Associated with Poor Outcomes in Patients with Metastatic Castration-Resistant Prostate Cancer

HER2-dependent signaling may support the development of metastatic castration-resistant prostate cancer (mCRPC) by activating androgen receptor signaling through ligand-independent mechanisms. From 41 mCRPC patients (including 31 treated with Androgen Receptor Signaling Inhibitors [ARSI]), Circulating Tumor Cells (CTCs) were prospectively enriched with AdnaTest platform and analyzed with a multiplexed assay for HER2 and AR-V7 mRNA expression. Then, we evaluated the impact of HER2 expression on PSA-response, Progression Free Survival (PFS) and Overall Survival (OS). HER2 expression was detected in CTCs of 26 patients (63%). Although PSA response was similar regardless of HER2 status, patients with HER2 positive CTCs had shorter PSA-PFS (median: 6.2 months versus 13.0 months, p = 0.034) and radiological-PFS (6.8 months versus 25.6 months, p = 0.022) than patients without HER2 expression. HER2 expression was also associated with a shorter OS (22.7 months versus not reached, p = 0.05). In patients treated with ARSI, multivariate analyses revealed that the prognostic impact of HER2 status on PSA-PFS was independent of AR-V7 expression and of the detection of CTCs by an AdnaTest. We showed for the first time the poor prognostic value of HER2 expression in CTCs from patients with mCRPC. The therapeutic interest of targeting this actionable pathway remains to be explored.

Cabazitaxel multiple rechallenges in metastatic castration-resistant prostate cancer

Introduction

Cabazitaxel multiple rechallenges may be a treatment option in heavily pretreated patients with metastatic castration‐resistant prostate cancer (mCRPC) who had a good initial response to cabazitaxel and who are still fit to receive it. Our objective was to assess the efficacy and toxicity of multiple rechallenges.

Patients and methods

We retrospectively identified 22 mCRPC patients previously treated with docetaxel and/or androgen receptor‐targeted agents who received multiple cabazitaxel rechallenges in 9 French centers. Cabazitaxel was initiated at a dose of 25 mg/m² q3week. A reduced dose (20 mg/m² q3w) or an alternative schedule (mainly 16 mg/m² q2w) was increasingly used for subsequent rechallenges. Progression‐free survival, prostate‐specific antigen (PSA) response, best clinical response, and grade ≥3 toxicities were collected. Overall survival was calculated from various time points.

Results

Twenty‐two patients with an initial response to cabazitaxel were rechallenged at least twice. The median number of cabazitaxel cycles was 7 at first cabazitaxel treatment, 6 at first rechallenge, and 5 at subsequent rechallenges. Median progression‐free survival at first rechallenge was 9.6 months and 5.6 months at second rechallenge. Median overall survival was 50.9 months from the first cabazitaxel dose, 114.9 months from first life‐extending therapy initiation in mCRPC, and 105 months from mCRPC diagnosis. There was no cumulative grade ≥3 neuropathy or nail disorder and one case of febrile neutropenia.

Conclusion

Cabazitaxel multiple rechallenges may be a treatment option without cumulative toxicity in heavily pretreated patients having a good response to first cabazitaxel use and still fit to receive it.

Novelty & Impact Statements

Patients with metastatic castration‐resistant prostate cancer can be treated with Cabazitaxel after docetaxel and androgen receptor‐targeted agent. This chemotherapy can be used multiple times with efficacy and manageable toxicity.

Impact of Social Frailty on Relocation of Older Adults

BACKGROUND

The relationship between frailty and variables such as housing are the least included in models of frailty and research on frailty or social frailty and relocation is negligible. The decision to relocate is complex and demanding for older adults with a loss of independence but little is known about what makes older adults relocate to congregated housing designated for older adults, let alone in combination with social frailty, and how they navigate this transition.

OBJECTIVES

This mixed method descriptive study aims to understand the influence of social frailty for a population of French-speaking semi-independent older adults relocating to a housing continuum community.

DESIGN

Semi-structured individual interviews including sociodemographic data and the PRISMA-7 Frailty Scale were conducted with recently relocated older adults.

SETTING

A newly opened French-speaking housing continuum community in Eastern Canada that offers luxury apartments for independent older adults, two assisted living facilities for semi-independent older adults along with a long-term care facility.

