Choueiri, Toni K.

TPS5100 Background: First-line treatment of mRCC has rapidly changed to include IPI-NIVO or CABO, with clinical benefit of each based on the Checkmate 214 and CABOSUN (A031203) trials. Combination immunotherapy with VEGF therapies has shown benefit over sunitinib in the JAVELIN 101 and KEYNOTE 426 trials. It is yet unclear which patients (pts) benefit most from combination immunotherapy-VEGF inhibitors, and the optimal sequence of drugs. Methods: In an adaptive, randomized, multicenter phase 3 trial (Alliance A031704, PDIGREE), pts start treatment with induction IPI 1 mg/kg and NIVO 3 mg/kg intravenously (IV) once every 3 weeks. Key inclusion criteria include clear cell mRCC, International Metastatic RCC Database Consortium (IMDC) intermediate or poor risk, Karnofsky performance status > 70, and no prior treatments for mRCC. Based on 3-month radiographic assessment (after completing IPI-NIVO combination), pts with complete responses (CR) undergo maintenance NIVO 480 mg IV every 4 weeks; pts with progression of disease (PD) switch to CABO 60 mg oral daily; pts with non-CR/non-PD are randomized to NIVO 480 mg IV every 4 weeks versus NIVO 480 mg IV every 4 weeks with CABO 40 mg oral daily. Randomization is stratified by IMDC risk criteria and presence of bone metastases. The primary endpoint of the study is overall survival (OS). We hypothesize that 3-year OS will improve to 70% for NIVO-CABO compared to 60% for NIVO alone; to achieve 85% power with a two-sided alpha of 0.05 and exponential distribution, 696 patients will be randomized. Accounting for 30% patients with either CR or PD, and 5% dropout from toxicity, up to 1046 pts will be enrolled. Key secondary endpoints include progression-free survival, 12-month CR rate, overall response rate based on RECIST 1.1 and irRECIST criteria, and toxicity profiles. Quality of life will be assessed based on the FKSI-19, PROMIS-fatigue, and EQ5D-5L questionnaires. Biomarkers associated with CR, tissue-based and plasma-based biomarkers will be assessed. Updated enrollment through May 2020 will be presented. Clinical trial information: NCT03793166 .

5564 Background: Cabozantinib (C) may enhance response to immune checkpoint inhibitors (ICIs) by promoting an immune-permissive microenvironment and has shown encouraging activity in combination with ICIs in tumor types including RCC and HCC. C and atezolizumab (A) have shown low objective response rates as monotherapy in metastatic castration-resistant prostate cancer (mCRPC) (Smith JCO 2012; Kim JCO 2018). COSMIC-021 (NCT03170960), a multinational phase 1b study, is evaluating the combination of C + A in various solid tumors. We report results for Cohort 6 in mCRPC. Methods: Eligible patients (pts) were required to have radiographic progression in soft tissue after enzalutamide and/or abiraterone, measurable disease, and an ECOG PS of 0 or 1. Prior chemotherapy for mCSPC was permitted. Pts received C 40 mg PO QD and A 1200 mg IV Q3W. CT/MRI scans were performed Q6W for the first year and Q12W thereafter. The primary endpoint is ORR per RECIST 1.1. Other endpoints include safety, ORR per irRECIST, duration of response (DOR), PFS, and OS. Results are presented for the first 44 pts enrolled. Results: Median follow-up as of Dec 20, 2019 was 12.6 mo (range 5, 20) for the 44 mCRPC pts. Median age was 70 y (range 49, 90), 50% had ECOG PS 1, 34% had visceral metastases, and 61% had extrapelvic lymph node metastases. 27% had prior docetaxel and 52% had 2 prior novel hormonal therapies. The most common any grade treatment-related adverse events (TRAEs) were fatigue (50%), nausea (43%), decreased appetite (39%), diarrhea (39%), dysgeusia (34%), and PPE (32%). One grade 5 TRAE of dehydration was reported in a 90 y/o. Median duration of treatment was 6.3 mo. ORR per RECIST 1.1 among all 44 pts was 32% (2 CRs [4.5%] and 12 PRs [27%]); 21 (48%) pts had SD resulting in a disease control rate of 80% in all pts. One pt with PD per RECIST 1.1 had an irPR per irRECIST. ORR per RECIST 1.1 was 33% in 36 pts with high-risk disease (visceral and/or extrapelvic lymph node metastases). Median DOR for all pts with response per RECIST 1.1 was 8.3 mo (range 2.8, 9.8+). 17 (50%) of 34 pts with post-baseline PSA evaluation had a decrease in PSA. In 12 responders with post-baseline PSA evaluation, 8 (67%) had a PSA decrease ≥50%. Tumor PD-L1 expression will also be reported. Conclusions: The combination of C + A had a tolerable safety profile and demonstrated clinically meaningful activity with durable responses in men with mCRPC. Given the encouraging activity in these pts, especially in those with high-risk disease, further evaluation of C + A in men with mCRPC is being pursued. Clinical trial information: NCT03170960 .

