The impact of antibiotic (Ab) exposure on clinical outcomes in patients with metastatic renal cell carcinoma (mRCC) treated with immune checkpoint inhibitors (ICI) or VEGF targeted therapy (VEGF-TT)

4552

Background: Retrospective studies have shown an association between Ab exposure and inferior clinical outcomes in patients receiving ICI across various tumor types, including mRCC. However, it is unclear whether Ab exposure has a unique interaction with ICI or is an independent prognostic marker, regardless of treatment. We sought to examine Ab exposure and its association with clinical outcomes in patients with mRCC treated with ICI compared to VEGF-TT. Methods: We identified patients treated with ICI (anti-PD-L1 alone or in combination with VEGF or CTLA4 inhibitor) or VEGF-TT alone in first to fourth line settings from 2009-2020 across 3 academic centers in North America. Ab exposure was defined as administration of Ab within 60 days prior to initiation of systemic therapy. Outcomes of interest were response rate (RR), time to treatment failure (TTF) and overall survival (OS). Multivariable Cox regression was performed to control for imbalances in International mRCC Database Consortium (IMDC) risk factors, histology, and treatment line. Results: We identified 748 patients. Among the ICI (n=427) and VEGF-TT (n=321) cohorts, 13% vs 15% (p=0.47) had Ab exposure and 57% vs 48% (p=0.046) were treated in the first line setting. The proportion of favorable, intermediate, and poor risk disease by IMDC criteria differed between Ab exposed and unexposed patients in the ICI (14% vs 18%, 47% vs 62%, 39% vs 21% p=0.03) and VEGF-TT (7% vs 13%, 43% vs 60%, 50% vs 27%, p=0.01) cohorts. RR, TTF and OS results are displayed in Table 1. Multivariable analysis did not show a significant independent association between Ab exposure and OS in both the ICI (HR 1.13, p=0.62) and VEGF-TT (HR 1.32, p=0.16) cohorts. Treatment modality (ICI vs VEGF-TT) did not modify the effect of Ab exposure on OS (p=0.84). Conclusions: Ab exposure was associated with higher IMDC risk scores in both the ICI and VEGF-TT cohorts as well as inferior OS on univariable analysis. After adjusting for IMDC risk factors, histology and treatment line, we were unable to find an independent association between Ab exposure and OS in multivariable analysis for either cohort.[Table: see text]

Outcomes of first-line (1L) ipilimumab and nivolumab (IPI-NIVO) and subsequent therapy in metastatic renal cell carcinoma (mRCC): Results from the International mRCC Database Consortium (IMDC)

4554

Background: IPI NIVO is approved for 1L treatment of IMDC intermediate/poor risk mRCC based on the CHECKMATE 214 trial. Herein, we report the clinical effectiveness of 1L IPI NIVO and second line (2L) therapy in the real-world setting. Methods: Using the IMDC dataset, patients (pts) treated with 1L IPI NIVO were identified. The outcomes of interest were 1L and 2L overall response rate (ORR), treatment duration (TD), time to next treatment (TTNT), and overall survival (OS). Results: 706 pts were included: 9% (57/614), 58% (354/614), and 33% (203/614) were IMDC favorable (fav), intermediate (int), and poor risk, respectively. Median age was 61 years. The majority of pts were males (71%), had clear cell histology (85%), and underwent nephrectomy (61%). 36%, 19%, and 8% of patients had bone, liver, and brain metastases, respectively. The 12-month OS for pts with IMDC fav, int, and poor risk disease was 92%, 79%, and 56%, respectively (p<0.01). The corresponding estimates for 24 months were 80%, 69%, and 38% (p<0.01). Pts who responded (39%) were more likely to have better IMDC risk category (p=0.02), received nephrectomy (p=0.04), normal neutrophil count (p<0.01), and clear cell histology (p=0.01). Pts with progressive disease as best response (27%) were more likely to have not received nephrectomy (p<0.01), worse IMDC risk category (p=0.02), bone metastases (p=0.01), liver metastases (p=0.04), and non-clear cell histology (p=0.01). Of the 66% (466/706) of pts who discontinued 1L IPI NIVO, 51% (236/466) received 2L therapy: sunitinib (40%), cabozantinib (25%), pazopanib (18%), axitinib (8%), and others (9%). The ORR, median TD, and median OS for those who received either sunitinib, cabozantinib, pazopanib or axitinib was 16%, 4.5 months (mo) (95% CI 3.7-5.6), and 14.5 mo (95% CI 10.9-25.9), respectively. 33% (129/386) of pts discontinued IPI NIVO due to irAEs. Conclusions: Our study benchmarks the real-world experience of 1L IPI NIVO in mRCC. IMDC criteria is prognostic for clinical outcome. Tyrosine kinase inhibitors have clinical activity post IPI NIVO.[Table: see text]