PARTICIPANTS

Twenty-nine older adults with a mean age of 85 years, mostly female, married or widowed and highly educated.

MEASUREMENTS

Content analysis of the transcribed recorded interviews and descriptive statistical analyses to examine relationships between the frailty PRISMA-7 scale, answers to additional questions and the sociodemographic data.

RESULTS

There was not a significant difference in the scores for socialization before and after relocation nor between prior help and current help; however, there was a significant negative correlation between help and socialization before and after relocation. Three main themes included: imposed influences, push and pull factors and post relocation.

CONCLUSIONS

The results indicate that several social factors contributed to relocation and that participants were experiencing social frailty. Participants were at the crossover point of being vulnerable to experiencing additional deficits which would potentially have led to higher frailty had they not relocated.

Investigating the Impact of Immune-Related Adverse Events, Glucocorticoid Use and Immunotherapy Interruption on Long-Term Survival Outcomes

Simple Summary

Immunotherapy has modified our clinical practices for the treatment of various solid cancers. Many studies have been done but it remains unclear whether adverse events induced by immunotherapy and the corticoids used for their management could impact long-term outcomes in patients treated by immunotherapy. A data collection of 828 patients was made to assess the impact of adverse events, immunotherapy interruption and the use of corticoids in long-term outcomes. In this cohort, we did not find any association between adverse events and survival outcomes. However, corticoid use was associated with a significantly shorter time before disease progression. Immunotherapy interruption was associated with a significantly shorter time before progression and survival. The impact of severe adverse events related to immunotherapy reported in other studies might be explained by their management. The use of corticoids must be careful, and resuming immunotherapy after adverse events may be important for long-term prognosis and should be considered as often as possible.

Abstract

It remains unclear whether immune-related adverse events (irAEs) and glucocorticoid use could impact long-term outcomes in patients treated for solid tumors with immune checkpoint inhibitors (ICI). All patients treated with a single-agent ICI for any advanced cancer were included in this retrospective unicentric study. The objectives were to assess the impact of grade ≥3 irAEs, glucocorticoid use and the interruption of immunotherapy on progression-free survival (PFS) and overall survival (OS). In this 828-patient cohort, the first occurrence of grade ≥3 irAEs had no significant impact on PFS or OS. Glucocorticoid administration for the irAEs was associated with a significantly shorter PFS (adjusted HR 3.0; p = 0.00040) and a trend toward shorter OS. ICI interruption was associated with a significantly shorter PFS (adjusted HR 3.5; p < 0.00043) and shorter OS (HR 4.5; p = 0.0027). Glucocorticoid administration and ICI interruption were correlated. In our population of patients treated with single agent ICI, grade ≥3 irAEs did not impact long-term outcomes. However, the need for glucocorticoids and the interruption of immunotherapy resulted in poorer long-term outcomes. The impact of grade ≥3 irAEs reported in other studies might then be explained by the management of the irAEs.

[Rheumatic immune adverse events related to immune checkpoint inhibitors-(IrAEs related to ICI)]

New anti-cancer therapeutics have been developed in the recent years and dramatically change prognosis and patient management. Either used alone or in combination, immune checkpoint inhibitors (ICI), such as anti-CTLA-4 and anti-PD1/PD-(L)1, act by removing T-cell inhibition to enhance their antitumor response. This change in therapeutic targets leads to a break in immune-tolerance and a unique toxicity profile resulting in immune complications. These side effects, called Immune-Related Adverse Events (IrAEs), can affect all organs, with a wide range of clinical and biological presentations and severity. Various rheumatic and musculoskeletal manifestations have been reported in the literature, ranging from mild arthralgia, polymyalgia rheumatica, to genuine serodefined rheumatoid arthritis and myositis. Tolerance studies suggest some correlations between IrAEs occurrence and tumor response. Assessment of patient musculoskeletal status prior to the start of the ICI is warranted. Management of rheumatic IrAEs does not usually request ICI discontinuation, exception for myositis or very severe forms where it should be discussed. Treatment relies on non-steroidal anti-inflammatory drugs (NSAIDs) or low dose glucocortioids (<20mg per day). Dose should be adjusted according to severity. The use of disease modifying anti-rheumatic drugs (DMARDs), either conventional and/or biological should be very cautious and result from a shared decision between oncologist and rheumatologist to best manage dysimmunitary complications without hampering the antitumor efficacy of ICI.

