Pembrolizumab Plus Axitinib Versus Sunitinib as First-line Treatment of Advanced Renal Cell Carcinoma: 43-month Follow-up of the Phase 3 KEYNOTE-426 Study

Previous analyses of KEYNOTE-426, an open-label, phase 3 randomized study, showed superior efficacy of first-line pembrolizumab plus axitinib to sunitinib in advanced clear cell renal cell carcinoma (ccRCC). We report results of the final protocol-prespecified analysis of KEYNOTE-426. Patients received pembrolizumab 200 mg intravenously every 3 wk plus axitinib 5 mg orally twice daily or sunitinib 50 mg orally once daily (4 wk per 6-wk cycle). The dual primary endpoints were overall survival (OS) and progression-free survival (PFS) as per RECIST v1.1 by a blinded independent central review. The secondary endpoints included objective response rate (ORR) and duration of response (DOR). The median study follow-up was 43 (range, 36-51) mo. Benefit with pembrolizumab plus axitinib versus sunitinib was maintained for OS (hazard ratio [HR], 0.73 [95% confidence interval {CI}, 0.60-0.88]), PFS (HR, 0.68 [95% CI, 0.58-0.80]), and ORR (60% vs 40%). The median DOR was 24 (range, 1.4+ to 43+) versus 15 (range, 2.3-43+) mo in the pembrolizumab plus axitinib versus the sunitinib arm. No new safety signals emerged. These results support pembrolizumab plus axitinib as a standard of care for patients with previously untreated advanced ccRCC. PATIENT SUMMARY: Extended results of KEYNOTE-426 support pembrolizumab plus axitinib as the standard of care for advanced clear cell renal cell carcinoma.

Health-related quality of life in GALAHAD: A multicenter, open-label, phase 2 study of niraparib for patients with metastatic castration-resistant prostate cancer and DNA-repair gene defects

BACKGROUND: Niraparib is a highly selective poly (adenosine diphosphateribose) polymerase-1 and poly (adenosine diphosphate-ribose) polymerase-2 inhibitor indicated for select patients with ovarian, fallopian tube, and primary peritoneal cancer. The phase 2 GALAHAD trial (NCT02854436) demonstrated that niraparib monotherapy is tolerable and efficacious in patients with metastatic castration-resistant prostate cancer (mCRPC) and homologous recombination repair (HRR) gene alterations, particularly those with breast cancer gene (BRCA) alterations who had progressed on prior androgen signaling inhibitor therapy and taxane-based chemotherapy. OBJECTIVE: To report the prespecified patient-reported outcomes analysis from GALAHAD. METHODS: Eligible patients with alterations to BRCA1 and/or BRCA2 (BRCA cohort) and with pathogenic alterations in other HRR genes (other HRR cohort) were enrolled and received niraparib 300 mg once daily. Patient-reported outcome instruments included the Functional Assessment of Cancer Therapy-Prostate and the Brief Pain Inventory-Short Form. Changes from baseline were compared using a mixed-effect model for repeated measures. RESULTS: On average, health-related quality of life (HRQoL) improved in the BRCA cohort by cycle 3 (mean change = 6.03; 95% CI = 2.76-9.29) and was maintained above baseline until cycle 10 (mean change = 2.84; 95% CI = -1.95 to 7.63), whereas the other HRR cohort showed no early change in HRQoL from baseline (mean change = -0.07; 95% CI = -4.69 to 4.55) and declined by cycle 10 (mean change = -5.10; 95% CI = -15.3 to 5.06). Median time to deterioration in pain intensity and pain interference could not be estimated in either cohort. CONCLUSIONS: Patients with advanced mCRPC and BRCA alterations treated with niraparib experienced more meaningful improvement in overall HRQoL, pain intensity, and pain interference compared with those with other HRR alterations. In this population of castrate, heavily pretreated patients with mCRPC and HRR alterations, stabilization, and improvement in HRQoL may be relevant to consider when making treatment decisions. DISCLOSURES: This work was supported by Janssen Research & Development, LLC (no grant number). Dr Smith has received grants and personal fees from Bayer, Amgen, Janssen, and Lilly; and has received personal fees from Astellas Pharma, Novartis, and Pfizer. Dr Sandhu has received grants from Amgen, Endocyte, and Genentech; has received grants and personal fees from AstraZeneca and Merck; and has received personal fees from Bristol Myers Squibb and Merck Serono. Dr George has received personal fees from the American Association for Cancer Research, Axess Oncology, Capio Biosciences, Constellation Pharma, EMD Serono, Flatiron, Ipsen, Merck Sharp & Dohme, Michael J. Hennessey Association, Millennium Medical Publishing, Modra Pharma, Myovant Sciences, Inc., NCI Genitourinary, Nektar Therapeutics, Physician Education Resource, Propella TX, RevHealth, LLC, and UroGPO; has received grants and personal fees from Astellas Pharma, AstraZeneca, Bristol Myers Squibb, and Pfizer; has received personal fees and nonfinancial support from Bayer and UroToday; has received grants from Calithera and Novartis; and has received grants, personal fees, and nonfinancial support from Exelixis, Inc., Sanofi, and Janssen Pharma. Dr Chi has received grants from Janssen during the conduct of the study; has received grants and personal fees from AstraZeneca, Bayer, Astellas Pharma, Novartis, Pfizer, POINT Biopharma, Roche, and Sanofi; and has received personal fees from Daiichi Sankyo, Merck, and Bristol Myers Squibb. Dr Saad has received grants, personal fees, and nonfinancial support from Janssen during the conduct of the study; and has received grants, personal fees, and nonfinancial support from AstraZeneca, Astellas Pharma, Pfizer, Bayer, Myovant, Sanofi, and Novartis. Dr Thiery-Vuillemin has received grants, personal fees, and nonfinancial support from Pfizer; has received personal fees and nonfinancial support from AstraZeneca, Janssen, Ipsen, Roche/Genentech, Merck Sharp & Dohme, and Astellas Pharma; and has received personal fees from Sanofi, Novartis, and Bristol Myers Squibb. Dr Olmos has received grants, personal fees, and nonfinancial support from AstraZeneca, Bayer, Janssen, and Pfizer; has received personal fees from Clovis, Daiichi Sankyo, and Merck Sharp & Dohme; and has received nonfinancial support from Astellas Pharma, F. Hoffman-LaRoche, Genentech, and Ipsen. Dr Danila has received research support from the US Department of Defense, the American Society of Clinical Oncology, the Prostate Cancer Foundation, Stand Up to Cancer, Janssen Research & Development, Astellas Pharma, Medivation, Agensys, Genentech, and CreaTV. Dr Gafanov has received grants from Janssen during the conduct of the study. Dr Castro has received grants from Janssen during the conduct of the study; has received grants and personal fees from Janssen, Bayer, AstraZeneca, and Pfizer; and has received personal fees from Astellas Pharma, Merck Sharp & Dohme, Roche, and Clovis. Dr Moon has received research funding from SeaGen, HuyaBio, Janssen, BMS, Aveo, Xencor, and has received personal fees from Axess Oncology, MJH, EMD Serono, and Pfizer. Dr Joshua has received nonfinancial support from Janssen; consulted or served in an advisory role for Neoleukin, Janssen Oncology, Ipsen, AstraZeneca, Sanofi, Noxopharm, IQvia, Pfizer, Novartis, Bristol Myers Squibb, Merck Serono, and Eisai; and received research funding from Bristol Myers Squibb, Janssen Oncology, Merck Sharp & Dohme, Mayne Pharma, Roche/Genentech, Bayer, MacroGenics, Lilly, Pfizer, AstraZeneca, and Corvus Pharmaceuticals. Drs Mason, Liu, Bevans, Lopez-Gitlitz, and Francis and Mr Espina are employees of Janssen Research & Development. Dr Mason owns stocks with Janssen. Dr Fizazi has participated in advisory boards and talks for Amgen, Astellas, AstraZeneca, Bayer, Clovis, Daiichi Sankyo, Janssen, MSD, Novartis/AAA, Pfizer, and Sanofi, with honoraria to his institution (Institut Gustave Roussy); has participated in advisory boards for, with personal honoraria from, Arvinas, CureVac, MacroGenics, and Orion. Study registration number: NCT02854436.