PROSPER: Phase III RandOmized Study Comparing PERioperative nivolumab versus observation in patients with renal cell carcinoma (RCC) undergoing nephrectomy (ECOG-ACRIN EA8143)

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.

Assessment of the alignment between research funding allocation and consensus research priority areas in kidney cancer

e16538

Background: Finite resources are available to fund research, and it is important to ensure stakeholder input is identified and prioritized. In this light, the KCRNC and CIHR sponsored a consensus-based priority-setting partnership that brought together a group of patients, caregivers, and clinicians to identify the top 10 research priorities in kidney cancer (Table), with a consensus document published in 2017. The final step of the prioritization process was to determine how research funding allocation has aligned with these previously identified priority areas. We report the results of this assessment. Methods: We queried publicly available Canadian and American research databases to identify all research funds allocated to kidney cancer from 2018-2020. Each funded project was assessed to determine which priority areas were addressed. We evaluated the percent of projects and percent of funding dollars (converted to USD) allocated to priority areas. Projects were stratified by country, type of research (basic science/translational or clinical), and cancer stage of focus (localized and/or metastatic). Results: A total of 121 kidney cancer research projects were funded between 2018-2020, with 15 Canadian projects (total $ = 1,906,398 USD) and 106 American projects (total $ = 56,317,386 USD). Most projects were basic science or translational (88%). Half (50%) of the projects focused on localized cancer while 26% of projects focused on metastatic kidney cancer. Overall, 49% of projects aligned to one priority area, 47% of projects aligned to multiple priority areas, and 4% of projects were not aligned to priority areas. The priority areas which received the most funding were causes of kidney cancer (priority #10, 64% of funds), biomarkers (priorities #1b+1c+5, 59%), and immunotherapies (priority #4, 41%)(Table). Unfunded priority areas were supportive care (priority #6) and the role of biopsy in kidney cancer management (priority #8). Conclusions: Nearly all kidney cancer projects funded since 2018 were aligned with one or multiple stakeholder-identified research priority areas, although some priority areas remain underfunded. Mechanisms to improve distribution of funding to all priority areas may be warranted.[Table: see text]

Patient-reported experience of diagnosis, management, and burden of renal cell carcinomas: Results from the 2020 Global Patient Survey from 41 countries

