Sacituzumab Govitecan in Combination With Pembrolizumab for Patients With Metastatic Urothelial Cancer That Progressed After Platinum-Based Chemotherapy: TROPHY-U-01 Cohort 3

PURPOSE

Pembrolizumab is standard therapy for patients with metastatic urothelial cancer (mUC) who progress after first-line platinum-based chemotherapy; however, only approximately 21% of patients respond. Sacituzumab govitecan (SG) is a trophoblast cell surface antigen-2-directed antibody-drug conjugate with US Food and Drug Administration-accelerated approval to treat patients with locally advanced or mUC who previously received platinum-based chemotherapy and a checkpoint inhibitor (CPI). Here, we report the primary analysis of TROPHY-U-01 cohort 3.

METHODS

TROPHY-U-01 (ClinicalTrials.gov identifier: NCT03547973) is a multicohort, open-label phase II study. Patients were CPI-naïve and had mUC progression after platinum-based chemotherapy in the metastatic setting or ≤12 months in the (neo)adjuvant setting. Patients received 10 mg/kg of SG once on days 1 and 8 and 200 mg of pembrolizumab once on day 1 of 21-day cycles. The primary end point was objective response rate (ORR) per central review. Secondary end points included clinical benefit rate (CBR), duration of response (DOR) and progression-free survival (PFS) per central review, and safety.

RESULTS

Cohort 3 included 41 patients (median age 67 years; 83% male; 78% visceral metastases [29% liver]). With a median follow-up of 14.8 months, the ORR was 41% (95% CI, 26.3 to 57.9; 20% complete response rate), CBR was 46% (95% CI, 30.7 to 62.6), median DOR was 11.1 months (95% CI, 4.8 to not estimable [NE]), and median PFS was 5.3 months (95% CI, 3.4 to 10.2). The median overall survival was 12.7 months (range, 10.7-NE). Grade ≥3 treatment-related adverse events occurred in 61% of patients; most common were neutropenia (37%), leukopenia (20%), and diarrhea (20%).

CONCLUSION

SG plus pembrolizumab demonstrated a high response rate with an overall manageable toxicity profile in patients with mUC who progressed after platinum-based chemotherapy. No new safety signals were detected. These data support further evaluation of SG plus CPI in mUC.

Development and Validation of an Inflammatory Prognostic Index to Predict Outcomes in Advanced/Metastatic Urothelial Cancer Patients Receiving Immune Checkpoint Inhibitors

BACKGROUND

Immune checkpoint inhibitors (ICIs) improve overall survival (OS) in advanced/metastatic urothelial cancer (a/mUC) patients. Preliminary evidence suggests a prognostic role of inflammatory biomarkers in this setting. We aimed to develop a disease-specific prognostic inflammatory index for a/mUC patients on ICIs.

METHODS

Fifteen variables were retrospectively correlated with OS and progression-free survival (PFS) in a development (D, n = 264) and a validation (V, n = 132) cohort of platinum-pretreated a/mUC pts receiving ICIs at L2 or further line. A nomogram and inflammatory prognostic index (U-IPI) were developed. The index was also tested in a control cohort of patients treated with chemotherapy only (C, n = 114).

RESULTS

The strongest predictors of OS were baseline platelet/lymphocyte (PLR) and neutrophil/lymphocyte (NLR) ratios, and lactate dehydrogenase (LDH), NLR, and albumin changes at 4 weeks. These were used to build the U-IPI, which can distinctly classify patients into good or poor response groups. The nomogram scoring is significant for PFS and OS (p < 0.001 in the D, V, and combined cohorts) for the immunotherapy (IO) cohort, but not for the control cohort.

CONCLUSIONS

The lack of a baseline systemic inflammatory profile and the absence of early serum inflammatory biomarker changes are associated with significantly better outcomes on ICIs in a/mUC pts. The U-IPI is an easily applicable dynamic prognostic tool for PFS and OS, allowing for the early identification of a sub-group with dismal outcomes that would not benefit from ICIs, while distinguishing another that draws an important benefit.

TROPHY-U-01, a phase II open-label study of sacituzumab govitecan in patients with metastatic urothelial carcinoma progressing after platinum-based chemotherapy and checkpoint inhibitors: updated safety and efficacy outcomes

BACKGROUND

Sacituzumab govitecan (SG) is a Trop-2-directed antibody-drug conjugate containing cytotoxic SN-38, the active metabolite of irinotecan. SG received accelerated US Food and Drug Administration approval for locally advanced (LA) or metastatic urothelial carcinoma (mUC) previously treated with platinum-based chemotherapy and a checkpoint inhibitor, based on cohort 1 of the TROPHY-U-01 study. Mutations in the uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) gene are associated with increased adverse events (AEs) with irinotecan-based therapies. Whether UGT1A1 status could impact SG toxicity and efficacy remains unclear.

PATIENTS AND METHODS

TROPHY-U-01 (NCT03547973) is a multicohort, open-label, phase II registrational study. Cohort 1 includes patients with LA or mUC who progressed after platinum- and checkpoint inhibitor-based therapies. SG was administered at 10 mg/kg intravenously on days 1 and 8 of 21-day cycles. The primary endpoint was objective response rate (ORR) per central review; secondary endpoints included progression-free survival, overall survival, and safety. Post hoc safety analyses were exploratory with descriptive statistics. Updated analyses include longer follow-up.

RESULTS

Cohort 1 included 113 patients. At a median follow-up of 10.5 months, ORR was 28% (95% CI 20.2% to 37.6%). Median progression-free survival and overall survival were 5.4 months (95% CI 3.5-6.9 months) and 10.9 months (95% CI 8.9-13.8 months), respectively. Occurrence of grade ≥3 treatment-related AEs and treatment-related discontinuation were consistent with prior reports. UGT1A1 status was wildtype (∗1|∗1) in 40%, heterozygous (∗1|∗28) in 42%, homozygous (∗28|∗28) in 12%, and missing in 6% of patients. In patients with ∗1|∗1, ∗1|∗28, and ∗28|∗28 genotypes, any grade treatment-related AEs occurred in 93%, 94%, and 100% of patients, respectively, and were managed similarly regardless of UGT1A1 status.

CONCLUSIONS

With longer follow-up, the ORR remains high in patients with heavily pretreated LA or mUC. Safety data were consistent with the known SG toxicity profile. AE incidence varied across UGT1A1 subgroups; however, discontinuation rates remained relatively low for all groups.

FGFR-targeted therapeutics: clinical activity, mechanisms of resistance and new directions

Fibroblast growth factor (FGF) signalling via FGF receptors (FGFR1-4) orchestrates fetal development and contributes to tissue and whole-body homeostasis, but can also promote tumorigenesis. Various agents, including pan-FGFR inhibitors (erdafitinib and futibatinib), FGFR1/2/3 inhibitors (infigratinib and pemigatinib), as well as a range of more-specific agents, have been developed and several have entered clinical use. Erdafitinib is approved for patients with urothelial carcinoma harbouring FGFR2/3 alterations, and futibatinib and pemigatinib are approved for patients with cholangiocarcinoma harbouring FGFR2 fusions and/or rearrangements. Clinical benefit from these agents is in part limited by hyperphosphataemia owing to off-target inhibition of FGFR1 as well as the emergence of resistance mutations in FGFR genes, activation of bypass signalling pathways, concurrent TP53 alterations and possibly epithelial-mesenchymal transition-related isoform switching. The next generation of small-molecule inhibitors, such as lirafugratinib and LOXO-435, and the FGFR2-specific antibody bemarituzumab are expected to have a reduced risk of hyperphosphataemia and the ability to overcome certain resistance mutations. In this Review, we describe the development and current clinical role of FGFR inhibitors and provide perspective on future research directions including expansion of the therapeutic indications for use of FGFR inhibitors, combination of these agents with immune-checkpoint inhibitors and the application of novel technologies, such as artificial intelligence.

Enfortumab Vedotin and Pembrolizumab in Untreated Advanced Urothelial Cancer

BACKGROUND

No treatment has surpassed platinum-based chemotherapy in improving overall survival in patients with previously untreated locally advanced or metastatic urothelial carcinoma.

METHODS

We conducted a phase 3, global, open-label, randomized trial to compare the efficacy and safety of enfortumab vedotin and pembrolizumab with the efficacy and safety of platinum-based chemotherapy in patients with previously untreated locally advanced or metastatic urothelial carcinoma. Patients were randomly assigned in a 1:1 ratio to receive 3-week cycles of enfortumab vedotin (at a dose of 1.25 mg per kilogram of body weight intravenously on days 1 and 8) and pembrolizumab (at a dose of 200 mg intravenously on day 1) (enfortumab vedotin-pembrolizumab group) or gemcitabine and either cisplatin or carboplatin (determined on the basis of eligibility to receive cisplatin) (chemotherapy group). The primary end points were progression-free survival as assessed by blinded independent central review and overall survival.

RESULTS

A total of 886 patients underwent randomization: 442 to the enfortumab vedotin-pembrolizumab group and 444 to the chemotherapy group. As of August 8, 2023, the median duration of follow-up for survival was 17.2 months. Progression-free survival was longer in the enfortumab vedotin-pembrolizumab group than in the chemotherapy group (median, 12.5 months vs. 6.3 months; hazard ratio for disease progression or death, 0.45; 95% confidence interval [CI], 0.38 to 0.54; P<0.001), as was overall survival (median, 31.5 months vs. 16.1 months; hazard ratio for death, 0.47; 95% CI, 0.38 to 0.58; P<0.001). The median number of cycles was 12 (range, 1 to 46) in the enfortumab vedotin-pembrolizumab group and 6 (range, 1 to 6) in the chemotherapy group. Treatment-related adverse events of grade 3 or higher occurred in 55.9% of the patients in the enfortumab vedotin-pembrolizumab group and in 69.5% of those in the chemotherapy group.

CONCLUSIONS

Treatment with enfortumab vedotin and pembrolizumab resulted in significantly better outcomes than chemotherapy in patients with untreated locally advanced or metastatic urothelial carcinoma, with a safety profile consistent with that in previous reports. (Funded by Astellas Pharma US and others; EV-302 ClinicalTrials.gov number, NCT04223856.).

Pembrolizumab with or Without Lenvatinib as First-line Therapy for Patients with Advanced Urothelial Carcinoma (LEAP-011): A Phase 3, Randomized, Double-Blind Trial

BACKGROUND

Pembrolizumab plus lenvatinib has shown antitumor activity and acceptable safety in patients with platinum-refractory urothelial carcinoma (UC).

OBJECTIVE

To evaluate pembrolizumab plus either lenvatinib or placebo as first-line therapy for advanced UC in the phase 3 LEAP-011 study.

DESIGN, SETTING, AND PARTICIPANTS

Patients with advanced UC who were ineligible for cisplatin-based therapy or any platinum-based chemotherapy were enrolled.

INTERVENTION

Patients were randomly assigned (1:1) to pembrolizumab 200 mg intravenously every 3 wk plus either lenvatinib 20 mg or placebo orally once daily.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Dual primary endpoints were progression-free survival (PFS) and overall survival (OS). An external data monitoring committee (DMC) regularly reviewed safety and efficacy data every 3 mo.

RESULTS AND LIMITATIONS

Between June 25, 2019 and July 21, 2021, 487 patients were allocated to receive lenvatinib plus pembrolizumab (n = 245) or placebo plus pembrolizumab (n = 242). The median time from randomization to the data cutoff date (July 26, 2021) was 12.8 mo (interquartile range, 6.9-19.3). The median PFS was 4.5 mo in the combination arm and 4.0 mo in the pembrolizumab arm (hazard ratio [HR] 0.90 [95% confidence interval {CI} 0.72-1.14]). The median OS was 11.8 mo for the combination arm and 12.9 mo for the pembrolizumab arm (HR 1.14 [95% CI 0.87-1.48]). Grade 3-5 adverse events attributed to trial treatment occurred in 123 of 241 patients (51%) treated with lenvatinib plus pembrolizumab and in 66 of 242 patients (27%) treated with placebo plus pembrolizumab. This trial was terminated earlier than initially planned based on recommendation from the DMC.

CONCLUSIONS

The benefit-to-risk ratio for first-line lenvatinib plus pembrolizumab was not considered favorable versus pembrolizumab plus placebo as first-line therapy in patients with advanced UC.

PATIENT SUMMARY

Lenvatinib plus pembrolizumab was not more effective than pembrolizumab plus placebo in patients with advanced urothelial carcinoma.