Patient-reported outcomes (PROs) in KEYNOTE-921: Pembrolizumab (pembro) plus docetaxel for patients (pts) with metastatic castration-resistant prostate cancer (mCRPC)

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Background: The double-blind, phase 3, randomized KEYNOTE-921 trial (NCT03834506) showed that pembro + docetaxel did not significantly improve rPFS or OS for pts with mCRPC treated with prior next-generation hormonal agent (NHA) therapy. We present PROs for pembro + docetaxel vs placebo + docetaxel in KEYNOTE-921. Methods: Pts were randomly assigned 1:1 to receive pembro 200 mg or placebo IV Q3W (≤35 cycles) + docetaxel 75 mg/m2 IV Q3W (≤10 cycles) and prednisone 5 mg orally BID. PROs were evaluated in pts who received ≥1 dose of study treatment and had ≥1 PRO assessment. FACT-P and BPI-SF were administered at baseline, Q3W until wk 24, Q6W until wk 72, then Q12W for ≤2 y. A prespecified secondary end point was time to pain progression (TTPP) based on BPI-SF. Prespecified exploratory end points included least squares mean (LSM) change from baseline to wk 27 for FACT-P total and subscale scores (FACT-G total, TOI, FAPSI-6, FWB, PWB, and PCS) and wk 24 for BPI-SF scores (pain interference, pain severity, and worst pain), and time to deterioration (TTD) and overall improvement rate in FACT-P total and subscale scores. Differences were evaluated using 2-sided nominal P values not controlled for multiplicity. Results: Of 1030 pts enrolled, the PRO analysis population included 1028 (n = 514 in each arm). At the prespecified final analysis, median time from randomization to data cutoff of June 20, 2022, was 22.7 mo (range, 12.1-36.7). Completion rates for FACT-P and BPI-SF were >78% at baseline, >65% for FACT-P at wk 27, and >63% for BPI-SF at wk 24. Median TTPP was 21.1 mo (95% CI, 13.7-NR) for pembro + docetaxel vs NR (95% CI, 13.8-NR) for placebo + docetaxel (HR, 1.05 [95% CI, 0.77-1.43]). No LSM differences were observed in FACT-P total scores with pembro + docetaxel (–5.31 [95% CI, –7.02 to –3.61]) vs placebo + docetaxel (–3.89 [95% CI, –5.59 to –2.19]) or BPI-SF scores. Median TTD in FACT-P total scores was 21.8 mo (95% CI, 20.0-NR) for pembro + docetaxel and NR (95% CI, 11.1-NR) for placebo + docetaxel (HR, 1.09 [95% CI, 0.88-1.35]). No differences were observed for TTD in FACT-G total, TOI, FAPSI-6, FWB, PWB, and PCS scores between groups. A numerically lower proportion of pts receiving pembro + docetaxel (39.9%) had improved + stable FACT-P total scores compared with placebo + docetaxel (45.3%). FACT-P and BPI-SF scores were generally maintained across all evaluated time points up to wk 81. Conclusions: HRQoL and disease-related symptom scores at all analyzed time points, as well as TTD and TTPP, were similar between the 2 trial arms. These data suggest that pembro + docetaxel did not negatively impact QoL in pts with mCRPC treated with prior NHA. Clinical trial information: NCT03834506 . [Table: see text]

Pembrolizumab plus docetaxel for patients with metastatic castration-resistant prostate cancer (mCRPC): Randomized, double-blind, phase 3 KEYNOTE-921 study

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Background: Docetaxel is a treatment option following disease progression on a next-generation hormonal agent (NHA) for patients with mCRPC, but there is an urgent need for more efficacious treatments. The randomized, double-blind, phase 3 KEYNOTE-921 study (NCT03834506) evaluated the efficacy and safety of pembrolizumab + docetaxel vs placebo + docetaxel for participants (pts) with mCRPC who had received prior NHA therapy. Methods: Eligible pts were ≥18 years old, had mCRPC that progressed on androgen deprivation therapy, had received 1 prior NHA, and had an ECOG performance status of 0 or 1. Pts were randomized 1:1 to receive 200 mg pembrolizumab Q3W or placebo for ≤35 cycles (~2 years) in combination with 75 mg/m2 docetaxel Q3W for ≤10 cycles and 5 mg prednisone BID. The dual primary endpoints were radiographic progression-free survival (rPFS; tested at first interim analysis) per PCWG-modified RECIST 1.1 by blinded independent central review and overall survival (OS; tested at final analysis). The key secondary endpoint was time to initiation of the first subsequent anticancer therapy (TFST; at first interim analysis). Safety was one of the secondary endpoints. Results: Between May 30, 2019 and June 17, 2021, 1030 pts were randomized to receive pembrolizumab + docetaxel (n=515) or placebo + docetaxel (n=515). The median (range) time from randomization to data cutoff date of June 20, 2022 at final analysis was 22.7 mo (12.1−36.7). Baseline characteristics were generally balanced between arms; approximately half of pts in each arm had received prior abiraterone. Pts in the pembrolizumab + docetaxel arm received a median (range) of 12 (1–35) cycles of pembrolizumab and 9 (1–12) cycles of docetaxel; pts in the placebo + docetaxel arm received a median (range) of 12 (1–35) cycles of placebo and 9 (1–10) cycles of docetaxel. The dual primary endpoints of rPFS (median 8.6 mo with pembrolizumab + docetaxel vs 8.3 mo with placebo + docetaxel; HR 0.85, 95% CI 0.71−1.01; P=0.0335) and OS (median 19.6 mo vs 19.0 mo; HR 0.92, 95% CI 0.78−1.09; P=0.1677) were not met. Median TFST was 10.7 mo vs 10.4 mo, respectively (HR 0.86, 95% CI 0.74−1.01). Treatment-related AEs occurred in 94.6% (grade ≥3 in 43.2%) and 94.9% (grade ≥3 in 36.6%) of pts with pembrolizumab + docetaxel vs placebo + docetaxel. 2 treatment-related deaths with pembrolizumab + docetaxel and 7 with placebo + docetaxel were reported. Immune-mediated AEs and infusion reactions occurred in 23.3% (grade ≥3 in 6.2%) and 12.3% (grade ≥3 in 1.2%) of pts with pembrolizumab + docetaxel vs placebo + docetaxel, most commonly pneumonitis (7.0% vs 3.1%) and hypothyroidism (6.4% vs 3.3%). Conclusions: The addition of pembrolizumab to docetaxel did not significantly improve rPFS or OS for pts with mCRPC and did not result in a notable increase in treatment-related AEs. Clinical trial information: NCT03834506 .

Health-related Quality of Life Analysis from KEYNOTE-426: Pembrolizumab plus Axitinib Versus Sunitinib for Advanced Renal Cell Carcinoma

BACKGROUND

In the phase 3 KEYNOTE-426 (NCT02853331) trial, pembrolizumab + axitinib demonstrated improvement in overall survival, progression-free survival, and objective response rate over sunitinib monotherapy for advanced renal cell carcinoma (RCC).