A133 GASTRIC ESD: PRELIMINARY EXPERIENCE IN A TERTIARY CENTER IN QUEBEC

Background

Endoscopic submucosal dissection (ESD) is an endoscopic procedure developed in Asian countries to treat early gastric cancer (EGC). Western countries have less experience with this challenging technique.

Aims

The goal of this study is to evaluate the effectiveness of ESD as a preliminary experience.

Methods

This is an unicentric retrospective study of all consecutive gastric ESD for adenomas or EGC from 07/2017 to 08/2020. The primary endpoints were en bloc and R0 resection rates.

Results

Nineteen patients (mean age 74.2 (54–88), sex ratio 3F/16M) and 23 lesions were included. Mean diameter was 25 mm (10–90). Treatment was previously performed in 7 cases (30.4%), by ESD (5) or EMR (2). The procedure, performed under general anaesthesia, lasted on average 148 minutes (45–412). En bloc resections were performed in 16 cases (69.6%); 5 cases (21.7%) were converted to P-EMR and there was a failure to resect the lesion because of deep invasion or perforation in 2 cases (8.7%). Pathologic examination demonstrated 2 low-grade dysplasia, 4 high-grade dysplasia and 15 adenocarcinomas: intramucosal (8), sm1 (2), sm2 (2), sm3 (1) or sm deep (2). R0 and curative resection rates were 43.5% and 39.1% respectively. The complication rate related to the procedure was 30.4% including 5 perforations and 2 delayed bleeding: all were managed endoscopically. Five patients (21.7%) underwent subsequent gastrectomy for non-curative resection (4) or failed resection (1); 3 had no residual disease on final pathology, 1 had high grade dysplasia and 1 had intramucosal adenocarcinoma. One patient went to palliative care because he was unfit for surgery. Follow-up endoscopy was completed in all 17 patients who underwent endoscopic resection (mean 10 months (2–24)). Recurrence occurred in 23.5% (4/17); all were successfully treated by another ESD.

Conclusions

In our preliminary experience, the rate of en bloc and R0 resection were 70% and 44%. Compared to other studies, these low en bloc and curative resection rates may be explained by technically difficult lesions during the learning curve and might improve with experience. Nevertheless, surgery has been avoided in 13/19 patients (68%) with endoscopic intervention.

Funding Agencies

None

Cabazitaxel multiple rechallenge in metastatic castration-resistant prostate cancer: A therapeutic option to increase overall survival?

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Background: Cabazitaxel rechallenge could be a more efficient therapy with an acceptable toxicity than docetaxel in the treatment of patients with a metastatic castration resistant prostate cancer (mCRPC). The aim of this study was to assess the feasibility and efficacy of cabazitaxel multiple rechallenge. Methods: This is a multicenter, retrospective cohort study including patients from 9 centers in France who received 3 lines or more of cabazitaxel from February 2012 to July 2020. Cabazitaxel schedule differed between patients: 25 mg/m2 q3w, 20 mg/m2 q3w, 16 mg/m2 q2w or 10 mg/m2 weekly. Efficacy was assessed by overall survival (OS) and progression-free survival (PFS) from each cabazitaxel line start. Only toxicities grade ≥ 3 were reported. Results: Twenty-two patients were included. The median follow-up from mCRPC was 94.7 months, median age at initial diagnosis was 59.5 years old, median ISUP score at diagnosis was 4 and median PSA at diagnosis was 55 ng/ml. Median number of cabazitaxel cycles was 7 at first-line, 6 at first rechallenge, and 5 for subsequent rechallenges. Median OS from mCRPC diagnosis was 105 months. Median PFS from cabazitaxel line start was 11.8 months at first use, 9.6 for first rechallenge and 5.6 in second rechallenge (table). Only one case of febrile neutropenia and 6 events of grade ≥ 3 toxicity were reported. Conclusions: Cabazitaxel multiple rechallenge could efficiently extend OS with manageable toxicities for patients. Even if anti-PARP therapy and immunotherapy are promising treatments, cabazitaxel rechallenge could be also a relevant therapeutic option for long responder patients. Specific biomarkers should be explored to predict the efficacy of cabazitaxel rechallenge. [Table: see text]