Health-related Quality of Life in Patients with Previously Treated Advanced Urothelial Carcinoma from EV-301: A Phase 3 Trial of Enfortumab Vedotin Versus Chemotherapy

BACKGROUND AND OBJECTIVE

In comparison to chemotherapy, enfortumab vedotin (EV) prolonged overall survival in patients with previously treated advanced urothelial carcinoma in EV-301. The objective of the present study was to assess patient experiences of EV versus chemotherapy using patient-reported outcome (PRO) analysis of health-related quality of life (HRQoL).

METHODS

For patients in the phase 3 EV-301 trial randomized to EV or chemotherapy we assessed responses to the validated European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (QLQ-C30) at baseline, weekly for the first 12 wk, and then every 12 wk until discontinuation. We analyzed the QLQ-C30 change from baseline to week 12, the confirmed improvement rate, and the time to improvement or deterioration.

KEY FINDINGS AND LIMITATIONS

Baseline PRO compliance rates were 91% for the EV arm (n = 301) and 89% for the chemotherapy arm (n = 307); the corresponding average rates from baseline to week 12 were 70% and 67%. Patients receiving EV versus chemotherapy had reduced pain (difference in change from baseline to week 12: -5.7, 95% confidence interval [CI] -10.8 to -0.7; p = 0.027) and worsening appetite loss (7.3, 95% CI 0.90-13.69; p = 0.026). Larger proportions of patients in the EV arm reported HRQoL improvement from baseline than in the chemotherapy arm; the odds of a confirmed improvement across ten QLQ-C30 function/symptom scales were 1.67 to 2.76 times higher for EV than for chemotherapy. Patients in the EV arm had a shorter time to first confirmed improvement in global health status (GHS)/QoL, fatigue, pain, and physical, role, emotional, and social functioning (all p < 0.05). EV delayed the time to first confirmed deterioration in GHS/QoL (p = 0.027), but worsening appetite loss occurred earlier (p = 0.009) in comparison to chemotherapy.

CONCLUSIONS AND CLINICAL IMPLICATIONS

HRQoL with EV was maintained, and deterioration in HRQoL was delayed with EV in comparison to chemotherapy. Better results with EV were reported for some scales, with the greatest difference observed for pain. These findings reinforce the EV safety and efficacy outcomes and benefits observed in EV-301.

PATIENT SUMMARY

Patients with previously treated advanced cancer of the urinary tract receiving the drug enfortumab vedotin maintained their HRQoL in comparison to patients treated with chemotherapy. The EV-301 trial is registered on ClinicalTrials.gov as NCT03474107 and on EudraCT as 2017-003344-21.

Plain language summary of erdafitinib in locally advanced or metastatic urothelial carcinoma: a phase 2 study with long-term follow-up

WHAT IS THIS SUMMARY ABOUT?

This is a plain language summary of two articles describing the results from a study called BLC2001. The study examined the effect of a medication called erdafitinib on participants with a type of cancer known as urothelial carcinoma that had either spread beyond the bladder or urinary tract into surrounding organs and/or nearby muscles (locally advanced) and was not removable by surgery (unresectable) or had spread to other parts of the body (metastatic). In this study, researchers wanted to learn if erdafitinib was safe and effective at stopping or reducing tumor growth in participants with locally advanced and unresectable or metastatic urothelial carcinoma with certain genetic alterations (changes in DNA sequence) in two related genes called fibroblast growth factor receptor 2 (FGFR2) and 3 (FGFR3). Treatment options for people with this disease are very limited; some may not have responded to other therapies, or their tumors continued to grow after they received other treatments. 212 participants took part in the study. 111 participants were treated with oral (by mouth) erdafitinib at different doses to find a recommended dose regimen. 101 additional participants then received the recommended starting dose of erdafitinib at 8 mg daily with possible increase to 9 mg daily, these participants make up the 8 mg regimen group.

WHAT WERE THE RESULTS OF THE BLC2001 STUDY IN THE 8 MG REGIMEN GROUP?

Researchers found that tumors decreased in size or completely disappeared in 40% of participants. With approximately 1 year of follow-up, an estimated 55% of participants were still alive, and after 2 years, an estimated 31% of participants were still alive. Common side effects of erdafitinib included high phosphate levels in the blood (hyperphosphatemia), an inflamed and sore mouth, diarrhea, and dry mouth.

WHAT DO THE RESULTS MEAN?

Participants had locally advanced and unresectable or metastatic urothelial carcinoma with certain FGFR gene alterations that had been treated with erdafitinib after previous chemotherapy and/or a type of medicine that uses the immune system to help the body fight cancer (immunotherapy). The BLC2001 study found that some participants treated with 8 mg erdafitinib had the benefit of a longer period without their cancer growing or spreading to other parts of the body. About 80% of participants achieved some level of disease control where their tumor shrank or remained stable.

Pemigatinib for metastatic or surgically unresectable urothelial carcinoma with FGF/FGFR genomic alterations: final results from FIGHT-201

BACKGROUND

Fibroblast growth factor receptor 3 (FGFR3) alterations are oncogenic drivers of urothelial carcinoma (UC). Pemigatinib is a selective, oral inhibitor of FGFR1-3 with antitumor activity. We report the efficacy and safety of pemigatinib in the open-label, single-arm, phase II study of previously treated, unresectable or metastatic UC with FGFR3 alterations (FIGHT-201; NCT02872714).

PATIENTS AND METHODS

Patients ≥18 years old with FGFR3 mutations or fusions/rearrangements (cohort A) and other FGF/FGFR alterations (cohort B) were included. Patients received pemigatinib 13.5 mg once daily continuously (CD) or intermittently (ID) until disease progression or unacceptable toxicity. The primary endpoint was centrally confirmed objective response rate (ORR) as per RECIST v1.1 in cohort A-CD. Secondary endpoints included ORR in cohorts A-ID and B, duration of response (DOR), progression-free survival (PFS), overall survival (OS), and safety.

RESULTS

Overall, 260 patients were enrolled and treated (A-CD, n = 101; A-ID, n = 103; B, n = 44; unconfirmed FGF/FGFR status, n = 12). All discontinued treatment, most commonly due to progressive disease (68.5%). ORR [95% confidence interval (CI)] in cohorts A-CD and A-ID was 17.8% (10.9% to 26.7%) and 23.3% (15.5% to 32.7%), respectively. Among patients with the most common FGFR3 mutation (S249C; n = 107), ORR was similar between cohorts (A-CD, 23.9%; A-ID, 24.6%). In cohorts A-CD/A-ID, median (95% CI) DOR was 6.2 (4.1-8.3)/6.2 (4.6-8.0) months, PFS was 4.0 (3.5-4.2)/4.3 (3.9-6.1) months, and OS was 6.8 (5.3-9.1)/8.9 (7.5-15.2) months. Pemigatinib had limited clinical activity among patients in cohort B. Of 36 patients with samples available at progression, 6 patients had 8 acquired FGFR3 secondary resistance mutations (V555M/L, n = 3; V553M, n = 1; N540K/S, n = 2; M528I, n = 2). The most common treatment-emergent adverse events overall were diarrhea (44.6%) and alopecia, stomatitis, and hyperphosphatemia (42.7% each).

CONCLUSIONS

Pemigatinib was generally well tolerated and demonstrated clinical activity in previously treated, unresectable or metastatic UC with FGFR3 mutations or fusions/rearrangements.

Avelumab First-line Maintenance for Advanced Urothelial Carcinoma: Analysis from JAVELIN Bladder 100 by Duration of First-line Chemotherapy and Interval Before Maintenance

BACKGROUND

In the JAVELIN Bladder 100 phase 3 trial, avelumab first-line maintenance + best supportive care (BSC) prolonged overall survival (OS) and progression-free survival (PFS) versus BSC alone in patients with advanced urothelial carcinoma (advanced UC) without progression after first-line platinum-based chemotherapy.

OBJECTIVE

To report post hoc analyses of subgroups defined by the duration of first-line chemotherapy and interval before maintenance.

DESIGN, SETTING, AND PARTICIPANTS

Patients with advanced UC without progression after four to six cycles of platinum-based chemotherapy and a 4-10-wk interval after chemotherapy (n = 700) were randomized to receive avelumab + BSC or BSC alone. Subgroups were defined by duration (quartile [Q]) and estimated number of cycles of chemotherapy, and interval between chemotherapy and maintenance. The median follow-up was >19 mo in both arms.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

OS (primary endpoint), PFS, and safety were assessed.

RESULTS AND LIMITATIONS

Hazard ratios (95% confidence interval) for OS with avelumab + BSC versus BSC alone were as follows: by chemotherapy duration-Q3: 0.63 (0.39-1.00); by number of cycles-four cycles: 0.69 (0.48-1.00), five cycles: 0.98 (0.57-1.71), and six cycles: 0.66 (0.47-0.92); and by interval-4-<6 wk: 0.75 (0.54-1.04), 6-<8 wk: 0.67 (0.43-1.06), and 8-10 wk: 0.69 (0.47-1.02). Results were similar for PFS. Safety was similar across subgroups. All analyses were exploratory.

CONCLUSIONS

Post hoc analyses of OS and PFS in subgroups defined by first-line chemotherapy duration and interval before maintenance were generally consistent with the results in the overall population, with similar safety findings. Prospective trials are warranted to confirm these findings.

PATIENT SUMMARY

Avelumab maintenance treatment helped patients with advanced urothelial cancer without disease progression after at least four cycles of prior chemotherapy, and who started maintenance treatment at least 4 wk after chemotherapy, to live longer.

A Phase 2 Randomized Open-label Study of Oral Darolutamide Monotherapy Versus Androgen Deprivation Therapy in Men with Hormone-sensitive Prostate Cancer (EORTC-GUCG 1532)

BACKGROUND AND OBJECTIVE

Darolutamide is an androgen receptor inhibitor that increases overall survival in combination with androgen deprivation therapy (ADT) in patients with metastatic hormone-sensitive and nonmetastatic castration-resistant prostate cancer (PCa). This phase 2 study assessed the efficacy and safety of darolutamide as monotherapy without ADT in patients with eugonadal testosterone levels.

METHODS

This was a 24-wk, open-label, randomized study of patients with hormone-sensitive, histologically confirmed PCa requiring gonadotropin-releasing hormone (GnRH); an Eastern Cooperative Oncology Group performance status score of 0/1; and life expectancy >1 yr. All patients received darolutamide 600 mg bid or a commercially available GnRH analog. The primary endpoint is a prostate-specific antigen (PSA) response, defined as a ≥80% decline at week 24 relative to baseline in the darolutamide study arm. The GnRH arm is used as an internal control. The secondary endpoints included changes in T levels, safety/tolerability, and quality of life.

KEY FINDINGS AND LIMITATIONS

Among 61 men enrolled, the median (range) age was 72 yr (53-86 yr); 42.6% of them had metastases. In the darolutamide arm, the evaluable population with available PSA values at baseline and week 24 consisted of 23 patients. Twenty-three (100%) evaluable darolutamide patients achieved a PSA decline of >80% at week 24 (primary endpoint), with a median (range) decrease of -99.1% (-91.9%, -100%). Serum T levels increased by a median (range) of 44.3 (5.7-144.0) at week 24, compared with baseline. In the darolutamide arm, 48.4% of men reported drug-related adverse events (AEs; mostly grade 1 or 2). The most frequent treatment-emergent AEs included gynecomastia (35.5%), fatigue (12.9%), hot flush (12.9%), and hypertension (12.9%). Health-related quality of life measures are descriptive, and GnRH arm results will be presented as an internal reference.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Darolutamide monotherapy was associated with a significant PSA response in nearly all men with hormone-naïve PCa. Testosterone-level changes and most common AEs (gynecomastia, fatigue, hypertension, and hot flush) were consistent with potent androgen receptor inhibition.

PATIENT SUMMARY

In this study, we report the first use of darolutamide, a novel antiandrogen, as monotherapy without androgen deprivation therapy (ADT). The study shows that darolutamide induce a profound suppression of prostate-specific antigen in all patients, with a safety profile different from that of ADT.

Antibody drug conjugates in older patients: State of the art

More than half of cancer cases occur in patients aged 65 years or older. The efficacy and safety of antibody drug conjugates (ADCs) in older patients remains an unclear subject as available evidence is limited. Geriatric population is underrepresented in clinical trials. Consequently, most of our knowledge regarding innovative therapeutics was studied on a younger population. In this review of published literature, we report the available information on efficacy, safety and pharmacokinetics of FDA approved ADCs for hematologic malignancies and solid tumors in the geriatric population. We explore the results of clinical trials dedicated for older individuals as well as subgroup analyses of the geriatric population in major trials evaluating these drugs. Available data suggest a similar efficacy in older adults as compared to general population. However, older patients might be prone to a higher rate of adverse events in incidence with a potential impact on quality of life. We lack data to support primary dose reductions or schedule modifications in this category of patients. No pharmacokinetic differences were reported between age groups. It is crucial to encourage the development of clinical trials dedicated to older patients with geriatric parameters (G8 score, G-CODE…) so that results can be more representative of this population outside of clinical trials.