OBJECTIVE

To evaluate health-related quality of life (HRQoL) in KEYNOTE-426.

DESIGN, SETTING, AND PARTICIPANTS

A total of 861 patients were randomly assigned to receive pembrolizumab + axitinib (n = 432) or sunitinib (n = 429). HRQoL data were available for 429 patients treated with pembrolizumab + axitinib and 423 patients treated with sunitinib.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

HRQoL end points were measured using the European Organisation for the Research and Treatment of Cancer Core (EORTC) Quality of Life Questionnaire (QLQ-C30), EQ-5D visual analog rating scale (VAS), and Functional Assessment of Cancer Therapy Kidney Cancer Symptom Index-Disease-Related Symptoms (FKSI-DRS) questionnaires.

RESULTS AND LIMITATIONS

Better or not different overall improvement rates from baseline between pembrolizumab + axitinib and sunitinib were observed for the FKSI-DRS (-0.79% improvement vs sunitinib; 95% confidence interval [CI] -7.2 to 5.6), QLQ-C30 (7.5% improvement vs sunitinib; 95% CI 1.0-14), and EQ-5D VAS (9.9% improvement vs sunitinib; 95% CI 3.2-17). For time to confirmed deterioration (TTcD) and time to first deterioration (TTfD), no differences were observed between arms for the QLQ-C30 (TTcD hazard ratio [HR] 1.0; 95% CI 0.82-1.3; TTfD HR 0.82; 95% CI 0.69-0.97) and EQ-5D VAS (TTcD HR 1.1; 95% CI 0.87-1.3; TTfD HR 0.98; 95% CI 0.83-1.2). TTfD was not different between treatment arms (HR 1.1; 95% CI 0.95-1.3) for the FKSI-DRS, but TTcD favored sunitinib (HR 1.4; 95% CI 1.1-1.7). Patients were assessed during the off-treatment period for sunitinib, which may have underestimated the negative impact of sunitinib on HRQoL.

CONCLUSIONS

Overall, patient-reported outcome scales showed that results between the pembrolizumab + axitinib and sunitinib arms were not different, with the exception of TTcD by the FKSI-DRS.

PATIENT SUMMARY

Compared with sunitinib, pembrolizumab + axitinib delays disease progression and extends survival, while HRQoL outcomes were not different between groups.

Abstract CT106: Primary tumor response in T1aN0M0 renal cell carcinoma patients ineligible for surgery and treated with nivolumab and ipilimumab: Results from phase 2 pilot study

Background: Some patients with primary renal cell carcinoma (RCC) are unable to have surgery for different reasons (functional single kidney with a central, high-complexity RCC, high risk of nephrectomy and dialysis, patients with complex coagulation disorders, etc.). We hypothesize that combination of nivolumab and ipilimumab could eliminate the primary tumor in T1aN0M0 patients ineligible for surgical treatment.

Methods: This is a prospective, multicenter, non-randomized phase 2 pilot study. Patients with biopsy-proven clear-cell RCC of ≤4 cm (cT1a), no evidence of any metastases, and unable to have surgery or other nephron-sparing interventions (ablation) or with preference to have no surgery or intervention for any reason received combination of ipilimumab (1 mg/kg intravenously) every 3 weeks for four doses, and nivolumab (240 mg intravenously) every 2 weeks during 16 weeks. The primary endpoint was complete response rate. Simon's two-stage design was used. The null hypothesis that the true complete response rate was 11% and was tested against a one-sided alternative. This design yields a type I error rate of 0.05 and power of 0.9 when the true complete response rate is 60% (alternative hypothesis). The null hypothesis should be rejected if 3 or more responses are observed in 8 patients.

Results: Between February 2020 and June 2021, 8 patients were included. Median age was 77.9 years (range 73-89). Patients were Caucasian (100%), predominantly male (75%), 62.5% had centrally located RCC, 25% had ECOG PS 1, and 6 of 8 patients had moderate and severe comorbidities. Median follow-up was 12.7 months (95% CI 5.2-16.5). All patients received immunotherapy during 4 months without grade ≥2 adverse events. No complete responses were observed. Partial responses were found in 2 patients (25%). Median size of the primary tumor at RCC diagnosis and after immunotherapy was 3.11 cm (range 2.2-3.9) and 2.86 cm (range 1.5-4.0), respectively. Any shrinkage of the primary tumor was reported in 4 (50%) patients (change in median sum of diameters -18%). Only one patient had tumor enlargement (+0.5 cm (+13%) after 9 months. SBRT was used in this patient. All other patients are under active surveillance. Next secondary end-point of 3-year progression-free survival will be reported.

Conclusions: The activity of immunotherapy against primary tumor was limited in patients with T1aN0M0 RCC ineligible for surgical treatment. Duration of stable disease will be studied with long-term follow-up of these patients. Treatment with nivolumab and ipilimumab was safe in patients with moderate and severe comorbidities.

Citation Format: Ilya Tsimafeyeu, Maria Volkova, Rustem Gafanov, Igor Myslevtsev, Andrey Andrianov, Axel Bex. Primary tumor response in T1aN0M0 renal cell carcinoma patients ineligible for surgery and treated with nivolumab and ipilimumab: Results from phase 2 pilot study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT106.

Pembrolizumab (pembro) plus axitinib (axi) versus sunitinib as first-line therapy for advanced clear cell renal cell carcinoma (ccRCC): Analysis of progression after first subsequent therapy in KEYNOTE-426

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Background: The randomized, open-label, phase 3 KEYNOTE-426 study (NCT02853331) met its primary and key secondary end points of improved OS, PFS, and ORR with pembro + axi versus sunitinib as first-line treatment for patients with advanced ccRCC. Extended follow-up (42.8-mo median follow-up) continued to show the superior efficacy of pembro + axi versus sunitinib in this patient population. We describe the results of PFS2 for all randomly assigned patients and across IMDC risk categories. Methods: Treatment-naive patients with advanced ccRCC, Karnofsky Performance Status Scale score ≥70% and measurable disease per RECIST v1.1 were randomly assigned 1:1 to receive pembro 200 mg IV every 3 weeks for up to 35 doses (̃2 y) + axi 5 mg orally twice daily or sunitinib 50 mg orally once daily on a 4-wk on/2-wk off schedule. The end point of this exploratory analysis was PFS2, defined as time from randomization to progression after first subsequent therapy or any-cause death. The Kaplan-Meier method was used to estimate PFS2 and hazard ratios were estimated using a Cox regression model. Results: Of 861 patients, 432 were assigned to receive pembro + axi; 429, to sunitinib. Median time from randomization to the database cutoff date (January 11, 2021) was 42.8 mo (range, 35.6-50.6). Overall, 47.2% of patients (204/432) in the pembro + axi arm and 65.5% of patients (281/429) in the sunitinib arm received ≥1 line of subsequent anticancer therapy. For patients who received subsequent therapy, anti–PD-1/PD-L1 agents were the first subsequent treatment for 11.3% of patients (23/204) in the pembro + axi arm and 54.8% of patients (154/281) in the sunitinib arm. In the pembro + axi arm, 82.8% of patients (169/204) received a VEGF/VEGFR inhibitor as first subsequent therapy, as did 43.4% (122/281) in the sunitinib arm. PFS2 results are displayed in the Table. Conclusions: In this exploratory analysis, PFS2 was longer for patients randomized to pembro + axi compared to sunitinib. Results were consistent across IMDC risk groups. These data support use of pembro + axi for the first-line treatment of patients with advanced ccRCC. Clinical trial information: NCT02853331. [Table: see text]

Ipatasertib plus abiraterone and prednisolone in metastatic castration-resistant prostate cancer (IPATential150): a multicentre, randomised, double-blind, phase 3 trial

BACKGROUND

The PI3K/AKT and androgen-receptor pathways are dysregulated in metastatic castration-resistant prostate cancers (mCRPCs); tumours with functional PTEN-loss status have hyperactivated AKT signalling. Dual pathway inhibition with AKT inhibitor ipatasertib plus abiraterone might have greater benefit than abiraterone alone. We aimed to compare ipatasertib plus abiraterone with placebo plus abiraterone in patients with previously untreated mCRPC with or without tumour PTEN loss.