Renal adverse effects of immune checkpoints inhibitors in clinical practice: ImmuNoTox study

BACKGROUND/OBJECTIVES

Acute Kidney Injury (AKI), induced by Checkpoint Inhibitors therapies (CPI-induced AKI), is an uncommon but severe Immune-Related Adverse Event (IRAE). The aim was to describe the epidemiology, risks factors, clinical, and laboratory characteristics of these renal adverse events (AEs) in a real-life cohort treatment.

DESIGN/PARTICIPANTS

Consecutive patients undergoing a checkpoint inhibitor (CPI) therapy at the Hôpital Lyon Sud from January 2015 to July 2017 were included. A systematic retrospective analysis of medical files was performed, monthly serum creatinine levels, associated treatments, and occurrence of other IRAEs data were collected. AKI episodes explained by classic AKI aetiologies (prerenal, obstructive, septic) were excluded from the analysis.

RESULTS

CPI-induced AKI incidence was 3.7% (13/352) and appeared to be time-dependent (7.7% (11/143) for patients with >3 months of CPI exposure), ranging from 1 to 16 months. All cases with available histology were acute tubulointerstitial nephritis (ATIN), with poor urinary sediment. The severity of AKI was mild (stage 1 in 50% of cases), with no need for renal-replacement therapy. Although CPI-induced AKI patients had more frequently other IRAEs (77% versus 39%), this was not associated with a greater risk of AKI. Pre-existing chronic kidney disease (defined as an estimated glomerular filtration rate (eGFR) <60 ml/min) was not associated with a greater risk of CPI-induced AKI. Treatments of CPI-induced AKI were heterogeneous, with discontinuation of CPIs, and inconstant systemic corticosteroid therapy.

CONCLUSION

The monitoring of renal function and early identification of AKI during CPIs treatment is essential. The optimal management of CPI-induced AKI remains unclear and requires a close collaboration between the oncology and nephrology departments.

CLINICAL RELEVANCY STATEMENT

Immune checkpoint inhibitors (CPIs) have dramatically improved patient outcomes in different malignant contexts such as melanoma, non-small cell lung cancers (NSCLC) and urologic cancers. Usually well-tolerated, CPIs are however associated with immune-related adverse events (IRAEs). Among them, acute kidney injury (AKI) is uncommon, and not well-described. Following the exponential increase in the prescription of CPIs, previously uncommon cases of IRAEs (such as AKI) have become common occurrence in referral centres. Data regarding the epidemiology, risk factors, or management of CPI-induced AKI are currently lacking or can be discordant. Data regarding CPI-induced AKI, in a large real-life cohort were reported herein.

Abstract CT148: Clinical results of the multiparameter phase 1 trial EVESOR meant to optimize the doses and dosing schedules of the combination EVErolimus and SORafenib in solid tumors