Erdafitinib in BCG-treated high-risk non-muscle-invasive bladder cancer

BACKGROUND

Treatment options are limited for patients with high-risk non-muscle-invasive bladder cancer (NMIBC) with disease recurrence after bacillus Calmette-Guérin (BCG) treatment and who are ineligible for/refuse radical cystectomy. FGFR alterations are commonly detected in NMIBC. We evaluated the activity of oral erdafitinib, a selective pan-fibroblast growth factor receptor (FGFR) tyrosine kinase inhibitor, versus intravesical chemotherapy in patients with high-risk NMIBC and select FGFR3/2 alterations following recurrence after BCG treatment.

PATIENTS AND METHODS

Patients aged ≥18 years with recurrent, BCG-treated, papillary-only high-risk NMIBC (high-grade Ta/T1) and select FGFR alterations refusing or ineligible for radical cystectomy were randomized to 6 mg daily oral erdafitinib or investigator's choice of intravesical chemotherapy (mitomycin C or gemcitabine). The primary endpoint was recurrence-free survival (RFS). The key secondary endpoint was safety.

RESULTS

Study enrollment was discontinued due to slow accrual. Seventy-three patients were randomized 2 : 1 to erdafitinib (n = 49) and chemotherapy (n = 24). Median follow-up for RFS was 13.4 months for both groups. Median RFS was not reached for erdafitinib [95% confidence interval (CI) 16.9 months-not estimable] and was 11.6 months (95% CI 6.4-20.1 months) for chemotherapy, with an estimated hazard ratio of 0.28 (95% CI 0.1-0.6; nominal P value = 0.0008). In this population, safety results were generally consistent with known profiles for erdafitinib and chemotherapy.

CONCLUSIONS

Erdafitinib prolonged RFS compared with intravesical chemotherapy in patients with papillary-only, high-risk NMIBC harboring FGFR alterations who had disease recurrence after BCG therapy and refused or were ineligible for radical cystectomy.

Erdafitinib versus pembrolizumab in pretreated patients with advanced or metastatic urothelial cancer with select FGFR alterations: cohort 2 of the randomized phase III THOR trial

BACKGROUND

Erdafitinib is an oral pan-fibroblast growth factor receptor (FGFR) tyrosine kinase inhibitor approved to treat locally advanced/metastatic urothelial carcinoma (mUC) in patients with susceptible FGFR3/2 alterations (FGFRalt) who progressed after platinum-containing chemotherapy. FGFR-altered tumours are enriched in luminal 1 subtype and may have limited clinical benefit from anti-programmed death-(ligand) 1 [PD-(L)1] treatment. This cohort in the randomized, open-label phase III THOR study assessed erdafitinib versus pembrolizumab in anti-PD-(L)1-naive patients with mUC.

PATIENTS AND METHODS

Patients ≥18 years with unresectable advanced/mUC, with select FGFRalt, disease progression on one prior treatment, and who were anti-PD-(L)1-naive were randomized 1 : 1 to receive erdafitinib 8 mg once daily with pharmacodynamically guided uptitration to 9 mg or pembrolizumab 200 mg every 3 weeks. The primary endpoint was overall survival (OS). Secondary endpoints included progression-free survival (PFS), objective response rate (ORR), and safety.

RESULTS

The intent-to-treat population (median follow-up 33 months) comprised 175 and 176 patients in the erdafitinib and pembrolizumab arms, respectively. There was no statistically significant difference in OS between erdafitinib and pembrolizumab [median 10.9 versus 11.1 months, respectively; hazard ratio (HR) 1.18; 95% confidence interval (CI) 0.92-1.51; P = 0.18]. Median PFS for erdafitinib and pembrolizumab was 4.4 and 2.7 months, respectively (HR 0.88; 95% CI 0.70-1.10). ORR was 40.0% and 21.6% (relative risk 1.85; 95% CI 1.32-2.59) and median duration of response was 4.3 and 14.4 months for erdafitinib and pembrolizumab, respectively. 64.7% and 50.9% of patients in the erdafitinib and pembrolizumab arms had ≥1 grade 3-4 adverse events (AEs); 5 (2.9%) and 12 (6.9%) patients, respectively, had AEs that led to death.

CONCLUSIONS

Erdafitinib and pembrolizumab had similar median OS in this anti-PD-(L)1-naive, FGFR-altered mUC population. Outcomes with pembrolizumab were better than assumed and aligned with previous reports in non- FGFR-altered populations. Safety results were consistent with the known profiles for erdafitinib and pembrolizumab in this patient population.

Cabozantinib plus atezolizumab in previously untreated advanced hepatocellular carcinoma and previously treated gastric cancer and gastroesophageal junction adenocarcinoma: results from two expansion cohorts of a multicentre, open-label, phase 1b trial (COSMIC-021)

Background

Cabozantinib is approved for previously treated advanced hepatocellular carcinoma (aHCC) and has been investigated in gastric cancer (GC) and gastroesophageal junction adenocarcinoma (GEJ). Atezolizumab plus bevacizumab is approved for unresectable or metastatic HCC untreated with prior systemic therapy. We evaluated efficacy and safety of cabozantinib plus atezolizumab in aHCC previously untreated with systemic anticancer therapy or previously treated GC/GEJ.

Methods

COSMIC-021 (ClinicalTrials.gov, NCT03170960) is an open-label, phase 1b study in solid tumours with a dose-escalation stage followed by tumour-specific expansion cohorts, including aHCC (cohort 14) and GC/GEJ (cohort 15). Eligible patients were aged ≥18 years with measurable locally advanced, metastatic, or recurrent disease per RECIST version 1.1. Patients received oral cabozantinib 40 mg daily and intravenous atezolizumab 1200 mg once every 3 weeks until progressive disease or unacceptable toxicity. The primary endpoint was investigator-assessed objective response rate per RECIST version 1.1.

Findings

Patients were screened between February 14, 2019, and May 7, 2020, and 61 (30 aHCC, 31 GC/GEJ) were enrolled and received at least one dose of study treatment. Median duration of follow-up was 31.2 months (IQR 28.5-32.7) for aHCC and 30.4 months (28.7-31.9) for GC/GEJ. Objective response rate was 13% (4/30, 95% CI 4-31) for aHCC and 0% (95% CI 0-11) for GC/GEJ. Six (20%) aHCC patients and three (10%) GC/GEJ patients had treatment-related adverse events resulting in discontinuation of either study drug.

Interpretation

Cabozantinib plus atezolizumab had clinical activity with a manageable safety profile in aHCC previously untreated with systemic anticancer therapy. Clinical activity of cabozantinib plus atezolizumab was minimal in previously treated GC/GEJ.

Funding

Exelixis, Inc., Alameda, CA, USA.

Long term activity of vemurafenib in cancers with BRAF mutations: the ACSE basket study for advanced cancers other than BRAFV600-mutated melanoma

BACKGROUND

BRAF inhibitors are approved in BRAFV600-mutated metastatic melanoma, non-small-cell lung cancer (NSCLC), Erdheim-Chester disease (ECD), and thyroid cancer. We report here the efficacy, safety, and long-term results of single-agent vemurafenib given in the AcSé vemurafenib basket study to patients with various BRAF-mutated advanced tumours other than BRAFV600-mutated melanoma and NSCLC.

PATIENTS AND METHODS

Patients with advanced tumours other than BRAFV600E melanoma and progressing after standard treatment were eligible for inclusion in nine cohorts (including a miscellaneous cohort) and received oral vemurafenib 960 mg two times daily. The primary endpoint was the objective response rate (ORR) estimated with a Bayesian design. The secondary outcomes were disease control rate, duration of response, progression-free survival (PFS), overall survival (OS), and vemurafenib safety.

RESULTS

A total of 98 advanced patients with various solid or haematological cancers, 88 with BRAFV600 mutations and 10 with BRAFnonV600 mutations, were included. The median follow-up duration was 47.7 months. The Bayesian estimate of ORR was 89.7% in hairy cell leukaemias (HCLs), 33.3% in the glioblastomas cohort, 18.2% in cholangiocarcinomas, 80.0% in ECD, 50.0% in ovarian cancers, 50.0% in xanthoastrocytomas, 66.7% in gangliogliomas, and 60.0% in sarcomas. The median PFS of the whole series was 8.8 months. The 12-, 24-, and 36-month PFS rates were 42.2%, 23.8%, and 17.9%, respectively. Overall, 54 patients died with a median OS of 25.9 months, with a projected 4-year OS of 40%. Adverse events were similar to those previously reported with vemurafenib.

CONCLUSION

Responses and prolonged PFS were observed in many tumours with BRAF mutations, including HCL, ECD, ovarian carcinoma, gliomas, ganglioglioma, and sarcomas. Although not all cancer types responded, vemurafenib is an agnostic oncogene therapy of cancers.

Clinical utility of plasma ctDNA sequencing in metastatic urothelial cancer

BACKGROUND

Genomic stratification may help improve the management of patients with metastatic urothelial cancer (mUC), given the recent identification of targetable alterations. However, the collection of tissue samples remains challenging. Here, we assessed the clinical utility of plasma circulating tumour DNA (ctDNA) sequencing in these patients.

METHODS

Patients with mUC were prospectively enroled in the STING trial (NCT04932525), in which ctDNA was profiled using the Foundation One Liquid CDx Assay (324 genes, blood tumour mutational burden [bTMB], microsatellite instability status). Each genomic report was reviewed by a multidisciplinary tumor board (MTB).

RESULTS

Between January 2021 and June 2022, 140 mUC patients underwent molecular profiling. The median time to obtain the assay results was 20 days ((confidence interval) CI95%: [20,21]). The ctDNA analysis reproduced the somatic genomic landscape of previous tissue-based cohorts. Concordance for serial ctDNA samples was strong (r = 0.843 CI95%: [0.631-0.938], p < 0.001). At least one actionable target was detected in 63 patients (45%) with a total of 35 actionable alterations, including bTMB high (≥10 mutations/Mb) (N = 39, 21.1%), FGFR3 (N = 20, 10.8%), and Homologous recombination deficiency (HRD) alterations (N = 14, 7.6%). MTB recommended matched therapy in 63 patients (45.0%). Eight patients (5.7%) were treated, with an overall response rate of 50% (CI95%: 15.70-84.30) and a median progression-free survival (PFS) of 5.2 months (CI95%: 4.1 - NR). FGFR3 alterations were associated with a shorter PFS in patients treated with immunotherapy.

CONCLUSION

Overall, we demonstrated that genomic profiling with ctDNAs in mUC is a reliable and feasible approach for the timely initiation of genotype-matched therapies.

Erdafitinib or Chemotherapy in Advanced or Metastatic Urothelial Carcinoma

BACKGROUND

Erdafitinib is a pan-fibroblast growth factor receptor (FGFR) inhibitor approved for the treatment of locally advanced or metastatic urothelial carcinoma in adults with susceptible FGFR3/2 alterations who have progression after platinum-containing chemotherapy. The effects of erdafitinib in patients with FGFR-altered metastatic urothelial carcinoma who have progression during or after treatment with checkpoint inhibitors (anti-programmed cell death protein 1 [PD-1] or anti-programmed death ligand 1 [PD-L1] agents) are unclear.

METHODS

We conducted a global phase 3 trial of erdafitinib as compared with chemotherapy in patients with metastatic urothelial carcinoma with susceptible FGFR3/2 alterations who had progression after one or two previous treatments that included an anti-PD-1 or anti-PD-L1. Patients were randomly assigned in a 1:1 ratio to receive erdafitinib or the investigator's choice of chemotherapy (docetaxel or vinflunine). The primary end point was overall survival.

RESULTS

A total of 266 patients underwent randomization: 136 to the erdafitinib group and 130 to the chemotherapy group. The median follow-up was 15.9 months. The median overall survival was significantly longer with erdafitinib than with chemotherapy (12.1 months vs. 7.8 months; hazard ratio for death, 0.64; 95% confidence interval [CI], 0.47 to 0.88; P = 0.005). The median progression-free survival was also longer with erdafitinib than with chemotherapy (5.6 months vs. 2.7 months; hazard ratio for progression or death, 0.58; 95% CI, 0.44 to 0.78; P<0.001). The incidence of grade 3 or 4 treatment-related adverse events was similar in the two groups (45.9% in the erdafitinib group and 46.4% in the chemotherapy group). Treatment-related adverse events that led to death were less common with erdafitinib than with chemotherapy (in 0.7% vs. 5.4% of patients).