METHODS

We did a randomised, double-blind, phase 3 trial at 200 sites across 26 countries or regions. Patients aged 18 years or older with previously untreated asymptomatic or mildly symptomatic mCRPC who had progressive disease and Eastern Collaborative Oncology Group performance status of 0 or 1 were randomly assigned (1:1; permuted block method) to receive ipatasertib (400 mg once daily orally) plus abiraterone (1000 mg once daily orally) and prednisolone (5 mg twice a day orally) or placebo plus abiraterone and prednisolone (with the same dosing schedule). Patients received study treatment until disease progression, intolerable toxicity, withdrawal from the study, or study completion. Stratification factors were previous taxane-based therapy for hormone-sensitive prostate cancer, type of progression, presence of visceral metastasis, and tumour PTEN-loss status by immunohistochemistry. Patients, investigators, and the study sponsor were masked to the treatment allocation. The coprimary endpoints were investigator-assessed radiographical progression-free survival in the PTEN-loss-by-immunohistochemistry population and in the intention-to-treat population. This study is ongoing and is registered with ClinicalTrials.gov, NCT03072238.

FINDINGS

Between June 30, 2017, and Jan 17, 2019, 1611 patients were screened for eligibility and 1101 (68%) were enrolled; 554 (50%) were assigned to the placebo-abiraterone group and 547 (50%) to the ipatasertib-abiraterone group. At data cutoff (March 16, 2020), median follow-up duration was 19 months (range 0-33). In the 521 (47%) patients who had tumours with PTEN loss by immunohistochemistry (261 in the placebo-abiraterone group and 260 in the ipatasertib-abiraterone group), median radiographical progression-free survival was 16·5 months (95% CI 13·9-17·0) in the placebo-abiraterone group and 18·5 months (16·3-22·1) in the ipatasertib-abiraterone group (hazard ratio [HR] 0·77 [95% CI 0·61-0·98]; p=0·034; significant at α=0·04). In the intention-to-treat population, median progression-free survival was 16·6 months (95% CI 15·6-19·1) in the placebo-abiraterone group and 19·2 months (16·5-22·3) in the ipatasertib-abiraterone group (HR 0·84 [95% CI 0·71-0·99]; p=0·043; not significant at α=0·01). Grade 3 or higher adverse events occurred in 213 (39%) of 546 patients in the placebo-abiraterone group and in 386 (70%) of 551 patients in the ipatasertib-abiraterone group; adverse events leading to discontinuation of placebo or ipatasertib occurred in 28 (5%) in the placebo-abiraterone group and 116 (21%) in the ipatasertib-abiraterone group. Deaths due to adverse events deemed related to treatment occurred in two patients (<1%; acute myocardial infarction [n=1] and lower respiratory tract infection [n=1]) in the placebo-abiraterone group and in two patients (<1%; hyperglycaemia [n=1] and chemical pneumonitis [n=1]) in the ipastasertb-abiraterone group.

INTERPRETATION

Ipatasertib plus abiraterone significantly improved radiographical progression-free survival compared with placebo plus abiraterone among patients with mCRPC with PTEN-loss tumours, but there was no significant difference between the groups in the intention-to-treat population. Adverse events were consistent with the known safety profiles of each agent. These data suggest that combined AKT and androgen-receptor signalling pathway inhibition with ipatasertib and abiraterone is a potential treatment for men with PTEN-loss mCRPC, a population with a poor prognosis.

FUNDING

F Hoffmann-La Roche and Genentech.

KEYNOTE-921: Phase III study of pembrolizumab plus docetaxel for metastatic castration-resistant prostate cancer

Despite recent advances, treatment options for men with metastatic castration-resistant prostate cancer (mCRPC) progressing after next-generation hormonal agents (NHAs) are limited and provide only modest survival benefit. Thus, an unmet need remains for mCRPC patients after treatment with targeted endocrine therapy or NHA therapy. Pembrolizumab, a humanized monoclonal antibody for PD-1, has been found to have activity as monotherapy in patients with mCRPC and as combination therapy in a Phase Ib/II study with docetaxel and prednisone/prednisolone for patients previously treated with enzalutamide or abiraterone acetate. The aim of the randomized, double-blind, Phase III KEYNOTE-921 study is to evaluate the efficacy and safety of pembrolizumab plus docetaxel in patients with mCRPC who were previously treated with an NHA. Clinical trial registration: NCT03834506 (ClinicalTrials.gov).

Pembrolizumab (pembro) plus axitinib (axi) versus sunitinib as first-line therapy for advanced clear cell renal cell carcinoma (ccRCC): Results from 42-month follow-up of KEYNOTE-426

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Background: In the first interim analysis of the randomized, multicenter, open-label, phase 3 KEYNOTE-426 study (NCT02853331), treatment with pembro + axi significantly improved OS, PFS, and ORR vs sunitinib monotherapy in treatment-naive advanced ccRCC. Extended follow-up (median, 30.6 mo) continued to demonstrate the superior efficacy of pembro + axi vs sunitinib monotherapy in this patient population. Here, we present the results of the prespecified final analysis with 42.8-mo median follow-up. Methods: Treatment-naive patients (pts) with advanced ccRCC, KPS ≥70%, and measurable disease (RECIST v1.1) were randomly assigned 1:1 to receive pembro 200 mg IV Q3W for up to 35 doses + axi 5 mg orally BID or sunitinib 50 mg orally QD on a 4-wk on/2-wk off schedule until progression, intolerable toxicity, or withdrawal. Randomization was stratified by IMDC risk (favorable vs intermediate vs poor) and geographic region (North America vs Western Europe vs Rest of World). Dual primary endpoints were OS and PFS. Secondary endpoints were ORR, DOR, and safety. The protocol-specified final analysis was based on a target of 404 OS events. No formal hypothesis testing was performed because all efficacy endpoints were met previously at the first interim analysis; nominal P values are reported. Results: Overall, 861 pts were randomly assigned to receive pembro + axi (n=432) or sunitinib (n=429). Median duration of follow-up, defined as time from randomization to the database cutoff date, was 42.8 mo (range, 35.6-50.6). At data cutoff, 418 pts had died: 193 (44.7%) of 432 pts in the pembro + axi arm vs 225 (52.4%) of 429 pts in the sunitinib arm. Compared with sunitinib, pembro + axi improved OS (median: 45.7 vs 40.1 mo; HR, 0.73 [95% CI, 0.60-0.88]; P<0.001) and PFS (median: 15.7 vs 11.1 mo; HR, 0.68 [95% CI, 0.58-0.80]; P<0.0001). The 42-mo OS rate was 57.5% with pembro + axi vs 48.5% with sunitinib; the 42-mo PFS rate was 25.1% with pembro + axi vs 10.6% with sunitinib. For pembro + axi vs sunitinib, ORR was 60.4% vs 39.6% ( P<0.0001); CR rate was 10.0% vs 3.5%; median DOR was 23.6 mo (range 1.4+ to 43.4+) vs 15.3 mo (range, 2.3-42.8+). Subsequent anticancer therapy was administered to 47.2% of pts in pembro + axi arm vs 65.5% of pts in sunitinib arm. Although a similar proportion of pts in each arm received VEGF/VEGFR inhibitors, only 10.2% of pts in the pembro + axi arm received subsequent treatment with a PD-1/L1 inhibitor compared to 48.7% of pts in the sunitinib arm. No new safety signals were observed. Conclusions: With a median follow-up of 42.8 mo, this is the longest follow-up of an anti-PD–1/L1 immunotherapy combined with a VEGF/VEGFR inhibitor for first-line RCC. These results show that pembro + axi continues to demonstrate superior efficacy over sunitinib with respect to OS, PFS, and ORR, with no new safety signals. Clinical trial information: NCT02853331.