Objectives: Defining the optimal doses & dosing schedules of combined targeted drugs is a challenge. Blocking both the PI3K-AKT-mTor and RAS-RAF-ERK pathways is a rationale therapeutic strategy in solid tumors. However, the phase 1 trials of everolimus (EVE) and sorafenib (SOR) failed to define the recommended phase II trial doses (RP2D) of both drugs, due to the toxicity when given continuously; and the combination was abandoned. The academic multi-parameter EVESOR trial (NCT01932177) was designed to assess alternative doses & dosing schedules of EVE & SOR, and to provide data that would be used to define the optimal doses & dosing schedules of both drugs associated with the best efficacy/toxicity ratio by modeling/simulation. Methods: EVESOR is an open dose-escalation phase 1 trial assessing the combination of EVE and SOR in patients with multi-treated advanced solid tumors. Enrolled patients were allocated to 1 of the 4 arms: A) EVE 5 mg QD for 2 weeks followed by continuous EVE + SOR 200 mg BID; B) SOR 200 mg BID for 2 weeks followed by continuous EVE 5 mg QD + SOR; C) alternating EVE 5-10 mg QD with SOR 200-400 mg BID every week; D) continuous EVE 5-10 mg QD + SOR 200-400 mg BID for 3 days on-4 days off. Multiple tumor & blood pharmacokinetic (PK) and pharmacodynamic (PD) parameters were sampled at baseline and during treatment (Nanostring panels). The 1st endpoint was the RP2D of both drugs in each arm A+B; C; and D. Results: 43 patients were included from 2013 to 2019: arm A n= 7; arm B n= 7; arm C n= 16; arm D n = 13. Most of them had gynecological (25.6%), cholangiocarcinomas (23.2%), colorectal (14%), and breast cancers (11.6%). Dose escalations to EVE 10 mg QD and SOR 400 mg BID were possible in both arms C and D. Five dose-limiting toxicities (DLTs) were observed (1; 3; and 1 in arms B, C and D respectively). Dose reductions were needed in 40% patients, stabilizing at EVE 5 mg and SOR 200 mg BID for the majority of them (58%). The overall response rate was 7%, and the disease control rate (DCR) was 73%. No relationships between dose levels and efficacy were found. However, the intermittent dosing schedules (arms C and D) were associated with better DCR. The median progression-free survival (PFS) was 3.6 months (2.7; 6.3; 2.7; and 3.6 months in arms A, B, C and D). Longer PFS were observed with cholangiocarcinomas (9.8 months) and gynecological cancers (3.7 months). Baseline activation of RAS-RAF-ERK was associated with higher non-progression rates at 4 months (50% vs 10%, P=0.12) and longer PFS (4.2 vs 2.1 months, P = 0.016). Decreases in S6K and AKT phosphorylations were observed in 89% and 70% of patients, respectively, with no significant impact on efficacy. Conclusions: EVE 5 mg QD and SOR 200 mg BID combination is the RP2D in solid tumor patients, in both intermittent arms C & D. Intermittent dosing was associated with higher efficacy. Long responses were found in cholangiocarcinomas. Adequately designed multi-schedules phase 1 trials can help for drug development, and avoid abandon of effective targeted drug combinations. Modeling/simulation will be used to optimize dose & dosing schedules of EVE and SOR based on collected data, and then tested.

Citation Format: Benoit You, Michel Tod, Lea Payen, Jonathan Lopez, Jerome Guitton, Pascal Rousset, Juliette Fontaine, Julien Peron, Denis Maillet, Sophie Tartas, Nathalie Bonnin, Veronique Trillet-Lenoir, Olivier Colomban, Diane Augu-Denechere, Gilles Freyer, Alicja Puszkiel. Clinical results of the multiparameter phase 1 trial EVESOR meant to optimize the doses and dosing schedules of the combination EVErolimus and SORafenib in solid tumors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT148.

Publisher Correction: Clinical efficacy and biomarker analysis of neoadjuvant atezolizumab in operable urothelial carcinoma in the ABACUS trial

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Association between immune-related adverse events and long-term survival outcomes in patients treated with immune checkpoint inhibitors

BACKGROUND

The impact of immune-related adverse events (irAE) on survival outcomes after single-agent immune checkpoint inhibitors (ICIs) remains unclear. We aimed to evaluate the association between irAEs and ICI efficacy in various malignancies.

METHODS

All patients treated with a single-agent ICI for any advanced cancer were included in this retrospective multicentric series. The primary objective was to assess the impact of all type grade ≥II irAEs on progression-free survival (PFS) and overall survival (OS). IrAEs were first considered as a fixed covariate and included in Cox-regression models. In addition, as irAEs are time-related events and can occur at any point during follow-up, we analysed the occurrence of irAEs as a time-varying covariate.

RESULTS

In this cohort of 410 patients, the majority of patients (70%) were treated for non-small cell lung cancer. The ICI was an anti-PD(L)1 for 356 patients (82%) and an anti-CTLA4 for 79 patients (18%). In total 126 (29%) of the patients presented at least one grade ≥II irAEs. The first occurrence of a grade ≥II irAE had a positive impact on PFS and OS when considered as a fixed or as a time-varying covariate (hazard ratio [HR] for PFS = 0.63, 95% confidence interval [CI] 0.50-0.81; P = 0.00022; HR for OS = 0.57, 95% CI 0.43-0.74, P < 0.0001). This overall finding was confirmed in patients treated with an anti-PD(L)1 and among patients with lung cancer.