CONCLUSIONS

Erdafitinib therapy resulted in significantly longer overall survival than chemotherapy among patients with metastatic urothelial carcinoma and FGFR alterations after previous anti-PD-1 or anti-PD-L1 treatment. (Funded by Janssen Research and Development; THOR ClinicalTrials.gov number, NCT03390504.).

Circulating tumor DNA landscape and prognostic impact of acquired resistance to targeted therapies in cancer patients: a national center for precision medicine (PRISM) study

BACKGROUND

Despite the effectiveness of the various targeted therapies currently approved for solid tumors, acquired resistance remains a persistent problem that limits the ultimate effectiveness of these treatments. Polyclonal resistance to targeted therapy has been described in multiple solid tumors through high-throughput analysis of multiple tumor tissue samples from a single patient. However, biopsies at the time of acquired resistance to targeted agents may not always be feasible and may not capture the genetic heterogeneity that could exist within a patient.

METHODS

We analyzed circulating tumor DNA (ctDNA) with a large next-generation sequencing panel to characterize the landscape of secondary resistance mechanisms in two independent prospective cohorts of patients (STING: n = 626; BIP: n = 437) with solid tumors who were treated with various types of targeted therapies: tyrosine kinase inhibitors, monoclonal antibodies and hormonal therapies.

RESULTS

Emerging alterations involved in secondary resistance were observed in the plasma of up 34% of patients regardless of the type of targeted therapy. Alterations were polyclonal in up to 14% of patients. Emerging ctDNA alterations were associated with significantly shorter overall survival for patients with some tumor types.

CONCLUSION

This comprehensive landscape of genomic aberrations indicates that genetic alterations involved in secondary resistance to targeted therapy occur frequently and suggests that the detection of such alterations before disease progression may guide personalized treatment and improve patient outcome.

EV-301 long-term outcomes: 24-month findings from the phase III trial of enfortumab vedotin versus chemotherapy in patients with previously treated advanced urothelial carcinoma

INTRODUCTION

This exploratory analysis evaluated efficacy and safety data for enfortumab vedotin versus chemotherapy over a median follow-up of ∼2 years from EV-301.

MATERIALS AND METHODS

Patients with locally advanced/metastatic urothelial carcinoma with prior platinum-containing chemotherapy and disease progression during/after programmed cell death protein 1/ligand 1 inhibitor treatment were randomized to enfortumab vedotin or chemotherapy (docetaxel, paclitaxel, vinflunine). Endpoints were overall survival (primary), progression-free survival (PFS), objective response, and safety.

RESULTS

In total, 608 patients were included (enfortumab vedotin, n = 301; chemotherapy, n = 307). With a median follow-up of 23.75 months, 444 deaths had occurred (enfortumab vedotin, n = 207; chemotherapy, n = 237). Risk of death was reduced by 30% with enfortumab vedotin versus chemotherapy [hazard ratio (HR) 0.70 (95% confidence interval [CI] 0.58-0.85); one-sided, log-rank P = 0.00015]; PFS improved with enfortumab vedotin [HR 0.63 (95% CI 0.53-0.76); one-sided, log-rank P < 0.00001]. Treatment-related adverse event rates were 93.9% for enfortumab vedotin and 91.8% for chemotherapy; grade ≥ 3 event rates were 52.4% and 50.5%, respectively. Grade ≥ 3 treatment-related decreased neutrophil count (14.1% versus 6.1%), decreased white blood cell count (7.2% versus 1.4%), and anemia (7.9% versus 2.7%) were more common with chemotherapy versus enfortumab vedotin; maculopapular rash (7.4% versus 0%), fatigue (6.8% versus 4.5%), and peripheral sensory neuropathy (5.1% versus 2.1%) were more common with enfortumab vedotin. Of special interest adverse events, treatment-related skin reactions occurred in 47.3% of patients receiving enfortumab vedotin and 15.8% of patients receiving chemotherapy; peripheral neuropathy occurred in 48.0% versus 31.6%, respectively, and hyperglycemia in 6.8% versus 0.3%.

CONCLUSIONS

After a median follow-up of ∼2 years, enfortumab vedotin maintained clinically meaningful overall survival benefit versus chemotherapy, consistent with findings from the EV-301 primary analysis; PFS and overall response benefit remained consistent. Adverse events were manageable; no new safety signals were observed.

Genomic Profiling of Metastatic Castration-Resistant Prostate Cancer Samples Resistant to Androgen Receptor Pathway Inhibitors

PURPOSE

The androgen receptor axis inhibitors (ARPI; e.g., enzalutamide, abiraterone acetate) are administered in daily practice for men with metastatic castration-resistant prostate cancer (mCRPC). However, not all patients respond, and mechanisms of both primary and acquired resistance remain largely unknown.

EXPERIMENTAL DESIGN

In the prospective trial MATCH-R (NCT02517892), 59 patients with mCRPC underwent whole-exome sequencing (WES) and/or RNA sequencing (RNA-seq) of samples collected before starting ARPI. Also, 18 patients with mCRPC underwent biopsy at time of resistance. The objectives were to identify genomic alterations associated with resistance to ARPIs as well as to describe clonal evolution. Associations of genomic and transcriptomic alterations with primary resistance were determined using Wilcoxon and Fisher exact tests.

RESULTS

WES analysis indicated that no single-gene genomic alterations were strongly associated with primary resistance. RNA-seq analysis showed that androgen receptor (AR) gene alterations and expression levels were similar between responders and nonresponders. RNA-based pathway analysis found that patients with primary resistance had a higher Hedgehog pathway score, a lower AR pathway score and a lower NOTCH pathway score than patients with a response. Subclonal evolution and acquisition of new alterations in AR-related genes or neuroendocrine differentiation are associated with acquired resistance. ARPIs do not induce significant changes in the tumor transcriptome of most patients; however, programs associated with cell proliferation are enriched in resistant samples.

CONCLUSIONS

Low AR activity, activation of stemness programs, and Hedgehog pathway were associated with primary ARPIs' resistance, whereas most acquired resistance was associated with subclonal evolution, AR-related events, and neuroendocrine differentiation. See related commentary by Slovin, p. 4323.

Development of Novel Models of Aggressive Variants of Castration-resistant Prostate Cancer

BACKGROUND

Genomic studies have identified new subsets of aggressive prostate cancer (PCa) with poor prognosis (eg, neuroendocrine prostate cancer [NEPC], PCa with DNA damage response [DDR] alterations, or PCa resistant to androgen receptor pathway inhibitors [ARPIs]). Development of novel therapies relies on the availability of relevant preclinical models.

OBJECTIVE

To develop new preclinical models (patient-derived xenograft [PDX], PDX-derived organoid [PDXO], and patient-derived organoid [PDO]) representative of the most aggressive variants of PCa and to develop a new drug evaluation strategy.

DESIGN, SETTING, AND PARTICIPANTS

NEPC (n = 5), DDR (n = 7), and microsatellite instability (MSI)-high (n = 1) PDXs were established from 51 patients with metastatic PCa; PDXOs (n = 16) and PDOs (n = 6) were developed to perform drug screening. Histopathology and treatment response were characterized. Molecular profiling was performed by whole-exome sequencing (WES; n = 13), RNA sequencing (RNA-seq; n = 13), and single-cell RNA-seq (n = 14). WES and RNA-seq data from patient tumors were compared with the models.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Relationships with outcome were analyzed using the multivariable chi-square test and the tumor growth inhibition test.

RESULTS AND LIMITATIONS

Our PDXs captured both common and rare molecular phenotypes and their molecular drivers, including alterations of BRCA2, CDK12, MSI-high status, and NEPC. RNA-seq profiling demonstrated broad representation of PCa subtypes. Single-cell RNA-seq indicates that PDXs reproduce cellular and molecular intratumor heterogeneity. WES of matched patient tumors showed preservation of most genetic driver alterations. PDXOs and PDOs preserve drug sensitivity of the matched tissue and can be used to determine drug sensitivity.

CONCLUSIONS

Our models reproduce the phenotypic and genomic features of both common and aggressive PCa variants and capture their molecular heterogeneity. Successfully developed aggressive-variant PCa preclinical models provide an important tool for predicting tumor response to anticancer therapy and studying resistance mechanisms.

PATIENT SUMMARY

In this report, we looked at the outcomes of preclinical models from patients with metastatic prostate cancer enrolled in the MATCH-R trial (NCT02517892).

Definition and Diagnosis of Oligometastatic Bladder Cancer: A Delphi Consensus Study Endorsed by the European Association of Urology, European Society for Radiotherapy and Oncology, and European Society of Medical Oncology Genitourinary Faculty

BACKGROUND

In contrast to other cancers, the concept of oligometastatic disease (OMD) has not been investigated in bladder cancer (BC).

OBJECTIVE

To develop an acceptable definition, classification, and staging recommendations for oligometastatic BC (OMBC) spanning the issues of patient selection and the roles of systemic therapy and ablative local therapy.

DESIGN, SETTING, AND PARTICIPANTS

A European consensus group of 29 experts, led by the European Association of Urology (EAU), the European Society for Radiotherapy and Oncology (ESTRO), and the European Society of Medical Oncology (ESMO), and including members from all other relevant European societies, was established.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

A modified Delphi method was used. A systematic review was used to build consensus questions. Consensus statements were extracted from two consecutive surveys. The statements were formulated during two consensus meetings. Agreement levels were measured to determine if consensus was achieved (≥75% agreement).

RESULTS AND LIMITATIONS

The first survey included 14 questions and the second survey had 12. Owing to a considerable lack of evidence, which was the major limitation, definition was limited in the context of de novo OMBC, which was further classified as synchronous OMD, oligorecurrence, and oligoprogression. A maximum of three metastatic sites, all resectable or amenable to stereotactic therapy, was proposed as the definition of OMBC. Pelvic lymph nodes represented the only "organ" not included in the definition of OMBC. For staging, no consensus on the role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography was reached. A favourable response to systemic treatment was proposed as the criterion for selection of patients for metastasis-directed therapy.

CONCLUSIONS

A consensus statement on the definition and staging of OMBC has been formulated. This statement will help to standardise inclusion criteria in future trials, potentiate research on aspects of OMBC for which consensus was not achieved, and hopefully will lead to the development of guidelines on optimal management of OMBC.

PATIENT SUMMARY

As an intermediate state between localised cancer and disease with extensive metastasis, oligometastatic bladder cancer (OMBC) might benefit from a combination of systemic treatment and local therapy. We report the first consensus statements on OMBC drawn up by an international expert group. These statements can provide a basis for standardisation of future research, which will lead to high-quality evidence in the field.

Resistance to Selective FGFR Inhibitors in FGFR-Driven Urothelial Cancer

Several fibroblast growth factor receptor (FGFR) inhibitors are approved or in clinical development for the treatment of FGFR-driven urothelial cancer, and molecular mechanisms of resistance leading to patient relapses have not been fully explored. We identified 21 patients with FGFR-driven urothelial cancer treated with selective FGFR inhibitors and analyzed postprogression tissue and/or circulating tumor DNA (ctDNA). We detected single mutations in the FGFR tyrosine kinase domain in seven (33%) patients (FGFR3 N540K, V553L/M, V555L/M, E587Q; FGFR2 L551F) and multiple mutations in one (5%) case (FGFR3 N540K, V555L, and L608V). Using Ba/F3 cells, we defined their spectrum of resistance/sensitivity to multiple selective FGFR inhibitors. Eleven (52%) patients harbored alterations in the PI3K-mTOR pathway (n = 4 TSC1/2, n = 4 PIK3CA, n = 1 TSC1 and PIK3CA, n = 1 NF2, n = 1 PTEN). In patient-derived models, erdafitinib was synergistic with pictilisib in the presence of PIK3CA E545K, whereas erdafitinib-gefitinib combination was able to overcome bypass resistance mediated by EGFR activation.

SIGNIFICANCE

In the largest study on the topic thus far, we detected a high frequency of FGFR kinase domain mutations responsible for resistance to FGFR inhibitors in urothelial cancer. Off-target resistance mechanisms involved primarily the PI3K-mTOR pathway. Our findings provide preclinical evidence sustaining combinatorial treatment strategies to overcome bypass resistance. See related commentary by Tripathi et al., p. 1964. This article is featured in Selected Articles from This Issue, p. 1949.

Erdafitinib in patients with advanced solid tumours with FGFR alterations (RAGNAR): an international, single-arm, phase 2 study

BACKGROUND

FGFR alterations are reported across various malignancies and might act as oncogenic drivers in multiple histologies. Erdafitinib is an oral, selective pan-FGFR tyrosine kinase inhibitor with activity in FGFR-altered advanced urothelial carcinoma. We aimed to evaluate the safety and activity of erdafitinib in previously treated patients with FGFR-altered advanced solid tumours.