Outcomes for patients in the pembrolizumab+axitinib arm with advanced renal cell carcinoma (RCC) who completed two years of treatment in the phase III KEYNOTE-426 study

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Background: In the randomized, open-label, phase III KEYNOTE-426 study (NCT02853331), pembrolizumab + axitinib significantly improved overall survival (OS), progression-free survival (PFS), and objective response rate (ORR) versus sunitinib as first-line therapy for advanced RCC. Per protocol, patients could discontinue pembrolizumab or axitinib and continue the other agent. Pembrolizumab was stopped for all patients at 2 years. Axitinib could be continued until progression or toxicity. This exploratory subgroup analysis of KEYNOTE-426 describes outcomes of patients who completed 2 years of pembrolizumab. Methods: Patients included in KEYNOTE-426 were treatment naive, with clear cell RCC, KPS ≥70%, and measurable disease (RECIST v1.1). Patients were randomly assigned 1:1 to receive pembrolizumab 200 mg intravenously every 3 weeks for up to 35 doses + axitinib 5 mg orally twice daily or sunitinib 50 mg once daily (4 weeks on/2 weeks off) until progression, toxicity, or withdrawal. Primary end points of the original analysis were OS and PFS. Key secondary end points were ORR and safety. Results: Of 432 patients treated with pembrolizumab + axitinib, 129 (29.9%) completed 2 years of study therapy. Median (range) age of these patients was 61 (36-82) years, and 72.1% were male; 42 (32.6%) and 87 (67.4%) patients had International mRCC Database Consortium favorable and intermediate/poor risk, respectively, consistent with the intention-to-treat population (31.9% vs 68.1%). Median (range) follow-up (time from randomization to data cutoff) was 31.1 (24.0-37.7) months. For patients who completed 2 years of study therapy, the OS rates at 36 months was 93.8% (95% CI, 85.5%-97.4%). The PFS rates at 24 and 36 months were 72.7% (95% CI, 64.0%-79.7%) and 57.7% (95% CI, 46.3%-67.5%), respectively. The ORR was 85.3%, and the CR rate was 14.0%. 59.7% of patients experienced grade 3-5 treatment-related adverse events and 8.5% experienced grade 3-5 immune-mediated adverse events. Conclusions: In this exploratory analysis, a significant proportion of patients in the pembrolizumab + axitinib arm completed 2 years of pembrolizumab with ongoing clinical benefit. Clinical trial information: NCT02853331 .

Pembrolizumab plus axitinib versus sunitinib monotherapy as first-line treatment of advanced renal cell carcinoma (KEYNOTE-426): extended follow-up from a randomised, open-label, phase 3 trial

BACKGROUND

The first interim analysis of the KEYNOTE-426 study showed superior efficacy of pembrolizumab plus axitinib over sunitinib monotherapy in treatment-naive, advanced renal cell carcinoma. The exploratory analysis with extended follow-up reported here aims to assess long-term efficacy and safety of pembrolizumab plus axitinib versus sunitinib monotherapy in patients with advanced renal cell carcinoma.

METHODS

In the ongoing, randomised, open-label, phase 3 KEYNOTE-426 study, adults (≥18 years old) with treatment-naive, advanced renal cell carcinoma with clear cell histology were enrolled in 129 sites (hospitals and cancer centres) across 16 countries. Patients were randomly assigned (1:1) to receive 200 mg pembrolizumab intravenously every 3 weeks for up to 35 cycles plus 5 mg axitinib orally twice daily or 50 mg sunitinib monotherapy orally once daily for 4 weeks per 6-week cycle. Randomisation was done using an interactive voice response system or integrated web response system, and was stratified by International Metastatic Renal Cell Carcinoma Database Consortium risk status and geographical region. Primary endpoints were overall survival and progression-free survival in the intention-to-treat population. Since the primary endpoints were met at the first interim analysis, updated data are reported with nominal p values. This study is registered with ClinicalTrials.gov, NCT02853331.

FINDINGS

Between Oct 24, 2016, and Jan 24, 2018, 861 patients were randomly assigned to receive pembrolizumab plus axitinib (n=432) or sunitinib monotherapy (n=429). With a median follow-up of 30·6 months (IQR 27·2-34·2), continued clinical benefit was observed with pembrolizumab plus axitinib over sunitinib in terms of overall survival (median not reached with pembrolizumab and axitinib vs 35·7 months [95% CI 33·3-not reached] with sunitinib); hazard ratio [HR] 0·68 [95% CI 0·55-0·85], p=0·0003) and progression-free survival (median 15·4 months [12·7-18·9] vs 11·1 months [9·1-12·5]; 0·71 [0·60-0·84], p<0·0001). The most frequent (≥10% patients in either group) treatment-related grade 3 or worse adverse events were hypertension (95 [22%] of 429 patients in the pembrolizumab plus axitinib group vs 84 [20%] of 425 patients in the sunitinib group), alanine aminotransferase increase (54 [13%] vs 11 [3%]), and diarrhoea (46 [11%] vs 23 [5%]). No new treatment-related deaths were reported since the first interim analysis.

INTERPRETATION

With extended study follow-up, results from KEYNOTE-426 show that pembrolizumab plus axitinib continues to have superior clinical outcomes over sunitinib. These results continue to support the first-line treatment with pembrolizumab plus axitinib as the standard of care of advanced renal cell carcinoma.

FUNDING

Merck Sharp & Dohme Corp, a subsidiary of Merck & Co, Inc.

First-line pembrolizumab (pembro) monotherapy in advanced clear cell renal cell carcinoma (ccRCC): Updated follow-up for KEYNOTE-427 cohort A

5069

Background: KEYNOTE-427 (NCT02853344), an open-label, single-arm, phase 2 study, showed clinical activity of first-line pembro monotherapy in patients (pts) with ccRCC (cohort A). Previous studies in RCC and immune-oncology suggest depth of response may correlate with long-term benefit. Association between depth of response and OS, along with updated efficacy and safety for cohort A of KEYNOTE-427, are presented. Methods: Pts with histologically confirmed ccRCC, measurable disease (RECIST v1.1), and no prior systemic therapy received pembro 200 mg IV Q3W for 2 y or until progressive disease, unacceptable toxicity, or withdrawal. End points: ORR (primary), DOR, and PFS (RECIST v1.1); OS, and safety. Association between depth of response (maximum reduction from baseline in the sum of target lesions) and OS was evaluated using Cox proportional hazards model with target lesion reduction group as time-varying covariate. Results: 110 pts enrolled; median time from enrollment to data cutoff was 23.1 (range, 16.7-27.5) mo. Overall, 38.2% of pts had favorable and 61.2% had intermediate/poor IMDC risk. ORR was 36.4% (95% CI, 27.4-46.1; 3 CRs, 37 PRs); median (range) DOR was not reached (2.3-23.5+ mo); 64.0% had a DOR ≥12 mo. Median PFS was 7.1 mo (95% CI, 5.6-11.0) and median OS was not reached; 18-mo PFS and OS rates were 26.6% and 80.0%, respectively. 69.1% had some reduction in target lesions. Pts with > 60% reduction in target lesions had a greater probability of survival than pts with a ≤60% reduction (Table). ORR observed in IMDC favorable and intermediate/poor risk was 31.0% and 39.7%, respectively; 18-mo OS rate was 95.2% for favorable and 70.5% for intermediate/poor IMDC risk. Treatment-related AEs (TRAEs) occurred in 81.8% of pts, primarily fatigue (29.1%) and pruritus (28.2%). Grade ≥3 TRAEs occurred in 29.1% of pts; 1 pt died of treatment-related pneumonitis. Conclusions: First-line pembro monotherapy was tolerable and showed promising antitumor activity in advanced ccRCC. In general, pts who had greater reductions in target lesions demonstrated a trend toward improved OS; pts with reduction of tumor burden ≥80% had comparable long term outcomes to those who achieved a RECIST 1.1 defined CR. Clinical trial information: NCT02853344 . [Table: see text]