5077 Background: Several ICIs are used in first and subsequent lines of therapy for mRCC, either alone or in combination with another ICI or targeted therapy (TT). There are no data on the efficacy and safety of using an ICI in patients who have already received an ICI in a prior line of therapy. Methods: We reviewed patients with mRCC at 8 institutions who received 2 separate lines of ICI therapy (ICI-1, ICI-2), including as a single-agent and/or combination with other agents. The primary outcomes were overall response rate (ORR) and time to progression (TTP) with ICI-1 and ICI-2. Immune-related adverse events (irAEs) were graded using CTCAEv5.0. Results: 65 patients were included. Median age at diagnosis of mRCC was 60 years (range 30-86) and the majority had clear cell RCC (n=56, 86%). Median follow-up was 3.5 years (95% CI 2.9-4.4). Median lines at which ICI-1 and ICI-2 were received were 1 (1-6) and 3 (2-8) respectively. Reasons for discontinuing ICI-1 were disease progression (n=47, 72%), toxicity (n=15, 23%) or other (n=3, 5%). Therapies received at ICI-2 were single-agent ICI (n=26, 40%), or combinations of ICI with another ICI (n=20, 31%), TT (n=11, 17%) or other agent (n=8, 12%). Responses to ICI-1 and ICI-2 are shown in the Table; ORR to ICI-2 was significantly lower than to ICI-1 (23% vs. 36%, p=0.044). Amongst those who responded to ICI-2 (n=14), 7 (50%) received single-agent ICI, and the remainder received ICI in combination with another ICI (n=4, 29%) or TT (n=3, 21%); 7 patients (50%) had previously responded to ICI-1. The ORR to ICI-2 was higher in responders to ICI-1 (32%) compared to those with SD (17%) or PD (15%) to ICI-1. Median TTP (mTTP) at ICI-2 was shorter compared to ICI-1 (5.3 months vs. 8.5 months, Wilcoxon p=0.024). 29 patients (45%) experienced an irAE with ICI-2; 8 (12%) and 3 (5%) had a grade 3 or 4 irAE respectively, with 3 (30%) of these patients having previously had ≥grade 3 irAE to ICI-1. There were no treatment-related deaths. Conclusions: The ORR to ICI-2 was 23%, which is comparable to that seen with ICI after prior TT. Responses were seen even amongst those receiving single-agent ICI at ICI-2 and the likelihood of response to ICI-2 was higher if a patient had previously responded to ICI-1. No increase in toxicity with ICI-2 was apparent. Additional data from prospective studies are needed to determine whether sequential ICI has a role in treatment of mRCC. [Table: see text]