METHODS

The single-arm, phase 2 RAGNAR study was conducted at 156 investigative centres (hospitals or oncology practices that are qualified oncology study centres) across 15 countries. The study consisted of four cohorts based on tumour histology and patient age; the results reported in this Article are for the primary cohort of the study, defined as the Broad Panel Cohort, which was histology-agnostic. We recruited patients aged 12 years or older with advanced or metastatic tumours of any histology (except urothelial cancer) with predefined FGFR1-4 alterations (mutations or fusions according to local or central testing). Eligible patients had disease progression on at least one previous line of systemic therapy and no alternative standard therapy available to them, and an Eastern Cooperative Oncology Group performance status of 0-1 (or equivalent for adolescents aged 12-17 years). Patients received once-daily oral erdafitinib (8 mg/day with provision for pharmacodynamically guided up-titration to 9 mg/day) on a continuous 21-day cycle until disease progression or intolerable toxicity. The primary endpoint was objective response rate by independent review committee according to Response Evaluation Criteria In Solid Tumors (RECIST), version 1.1, or Response Assessment In Neuro-Oncology (RANO). The primary analysis was conducted on the treated population of the Broad Panel Cohort. This ongoing study is registered with ClinicalTrials.gov, number NCT04083976.

FINDINGS

Patients were recruited between Dec 5, 2019, and Feb 15, 2022. Of 217 patients treated with erdafitinib, 97 (45%) patients were female and 120 (55%) were male. The data cutoff was Aug 15, 2022. At a median follow-up of 17·9 months (IQR 13·6-23·9), an objective response was observed in 64 (30% [95% CI 24-36]) of 217 patients across 16 distinct tumour types. The most common grade 3 or higher treatment-emergent adverse events related to erdafitinib were stomatitis (25 [12%]), palmar-plantar erythrodysaesthesia syndrome (12 [6%]), and hyperphosphataemia (11 [5%]). The most commonly occurring serious treatment-related adverse events (grade 3 or higher) were stomatitis in four (2%) patients and diarrhoea in two (1%). There were no treatment-related deaths.

INTERPRETATION

RAGNAR results show clinical benefit for erdafitinib in the tumour-agnostic setting in patients with advanced solid tumours with susceptible FGFR alterations who have exhausted other treatment options. These results support the continued development of FGFR inhibitors in patients with advanced solid tumours.

FUNDING

Janssen Research & Development.

Profile and outcome of cancer patients enrolled in contemporary phase I trials

BACKGROUND

Phase I trials historically involved heavily pretreated patients (pts) with no more effective therapeutic options available and with poor expected outcomes. There are scare data regarding profile and outcomes of pts enrolled into modern phase I trials. Here, we sought to provide an overview of pts' profile and outcome into phase I trials at Gustave Roussy (GR).

METHODS

This is a monocentric retrospective study, including all pts enrolled into phase I trials at GR from 2017 to 2021. Data regarding pts' demographics, tumour types, investigational treatments and survival outcomes were collected.

RESULTS

In total, 9482 pts were referred for early phase trials; 2478 pts were screened, among which 449 (18.1%) failed screening; 1693 pts finally received at least one treatment dose as part of a phase I trial. Median age of pts was 59 years old (range, 18-88) and most common tumour types included gastrointestinal (25.3%), haematological (15%), lung (13.6%), genitourinary (10.5%) and gynaecologic cancers (9.4%). Amongst all pts treated and evaluable for response (1634 pts), objective response rate was 15.9% and disease control rate was 45.4%. Median progression-free survival and overall survival were, respectively, 2.6 months (95% confidence interval [95% CI], 2.3; 2.8) and 12.4 months (95% CI, 11.7; 13.6).

CONCLUSION

As compared with historical data, our study shows that outcomes of pts included into modern phase I trials have improved and that these trials constitute nowadays a valid and safe therapeutic option. These updated data provide facts for adapting the methodology, role and place of phase I trials over the next years.

Liquid biopsies for detection, surveillance, and prognosis of urothelial cancer: a future standard?

INTRODUCTION

Liquid biopsies are used for the detection of tumor-specific elements in body fluid. Their application in prognosis and diagnosis of muscle/non-muscle invasive bladder cancer (MIBC/NMIBC) or upper tract urothelial cancer (UTUC) remains poorly known and rarely mentioned in clinical guidelines.

AREAS COVERED

Herein, we provide an overview of current data regarding the use of liquid biopsies in urothelial tumors.

EXPERT OPINION

Studies that were included analyzed liquid biopsies using the detection of circulating tumor cells (CTCs), deoxyribonucleic acid (DNA), ribonucleic acid (RNA), exosomes, or metabolomics. The sensitivity of blood CTC detection in patients with localized cancer was 35% and raised to 50% in patients with metastatic cancer. In NMIBC patients, blood CTC was associated with poor prognosis, whereas discrepancies were seen in MIBC patients. Circulating plasma DNA presented a superior sensitivity to urine and was a good indicator for diagnosis, follow-up, and oncological outcome. In urine, specific bladder cancer (BC) microRNA had an overall sensitivity of 85% and a specificity of 86% in the diagnosis of urothelial cancer. These results are in favor of the use of liquid biopsies as biomarkers for in urothelial cancer management.

Avelumab First-line Maintenance Therapy for Advanced Urothelial Carcinoma: Comprehensive Clinical Subgroup Analyses from the JAVELIN Bladder 100 Phase 3 Trial

BACKGROUND

In the phase 3 JAVELIN Bladder 100 trial, avelumab first-line (1L) maintenance + best supportive care (BSC) significantly prolonged overall survival (OS) and progression-free survival (PFS) versus BSC alone in patients with advanced urothelial carcinoma (aUC) who were progression-free following 1L platinum-based chemotherapy, leading to regulatory approval in various countries.

OBJECTIVE

To analyze clinically relevant subgroups from JAVELIN Bladder 100.

DESIGN, SETTING, AND PARTICIPANTS

Patients with unresectable locally advanced or metastatic UC without progression on 1L gemcitabine + cisplatin or carboplatin were randomized to receive avelumab + BSC (n = 350) or BSC alone (n = 350). Median follow-up was >19 mo in both arms (data cutoff October 21, 2019). This trial is registered on ClinicalTrials.gov as NCT02603432.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

OS (primary endpoint) and PFS were analyzed in protocol-specified and post hoc subgroups using the Kaplan-Meier method and Cox proportional hazards models.

RESULTS AND LIMITATIONS

Hazard ratios (HRs) for OS with avelumab + BSC versus BSC alone were <1.0 across all subgroups examined, including patients treated with 1L cisplatin + gemcitabine (HR 0.69, 95% confidence interval [CI] 0.50-0.93) or carboplatin + gemcitabine (HR 0.64, 95% CI 0.46-0.90), patients with PD-L1+ tumors treated with carboplatin + gemcitabine (HR 0.67, 95% CI 0.39-1.14), and patients whose best response to chemotherapy was a complete response (HR 0.80, 95% CI 0.46-1.37), partial response (HR 0.62, 95% CI 0.46-0.84), or stable disease (HR 0.70, 95% CI 0.46-1.06). Observations were similar for PFS. Limitations include the smaller size and post hoc evaluation without multiplicity adjustment for some subgroups.

CONCLUSIONS

Analyses of OS and PFS in clinically relevant subgroups were consistent with results for the overall population, further supporting avelumab 1L maintenance as standard-of-care treatment for patients with aUC who are progression-free following 1L platinum-based chemotherapy.

PATIENT SUMMARY

In the JAVELIN Bladder 100 study, maintenance treatment with avelumab helped many different groups of people with advanced cancer of the urinary tract to live longer.

Infections occurring following IL6 blockade for the management of cytokine release syndrome in onco-hematology patients

BACKGROUND

Cytokine release syndrome (CRS) is a common adverse event of CAR T cell or bispecific antibody (bsAb) therapy. Anti-IL6/IL6R drugs are used in the management of auto-immune diseases. Some reports showed increased risk of bacterial infection in this context. In onco-hematology, there are few data about the occurrence of infection after administration of an anti-IL6/IL6R for CRS.

METHODS

We retrospectively reviewed all consecutive patients treated in Gustave Roussy Cancer Campus between 2018 and 2021, who received anti-IL6/IL6R for CRS due to bsAb in phase I clinical trials or adoptive cellular therapy (ACT). We constituted a control group including all the patients treated in the same clinical trials or standard of care ACT, naïve of anti-IL6/IL6R.

RESULTS

Fifty-two patients have been included. In the anti-IL6/IL6R group (n = 26), five patients developed a grade 2 to 5 infection within a month after anti-IL6/IL6R treatment, including two grade 5 infections. In the control group (n = 26), only one patient had a grade 3 infection. The two patients who had grade 5 infections were treated for diffuse large B cell lymphoma (DLBCL), one with bsAb and the other with CAR T cell. Fifty percent (3/6) of DLBCL patients who received an anti-IL6/IL6R presented an infection, one of which was a grade 5. In solid tumor patients treated with bsAb and anti-IL6/IL6R, only one patient (/9, 11%) developed a grade 2 viral infection.

CONCLUSION

It seems that the use of anti-IL6/IL6R in CRS secondary to bsAb administration in solid tumors patients does not significantly increase the risk of infection, as opposed to DLBCL patients where secondary infection might be a concern.

Avelumab First-Line Maintenance for Advanced Urothelial Carcinoma: Results From the JAVELIN Bladder 100 Trial After ≥2 Years of Follow-Up

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned coprimary or secondary analyses are not yet available. Clinical trial updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.Initial results from the phase III JAVELIN Bladder 100 trial (ClinicalTrials.gov identifier: NCT02603432) showed that avelumab first-line (1L) maintenance plus best supportive care (BSC) significantly prolonged overall survival (OS) and progression-free survival (PFS) versus BSC alone in patients with advanced urothelial carcinoma (aUC) who were progression-free after 1L platinum-containing chemotherapy. Avelumab 1L maintenance treatment is now a standard of care for aUC. Here, we report updated data with ≥ 2 years of follow-up in all patients, including OS (primary end point), PFS, safety, and additional novel analyses. Patients were randomly assigned 1:1 to receive avelumab plus BSC (n = 350) or BSC alone (n = 350). At data cutoff (June 4, 2021), median follow-up was 38.0 months and 39.6 months, respectively; 67 patients (19.5%) had received ≥2 years of avelumab treatment. OS remained longer with avelumab plus BSC versus BSC alone in all patients (hazard ratio, 0.76 [95% CI, 0.63 to 0.91]; 2-sided P = .0036). Investigator-assessed PFS analyses also favored avelumab. Longer-term safety was consistent with previous analyses; no new safety signals were identified with longer treatment duration. In conclusion, longer-term follow-up continues to show clinically meaningful efficacy benefits with avelumab 1L maintenance plus BSC versus BSC alone in patients with aUC. An interactive visualization of data reported in this article is available.

Abstract 4526: Molecular landscape of clonal hematopoiesis in patients with lung cancer: First results of the CHIC study

Introduction: CHIC (Clonal Hematopoiesis In Lung Cancer) is a retro-prospective study that aims to describe the characteristics of clonal hematopoiesis (CH) in patients with non-small cell lung cancer (NSCLC). We present preliminary results from the retrospective cohort.

Experimental procedures: A retrospective analysis conducted in patients with metastatic or recurrent NSCLC included in the MATCH-R study (NCT02517892) at Gustave Roussy (Villejuif, France). CH was evaluated by a 74-gene targeted NGS panel (HaloPlex - Agilent) performed on DNA extracted by isolated-by-blood leukocytes. The variant allele frequency (VAF) threshold of detection was set at 1%.