Pembrolizumab plus axitinib versus sunitinib as first-line therapy for advanced renal cell carcinoma (RCC): Updated analysis of KEYNOTE-426

5001

Background: The randomized, open-label, phase 3 KEYNOTE-426 study (NCT02853331) demonstrated that pembrolizumab (pembro) + axitinib (axi) significantly improved OS, PFS, and ORR vs sunitinib as first-line therapy for advanced RCC (aRCC) at the first pre-planned interim analysis (minimum study follow-up of 7 mo). Updated analyses are presented here. Methods: Treatment-naive patients (pts) with clear cell aRCC, KPS ≥70%, and measurable disease (RECIST v1.1) were randomly assigned 1:1 to receive pembro 200 mg IV Q3W for up to 35 doses + axi 5 mg orally BID or sunitinib 50 mg orally QD on a 4-wk on/2-wk off schedule until progression, toxicity, or withdrawal. Randomization was stratified by IMDC risk (favorable vs intermediate vs poor) and geographic region (North America vs Western Europe vs rest of world). Primary end points were OS and PFS. Secondary end points were ORR, DOR, and safety. All P values are nominal. A post-hoc exploratory analysis was done to evaluate association of depth of response (maximum reduction from baseline in sum of diameters of target lesions) and OS using landmark analysis up to 6 mo after randomization. Results: 861 pts were randomly assigned (pembro + axi, n = 432; sunitinib, n = 429). Median (range) duration of follow-up for all pts was 27.0 mo (0.1-38.4). Pembro + axi improved OS (HR, 0.68 [95% CI, 0.55-0.85]; P < 0.001; 24-mo OS rate, 74% vs 66%) vs sunitinib. Median (95% CI) OS was not reached with pembro + axi and was 35.7 mo (33.3-NR) with sunitinib. Pembro + axi improved PFS (HR, 0.71 [95% CI, 0.60-0.84]; P < 0.001; 24-mo PFS rate, 38% vs 27%) vs sunitinib. For pembro +axi vs sunitinib respectively, median (95% CI) PFS was 15.4 (12.7-18.9) vs 11.1 mo (9.1-12.5); ORR was 60% vs 40% ( P < 0.0001); CR rate was 9% vs 3%; and median DOR was 23.5 mo (range 1.4+ to 34.5+) vs 15.9 mo (range 2.3-31.8+). In general, the pembro + axi benefit was observed in all subgroups tested, including IMDC risk and PD-L1 expression subgroups. Post-hoc landmark analysis at 6-mo showed that pts on pembro + axi with ≥80% target lesion reduction had OS similar to that of pts with CR per RECIST v1.1 based on Kaplan-Meier curves and HR [95% CI] estimates (0.20 [0.05-0.84] vs. 0.10 [0.01-0.76], respectively) vs pts with 0-30% target lesion reduction. No new safety signals were observed. Conclusions: Pembro + axi continued to demonstrate superior and durable antitumor activity vs sunitinib in pts with first-line aRCC with a 27-mo median follow up; no new safety signals were observed. Clinical trial information: NCT02853331 .

First-line pembrolizumab (pembro) monotherapy in advanced non-clear cell renal cell carcinoma (nccRCC): Updated follow-up for KEYNOTE-427 cohort B

5034

Background: KEYNOTE-427 (NCT02853344), a single-arm, open-label, phase 2 study, showed antitumor activity with first-line pembro monotherapy in nccRCC (cohort B). Studies of RCC and immune-oncology have shown that depth of tumor response may correlate with long-term benefit. We present the association between depth of response and OS plus updated efficacy and safety data in cohort B. Methods: Pts with histologically confirmed nccRCC, who did not receive prior systemic therapy, and who have measurable disease (RECIST v1.1) received pembro 200 mg IV Q3W for 2 y or until progressive disease, unacceptable toxicity, or withdrawal. End points were ORR (primary), DOR, and PFS (RECIST v1.1); OS; and safety. Association between depth of response, defined as maximum reduction from baseline in sum of target lesions, and OS was evaluated using a Cox proportional hazards model with target lesion reduction group as time-varying covariate. Results: Of 165 pts, 72% had papillary histology, 13% had chromophobe histology, and 16% were unclassified. Median time from enrollment to data cutoff was 18.7 mo (range, 9.9-26.0). ORR was 26.1% (95% CI, 19.5-33.5; 10 CRs, 33 PRs). Median (range) DOR was 15.3 mo (2.8-21.0+); 57.3% had DOR ≥12 mo. At 18-mo, PFS rate was 18.9% and OS rate was 67.0%. Most pts (58.8%) had some reduction in target lesions. Pts with a > 30% reduction in target lesions had an increased probability of survival (Table). ORR (95% CI) was similar for papillary (28.0% [20.1-37.0]) and unclassified (30.8% [14.3-51.8]) histology but lower for chromophobe (9.5% [1.2-30.4]). OS rates at 18 mo were 70.8%, 66.7%, and 50.0 in the papillary, chromophobe, and unclassified groups, respectively. Treatment-related AEs (TRAEs) occurred in 67.9% of all pts, primarily pruritus (19%), hypothyroidism (14%), and fatigue (14%). Grade 3-5 TRAEs occurred in 14% of pts; 2 pts died of TRAEs (pneumonia and cardiac arrest). Conclusions: First-line pembro monotherapy continued to show antitumor activity in nccRCC with no new safety concerns. In general, for pts who had greater reductions in target lesions, the trend was toward improved OS; pts with reduction of tumor burden ≥80% had comparable long term outcomes to those who achieved a RECIST 1.1 defined CR. Clinical trial information: NCT02853344 . [Table: see text]

Association of gene expression with clinical outcomes in patients with renal cell carcinoma treated with pembrolizumab in KEYNOTE-427