4579

Background: The sustained increased global prevalence of kidney cancer (renal cell carcinoma, RCC) has increased the burden to health systems, and most of all, to individual patients and their families. Although individual national surveys have been held, no conclusions could be drawn about country-level variation in patient experience or best practice. Here, we report on the second biennial Global Patient Survey on the diagnosis, management, and burden of RCC. Conducted by the International Kidney Cancer Coalition (IKCC) and involving its Affiliate Organizations worldwide, the survey aims to improve collective understanding and to contribute toward the reduction of the burden of kidney cancer around the world. Methods: A 35-question survey on the diagnosis, management, and burden of RCC was designed by a multi-country steering committee of patient leaders to identify geographic variations in 6 key dimensions: patient education, experience and awareness, access to care and clinical trials, best practices, quality of life, and unmet psychosocial needs. The survey was distributed in 13 languages to patients with kidney cancer and their caregivers, through IKCC’s 46 Affiliate Organisations and social media. It was completed online or in paper form between 29 Oct 2020 and 5 Jan 2021. Results: 2,012 (1,586 patients, 417 carers, 9 undisclosed) responses were recorded from 41 countries in 13 languages. Survey results were analyzed using cross-tabulations by an independent third-party organization. The full global report will be publicly available, as well as 7 individual country reports where at least 100 responses were received. 52% lacked understanding of subtype at diagnosis. 42% reported that the likelihood of surviving their cancer beyond 5 years was not explained. 51% reported that they were involved as much as they wanted to be in developing their treatment plan. 41% indicated that “No one” discussed cancer clinical trials with them. 31% were invited to take part in a clinical trial. 56% experienced barriers to their treatment. 45% self-reported that they were insufficiently physically active; 15% were completely sedentary. 50% indicated that they ‘very often’ or ‘always’ experienced disease-related anxiety. 55% indicated that they ‘very often’ or ‘always’ experienced a fear of recurrence. 52% reported having talked to their doctor/healthcare professional about their concerns. Conclusions: The IKCC and its global affiliates will use these results to ensure that patient and caregiver voices are heard and acted upon, with ultimate incorporation of these findings by much broader communities into care pathways, clinical practice, or health technology assessments. Furthermore, individual countries can use their reports to advance understanding of patient experiences and to drive improvements in providing care locally.

Evaluation of cabozantinib (cabo) in combination with direct oral anticoagulants (DOAC) or low molecular weight heparin (LMWH) in renal cell carcinoma (RCC)

291

Background: Venous thromboembolism (VTE) is the second leading cause of death in patients with cancer. Despite cabo improving RCC outcomes, VTE management in these patients remains a challenge, partly due to poor understanding of cabo safety profile and drug interactions with anticoagulants. Recent anti-Xa DOAC studies demonstrated comparable efficacy and safety with LMWH for VTE treatment in patients with cancer. Thus far, cabo clinical trials have largely allowed concurrent LMWH use but not DOACs. Herein, we investigated the hemostasis safety profile of cabo with different anticoagulants in patients with RCC. Methods: We performed a retrospective multicenter study (7 sites) of patients with advanced RCC receiving treatment with cabo. Patients were allocated into three groups: cabo with concomitant use (at least 1 week) of 1) DOACs (anti-Xa inhibitors), 2) LMWH, or 3) no anticoagulant. Primary endpoint was to evaluate the rate of major bleeding events (defined per the International Society of Hemostasis and Thrombosis criteria) in the above groups. Secondary endpoint was rate of new/recurrent VTE while on anticoagulation. Overall comparison between groups was analyzed by Fisher exact test. If a difference was found, then pairwise comparison was done. Results: Between 2016-2020, 172 patients with RCC received cabo (DOAC 50, LMWH 18, and no anticoagulant 104). At initiation, cabo median dose was 60 mg but 45% had dose reduction. Median age was 63 [IQR 57-69]. Most were males (77%), had clear cell histology (81.5%), underwent nephrectomy (76.7%), and had intermediate IMDC risk disease (59%). Cabo was first, second, and subsequent line of therapy in 19.8%, 34.9%, and 45.3% of patients, respectively. The table below shows major bleeding and VTE events between groups. An overall difference of major bleeding was found between the three groups comparison ( p=0.009). There was no difference in major bleeding events between patients who received DOAC vs LMWH ( p=0.28) and DOAC vs no anticoagulant ( p=0.1) but there was a difference between LMWH vs no anticoagulant ( p=0.02). Two patients died from bleeding (one in LMWH and one in DOAC group). Conclusions: This study highlights the first reported real world experience of cabo with different anticoagulants in patients with advanced RCC. Cabo use with a DOAC had a similar bleeding risk in comparison to patients not receiving any anticoagulation. In carefully selected patients, DOACs can be considered as concurrent medications in those receiving cabo. Given the low number of patients receiving LMWH, it is difficult to draw conclusions from this group. Data are currently being updated to expand subjects receiving DOAC and LMWH in our cohort. [Table: see text]