Results: 108 consecutive patients with advanced NSCLC included from October 2015 to July 2019 were evaluated, irrespective of the tumor molecular profile. 46% of the patients were female, 67% were former or current smokers. 82% of the patients had adenocarcinoma and 44%, 23%, 33% had bone, liver and/or brain metastases, respectively. Patients had received a median of 2 lines of systemic therapy and 81% were on active anticancer treatment at the time of CH assessment. At least one CH mutation was found in 38 out of 108 patients (35% prevalence), with an increasing with age trend. Patients carrying CH were older as compared to those without CH and had in 29% vs. 11% of cases tumor histology other than adenocarcinoma (p=0.009). No difference in overall survival was observed according to CH detection (log rank p=0.318). We found 64 mutations in 19 different genes: 63% of the patients carried a single mutation, while co-occurrence of two, three, four or five mutations, within the same gene or in more than one, was found in seven (18%), four (11%), one (3%) and two patients (5%), respectively. Epigenetic modifiers (DNMT3A, TET2, ASXL1) were the most frequently mutated genes: 38 mutations with a median VAF of 6.5% detected in 32 patients. DNA repair genes (PPM1D, TP53, CHEK2, ATM) were the second most frequently mutated: 11 mutations at a median VAF of 4% were detected in 9 patients. 7 mutations in genes encoding for the cohesin complex (SMC3, SMC1A, RAD21, STAG2) were found in 6 patients, with a median VAF of 5%. A non-simultaneous cfDNA sequencing by FoundationOne Liquid CDx assay (324-gene panel) was performed in 9 patients for tumor profiling. In 2 out of 3 tested cases the presence of CH was confirmed in plasma liquid biopsy. 4 patients with no detectable CH by the targeted blood sequencing subsequently were found having CH mutations in plasma NGS, on average 45 months apart. To note, as many as 5 out of the 19 detected mutated genes (PPM1D, SMC3, SMC1A, PRPF8, ZRSR2) are not part of the FDA-approved NGS panel used for cfDNA profiling in solid tumors.

Conclusion: We found a consistent prevalence of CH in patients with NSCLC by using a sequencing approach targeted for hematologic disorders. Prognostic implications of CH are under investigation and will be evaluated in the full cohort.

Citation Format: Marco Tagliamento, Christophe Marzac, Mihaela Aldea, Damien Vasseur, Arnaud Bayle, Anas Gazzah, Maud Ngocamus, Claudio Nicotra, Julieta Rodriguez, Antonin Levy, Capucine Baldini, Santiago Ponce, Felix Blanc-Durand, Etienne Rouleau, Antoine Italiano, Ludovic Lacroix, Luc Friboulet, David Planchard, Fabrice Barlesi, Yohann Loriot, Jean-Baptiste Micol, Benjamin Besse. Molecular landscape of clonal hematopoiesis in patients with lung cancer: First results of the CHIC study. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4526.

Abstract 4664: MatchR a preclinical platform of models resistant to innovative therapies

Introduction: In the last 20 years, the advances in molecular oncology and cancer genetics allowed the identification of an increasing number of actionable oncogenic drivers and the development and clinical use of specific inhibitors. Despite these successes, it is now well established that tumour cells adapt and develop acquired resistance. It is crucial to understand these mechanisms of acquired resistance to develop overcoming therapeutic strategies. At Gustave Roussy, a prospective clinical trial MATCH-R (NCT02517892) is conducted to study the acquired resistance mechanisms and to find new therapeutic approaches for patients.. In parallel, of genetics analysis from patients biopsies, we develop Patient Derived Xenograft (PDX) to deepen our understanding of the resistance mechanism and to investigate new therapeutic approaches.

Material and Method: Fresh tumor biopsy specimens were obtained prospectively from patients through a prospective single-institution clinical trial (MATCH-R, NCT02517892). Patient derived xenografts (PDX) in NOD Scid Gamma (NSG) mice as well as patient derived organoids from PDX (PDXO) and Patient derived cell lines were developed and characterized. Extensive molecular profiling including whole exome sequencing (WES), RNA sequencing (RNAseq) and immunohistochemistry were performed on human samples; PDX; Patient derived cells lines and PDXO.

Results and Discussion: As of November 2022, 145 PDX models have been successfully obtained from 371 biopsies (global take rate of 39%). Our focus is the development of models from different cohorts: Androgen receptor inhibitors in castration-resistant prostate cancer, (18 PDX), ALK inhibitors in lung cancers (16 PDX including 3 post brigatinib, 7 post Lorlatinib and 6 Alectinib), EGFR inhibitors in lung cancers (33 PDX includind 24 post osimertinib), FGFR inhibitors in urothelial carcinoma and cholangiocarcinoma (29 PDX including 14 post erdafitinib, 4 post pemigatinib, 4 post futibatinib) and KRAS inhibitors in lung cancer and pancreatic cancers (20 PDX). The PDX models recapitulate the genetics, the phenotype and the pharmacology of the original biopsies. Novel mechanisms of resistance to tyrosine kinase inhibitors (TKI) in solid tumors were identified. Adaptive treatment with novel TKI or combinatorial strategies were evaluated to restore the sensitivity in PDX (readout: mean tumor growth). These results confirmed that PDX models are crucial to study the resistance mechanism and to develop new therapeutic strategies.

Conclusion: Overall, the MATCH-R study provides a unique preclinical platform to identify resistance mechanisms to innovative therapies and to develop next generation therapeutic strategies.

Citation Format: Ludovic Bigot, Catline Nobre, Francesco Facchinetti, Loic Poiraudeau, Floriane Braye, Jonathan Sabio, Naoual Mensourri, Olivier Deas, Claudio Nicotra, Maud Ngo-Camus, Lambros Tselikas, Jean Yves Scoazec, Karim Fizazi, Siantiago Ponce, Benjamin Besse, Luc Friboulet, Yohann Loriot. MatchR a preclinical platform of models resistant to innovative therapies. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4664.

Management of Fibroblast Growth Factor Inhibitor Treatment-emergent Adverse Events of Interest in Patients with Locally Advanced or Metastatic Urothelial Carcinoma

Background

Erdafitinib is indicated for the treatment of adults with locally advanced/metastatic urothelial carcinoma and susceptible FGFR3/2 alterations progressing on/after one or more lines of prior platinum-based chemotherapy.

Objective

To better understand the frequency and management of select treatment-emergent adverse events (TEAEs) to enable optimal fibroblast growth factor receptor inhibitor (FGFRi) treatment.

Design setting and participants

Longer-term efficacy and safety results of the BLC2001 (NCT02365597) trial in patients with locally advanced and unresectable or metastatic urothelial carcinoma were studied.

Intervention

Erdafitinib schedule of 8 mg/d continuous in 28-d cycles, with uptitration to 9 mg/d if serum phosphate level was <5.5 mg/dl and no significant TEAEs occurred.

Outcome measurements and statistical analysis

Adverse events were graded using National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. The Kaplan-Meier methodology was used for the cumulative incidence of the first onset of TEAEs by grade. Time to resolution of TEAEs was summarized descriptively.

Results and limitations

At data cutoff, the median treatment duration was 5.4 mo among 101 patients receiving erdafitinib. Select TEAEs (total; grade 3) were hyperphosphatemia (78%; 2.0%), stomatitis (59%; 14%), nail events (59%; 15%), non-central serous retinopathy (non-CSR) eye disorders (56%; 5.0%), skin events (55%; 7.9%), diarrhea (55%; 4.0%), and CSR (27%; 4.0%). Select TEAEs were mostly of grade 1 or 2, and were managed effectively with dose modifications, including dose reductions or interruptions, and/or supportive concomitant therapies, resulting in few events leading to treatment discontinuation. Further work is needed to determine whether management is generalizable to the nonprotocol/general population.

Conclusions

Identification of select TEAEs and appropriate management with dose modification and/or concomitant therapies resulted in improvement or resolution of most TEAEs in patients, allowing for continuation of FGFRi treatment to ensure maximum benefit.

Patient summary

Early identification and proactive management are warranted to mitigate or possibly prevent erdafitinib side effects to allow for maximum drug benefit in patients with locally advanced or metastatic bladder cancer.

Integrative pan-cancer genomic and transcriptomic analyses of refractory metastatic cancer

Metastatic relapse after treatment is the leading cause of cancer mortality, and known resistance mechanisms are missing for most treatments administered to patients. To bridge this gap, we analyze a pan-cancer cohort (META-PRISM) of 1,031 refractory metastatic tumors profiled via whole-exome and transcriptome sequencing. META-PRISM tumors, particularly prostate, bladder, and pancreatic types, displayed the most transformed genomes compared to primary untreated tumors. Standard-of-care resistance biomarkers were identified only in lung and colon cancers - 9.6% of META-PRISM tumors, indicating that too few resistance mechanisms have received clinical validation. In contrast, we verified the enrichment of multiple investigational and hypothetical resistance mechanisms in treated compared to non-treated patients, thereby confirming their putative role in treatment resistance. Additionally, we demonstrated that molecular markers improve six-month survival prediction, particularly in patients with advanced breast cancer. Our analysis establishes the utility of META-PRISM cohort for investigating resistance mechanisms and performing predictive analyses in cancer.

Liquid Biopsies for Circulating Tumor DNA Detection May Reveal Occult Hematologic Malignancies in Patients With Solid Tumors

PURPOSE

High-risk clonal hematopoiesis (CH) is frequently incidentally found in patients with solid tumors undergoing plasma cell-free DNA sequencing. Here, we aimed to determine if the incidental detection of high-risk CH by liquid biopsy may reveal occult hematologic malignancies in patients with solid tumors.

MATERIALS AND METHODS

Adult patients with advanced solid cancers enrolled in the Gustave Roussy Cancer Profiling study (ClinicalTrials.gov identifier: NCT04932525) underwent at least one liquid biopsy (FoundationOne Liquid CDx). Molecular reports were discussed within the Gustave Roussy Molecular Tumor Board (MTB). Potential CH alterations were observed, and patients referred to hematology consultation in the case of pathogenic mutations in JAK2, MPL, or MYD88, irrespective of the variant allele frequency (VAF), or in DNMT3A, TET2, ASXL1, IDH1, IDH2, SF3B1, or U2AF1 with VAF ≥ 10%, while also considering patient cancer-related prognosis. TP53 mutations were discussed case-by-case.

RESULTS

Between March and October 2021, 1,416 patients were included. One hundred ten patients (7.7%) carried at least one high-risk CH mutation: DNMT3A (n = 32), JAK2 (n = 28), TET2 (n = 19), ASXL1 (n = 18), SF3B1 (n = 5), IDH1 (n = 4), IDH2 (n = 3), MPL (n = 3), and U2AF1 (n = 2). The MTB advised for hematologic consultation in 45 patients. Overall, 9 patients of 18 actually addressed had confirmed hematologic malignancies that were occult in six patients: two patients had myelodysplastic syndrome, two essential thrombocythemia, one a marginal lymphoma, and one a Waldenström macroglobulinemia. The other three patients were already followed up in hematology.

CONCLUSION

The incidental findings of high-risk CH through liquid biopsy may trigger diagnostic hematologic tests and reveal an occult hematologic malignancy. Patients should have a multidisciplinary case-by-case evaluation.

TROPHU-U-01 cohort 5: Evaluation of maintenance sacituzumab govitecan (SG) plus zimberelimab (ZIM), ZIM, or avelumab in cisplatin-eligible patients (pts) with unresectable or metastatic urothelial cancer (mUC)

TPS598

Background: SG is an antibody-drug conjugate composed of an anti-trophoblast cell-surface antigen-2 (Trop-2) antibody coupled to a topoisomerase-I inhibitor, SN-38, via a hydrolyzable linker. In Cohort 1 of the phase 2 TROPHY-U-01 trial, SG monotherapy resulted in a 27% objective response rate (ORR) and median overall survival (OS) of 10.9 months with an overall manageable toxicity profile in pts with locally advanced or mUC who previously received platinum-based therapy and a checkpoint inhibitor (CPI; Tagawa S, et al. J Clin Oncol. 2021). These results led to accelerated FDA approval of SG in this population. The CPI ZIM is a fully human IgG4 monoclonal antibody targeting PD-1. CPIs are active in mUC, including avelumab that is FDA-approved as switch maintenance therapy for locally advanced or mUC that has not progressed with first-line platinum-based chemotherapy. Cohort 5 of the TROPHY-U-01 trial will evaluate the safety, tolerability, and efficacy of SG + ZIM vs ZIM alone vs avelumab as switch maintenance in pts with mUC who have received gemcitabine (GEM)/cisplatin without progressive disease (PD). Methods: TROPHY-U-01 (NCT03547973) is a multicohort, open-label, global, phase 2 trial. Cohort 5 includes pts who have not progressed after completion of 4-6 cycles of GEM/cisplatin. Key eligibility requirements include ≥18 y; ECOG PS 0-1; available tissue for biomarker testing; adequate blood counts without transfusion or growth factor within 2 weeks of study drug initiation; creatinine clearance ≥30 mL/min. A safety lead-in of 6-8 pts will be conducted, where pts will be treated with SG 10 mg/kg IV on D1 and D8 of a 21-D cycle plus ZIM 360 mg IV q3wk on a 21-D cycle. On safety lead-in, if SG + ZIM is deemed safe, pts will be randomized 1:1:1. Those in Arm 1 will receive SG 10 mg/kg IV on D1 and D8 of a 21-D cycle followed by ZIM 360 mg IV, q3wk (D1 of a 21-D cycle). Pts in Arm 2 will receive avelumab 800 mg IV q2wk (D1 of a 14-D cycle). Pts in Arm 3 will receive ZIM 360 mg IV q3wk. All pts will continue treatment until PD, unacceptable toxicity, or loss of clinical benefit. The primary endpoint is progression-free survival based on central review by RECIST 1.1 criteria. Secondary endpoints include OS (all arms), safety/tolerability of SG in combination with ZIM (Arm 1). Cohort 5 aims to enroll an estimated 158 pts. A sample size of 50 pts per randomized arm is determined based on clinical consideration for exploring the activity of anticancer agents. Clinical trial information: NCT03547973 .