5024

Background: We assessed the association of baseline RNA-sequencing–based gene expression signatures and DNA alterations with response or resistance to pembrolizumab in patients with advanced renal cell carcinoma in cohorts A (clear cell; n = 110) and B (non-clear cell; n = 165) of the phase 2 KEYNOTE-427 study (NCT02853344). Methods: Using RNA-sequencing, we analyzed the association of gene expression signatures (18-gene T-cell–inflamed gene expression profile [GEP]; 10 non–T-cell–inflamed GEP canonical signatures [angiogenesis, gMDSC, glycolysis, hypoxia, mMDSC, MYC, proliferation, RAS, stromal/EMT/TGFβ, WNT]) quantifying tumor microenvironment elements (TME) with objective response rate (ORR) and progression-free survival (PFS). Canonical signatures were derived from 2 databases (TCGA, Moffit) using an algorithm that included genes based on their correlation to reference signatures in the literature. Signature definitions were finalized before linking to the clinical data, and significance was prespecified at 0.10 given the potential for limited power. Canonical signatures were analyzed through regression testing of response for association with consensus signatures after adjusting for T-cell–inflamed GEP and International Metastatic RCC Database Consortium scores in the model. P values were adjusted for multiplicity. Using whole exome sequencing, we also summarized the association of renal cell carcinoma driver gene mutations with ORR. Clinical data cutoff: Jan 30, 2019. Results: Patient characteristics for this analysis were comparable to the overall population. In cohort A, T-cell–inflamed GEP (n = 78) was statistically significantly associated with a better ORR ( P = 0.021; AUROC = 0.65) but not PFS ( P = 0.116). No other TME canonical signatures showed a correlation with ORR or PFS. ORR was estimated for mutations (Table). Conclusions: RNA-sequencing–based, T-cell–inflamed GEP was associated with ORR in patients with clear cell renal cell carcinoma receiving first-line pembrolizumab. Precision was limited by sample size for estimating ORR by specific gene mutation status. Evaluation of tissue-based biomarkers in larger studies are planned. Biomarker analyses from patients in cohort B will also be presented. Clinical trial information: NCT02853344 . [Table: see text]

Abstract A1: Clinical outcomes in patients with chronic hepatitis C and metastatic renal cell carcinoma (mRCC) after treatment with nivolumab

Clinical trials of immune checkpoint inhibitors have historically excluded patients with chronic hepatitis C (HCV) infection. The safety and efficacy profile of nivolumab is unknown in this under-represented population. Data were collected in a retrospective fashion on 36 patients with metastatic clear-cell mRCC. Patients were required to have a chronic HCV infection, no evidence of other malignancy or cirrhosis, and to have received nivolumab (3 mg/kg every 2 weeks) as second- or third-line therapy. Clinical outcomes included overall survival (OS), progression-free survival (PFS), and objective response rate (ORR). Safety was evaluated. Median follow-up was 17.5 months. Nivolumab was well tolerated in all HCV-infected patients (grade 3-4 toxicity was found in 6 of 36 cases [17%]). No unexpected toxicity was observed. Exposure to nivolumab was not associated with increased risk for hepatocellular carcinoma and cirrhosis (N=0). Medians OS and PFS were 23.9 (95% CI 20.7-26.5) and 6.8 (95% CI 4.9-8.7) months, respectively. 23% of patients had partial responses. The efficacy and safety profile observed in this study supports the administration of nivolumab in mRCC patients infected with HCV and warrants further investigation.

Citation Format: Ilya Tsimafeyeu, Rustem Gafanov, Anna Semenova, Ani Oganesyan, Anastasia Bondarenko, Sufia Safina, Kristina Zakurdaeva, Svetlana Protsenko. Clinical outcomes in patients with chronic hepatitis C and metastatic renal cell carcinoma (mRCC) after treatment with nivolumab [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr A1.

Pembrolizumab (pembro) plus axitinib (axi) versus sunitinib as first-line therapy for metastatic renal cell carcinoma (mRCC): Outcomes in the combined IMDC intermediate/poor risk and sarcomatoid subgroups of the phase 3 KEYNOTE-426 study

4500

Background: In KEYNOTE-426, pembro + axi significantly improved OS (HR 0.53, P < .0001), PFS (HR 0.69, P = .0001), and ORR (59.3% vs 35.7%, P < .0001) vs sunitinib and had manageable toxicity as first-line therapy for mRCC (NCT02853331). The pembro + axi benefit was observed across all IMDC risk groups and regardless of PD-L1 expression. We present data for the combined intermediate/poor risk group and for patients (pts) with sarcomatoid features. Methods: 861 eligible pts with clear-cell mRCC, no prior systemic therapy for mRCC, and KPS ≥70 were randomized 1:1 to pembro 200 mg IV Q3W for a maximum of 35 cycles plus axi 5 mg orally BID (N = 432) or sunitinib 50 mg orally QD (4-wk on/2-wk off) (N = 429). Primary endpoints were OS and PFS (RECIST v1.1 by blinded, independent central review [BICR]). ORR (RECIST v1.1 by BICR) was the key secondary endpoint. The intermediate/poor risk group was prespecified; the sarcomatoid group was exploratory. HRs and their 95% CIs were calculated with a Cox proportional hazards model. None of the analyses were multiplicity-controlled. Results: 592 (68.8%) of all randomized pts were of IMDC intermediate/poor risk — 294 in the pembro + axi arm, 298 in the sunitinib arm. Pembro + axi improved OS (HR 0.52, 95% CI 0.37-0.74; 12-mo rate 87.3% vs 71.3%), PFS (HR 0.67, 95% CI 0.53-0.85; median 12.6 vs 8.2 mo), and ORR (55.8% [95% CI 49.9-61.5] vs 29.5% [24.4-35.1]) in pts with intermediate/poor risk; CR rates were 4.8% (95% CI 2.6-7.9) vs 0.7% (0.1-2.4). Of the 578 pts with known status, 105 (18.2%) had sarcomatoid features — 51 in the pembro + axi arm, 54 in the sunitinib arm. Pembro + axi improved OS (HR 0.58, 95% CI 0.21-1.59; 12-mo rate 83.4% vs 79.5%), PFS (HR 0.54, 95% CI 0.29-1.00; median not reached vs 8.4 mo), and ORR (58.8% [95% CI 44.2-72.4] vs 31.5% [19.5-45.6]) in pts with sarcomatoid features; CR rates were 11.8% (95% CI 4.4-23.9) vs 0% (0.0-6.6). Conclusions: Pembro + axi provides benefit in the combined population of pts with IMDC intermediate or poor risk and in pts whose tumors had sarcomatoid features. The observed benefits were consistent with those seen in the total population. Clinical trial information: NCT02853331.

KEYNOTE-427 cohort B: First-line pembrolizumab (pembro) monotherapy for advanced non‒clear cell renal cell carcinoma (NCC-RCC)

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Background: Efficacy of PD-1 inhibitors (or any therapy) in NCC-RCC has not been established. KEYNOTE-427 (NCT02853344) is a single-arm, open-label, phase 2 study of pembro monotherapy in patients (pts) with advanced clear cell RCC (cohort A) and NCC-RCC (cohort B). Cohort B results are presented. Methods: 165 pts with histologically confirmed NCC-RCC, no prior systemic therapy, measurable disease (RECIST v1.1), and KPS ≥70% enrolled. Pts received pembro 200 mg IV Q3W for 35 cycles (~2 y) or until progressive disease (PD), unacceptable toxicity, or withdrawal. Primary end point: objective response rate (ORR) per RECIST v1.1 by blinded independent central review. Additional end points: duration of response (DOR), population description by sarcomatoid differentiation, histology and PD-L1 expression (combined positive score [CPS] ≥1 for PD-L1+). Results: Histology was confirmed by a central pathologist: papillary 72% (n = 118), chromophobe 13% (n = 21), unclassified 16% (n = 26); 62% were PD-L1+. At analysis, 49 pts had died and 3 had withdrawn. At median follow-up of 11.1 mo (range, 0.9-21.3), 56% of pts discontinued pembro due to PD or clinical progression. Overall ORR was 24.8% (95% CI, 18.5-32.2; 8 [4.8%] CR, 33 [20.0%] PR). Median DOR was not reached. For responding pts, 81.5% had a response ≥6 mo. 12-mo PFS and OS rates were 22.8% and 72.0%, respectively. ORR (95% CI) was 25.4% (17.9-34.3) with papillary, 9.5% (1.2-30.4) with chromophobe, and 34.6% (17.2-55.7) with unclassified NCC-RCC; for responding pts, 82.1%, 50.0%, and 87.5% had a response ≥6 mo, respectively. Median DOR was not reached in any group. ORR (95% CI) was 44.7% (28.6-61.7) for pts with sarcomatoid differentiation (n = 38). ORR (95% CI) was 33.3% (24.3-43.4) and 10.3% (3.9-21.2) with CPS≥1 and CPS < 1, respectively. Grade 3-5 treatment-related adverse events (TRAEs) occurred in 11% of pts. 6 pts died of AEs, 2 of TRAEs (pneumonia and cardiac arrest). Conclusions: Single-agent pembro showed encouraging antitumor activity in NCC-RCC, especially with papillary or unclassified histology. Safety profile of pembro was as expected. Updated data with additional follow-up will be presented. Clinical trial information: NCT02853344.