5061 Background: The phase 3 JAVELIN Renal 101 trial (NCT02684006) in treatment-naive patients with advanced renal cell carcinoma (aRCC) demonstrated significantly improved progression-free survival (PFS; hazard ratio [HR], 0.69; 95% CI, 0.56, 0.84; P < 0.001) and higher objective response rate (ORR; 51.4% vs 25.7%) with avelumab + axitinib vs sunitinib (Motzer RJ, et al. N Engl J Med. 2019;380:1103-15). NLR has emerged as a potential prognostic biomarker in aRCC; elevated NLR is associated with poorer prognosis. Here, we describe the association of NLR with the efficacy of avelumab + axitinib from JAVELIN Renal 101. Methods: We examined baseline NLR and its association with efficacy outcomes. PFS, best overall response (per blinded independent central review using RECIST 1.1), and overall survival (OS) data from the avelumab + axitinib arm from the first interim analysis of JAVELIN Renal 101 were analyzed (data cutoff, June 20, 2018). Multivariate Cox regression analyses of PFS and OS were also conducted. Results: In the avelumab + axitinib arm, patients with < median NLR (N = 217) had longer observed PFS (stratified HR, 0.85; 95% CI, 0.634, 1.153) and longer observed OS (stratified HR, 0.51; 95% CI, 0.300, 0.871) than patients with ≥ median NLR (N = 217). The ORR was 57.1% in patients with < median NLR vs 47.5% in patients with ≥ median NLR, with complete response in 5.5% vs 1.4%. Multivariate analysis showed that low NLR was associated with longer PFS and OS by treating baseline NLR as either a continuous variable or a binary variable (dichotomized by median). Conclusions: Low NLR was associated with better observed treatment outcomes in patients with aRCC who received avelumab + axitinib. Clinical trial information: NCT02684006 .

Objective To evaluate patient‐reported outcome (PRO) data from the IMmotion150 study. The phase 2 IMmotion150 study showed improved progression‐free survival with atezolizumab plus bevacizumab vs sunitinib in patients with programmed death‐ligand 1 (PD‐L1)+ tumours and suggested activity of atezolizumab monotherapy in previously untreated metastatic renal cell carcinoma (mRCC). Patients and methods Patients with previously untreated mRCC were randomised to atezolizumab 1200 mg intravenously (i.v.) every 3 weeks ( n = 103), the atezolizumab regimen plus bevacizumab 15 mg/kg i.v. every 3 weeks ( n = 101), or sunitinib 50 mg orally daily (4 weeks on, 2 weeks off; n = 101). The MD Anderson Symptom Inventory (MDASI) and Brief Fatigue Inventory (BFI) were administered on days 1 and 22 of each 6‐week cycle. Time to deterioration (TTD), change from baseline in MDASI core and RCC symptom severity, interference with daily life, and BFI fatigue severity and interference scores were reported for all comers. The TTD was the first ≥2‐point score increase over baseline. Absolute effect size ≥0.2 suggested a clinically important difference with checkpoint inhibitor therapy vs sunitinib. Results Completion rates were >90% at baseline and ≥80% at most visits. Delayed TTD in core and RCC symptoms, symptom interference, fatigue, and fatigue‐related interference was observed with atezolizumab (both alone and in combination) vs sunitinib. Improved TTD (hazard ratio [HR], 95% confidence interval [CI]) was more pronounced with atezolizumab monotherapy: core symptoms, 0.39 (0.22–0.71); RCC symptoms, 0.22 (0.12–0.41); and symptom interference, 0.36 (0.22–0.58). Change from baseline by visit, evaluated by the MDASI, also showed a trend favouring atezolizumab monotherapy vs sunitinib. Small sample sizes may have limited the ability to draw definitive conclusions. Conclusion PROs suggested that atezolizumab alone or with bevacizumab maintained daily function compared with sunitinib. Notably, symptoms were least severe with atezolizumab alone vs sunitinib (IMmotion150; ClinicalTrials.gov Identifier: NCT01984242).