A phase 2 randomized open-label study of oral darolutamide monotherapy vs. androgen deprivation therapy in men with hormone-naive prostate cancer (EORTC-GUCG 1532)

160

Background: Darolutamide is androgen-receptor (AR) inhibitor with low blood–brain barrier penetration and limited potential for clinically relevant drug–drug interactions. Darolutamide has been shown to increase overall survival in combination with androgen deprivation therapy (ADT) in patients with newly diagnosed metastatic hormone sensitive prostate cancer (PC) and, in combination with docetaxel, in men with non-metastatic castration resistant PC. This phase 2 study assessed the efficacy and safety of DARO as a monotherapy without ADT in patients with non-castrate testosterone (T) levels (≥230 ng/dL). Methods: This was a 24-wk, open-label, randomized study of patients with hormone-naïve, histologically confirmed prostate cancer (all stages, with a max of 4 metastatic lesions) requiring hormonal treatment, an ECOG PS score of 0, and a life expectancy >1 y. All patients received DARO 600 mg bid or commercially available LHRH analogue. The primary endpoint is PSA response defined as a ≥ 80% decline at week 24 relative to baseline, in the DARO study arm. The ADT arm is used as an internal control. Secondary endpoints included changes in T levels, safety/tolerability, and quality of life. Results: Among 61 men enrolled, the median (range) age was 72 y (53-86y); 49.2% had metastases; 14.8% and 62.3% had undergone prostatectomy or radiotherapy before study entry. The median (range) of PSA at baseline was 8.9 ng/mL (2.2-333.8). In the DARO arm, the evaluable population with available PSA values at baseline and week 24 consisted of 21 patients. The PSA response rate (>80% PSA decline at wk 24) was 100%, with a median (range) decrease of -99.6% (-94.3, -100) at wk 24 in the DARO arm. Serum T levels increased by a median (range) of 43.4% (5.7-144.0) at wk 24, compared with baseline. In the DARO arm, 45.2% of men reported drug-related AEs (mostly Grade 1 or 2). Most frequent treatment-emergent AEs included gynaecomastia (19.4%), fatigue (12.9%), and hot flush (12.9%). 3.1% of men experienced SAEs, none of which were drug related. HR-QoL measures and ADT arm results will be presented as internal reference. Conclusions: DARO monotherapy (600 mg bid) was associated with significant PSA response in nearly all men with hormone-naïve prostate cancer. Testosterone level changes and most common AEs (gynecomastica, fatigue and hot flush) were consistent with potent AR inhibition. Clinical trial information: NCT02972060 .

Phase 2 study of the efficacy and safety of erdafitinib in patients (pts) with bacillus Calmette-Guérin (BCG)-unresponsive, high-risk non–muscle-invasive bladder cancer (HR-NMIBC) with FGFR3/2 alterations (alt) in THOR-2: Cohort 2 interim analysis results

503

Background: Pts presenting with NMIBC carcinoma in situ (CIS) have a high risk of progression. FGFR inhibition may benefit CIS pts with FGFRalt who are unresponsive to first-line BCG, for whom treatment (tx) options, other than radical cystectomy, are limited. Erdafitinib (erda), an oral selective pan-FGFR tyrosine kinase inhibitor, is approved for locally advanced or metastatic urothelial cancer in adults with FGFR3/2alt who have progressed during or after ≥1 line of platinum-containing chemotherapy. THOR-2 (NCT04172675) is a multicohort phase 2 study of erda in pts with HR-NMIBC. Here we report results from an exploratory cohort of pts with BCG-unresponsive CIS with FGFRalt with or without papillary disease (Cohort 2). Methods: Inclusion criteria: age ≥18 y, with histologically confirmed, BCG-unresponsive HR-NMIBC with FGFR3/2alt (by local/central testing) presenting as CIS, with or without a papillary tumor and who refused or were not eligible for cystectomy. In this cohort, pts received continuous oral erda 6 mg once daily without uptitration in 28-d cycles (dose selected to improve tolerability while maintaining activity to prevent disease recurrence, for this population). Erda was discontinued if no complete response (CR) was observed within 3 mos. Exploratory efficacy end points are CR rates at the Cycle 3 Day 1 (C3D1) disease evaluation and the Cycle 6 Day 1 (C6D1) disease evaluation; safety was a key secondary end point. Results: As of the data cutoff (Sep 2022) (median follow-up of 10 mos), 10 pts have received erda (enrolled population; median age 72 y [range 52-83]; 90% CIS [1 pt with Ta was mis-enrolled]). Pts received erda for a median duration 5.9 mos (range 1.1-17.0). Of 10 enrolled pts, the CR rates at first evaluation (C3D1) and second evaluation (C6D1) were 100% (9/9 evaluable pts) and 75% (6/8 evaluable pts), respectively. The median duration of response was 3.0 mos. The most common tx-emergent adverse events (TEAEs) were dry mouth (60%; n=6), hyperphosphatemia (50%; n=5), dysgeusia (50%; n=5), and diarrhea (50.0%; n=5). 1 pt (10%) had Gr 2 retinal detachment which led to tx discontinuation and 1 pt (10%) had Gr 1 subretinal fluid; both reported as resolved. Gr ≥3 tx-related TEAEs occurred in 3 pts (30%), and included dry mouth, stomatitis, nail disorder, onychomadesis, acute kidney injury, chronic kidney disease, sepsis, and hypotension in 1 pt each. 1 pt (10%) had serious tx-related TEAEs (dry mouth, hypotension, pneumonitis, acute kidney injury, and sepsis), and 1 pt (10%) discontinued tx due to a tx-related TEAE. No tx-related deaths were observed. Conclusions: Data from Cohort 2 of THOR-2 demonstrate efficacy at C3D1 and C6D1 evaluations in pts with HR-NMIBC with FGFRalt. Safety data were consistent with the known safety profile of erda. Clinical trial information: NCT04172675 .

Perioperative enfortumab vedotin (EV) plus pembrolizumab (pembro) versus chemotherapy in cisplatin-eligible patients (pts) with muscle-invasive bladder cancer (MIBC): Phase 3 KEYNOTE-B15/EV-304

TPS588

Background: Neoadjuvant cisplatin-based chemotherapy followed by radical cystectomy + pelvic lymph node dissection (RC+PLND) is the standard of care for cisplatin-eligible pts with MIBC; however, up to 50% of pts will experience disease recurrence or progression following treatment. Pembro and EV monotherapies are approved for use in select pts with metastatic urothelial carcinoma (mUC). Furthermore, results of the phase 1/2 KEYNOTE-869/EV-103 study showed encouraging antitumor activity and an acceptable safety profile with first-line combination therapy EV + pembro in cisplatin-ineligible pts with mUC. The open-label, multicenter, phase 3, randomized KEYNOTE-B15/EV-304 study (NCT04700124) will compare the efficacy and safety of perioperative EV + pembro versus neoadjuvant cisplatin-based chemotherapy in cisplatin-eligible pts with MIBC. Methods: Eligible pts will have histologically confirmed UC/MIBC (T2-T4aN0M0 or T1-T4aN1M0) with predominant urothelial histology (≥50%), nonmetastatic disease (N≤1, M0) confirmed by blinded independent central review (BICR), ECOG performance status of 0-1, no prior systemic therapy for MIBC, and agree to undergo curative RC+PLND. Approximately 784 pts will be randomly assigned 1:1 to Arm A (4 cycles of neoadjuvant EV + pembro, followed by RC+PLND, followed by 5 cycles of adjuvant EV + 13 cycles of adjuvant pembro) or Arm B (4 cycles of neoadjuvant chemotherapy [gemcitabine + cisplatin] followed by RC+PLND, followed by observation). Neoadjuvant and adjuvant pembro 200 mg + EV 1.25 mg/kg will be administered intravenously every 3 weeks (Q3W) on day 1 (pembro + EV) and day 8 (EV) of each cycle. Neoadjuvant chemotherapy is gemcitabine 1000 mg/m2 + cisplatin 70 mg/m2 Q3W on day 1 (gemcitabine + cisplatin) and day 8 (gemcitabine) of each cycle. Stratification factors are disease stage (T2N0 vs T3/T4aN0 vs T1-T4aN1), PD-L1 combined positive score (≥10 vs <10), and geographic region (United States vs European Union vs most of the world). Imaging by CT (preferred) or MRI will be performed ≤6 weeks before cystectomy and 6 weeks after cystectomy. Imaging will occur following cystectomy then Q12W through year 2 and at discontinuation, then Q24W in year 3 and beyond. Adverse events (AEs) will be monitored throughout the study and for 30 days following cessation of treatment (90 days for serious AEs). The primary end points are pathologic complete response rate and event-free survival by BICR. Secondary end points are OS, DFS, pathologic downstaging rate, safety and tolerability, and patient-reported outcomes. KEYNOTE-B15/EV-304 is enrolling in Africa, Asia, Australia, Europe, and North America. © 2021 American Society of Clinical Oncology, Inc. Reused with permission. This abstract was accepted and previously presented at the 2021 ASCO Annual Meeting. All rights reserved. Clinical trial information: NCT04700124 .

Updated outcomes in TROPHY-U-01 cohort 1, a phase 2 study of sacituzumab govitecan (SG) in patients (pts) with metastatic urothelial cancer (mUC) that progressed after platinum (PT)-based chemotherapy and a checkpoint inhibitor (CPI)

526

Background: SG is an antibody-drug conjugate composed of an anti-Trop-2 antibody coupled to SN-38, a topoisomerase-I inhibitor, via a proprietary hydrolyzable linker. SG received accelerated FDA approval in April 2021 in pts with mUC who previously received PT-based therapy and a CPI based on the primary analysis of the pivotal TROPHY-U-01 Cohort 1 study. With 9.1 mo median (med) follow-up, SG monotherapy demonstrated a 27% objective response rate (ORR) and med overall survival (OS) of 10.9 mo in 113 pts with locally advanced or mUC progressing after receiving at least a PT-based therapy and a CPI (Tagawa, et al. J Clin Oncol. 2021). Here we report updated Cohort 1 outcomes. Methods: TROPHY-U-01 (NCT03547973) is a multicohort, open-label, phase 2 study. Cohort 1 pts (≥18 y) had progression of mUC following PT (as first-line metastatic therapy or as (neo)adjuvant therapy with recurrence/progression ≤12 mo) and CPI, had ECOG PS 0-1, and creatinine clearance ≥30 mL/min. Pts received 10 mg/kg of SG intravenously on D1 and D8 of 21-D cycles. The primary endpoint was ORR per central review by RECIST 1.1. Key secondary endpoints included duration of response (DOR), progression-free survival (PFS), clinical benefit rate (CBR), OS, and safety. Results: As of July 26, 2022, med follow-up was 10.5 mo (range, 0.3-40.9) for treated pts (N=113). As previously reported, pts (78% men; med age, 66 y; 66% with visceral metastases, 34% liver), were heavily pretreated with a med of 3 prior therapies (range, 1-8). Med time since last prior therapy was 1.5 mo (range, 0-60.0). At data cutoff, per central review, ORR was 28% (95% CI, 20.2-37.6); CBR was 38% (95% CI, 29.1-47.7), med DOR was 6.1 mo (95% CI, 4.7-9.7, n=32) and med PFS was 5.4 mo (95% CI, 3.5-6.9). Med time to response was 1.6 mo (range, 1.2-5.6) and med OS was 10.9 mo (95% CI, 8.9-13.8). DOR, PFS, and OS rates (95% CI) at 12 mo were 30% (13.6-48.8), 14% (7.2-23.3), and 45% (35.4-53.8), respectively, with 7 (6%) pts still receiving SG at 12 mo. In pts who received prior enfortumab vedotin (n=10) and prior PT in the (neo)adjuvant setting (n=39), results were consistent with the overall population. Grade ≥3 treatment-related adverse events (TRAEs) occurred in 65% of pts and were similar to prior reports; the most common Grade ≥3 TRAEs were neutropenia (35%), leukopenia (18%), anemia (14%), diarrhea (10%), and febrile neutropenia (10%). One treatment-related death occurred due to febrile neutropenia-related sepsis. Conclusions: At 10.5-mo med follow-up, the response rate remains high in pts with heavily pretreated mUC, including pts with visceral metastases, prior EV therapy and prior (neo)adjuvant PT therapy. No new safety signals were observed. These data support the use of SG in pts with mUC who received PT and a CPI and further evaluation of SG in earlier lines of therapy. Clinical trial information: NCT03547973 .