Phase III study evaluating efficacy and safety of MK-6482 + lenvatinib versus cabozantinib for second- or third-line therapy in patients with advanced renal cell carcinoma (RCC) who progressed after prior anti-PD-1/L1 therapy

TPS372

Background: There is an unmet need for treatment options in the second-line or later setting following anti–PD-1/L1 or VEGF tyrosine kinase inhibitor (TKI) therapy in patients with advanced RCC. Hypoxia-inducible factor (HIF)-2α is a transcription factor that has been established as an oncogenic driver in clear cell RCC (ccRCC). Promising antitumor activity has been reported for the first-in-class small molecular HIF-2α inhibitor, MK-6482, in heavily pretreated patients with ccRCC and patients with VHL disease–associated RCC. HIF-2α also regulates VEGF gene expression and plays a role in resistance to anti-VEGF therapy. Therefore, combining MK-6842 with a VEGF receptor TKI, such as lenvatinib, is an attractive treatment option in the advanced RCC setting. Methods: This is a randomized, open-label, active-controlled, multicenter phase III trial evaluating the efficacy and safety of MK-6482 + lenvatinib compared with cabozantinib in patients with advanced ccRCC who have progressed on prior anti–PD-1/L1 therapy (NCT04586231). Eligibility criteria include age ≥18 years; histologically confirmed, unresectable, locally advanced or metastatic ccRCC; disease progression on or after first- or second-line systemic treatment with an anti–PD-1/L1 therapy (monotherapy or in combination with other agent[s]) for locally advanced or metastatic disease, the immediately preceding line of treatment must be an anti–PD-1/L1 therapy; no more than 2 prior systemic regimens, with only 1 prior anti–PD-1/L1 therapy; measurable disease per RECIST v1.1; and Karnofsky performance status ≥70%. Patients must provide tissue for biomarker analysis. Approximately 708 patients will be randomly assigned in a 1:1 ratio to receive MK-6482 120 mg orally once daily (QD) + lenvatinib 20 mg orally QD or cabozantinib 60 mg orally QD. Treatment will continue until disease progression, unacceptable toxicity, or withdrawal of consent. The stratification factors are International mRCC Database Consortium prognostic scores (0, 1-2, or 3-6), number of prior lines of therapy (1 or 2), and geographic region (North America, Western Europe, or rest of the world). Imaging will be assessed by CT or MRI every 8 weeks through week 80, then every 12 weeks thereafter. The dual primary end points are progression-free survival per RECIST v1.1 as assessed by blinded independent central review (BICR) and overall survival. Secondary end points are objective response rate and duration of response per RECIST v1.1 as assessed by BICR, and safety. Safety and tolerability will be evaluated using a tiered approach. Clinical trial information: NCT04586231 .

Outcomes of first-line (1L) immuno-oncology (IO) combination therapies in metastatic renal cell carcinoma (mRCC): Results from the International mRCC Database Consortium (IMDC)