CONCLUSION

In this pooled multi-institutional cohort, the incidence of irAEs was associated with better long-term survival across different malignancies treated with ICI monotherapy.

Guillain-Barré Syndrome During Platinum-Based Chemotherapy: A Case Series and Review of the Literature

Platinum-based chemotherapy is commonly associated with toxic sensory neuropathies, but also, although rarely, with Guillain-Barré syndrome (GBS). We describe five patients who developed GBS while receiving platinum-based chemotherapy for a solid tumor and report the five cases published so far. Most patients had received cumulative platinum doses below known neurotoxic levels, and all of them had an optimal outcome after platinum discontinuation, associated in most cases with administration of intravenous immunoglobulin. Clinical presentation, electroneuromyography, and cerebrospinal fluid analysis help clinicians to differentiate GBS from toxic neuropathy. Platinum compounds are the only chemotherapeutic agents used for solid tumors that have been associated to GBS. Thus, we propose that GBS may constitute a non-dose-dependent side effect of platinum drugs and that awareness needs to be raised among oncologists on this rare but potentially life-threatening complication of platinum chemotherapy. IMPLICATIONS FOR PRACTICE: Many patients on platinum-based chemotherapy for solid tumors develop sensory neuropathy, a common dose-dependent side effect. The authors propose that Guillain-Barré syndrome may constitute an immune-mediated, non-dose-related side effect of platinum-based chemotherapy. Prompt diagnosis of Guillain-Barré syndrome and distinction from classical toxic neuropathy are crucial for optimal treatment. Platinum discontinuation, associated if needed to intravenous immunoglobulin administration, radically changes the course of the disease and minimizes neurological sequelae.

Clinical efficacy and biomarker analysis of neoadjuvant atezolizumab in operable urothelial carcinoma in the ABACUS trial

Antibodies targeting PD-1 or its ligand 1 PD-L1 such as atezolizumab, have great efficacy in a proportion of metastatic urothelial cancers^1,2. Biomarkers may facilitate identification of these responding tumors³. Neoadjuvant use of these agents is associated with pathological complete response in a spectrum of tumors, including urothelial cancer^4-7. Sequential tissue sampling from these studies allowed for detailed on-treatment biomarker analysis. Here, we present a single-arm phase 2 study, investigating two cycles of atezolizumab before cystectomy in 95 patients with muscle-invasive urothelial cancer (ClinicalTrials.gov identifier: NCT02662309). Pathological complete response was the primary endpoint. Secondary endpoints focused on safety, relapse-free survival and biomarker analysis. The pathological complete response rate was 31% (95% confidence interval: 21-41%), achieving the primary efficacy endpoint. Baseline biomarkers showed that the presence of preexisting activated T cells was more prominent than expected and correlated with outcome. Other established biomarkers, such as tumor mutational burden, did not predict outcome, differentiating this from the metastatic setting. Dynamic changes to gene expression signatures and protein biomarkers occurred with therapy, whereas changes in DNA alterations with treatment were uncommon. Responding tumors showed predominant expression of genes related to tissue repair after treatment, making tumor biomarker interpretation challenging in this group. Stromal factors such as transforming growth factor-β and fibroblast activation protein were linked to resistance, as was high expression of cell cycle gene signatures after treatment.

Improved Androgen Receptor Splice Variant 7 Detection Using a Highly Sensitive Assay to Predict Resistance to Abiraterone or Enzalutamide in Metastatic Prostate Cancer Patients

BACKGROUND

In metastatic castration-resistant prostate cancer (mCRPC), androgen receptor splice variant 7 (AR-V7) expression is associated with a low response to androgen receptor signaling (ARS) inhibitors such as abiraterone or enzalutamide.

OBJECTIVE

To perform a highly sensitive assay for detecting AR-V7 (hsAR-V7) in circulating tumor cells (CTCs) and evaluate its ability to predict response to ARS inhibitors.