TPS765 Background: There is no standard adjuvant systemic therapy that increases overall survival (OS) over surgery alone for non-metastatic RCC. Anti-PD-1 nivolumab (nivo) improves OS in metastatic RCC and is well tolerated. In mouse models, priming the immune system prior to surgery with anti-PD-1 results in superior OS compared to adjuvant dosing. Remarkable pathologic responses have been seen with neoadjuvant PD-1 in multiple ph 2 studies in bladder, lung and breast cancers. Phase 2 neoadjuvant RCC trials of nivo show preliminary feasibility and safety with no surgical delays. PROSPER RCC seeks to improve clinical outcomes by priming the immune system with neoadjuvant nivo prior to nephrectomy followed by continued immune system engagement with adjuvant blockade in patients (pts) with high risk RCC compared to standard of care surgery alone. Methods: This global, unblinded, phase 3 National Clinical Trials Network study is accruing pts with clinical stage ≥T2 or TanyN+ RCC of any histology planned for radical or partial nephrectomy. Select oligometastatic disease is permitted if the pt can be rendered ‘no evidence of disease’ within 12 weeks of nephrectomy (≤3 metastases; no brain, bone or liver). In the investigational arm, nivo is administered 480mg IV q4 weeks with 1 dose prior to surgery followed by 9 adjuvant doses. The control arm is nephrectomy followed by standard of care surveillance. There is no placebo. Baseline tumor biopsy is required only in the nivo arm but encouraged in both. Randomized pts are stratified by clinical T stage, node positivity, and M stage. 805 pts provide 84.2% power to detect a 14.4% absolute benefit in recurrence-free survival at 5 years assuming the ASSURE historical control of ~56% to 70% (HR = 0.70). The study is powered to evaluate a significant increase in OS (HR 0.67). Critical perioperative therapy considerations such as safety, feasibility, and quality of life metrics are integrated. PROSPER RCC embeds a wealth of translational studies to examine the contribution of the baseline immune milieu and neoadjuvant priming with anti-PD-1 on clinical outcomes. As of October 18, 2019, 317 patients have been enrolled. Clinical trial information: NCT03055013.

TPS760 Background: First-line treatment of mRCC has rapidly changed to include IPI-NIVO or CABO, with clinical benefit of each based on the Checkmate 214 and CABOSUN trials. Combination immunotherapy with VEGF therapies have shown benefit in the JAVELIN 101 and KEYNOTE 426 trials over sunitinib. It is yet unclear which patients (pts) benefit most from combination immunotherapy-VEGF inhibitors, and the optimal sequence of drugs. Methods: In an adaptive, randomized, multicenter, phase 3 trial (Alliance A031704, PDIGREE), pts start treatment with induction IPI 1mg/kg and NIVO 3mg/kg intravenously (IV) once every 3 weeks. Key inclusion criteria include clear cell mRCC, IMDC intermediate or poor risk, Karnofsky performance status >70, and no prior treatments for mRCC. Based on 3-month radiographic assessment (after completing IPI-NIVO combination), pts with complete responses (CR) undergo maintenance NIVO 480mg IV every 4 weeks, pts with progression of disease (PD) switch to CABO 60mg oral daily, and pts with non-CR/non-PD are randomized to NIVO 480mg IV every 4 weeks versus NIVO 480mg IV every 4 weeks with CABO 40mg oral daily. Randomization is stratified by IMDC risk criteria and presence of bone metastases. The primary endpoint of the study is overall survival (OS). We hypothesize that 3-year OS rate will improve to 70% for NIVO-CABO compared to 60% for NIVO alone; to achieve 85% power with a two-sided alpha of 0.05 and exponential distribution, 696 patients will be randomized. Accounting for 30% patients with either CR or PD, and 5% dropout from toxicity, up to 1046 pts will be enrolled. Key secondary endpoints include PFS, 12-month CR rate, ORR based on RECIST 1.1 and irRECIST criteria, and toxicity profiles. Quality of life will be assessed based on the FKSI-19, PROMIS-fatigue, and EQ5D-5L questionnaires. Biomarkers associated with CR and association of IL-6 with treatment benefit will be assessed. Other tissue-based and plasma-based biomarkers are planned. Updated enrollment will be presented. Clinical trial information: NCT03793166.