276

Background: Ipilimumab and nivolumab (IPI-NIVO) and IO/vascular endothelial growth factor (VEGF) inhibitor combinations (IOVE) are now standard of care 1L treatment options for mRCC. However, there is limited head-to-head comparative evidence between these strategies. Methods: Using the IMDC dataset, patients treated with a 1L IOVE combination (pembrolizumab axitinib, avelumab axitinib and nivolumab cabozantinib) were compared with those treated with IPI-NIVO. The outcomes of interest were overall response rate (ORR), treatment duration (TD), time to next treatment (TTNT), and overall survival (OS). A preplanned subgroup analysis of the IMDC intermediate/poor risk population was conducted. Hazard ratios were adjusted for IMDC risk factors. Results: 723 patients were included for analysis (N=571 for IPI-NIVO and N=152 for IOVE). The median age was 60 in both groups. The proportion of patients with IMDC favorable, intermediate and poor risk disease in IPI-NIVO vs. IOVE groups were 9% vs. 33%, 58% vs. 53%, 33% vs. 14%, respectively. In the intermediate/poor risk groups (Table), ORR and median TD were lower and shorter in IPI-NIVO vs IOVE while no difference in median TTNT and OS was detected. The HR for death adjusting for IMDC criteria for IPI-NIVO vs. IOVE was 0.92 (95% CI 0.61-1.40, p=0.71). IMDC risk groups and the presence or absence of sarcomatoid histology, brain, liver or bone metastases were not associated with differences in OS between these treatments (all p>0.2). Patients that had dose delays or steroid use (defined as >40mg of prednisone equivalent/day) for immune related adverse events (irAEs) were associated with longer median TTNT (21.6 vs. 9.5 mons, p=0.02) and OS (NR vs. 44.4 mons, p=0.01) despite similar treatment durations (7.6 vs. 8.9 mons, p=0.77) compared to those without dose delays or steroid use. Conclusions: We were unable to detect any differences in OS between IPI-NIVO and IOVE regimens in the IMDC intermediate/poor risk groups and amongst various subgroups. Patients who experienced irAEs requiring dose delay or steroids had longer overall survival. [Table: see text]

The very favorable metastatic renal cell carcinoma (mRCC) risk group: Data from the International Metastatic RCC Database Consortium (IMDC)

339

Background: The IMDC criteria have been used as a prognostic tool for patients with mRCC receiving single agent VEGF-targeted drugs, and more recently combination immuno-oncology (IO) +/- VEGF-targeted agents, which improve outcomes over VEGF TKI monotherapy. We sought to identify a subset of patients with very favorable outcomes, for which less intensive therapy might be considered. Methods: Utilizing the IMDC dataset, 1638 patients with IMDC favorable risk disease received first-line systemic therapy. Patients were randomly selected in a 2:1 ratio to the training and testing sets, stratified by year of systemic therapy initiation. Multivariable Cox regression estimated prognostic factors for overall survival (OS). Results: Median age was 63 (range 21-95) years and 98% had received prior nephrectomy. First-line systemic therapy consisted of targeted therapy (91%), IO-combination regimens (8%), or other (1%). From the training data, three variables (primary diagnosis to systemic therapy <3 vs ≥3yr; Karnofsky Performance Status 80 vs >80; presence of brain, liver, or bone metastasis) significantly predicted for OS in the multivariable model (hazard ratio 1.4~1.5, p-values<0.05). The model had similar performance in the test dataset (C-index=0.64). Using the 3 included risk factors, patients were classified to very favorable risk (0 risk factors, 29% of patients) or favorable risk disease (≥1 risk factors, 71% of patients). Clinical outcomes for the two risk groups are presented in the table below. Conclusions: We identified a very favorable risk group in the IMDC criteria in RCC patients treated with first-line therapy. External validation including populations receiving IO containing therapies is ongoing. [Table: see text]

Effectiveness of first-line immune checkpoint inhibitors (ICI) in advanced non-clear cell renal cell carcinoma (ccRCC)