First-line pembrolizumab (pembro) monotherapy in advanced clear cell renal cell carcinoma (ccRCC): Updated results for KEYNOTE-427 cohort A

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Background: KEYNOTE-427 (NCT02853344) is an open-label, single-arm, phase 2 study to evaluate efficacy and safety of first-line single-agent pembro, a programmed death 1 (PD-1) inhibitor, in patients (pts) with ccRCC (cohort A) and non–clear cell RCC (cohort B). Updated follow up from cohort A are presented. Methods: Pts with histologically confirmed ccRCC, measurable per RECIST v1.1, and no prior systemic therapy were eligible. Pts received pembro 200 mg IV Q3W for 2 y or until confirmed progressive disease, unacceptable toxicity, or pt decision to withdraw. Primary end point was objective response rate (ORR; per RECIST v1.1 blinded independent central review). Additional end points included duration of response (DOR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and safety. Results: 110 pts enrolled; median (range) follow-up was 18.0 (2.5-22.7) mo. Median age (range) was 64 (29-87); 38.2%, 47.3%, and 14.5% had favorable, intermediate, and poor IMDC risk, respectively; 47.3% were PD-L1 positive. Confirmed ORR was 36.4% with 3 (2.7%) CRs and 37 (33.6%) PRs. Median DOR was not reached. Median PFS was 7.1 mo (95% CI, 5.6-11.0) and median OS was not reached. Results by IMDC category are outlined in the table. By PD-L1 status, confirmed ORR was 44.2% and 29.3% for positive and negative, respectively. By sarcomatoid differentiation (n=11), confirmed ORR was 63.6%. Treatment-related AEs occurred in 80.9%, with pruritus (28.2%) and fatigue (28.2%) most commonly reported. One pt died of treatment-related pneumonitis. Conclusions: With a median 18-months’ follow up, first-line pembro monotherapy continued to show antitumor activity in pts with ccRCC. Meaningful responses were observed in pts with intermediate/poor IMDC risk, PD-L1 positive and sarcomatoid differentiated tumors. Safety profile was comparable to previously reported. Clinical trial information: NCT02853344. [Table: see text]

Pembrolizumab plus Axitinib versus Sunitinib for Advanced Renal-Cell Carcinoma

BACKGROUND

The combination of pembrolizumab and axitinib showed antitumor activity in a phase 1b trial involving patients with previously untreated advanced renal-cell carcinoma. Whether pembrolizumab plus axitinib would result in better outcomes than sunitinib in such patients was unclear.

METHODS

In an open-label, phase 3 trial, we randomly assigned 861 patients with previously untreated advanced clear-cell renal-cell carcinoma to receive pembrolizumab (200 mg) intravenously once every 3 weeks plus axitinib (5 mg) orally twice daily (432 patients) or sunitinib (50 mg) orally once daily for the first 4 weeks of each 6-week cycle (429 patients). The primary end points were overall survival and progression-free survival in the intention-to-treat population. The key secondary end point was the objective response rate. All reported results are from the protocol-specified first interim analysis.

RESULTS

After a median follow-up of 12.8 months, the estimated percentage of patients who were alive at 12 months was 89.9% in the pembrolizumab-axitinib group and 78.3% in the sunitinib group (hazard ratio for death, 0.53; 95% confidence interval [CI], 0.38 to 0.74; P<0.0001). Median progression-free survival was 15.1 months in the pembrolizumab-axitinib group and 11.1 months in the sunitinib group (hazard ratio for disease progression or death, 0.69; 95% CI, 0.57 to 0.84; P<0.001). The objective response rate was 59.3% (95% CI, 54.5 to 63.9) in the pembrolizumab-axitinib group and 35.7% (95% CI, 31.1 to 40.4) in the sunitinib group (P<0.001). The benefit of pembrolizumab plus axitinib was observed across the International Metastatic Renal Cell Carcinoma Database Consortium risk groups (i.e., favorable, intermediate, and poor risk) and regardless of programmed death ligand 1 expression. Grade 3 or higher adverse events of any cause occurred in 75.8% of patients in the pembrolizumab-axitinib group and in 70.6% in the sunitinib group.

CONCLUSIONS

Among patients with previously untreated advanced renal-cell carcinoma, treatment with pembrolizumab plus axitinib resulted in significantly longer overall survival and progression-free survival, as well as a higher objective response rate, than treatment with sunitinib. (Funded by Merck Sharp & Dohme; KEYNOTE-426 ClinicalTrials.gov number, NCT02853331.).

Phase 3 KEYNOTE-361 trial: Pembrolizumab (pembro) with or without chemotherapy versus chemotherapy alone in advanced urothelial cancer

TPS4590

Background: Only 5%-15% of patients (pts) with advanced bladder cancer attain long-term survival with standard first-line cisplatin-based chemotherapy. Programmed death 1 (PD-1)/PD-L1 inhibitors have proven effective in recurrent, advanced urothelial cancer. Emerging data suggest these agents may also be useful in the first-line setting. In KEYNOTE-052, first-line pembro, an anti–PD-1 antibody, demonstrated antitumor activity and acceptable safety in cisplatin-ineligible pts with advanced urothelial cancer. KEYNOTE-361 (NCT02853305) is a randomized, open-label, phase 3 study of pembro with or without chemotherapy versus chemotherapy alone in pts with advanced urothelial carcinoma. Methods: Key eligibility criteria include age ≥18 years; histologically or cytologically confirmed unresectable/metastatic urothelial carcinoma of the renal pelvis, ureter, bladder, or urethra; measurable disease (RECIST v1.1, investigator review); no prior systemic chemotherapy ([neo]adjuvant platinum-based chemotherapy with recurrence > 12 months after completion is allowed); ECOG PS 0-2; and provision of a tumor sample for biomarker analyses. Pts will be randomly assigned 1:1:1 to receive pembro 200 mg every 3 weeks (Q3W), pembro + investigator’s choice of chemotherapy (gemcitabine [1000 mg/m2 on day 1 and 8 Q3W] + cisplatin [70 mg/m2 Q3W]), or chemotherapy alone. Cisplatin-ineligible pts randomly assigned to chemotherapy will receive gemcitabine + carboplatin [AUC 5 Q3W]. Chemotherapy choice must be selected before randomization. Treatment will continue until progressive disease, unacceptable adverse events (AEs), or 35 cycles of pembro (pembro arms only). Response will be assessed Q9W for the first year and Q12W thereafter. AEs will be evaluated throughout and graded per NCI CTCAE v4.0. Primary end points are progression-free survival (RECIST v1.1 per central review) and overall survival; secondary end points include objective response rate and safety and tolerability. Efficacy outcomes will be compared for pembro vs chemotherapy and pembro + chemotherapy vs chemotherapy. Enrollment is ongoing; ~990 pts will be enrolled. Clinical trial information: NCT02853305.