DESIGN, SETTING, AND PARTICIPANTS

From 41 mCRPC patients, CTCs were prospectively enriched using AdnaTest platform and analyzed for AR-V7 with and without the highly sensitive assay.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The first objective of the study was to compare AR-V7 detection rates with and without the highly sensitive assay. Next, we investigated how AR-V7 (detected without the highly sensitive assay) and hsAR-V7 status influenced prostate-specific antigen (PSA) response and long-term clinical outcomes (PSA progression-free survival [PFS] and radiological PFS) after ARS-inhibitor treatment. Finally, discriminatory abilities of the assays were assessed by C-index to compare their impact on long-term clinical outcomes.

RESULTS AND LIMITATIONS

AR-V7 detection rates increased from 22% to 56% when the highly sensitive assay was used. The discriminatory abilities of hsAR-V7 for PSA PFS (C-index, 0.74; 95% confidence interval [CI], 0.60-0.88) and radiological PFS (0.70; 95% CI, 0.55-0.85) were higher than those of AR-V7 detected without the highly sensitive assay (0.60, 0.51-0.72, and 0.56, 0.44-0.67, respectively). After ARS-inhibitor treatment, PSA response was lower in hsAR-V7⁺ (53%) than in hsAR-V7^- (93%) patients (p = 0.016). AR-V7⁺ patients had shorter median PSA PFS (3.0 vs 10.6 mo, p = 0.032) and nonsignificantly shorter median radiological PFS (6.0 vs 14.8 mo, p = 0.24) compared with AR-V7^- patients. The hsAR-V7⁺ status was associated with shorter median PSA PFS (3.0 mo vs not reached, p = 0.0001) and radiological PFS (median, 6.0 mo vs not reached, p = 0.0026).

CONCLUSIONS

The hsAR-V7 assay achieved the highest AR-V7 detection rates among those reported in mCRPC. Discriminatory abilities for long-term clinical outcomes were better with hsAR-V7 assay.

PATIENT SUMMARY

We prospectively analyzed circulating tumor cells from men with metastatic castration-resistant prostate cancer for androgen receptor splice variant 7 (AR-V7) status using a highly sensitive assay. It yielded higher AR-V7 detection rates and predicted resistance to androgen receptor signaling inhibitors with better discriminatory abilities for long-term clinical outcomes.

P14.20 Anxiety level in a prospective cohort of newly diagnosed glioblastoma patients: preliminary results from the IMAGE study

BACKGROUND

Quality of life (QoL) is an important area of clinical neuro-oncology, especially in glioblastoma patients. Although previous studies showed an association between QoL and anxiety, few studies have focused on the anxiety level throughout the disease progression (Bunevicius et al., 2017; Kilbride et al., 2007). Underestimating anxiety may have several consequences: a low treatment compliance, exacerbation of somatic symptoms or side effects of treatment, difficulties with understanding medical information and lower cooperation with the medical staff (Spencer, 2010). In the present study, we aimed assessing the current state of anxiety in a prospective cohort of patients treated for glioblastoma. We also investigated potential correlations with other clinical and psychological variables to better understand determinants of anxiety in this population.

MATERIAL AND METHODS

At the beginning of their cycle of temozolomide cure and after radio-chemotherapy, 30 patients with glioblastoma were included. Inclusion criteria were: Karnofsky index (IK) ≥ 70% and absence of cognitive disorder that could interfere with the completion of questionnaires. The characteristics of patients were as follows: mean age of 56.6 years ± 12.5 (70% were more than 50 years old); 20% were women; 50% had a university degree and IK of 87% ± 5. Anxiety level was assessed using the State-Trait Anxiety Inventory. This scale consists of 40 items on a self-report basis measuring how patients feel right now (“state”) and how they generally feel (“trait”). We also assessed (i) QoL using the Cancer Quality of Life Questionnaire 30 and the Brain Cancer Module-20; (ii) the presence of depressive symptoms using the Hospital Anxiety and Depression Scale; (iii) the self-esteem using the Rosenberg self-esteem scale and (iv) memory complains using the Prospective and Retrospective Memory Questionnaire.