316

Background: Immune checkpoint inhibitors (ICI) have demonstrated impressive activity in metastatic clear-cell renal cell carcinoma (ccRCC) and have become standard treatment options in this setting. Data supporting the effectiveness of ICI based therapy in non-clear cell RCC (nccRCC) is more limited. Methods: We performed a retrospective analysis using the International Metastatic RCC Database Consortium (IMDC). Patients with nccRCC were classified into 3 groups based on first-line therapy: ICI based therapy (in monotherapy or in combination), vascular endothelial growth factor targeted therapy (VEGF-TT) monotherapy, or mammalian target of rapamycin (mTOR) inhibitor monotherapy. Primary outcome was overall survival (OS). Secondary outcomes were time to treatment failure (TTF) and objective response rate (ORR). We used Kaplan-Meier method to compare OS and TTF between treatment groups and Cox proportional hazards models to adjust for prognostic covariates. Results: We identified 1181 patients with nccRCC. In first-line, 78.2% received VEGF-TT, 15.8% mTOR inhibitors, and 5.5% ICI based therapy, of which 41.5% in monotherapy, 30.8% doublet-ICIs and 27.7% an ICI combined with VEGF-TT. Median OS in the ICI group was 28.6 months, compared to 19.2 and 12.6 in the VEGF-TT and mTOR groups, respectively. Median TTF was 6.9 months vs. 5.1 and 3.9 and ORR was 25% vs. 17.8% and 5.8% in the ICI, VEGF-TT and mTOR groups, respectively. After adjusting for IMDC risk group, histological subtype, and age, the hazard ratio (HR) for OS was 0.58 (95% CI 0.35-0.94, p=0.03) for ICI vs. VEGF-TT and 0.48 (95% CI 0.29-0.80, p=0.005) for ICI vs. mTOR. Conclusions: In advanced nccRCC, first-line ICI based treatment appears to be associated with improved OS compared to VEGF and mTOR targeted therapy. These results need to be confirmed in prospective randomized trials. [Table: see text]

Phase II trial of lenvatinib (LEN) at two starting doses + everolimus (EVE) in patients (pts) with renal cell carcinoma (RCC): Results by independent imaging review (IIR) and prior immune checkpoint inhibition (ICI)

307

Background: LEN 18 mg + EVE 5 mg is approved for advanced RCC following anti-angiogenic therapy. Study 218 was a phase II study evaluating LEN 14 mg vs LEN 18 mg, both in combination with EVE 5 mg, for the treatment of clear cell RCC following treatment with a VEGF-targeted therapy. We have previously reported that the LEN 14 mg arm did not demonstrate noninferiority vs the LEN 18 mg arm for objective response rate (ORR) as of wk 24 by investigator assessment, the primary endpoint of the study. In this exploratory analysis of Study 218 data, we evaluated the efficacy of LEN 14 mg vs LEN 18 mg, both in combination with EVE 5 mg, per IIR assessment and by prior ICI status per investigator assessment. Methods: Pts with measurable clear cell RCC (1 prior VEGF-targeted therapy; prior PD-1/PD-L1 therapy permitted) were randomly assigned 1:1 to LEN 14 mg or 18 mg (starting dose) + EVE 5 mg daily. 115 pts in the LEN 14 mg arm were titrated to LEN 18 mg at cycle 2 as they did not experience intolerable grade 2 or any grade ≥3 TEAEs requiring dose reduction within cycle 1. We analyzed ORR and PFS by IIR per RECIST v1.1; additionally, efficacy endpoints (ORR, PFS, and OS) were analyzed by investigator assessment per RECIST v1.1 by prior ICI status. Results: 311 pts (LEN 14 mg arm, n=156; LEN 18 mg arm, n=155) were included in the efficacy analysis and 341 pts (LEN 14 mg arm, n=173; LEN 18 mg arm, n=168) were included in the summary safety analysis. ORR by IIR (LEN 14 mg arm: 39.7%, 95% CI 32.1–47.4; LEN 18 mg arm: 38.7%, 95% CI 31.0–46.4) was similar between treatment arms. PFS by IIR was numerically longer in the LEN 18 mg arm (median 12.9 mos, 95% CI 9.2–17.1) vs the LEN 14 mg arm (median 11.0 mos, 95% CI 9.3–12.9). OS was numerically longer in the LEN 18 mg arm (median not evaluable [NE], 95% CI 23.8–NE) vs the LEN 14 mg arm (median 27.0 mos, 95% CI 18.3-NE) (previously reported). In 82 pts with prior ICI, for the LEN 14 mg (n=43) vs 18 mg (n=39) arms (95% CI): ORR was 30.2% (17.2–46.1) vs 51.3% (34.8–67.6) by investigator assessment, respectively; median PFS was 12.0 mos (8.9–16.7) vs 12.9 mos (8.4–NE) by investigator assessment, respectively; and median OS was 17.1 mos (10.6–NE) vs 18.0 mos (13.1–NE), respectively. Endpoints were generally numerically improved in the LEN 18 mg arm in pts without prior ICI (data will be presented). As previously reported, the safety profile was similar in both treatment arms: 71.7% of pts in the LEN 14 mg arm and 76.8% of pts in the LEN 18 mg arm had grade 3/4 TEAEs. Conclusions: ORR was similar between treatment arms and PFS was numerically longer in the LEN 18 mg arm per IIR. Efficacy outcomes were generally numerically improved for the LEN 18 mg arm compared with the LEN 14 mg arm, regardless of prior ICI. As previously reported, safety was similar in both treatment arms. These results further support starting pts with RCC at the higher 18 mg dose of LEN + EVE 5 mg. Clinical trial information: NCT03173560 .

