McDermott, David F.

Background Immune checkpoint inhibitor-based combinations represent the standard of care for advanced renal cell carcinoma. The OMNIVORE trial investigated a response-adaptive strategy, including treatment discontinuation in early nivolumab responders (Arm A) and salvage ipilimumab addition in non-responders (Arm B). Here we report outcomes with extended follow-up. Methods OMNIVORE was a phase II response-adaptive trial in which patients received induction nivolumab monotherapy. Patients achieving a confirmed complete or partial response discontinued nivolumab and entered observation (Arm A), while patients with stable disease or progressive disease received two doses of ipilimumab added to ongoing nivolumab (Arm B). This analysis characterizes long-term overall survival across the full study cohort and durability of response among patients who discontinued nivolumab following an early objective response. Results Of 83 patients who initiated treatment, 12 (14%) were allocated to Arm A and 57 (69%) to Arm B, with a median follow-up among living patients of 59.4 months (range 29.1–85.4 months) in Arm A and 31.4 months (range 4.6–62.6 months) in Arm B. The 3-year overall survival rate from nivolumab initiation was 64% (95% CI 51% to 74%) in the overall cohort, 83% (95% CI 48% to 96%) in Arm A, and 63% (95% CI 47% to 76%) in Arm B. Of the 12 Arm A patients, 6 (50%) remained off nivolumab at 1 year following treatment discontinuation, of whom 5 maintained responses beyond 43 months off therapy, with all remaining alive at last known follow-up, with overall survival ranging from 48.8 to 85.4 months from nivolumab initiation. Of the six patients who resumed treatment, only one achieved a durable complete response remaining on treatment at 83.2 months from nivolumab initiation. All 57 Arm B patients discontinued treatment with a median treatment duration of 3.7 months (range 1–24.8 months) and a median progression-free survival from nivolumab plus ipilimumab initiation of 4.6 months (95% CI 2.7 to 6.5 months). Conclusions With extended follow-up, a meaningful subset of patients achieving an early objective response to nivolumab maintained prolonged treatment-free survival following a short course of treatment. Salvage ipilimumab in nivolumab non-responders demonstrated limited benefit, reinforcing that upfront concurrent dual checkpoint blockade remains the preferred approach. Trial registration number NCT03203473 .

4541 Background: PROSPER is a phase 3 National Clinical Trials Network study that accrued pts with clinical stage ≥T2 or TanyN+ RCC of any histology planned for radical/ partial nephrectomy. Pts were randomized to perioperative nivo followed by primary tumor resection and 9 cycles of nivo postoperatively or standard surgery followed by observation. To address concerns that core kidney bx might 1) not provide accurate diagnosis and 2) delay surgery due to adverse events (AEs) or scheduling, the study was amended from requiring all patients to undergo core bx prior to treatment for confirmation of RCC, to only require bx in patients randomized to the nivo arm. Herein, we report the accuracy and safety of primary tumor core bxs in predicting final histology and nuclear grade by both site and central pathology review as well as time from enrollment to surgery. We also report AEs of preoperative nivo. Methods: Concordance of both core bx and primary tumor by site and central pathology review of histology and grade (1-2 vs 3-4) are reported, along with the Cohen’s Kappa value, which measures the agreement and concordance (kappa=0 is no concordance and 1 is highest). AEs relating to core bxs and preoperative nivo, as well as time from enrollment to surgery for each arm, comparing pre- and post-amendment (dropping bx requirement in surgery alone arm) are also reported. Results: 387/404 pts in the nivo arm and 171/415 pts in the surgery alone arm had core bxs. 632 patients had both central pathology and site review available. 41 of all randomized patients (819) were considered as non-RCC and 26/41 were identified via bx. The median times from enrollment to surgery for nivo and control arms pre-amendment were 32d vs 19 d, and post-amendment were 21 d vs 14 d, respectively. The median (25th-75th percentile) number of days from last preoperative nivo to surgery was 14 d (9-20). AEs related to core bx, generally from bleeding, were reported in 13/558 (2.3%) pts. 2/13 bxs resulted in life-threatening complications. 21/353 (6%) of pts receiving nivo pre-surgery had ≥ grade 3-5 AE attributed to nivo. 181/353 (51%) pts had any grade AE attributed to nivo. Concordance between bxs and primary tumor pathologies for determining histological subtype was Kappa = 0.62. Agreement between central pathology and originating site review of primary tumor for determining nuclear grade was Kappa = 0.56, and concordance of histology was Kappa = 0.78. Conclusions: The PROSPER trial use of core bxs in advance of neoadjuvant therapy was generally safe, largely consistent with primary tumor histology and grade, and did not delay resection of the primary tumor. AEs of preoperative nivo were consistent with nivo AEs in metastatic disease. This approach is valid for future neoadjuvant trials. Clinical trial information: NCT03055013 .