139 Background: C may enhance response to immune checkpoint inhibitors by promoting an immune-permissive microenvironment. COSMIC-021 (NCT03170960), a multinational phase 1b study, is evaluating the combination of C with A in various solid tumors. We report interim results from Cohort 6 in mCRPC. Methods: Eligible pts were required to have radiographic progression in soft tissue after enzalutamide and/or abiraterone, measurable disease, and an ECOG PS of 0 or 1. Prior chemotherapy for mCSPC was permitted. Pts received C 40 mg PO qd and A 1200 mg IV q3w. CT/MRI scans were performed q6w for 52w and q12w thereafter. Bone scans were performed q12w. The primary endpoint is ORR per RECIST 1.1. Other endpoints include safety, ORR per irRECIST, duration of response (DOR), PFS, and OS. Results: As of Oct 2019, 44 mCRPC pts were enrolled with a median follow-up of 10.6 mo (range 3.4+, 17.9). Median age was 70 y (range 49, 90), 50% had ECOG PS 1, 34% had visceral metastases, and 61% had extrapelvic lymph node metastases. 27% of pts had prior docetaxel and 52% had ≥2 prior novel hormonal therapies. The most common any grade TEAEs were fatigue (57%), nausea (48%), decreased appetite (45%), diarrhea (39%), PPE (32%), and vomiting (32%). One Grade 5 TRAE of dehydration was reported in a 90 y/o. Median duration of treatment was 5.3 mo. The ORR per RECIST 1.1 among all pts was 32% (2 CRs [4.5%] and 12 PRs [27%]); 21 (48%) pts had SD giving a disease control rate of 80% in all pts. One pt with initial PD per RECIST 1.1 had an irPR per irRECIST. ORR per RECIST 1.1 was 33% in 36 pts with high-risk clinical features (visceral and/or extrapelvic lymph node metastases). Median DOR for all pts with response per RECIST 1.1 was 8.3 mo (range 1.38+, 9.76+). In 12 responders with at least 1 post-baseline PSA evaluation, 8 (67%) had a PSA decline ≥50%. Conclusions: The combination of C+A had a tolerable safety profile and demonstrated clinically meaningful activity with durable responses in men with mCRPC. Given the encouraging activity in these pts, especially in those with visceral and/or extra pelvic lymph node metastases, further evaluation of C+A in men with mCRPC is being pursued. Clinical trial information: NCT03170960.

The NCCN Guidelines for Kidney Cancer provide multidisciplinary recommendations for the clinical management of patients with clear cell and non–clear cell renal cell carcinoma, and are intended to assist with clinical decision-making. These NCCN Guidelines Insights summarize the NCCN Kidney Cancer Panel discussions for the 2020 update to the guidelines regarding initial management and first-line systemic therapy options for patients with advanced clear cell renal cell carcinoma.

TPS4597 Background: The anti-PD-1 antibody nivo improves overall survival (OS) in metastatic RCC and is well tolerated. There is no standard adjuvant (adjuv) systemic therapy that increases OS over surgery alone for non-metastatic RCC. Priming the immune system prior to surgery with anti-PD-1 has shown an OS benefit compared to a pure adjuv approach in mouse solid tumor models. Multiple ph 2 studies in bladder, lung and breast cancers have shown remarkable pathologic responses with neoadjuvant (neoadj) PD-1 blockade. Two ongoing ph 2 studies of perioperative nivo in M0 RCC patients are showing preliminary feasibility and safety with no surgical delays (NCT02575222; NCT02595918). PROSPER RCC (NCT03055013) aims to improve clinical outcomes by priming the immune system prior to nephrectomy with neoadj nivo and continued engagement with adjuv blockade in patients with high risk RCC compared to surgery alone. Methods: This global, unblinded, phase 3 National Clinical Trials Network study is currently accruing patients with clinical stage ≥T2 or TanyN+ RCC of any histology planned for nephrectomy. Oligometastases are permitted if can be rendered NED. We amended the study to enhance accrual and patient quality of life by changing nivo dosing to 480mg q4 wks and requiring baseline tumor biopsy only in the nivo arm. The investigational arm receives 1 dose of nivo prior to surgery followed by 9 adjuv doses. The control arm undergoes standard nephrectomy followed by observation. Randomized patients are stratified by clinical T stage, node positivity, and M stage. Accrual of 805 patients provides 84.2% power to detect a 14.4% absolute benefit in recurrence-free survival (RFS) at 5 years assuming the ASSURE historical control of ~56% to 70% (HR = 0.70). The study is powered to evaluate a significant increase in OS (HR 0.67). Critical perioperative therapy considerations such as safety, feasibility, and quality of life endpoints have been integrated. PROSPER RCC embeds a wealth of translational work aimed at investigating the impact of the baseline immune milieu, the changes induced by neoadjuvant anti-PD-1 priming, and how both may predict clinical outcomes. Clinical trial information: NCT03055013.