Sunitinib versus cabozantinib, crizotinib or savolitinib in metastatic papillary renal cell carcinoma (pRCC): Results from the randomized phase II SWOG 1500 study

270

Background: MET signaling is a key molecular driver in pRCC. Given that there is no optimal therapy for metastatic pRCC, we sought to compare an existing standard (sunitinib) to putative MET kinase inhibitors. Methods: Eligible patients had pathologically verified pRCC, Zubrod performance status 0-1, and measurable metastatic disease. Patients may have received up to 1 prior systemic therapy excluding VEGF-directed agents. Patients were randomized 1:1:1:1 to receive either sunitinib 50 mg po qd (4 wks on/2 wks off), cabozantinib 60 mg po qd, crizotinib 250 mg po bid, or savolitinib 600 mg po qd. Patients were stratified by prior therapy and pRCC subtype (I vs II vs not otherwise specified [NOS]) based on local review. The primary objective was to compare progression-free survival (PFS) for each experimental arm versus sunitinib. With 41 eligible patients per arm, we estimated 85% power to detect a 75% improvement in median PFS with a 1-sided alpha of 0.10 using intent-to-treat analysis. A pre-planned futility analysis was performed after 50% of PFS events occurred. Secondary endpoints included toxicity, response rate, and overall survival. Results: Between 4/2016 and 12/2019, 152 patients were enrolled; 5 were ineligible. Median age was 66 (range:29-89) and 76% were male; 92% had no prior therapy. By local pathologic review, 18%, 54% and 28% of patients were characterized as having type I, type II and NOS histology, respectively. In contrast, the frequency of type I, type II, and NOS by central review was 30%, 45% and 25%, respectively. Accrual to the savolitinib and crizotinib arms was halted early for futility (PFS hazard ratio > 1.0 for both); accrual continued to completion in the sunitinib and cabozantinib arms. Median PFS was significantly higher with cabozantinib relative to sunitinib (Table). Grade 3 or 4 adverse events occurred in 69%, 72%, 37% and 39% of patients receiving sunitinib, cabozantinib, crizotinib and savolitinib, respectively; one grade 5 adverse event was seen with cabozantinib. Overall survival and response data will be presented. Conclusions: In this multi-arm randomized trial, only cabozantinib resulted in a statistically significant and clinically meaningful prolongation of PFS in pRCC patients compared to sunitinib. These data support cabozantinib as a reference standard for eligible patients with metastatic pRCC. Clinical trial information: NCT02761057 . [Table: see text]