Phase 2 clinical study evaluating the efficacy and safety of disitamab vedotin with or without pembrolizumab in patients with HER2-expressing urothelial carcinoma (RC48G001)

TPS594

Background: Urothelial carcinoma (UC) is the 10th most diagnosed cancer worldwide, and nearly 50% of patients cannot tolerate the current first-line (1L) standard of care. There is a need to improve outcomes in 1L and later lines of therapy. HER2 is overexpressed in UC and may be associated with poor outcomes. Despite this, no HER2-directed therapies are currently approved for UC. Disitamab vedotin (DV; RC48-ADC) is an investigational antibody-drug conjugate comprising a novel HER2-directed monoclonal antibody, disitamab, conjugated to monomethyl auristatin E (MMAE) via a protease-cleavable mc-vc linker. DV elicits antitumor activity through multimodal mechanisms of action including MMAE-mediated direct cytotoxicity, bystander effect, and immunogenic cell death. Methods: RC48G001 (NCT04879329) is a phase 2, multi-cohort, open-label, multicenter trial to evaluate DV in patients with HER2-expressing locally advanced/metastatic UC (LA/mUC). Patients are enrolled in 3 cohorts based on prior treatment and tumor HER2 expression by immunohistochemistry (IHC) and gene amplification (via in situ hybridization [ISH]), assessed centrally. Cohorts A and B are enrolling patients who have received prior systemic therapy (1 or 2 lines, including platinum-containing chemotherapy) and whose tumors are HER2-positive (IHC 3+, or 2+ and ISH-positive) or HER2-low (IHC 2+ and ISH-negative, or IHC 1+), respectively. Cohort C is enrolling 1L treatment-naive patients in the LA/mUC setting, whose tumors have HER2-positive or HER2-low expression. Cohorts A and B will evaluate DV as monotherapy (intravenous [IV] administration, once every 2 weeks [Q2W]). Cohort C will evaluate DV (IV, Q2W) +/– pembrolizumab (IV, Day 1 of each 6-week cycle). Patients in all cohorts must have measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 and an Eastern Cooperative Oncology Group Performance Status of 0–1 in Cohorts A and B, and 0–2 in Cohort C. The primary endpoint is confirmed objective response rate (cORR) per blinded independent central review (BICR). Secondary endpoints include cORR by investigator assessment, overall survival, duration of response, progression-free survival, disease control rate per RECIST v1.1 by BICR and investigator, safety, and pharmacokinetic parameters. Enrollment for all cohorts is ongoing in North America and Europe, and planned in Latin America, Asia-Pacific, and Israel. Clinical trial information: NCT04879329 .

Full analysis from AVENANCE: A real-world study of avelumab first-line (1L) maintenance treatment in patients (pts) with advanced urothelial carcinoma (aUC)

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Background: In the phase 3 JAVELIN Bladder 100 trial, avelumab 1L maintenance + best supportive care (BSC) significantly prolonged overall survival (OS) vs BSC alone in pts with aUC that had not progressed with 1L platinum-based chemotherapy (CTx). The JAVELIN Bladder regimen is now standard of care with level 1 evidence in international treatment guidelines. The AVENANCE study (NCT04822350), is investigating the efficacy and safety of avelumab 1L maintenance in a real-world population of pts with aUC in France. Data from the full analysis set are reported for the first time. Methods: In this ongoing, noninterventional, ambispective study, eligible pts have locally advanced or metastatic UC that has not progressed with 1L platinum-based CTx and previous, ongoing, or planned avelumab 1L maintenance treatment. The primary endpoint is OS from start of avelumab; secondary endpoints include progression-free survival (PFS), duration of treatment (DOT), and safety. Results: 591 pts received avelumab. At data cutoff (July 31, 2022), median follow-up was 12.0 mo (95% CI, 10.9-12.9). Median age was 73.1 y (IQR, 67.0-78.1). At start of 1L CTx (excluding pts with missing data), disease stage was metastatic in 524 pts (90.5%; visceral metastases in 426 [81.5%]) and locally advanced in 54 (9.3%). ECOG PS was 0-1 in 407 pts (85.3%) and 2-3 in 69 (14.5%). Tumor histology was pure UC in 528 pts (91.8%) and UC with variant or pure variant in 47 (8.2%). 1L CTx was gemcitabine + carboplatin (GemCarbo), gemcitabine + cisplatin (GemCis), dose-dense methotrexate + vinblastine + adriamycin + cisplatin (DD-MVAC), and other in 353 (61.0%), 170 (29.4%), 28 (4.8%), and 28 (4.8%) pts, respectively. Median number of cycles was 5 (range, 1-10). Median DOT with avelumab was 5.8 mo (95% CI, 5.2-7.0); 241 pts (40.8%) remained on treatment at data cutoff. The most common reasons for treatment discontinuation were disease progression (74.1% [n=258]), death (11.5% [n=40]), and adverse events ([AEs] 10.3% [n=36]). Median OS from start of avelumab was 18.4 mo (95% CI, 15.4-not estimable [NE]), the 12-month OS rate was 64.8% (95% CI, 60.0%-69.1%), and median PFS was 5.7 mo (95% CI, 5.3-7.0). In pts who had received GemCarbo, GemCis, or DD-MVAC, median OS (95% CI) was 16.2 mo (13.4-NE), not reached (NR; 18.1-NE), and NR (15.2-NE), respectively. Subgroups analyses will be presented. 218 pts received subsequent 2L, including CTx, antibody-drug conjugates, immunotherapy, and other in 186 (85.3%), 22 (10.1%), 6 (2.8%), and 4 (1.8%) pts, respectively. Any-grade treatment-related AEs (TRAEs) occurred in 217 pts (36.7%), including serious TRAEs in 29 (4.9%). Conclusions: Real-world data for avelumab 1L maintenance in pts with aUC from AVENANCE support the findings of JAVELIN Bladder 100 and confirm the clinical activity and acceptable safety profile of avelumab in a heterogeneous population. Clinical trial information: NCT04822350 .

Primary analysis of TROPHY-U-01 cohort 2, a phase 2 study of sacituzumab govitecan (SG) in platinum (PT)-ineligible patients (pts) with metastatic urothelial cancer (mUC) that progressed after prior checkpoint inhibitor (CPI) therapy

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Background: Pts with PT-ineligible mUC have limited treatment options following CPI therapies; thus, new treatment options are needed. SG is an antibody-drug conjugate composed of an anti-Trop-2 antibody coupled to SN-38, a topoisomerase-I inhibitor, via a proprietary hydrolyzable linker. SG received accelerated FDA approval in April 2021 for pts with mUC who progressed after PT and CPI therapies based on the positive results of the pivotal TROPHY-U-01 Cohort 1 study. In Cohort 1, SG demonstrated an objective response rate (ORR) of 27%, a median overall survival (OS) of 10.9 mo, and a manageable safety profile in 113 pts with locally advanced or mUC (Tagawa, et al. J Clin Oncol. 2021). SG demonstrated an ORR of 28% in PT-ineligible pts with mUC who progressed after CPI therapy in preliminary results of the phase 2 TROPHY-U-01 Cohort 2 study (Petrylak et al. J Clin Oncol. 2020). Here, we report the primary analysis of TROPHY-U-01 Cohort 2. Methods: Cohort 2 pts (≥18 y) were PT-ineligible at screening, had ECOG PS 0-1, and creatinine clearance ≥30 mL/min. Pts received 10 mg/kg of SG on D1 and D8 of 21-day continuous cycles. The primary endpoint was ORR per central review by RECIST 1.1. Secondary endpoints included duration of response (DOR) and progression-free survival (PFS), per central review, and OS. Target enrollment was approximately 40 pts. Assuming the second-line ORR of 40%, 40 pts would give a 95% CI with a lower limit of 25% (CI is 0.25 to 0.57) for ORR. Results: As of July 26, 2022, the median follow-up was 9.3 mo (range, 0.5-30.6) for treated pts (N=38); median age, 72.5 y (range, 41-87), 61% male, 50% ECOG PS 1, and 66% visceral metastases (29% liver). Median number of prior therapies was 2 (range, 1-5); 50% received prior (neo)adjuvant PT, 18% received prior enfortumab vedotin, and 3% received prior erdafitinib. Median time since last prior anticancer therapy was 1.6 mo (range, 1-8) and median duration of last prior anticancer therapy was 4.2 mo (range, 1-12). Per central review, ORR was 32% (95% CI, 17.5-48.7; 32% partial response); median DOR was 5.6 mo (95% CI, 2.8-13.3; n=12); and median PFS was 5.6 mo (95% CI, 4.1-8.3). Median time to response was 1.4 mo (range, 1.3-1.5) and median OS was 13.5 mo (95% CI, 7.6-15.6). Grade ≥3 treatment-related adverse events (TRAEs) occurred in 68% of pts; the most common Grade ≥3 TRAEs were neutropenia (34%), anemia (21%), leukopenia (18%), fatigue (18%), and diarrhea (16%). TRAEs resulted in an 18% discontinuation rate. No treatment-related deaths were reported. Conclusions: SG monotherapy demonstrated a high response rate with an overall manageable safety profile in PT-ineligible pts with mUC who progressed after CPI therapy. No new safety signals were observed. These data support further evaluation of SG in pts with mUC post CPI therapy. Clinical trial information: NCT03547973 .

Cabozantinib in combination with atezolizumab in non-clear cell renal cell carcinoma: Extended follow-up results of cohort 10 of the COSMIC-021 study

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Background: In the COSMIC-021 phase 1b study (NCT03170960) evaluating cabozantinib plus atezolizumab in advanced solid tumors, this combination therapy demonstrated encouraging clinical activity in patients with advanced non-clear cell renal cell carcinoma (nccRCC) with a median follow-up of 13 mo (Pal. JCO 2021). Results after extended follow-up in nccRCC are presented. Methods: Patients with advanced nccRCC and ECOG PS 0/1 who had ≤1 prior VEGFR-targeting tyrosine kinase inhibitor (TKI) were eligible. Prior treatment with TKIs targeting MET or immune checkpoint inhibitors was not allowed. Patients received cabozantinib 40 mg PO QD plus atezolizumab 1200 mg IV Q3W until unacceptable toxicity or progression; dose reductions of cabozantinib (40 mg QD to 20 mg QD, then to 20 mg QOD) were permitted to manage adverse events. The primary endpoint was objective response rate (ORR) per RECIST v1.1 by the investigator; other endpoints included safety, duration of response (DOR), PFS, and OS. Results: The study enrolled 32 patients with nccRCC (2 from dose escalation phase, and 30 from expansion phase of the study): median age, 62 y; male, 81%; ECOG PS 0/1, 75%/25%; histology, papillary/chromophobe/clear cell/other, 47%/28%/3%/22%; sarcomatoid feature, 13%; IMDC risk favorable/intermediate/poor, 50%/41%/9%; ≥3 tumor sites, 56%; tumor sites, lung/kidney/bone/liver, 50%/25%/16%/16%; prior nephrectomy, 63%; prior VEGFR TKI, 22%; 0/1 lines of prior therapy (locally advanced/metastatic setting), 81%/19%. As of July 21, 2022, median follow-up was 37.2 mo (range 32.1–58.5) with 5 (16%) patients remaining on study treatment. ORR by investigator was 31% (all PRs) and disease control rate was 94% (Table); median DOR was 8.1 mo. Median PFS was 9.3 mo (95% CI 5.5–12.3), and median OS was not reached (95% CI 23.0–NE). PFS and OS estimates at 12 mo were 34% and 84%, respectively; 24-mo estimates were 6% and 70%. Treatment-related AEs occurred in 97% (grade 3/4, 53%); the most common AEs included diarrhea (69%), palmar-plantar erythrodysesthesia (50%), fatigue (44%), dysgeusia (41%), hypertension (31%) and nausea (31%). One grade 5 treatment-related AE of pulmonary hemorrhage occurred. Treatment-related AEs leading to discontinuation of both study treatments occurred in 13% of patients. Conclusions: Extended 3-year follow-up reinforces the encouraging clinical activity of cabozantinib plus atezolizumab in advanced nccRCC with a manageable safety profile. Clinical trial information: NCT03170960 . [Table: see text]