Abstract Brain metastases are a challenging manifestation of renal cell carcinoma. We have a limited understanding of brain metastasis tumor and immune biology, drivers of resistance to systemic treatment, and their overall poor prognosis. Current data support a multimodal treatment strategy with radiation treatment and/or surgery. Nonetheless, the optimal approach for the management of brain metastases from renal cell carcinoma remains unclear. To improve patient care, the authors sought to standardize practical management strategies. They performed an unstructured literature review and elaborated on the current management strategies through an international group of experts from different disciplines assembled via the network of the International Kidney Cancer Coalition. Experts from different disciplines were administered a survey to answer questions related to current challenges and unmet patient needs. On the basis of the integrated approach of literature review and survey study results, the authors built algorithms for the management of single and multiple brain metastases in patients with renal cell carcinoma. The literature review, consensus statements, and algorithms presented in this report can serve as a framework guiding treatment decisions for patients. CA Cancer J Clin. 2022;72:454‐489.

TPS4596 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 February 10, 2021, 704 patients have been enrolled (N = 805). Clinical trial information: NCT03055013.

TPS5101 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 February 2020, 396 patients have been enrolled. Clinical trial information: NCT03055013 .

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]

8010 Background: In patients (pts) with metastatic melanoma (MM), tumor angiogenesis has been associated with tumor progression and survival (Ugurel et al, JCO 19:577). Microtubule and cyclooxygenase (COX)-2 inhibitors, both alone and in combination, have been shown to have inhibitory effects on endothelial cells and tumor angiogenesis both in vitro and in vivo (Merchan et al, Int J Ca 113:490. Jones et al, Nat Med 5:1418). We tested the safety and efficacy of a regimen involving low dose, continuous infusion (CIV) paclitaxel and oral celecoxib in pts with MM. Methods: Pts received paclitaxel 10mg/m2 for 96 hours weekly by CIV and Celecoxib 400 mg po/bid. Systemic tumor response was assessed at 6 wk intervals (1 cycle (C)). Pts without unacceptable toxicity or clinically significant disease progression (PD) received additional cycles. Pts exhibiting PD after C 2 relative to end of C 1 were removed from study. Pts on anticoagulants, with recent MI or untreated brain metastases were ineligible. Results: 20 pts (12 M/ 8 F), median age 55 (range 44–65), ECOG PS 0/1/2 (5/13/2), M1a/M1b/M1c: 1/1/18 (90%), and prior systemic therapy regimens 0/1/2/3+: 1/7/5/7 were enrolled in the protocol. Sites of systemic disease included: lung (13 pts), LN (14), soft tissue (13), liver (9), bone (4), brain (6), other (11). 3 pts came of study prior to treatment with rapid disease progression. Treatment related grade 3–4 toxicities included line related (LR) bacteremia (3 pts), LR DVT (3 pts), LR PE (3). There were no grade 3–4 toxicities attributed to paclitaxel or celecoxib. No pt exhibited a major tumor response; 6/20 (30%) pts had stable disease for 17, 18, 18, 18+, 30+, 60 wks. Median TTP was 6 wks (range 3- 60); median overall survival was 6 months (range 1–29). Conclusions: Low-dose, CIV paclitaxel and oral celecoxib leads to disease stabilization in a significant portion of previously treated pts with MM. This suggests a role for combination anti-angiogenic therapy in MM. The incidence of LR toxicities indicates that alternative microtubule inhibitors, such as oral taxanes, should be considered in combination with COX-2 inhibitors for future studies. Results of biomarker studies will be presented at the meeting. Supported by Pfizer Inc. and NIH R21 CA097730. [Table: see text]

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).

4521 Background: Expression of PDL1 by RCC has been associated with aggressive histology and poor survival. Tissue obtained from the patients enrolled in the IL-2 Select Trial, a prospective, single arm, multicenter CWG study, was analyzed by IHC to determine if PDL1or PDL3 expression predicted for response to initial or subsequent therapy. Methods: Paraffin embedded tumor tissue was stained for PDL1 and PDL3 expression, and results were correlated with RECIST defined response to IL2 treatment. Tumor tissue was considered positive for PDL1 if >5% of the tumor membranes stained for the marker. A cutoff of 10% was used for PDL3. Duration of subsequent VEGFR/mTOR inhibitor therapy was also correlated with tissue PDL1/3 expression. Results: 120 eligible pts were enrolled; 115 had clear cell histology. The overall response rate (ORR) to IL2 was 25% (30/120) with a median OS of 40.6 months. 113 tumors were stained. 18 (16%) were PDL1+. ORR was 19% and 50% in the patients PDL1- and PDL1+ tumors, respectively (p=0.012). 85 (75%) tumors were PDL3+. ORR was 10.7% and 29.4% in the PDL3- and PDL3+ tumors, respectively (p=0.075). In the 17 patients who were positive for both PDL1 and PDL3, ORR was 52.9%. In the 27 pts who were negative for both PDL1 and PDL3, ORR was 11.1%. 69 patients received at least 1 dose of a VEGFR TKI as next therapy following IL2 treatment. 66 tumors were stained. Pts who were PDL1+/PDL3+ had a shorter duration on VEGFR TKI therapy compared to pts who were PDL1-/PDL3- (see Table). Conclusions: This small, retrospective analysis suggests that PDL1 and PDL3 tissue expression may predict for better response to IL2. PDL1 expression has been suggested as a possible predictor of response to anti-PD1 therapy. The current data suggests that its expression may predict for benefit to other immune therapies. PDL3 (+/- PDL1) expression appears to correlate to less benefit from subsequent VEGFR TKI therapy. Funded by NCI SPORE Grant # 5 P50 CA101942-08. [Table: see text]