RESULTS

The preliminary results showed that - at baseline - 21% of our sample reported high levels of anxiety. Correlation analyses showed that state anxiety was correlated with trait anxiety (rho=0.799, p< .001), QoL (rho=0.678, p< .001), level of self-esteem (rho=-0.514, p=0.004) and memory complains (rho=0.618, p< .001). Any correlation was found with age, education level, lesional lateralization or depressive symptoms. Women had higher state anxiety scores than men (t(27)=-2.4, p=0.02).

CONCLUSION

These preliminary results suggest that higher current state of anxiety is associated with lower QoL and lower self-esteem, regardless the presence of depressive symptoms, age, education level or lesional lateralization. Anxiety level at the follow-up (4 and 6 months after the baseline) and determinants of its progression will also be presented and might help health professionals to understand patients’ experience and better meet their needs.

Is the optimal biological dose of oncologic molecular-targeted therapies also clinically effective?

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Background: The determination of the optimal biological dose (OBD) defined as the lowest safe dose associated with biological efficacy, appears to be a promising endpoint for defining the recommended phase 2 trial dose (RP2D) of novel oncologic targeted therapies in early-phase clinical trials. However, the clinical relevance of OBD is still unknown. We conducted a review to assess if the OBDs of molecular targeted therapies defined during early phase trials were useful during subsequent drug development and for oncologic drug approvals. Methods: A systematic review was conducted to identify all the molecular targeted therapies approved by FDA in solid and hematological malignancies, and for which early phase trials defined OBDs. The publications of efficacy trials leading to the first FDA approvals were reviewed, as were the FDA approved doses and dosing schedules, which were compared to OBDs found in the early phase trials. Results: OBDs were reported in the early phase trial articles of 39.5% (32/81) FDA approved targeted therapies from 1999 to 2017 (19 small molecules and 13 monoclonal antibodies (mAbs)). The maximum tolerated doses (MTD) had not been reached for 59.4% (19/32) of these drugs. When both MTD and OBD had been defined, OBD were lower than MTD in 84.6% of cases, and equal for the others. The OBDs were chosen as the RP2Ds for 56.3% of the molecules. In that case, the final FDA approved doses were consistent with the OBDs for 83.3% of the drugs. These percentages did not differ in between small molecules and mAbs. OBDs mainly relied on indirect effects on the involved signaling pathway elements for small molecules (11/19, 57.9%), and on involved receptor occupancies for mAbs (6/13, 46.2%). In total, 23.5% of all FDA approved molecular targeted therapies were approved at their OBDs. Conclusions: Although still poorly investigated, OBD may represent a relevant complementary endpoint in in early phase trials of novel anti-cancer targeted therapies, as OBDs are selected as the final FDA approved doses in 83.3 % of cases when chosen as the RP2Ds, which is much higher than the previously reported 58.0 % when MTDs are chosen as the RP2Ds (Fontes-Jardim et al. JNCI 2015).

A systematic review of adverse events in randomized trials assessing immune checkpoint inhibitors

The advent of immune checkpoint-inhibitors (CPI) has transformed treatment for several cancer types. This review was performed to assess the rate of adverse events (AEs) associated with the use of CPI, alone or in combinations. A review of AEs reporting quality was also performed. All publications of Randomized Clinical Trials (RCTs) assessing CPI published before December 2017 were included. To investigate the quality of AEs reporting, a set of items was defined based on the 2004 CONSORT harms extension statement. Rates of Grade 5, serious, and study-withdrawal related AEs were collected in each treatment category. Specific immune related AEs (irAEs) were also collected when available. Pooled estimates of adverse event rates were calculated by using generalized linear mixed model. A total of 35 RCTs including 16,485 patients were included. The overall quality of AEs reporting was satisfactory, but items pertaining to methods of data collection and analysis were infrequently reported. Grade ≥ 3 AEs were reported for 14% (95% CI 12-16) of patients treated with PD(L)-1 inhibitors, 34% (95% CI 27-42) of patients treated with CTLA-4 inhibitors, 55% (95% CI 51-59) of patients on CPI combinations and 46% (95% CI 40-53) of patients on immunotherapy-chemotherapy combination. The profile of irAEs was different among the treatment categories. The use of CPI, especially in combination, is associated with significant rates of Grade ≥ 3 AEs. Healthcare planning should anticipate the expected high number of patients presenting with irAEs in the future.