Health-related quality-of-life outcomes from a phase II open-label trial of two different starting doses of lenvatinib in combination with everolimus for treatment of renal cell carcinoma following one prior VEGF-targeted treatment

314

Background: Renal cell carcinoma (RCC) is the most common type of kidney cancer, constituting 80% to 85% of primary renal neoplasms. Preserving health-related quality of life (HRQOL) is an important goal during RCC treatment, but HRQOL analyses in prospective clinical trials in RCC are limited. We report changes in HRQOL, a secondary endpoint of this phase II trial. Methods: HRQOL data were collected during a multicenter, randomized, open-label phase II study comparing the safety and efficacy of two different starting doses of lenvatinib (18 mg vs. 14 mg daily [QD]) in combination with everolimus (5 mg QD), following one prior vascular endothelial growth factor–targeted treatment (NCT03173560). HRQOL was measured using three different instruments, including the FKSI-DRS, EORTC QLQ-C30, and EQ-5D-3L. Change from baseline HRQOL was assessed using linear mixed-effects models. Deterioration events for time to deterioration (TTD) analyses were defined using established thresholds for minimally important differences in the change from baseline for each scale (i.e., 10 points for EORTC, 3 points for FKSI-DRS, 0.08 points for EQ-5D index, and 10 points for EQ-VAS). The distribution of TTD and median TTD for each treatment arm were estimated using the Kaplan-Meier method. Results: Baseline characteristics, including baseline scores of the 343 participants randomly assigned to 14 mg QD lenvatinib (n = 172) and 18 mg QD lenvatinib (n = 171), were well balanced. The average scores for the 18 mg QD group were generally higher, with lower symptom severity than the 14 mg QD group. The least squares mean estimates for change from baseline were favorable for the 18 mg QD group over the 14 mg QD group for the FKSI-DRS and most EORTC QLQ-C30 scales; however, the differences between treatments did not exceed the minimally important difference for clinical significance. Both study arms showed an increase diarrhea severity. Median TTD was longer among participants in the 18 mg QD group than those in the 14 mg QD group for most scales. Conclusions: In most scales, participants who received an 18 mg QD lenvatinib starting dose had better HRQOL and longer time to deterioration than those who received a 14 mg QD starting dose. These findings suggest that the approved treatment regimen of an 18 mg starting dose of lenvatinib in combination with everolimus remains favorable for RCC treatment, following one prior vascular endothelial growth factor–targeted treatment. Clinical trial information: NCT03173560 .

A phase II multicenter study of stereotactic radiotherapy (SRT) for oligoprogression in metastatic renal cell cancer (mRCC) patients receiving tyrosine kinase inhibitor (TKI) therapy

5065

Background: SRT is increasingly considered to delay the need to change systemic therapy in metastatic cancer patients who develop oligoprogression. This prospective phase II study evaluated the use of SRT in the setting of mRCC patients who developed oligoprogression while on 1st or 2nd line TKI therapy. Methods: IMDC favourable or intermediate risk mRCC patients (pts) who had previous stability or response on ≥ 3 months of TKI therapy were eligible if they developed radiographic progression of ≤ 5 metastases. The oligoprogressive tumours were treated with SRT while other metastases which were stable or responding to TKI therapy were left alone. TKI therapy was temporarily stopped during SRT, and the same TKI drug then resumed. Endpoints included local control of the irradiated lesions, progression free survival (PFS), overall survival (OS), and cumulative incidence of changing systemic therapy after study entry. Results: 37 pts (median age 63, IMDC favourable 12, intermediate 25) with 57 oligoprogressive tumours were enrolled. 35 pts were on sunitinib and 2 on pazopanib. Median duration of TKI therapy prior to study entry was 18.6 months. 4 pts had IL-2 therapy prior to a 2nd line TKI. 21 pts had a solitary oligoprogressive tumour, while 17 pts had 2-3 oligoprogressive tumours treated with SRT. Median biological effective dose (BED10) was 72 Gy, corresponding to an SRT dose of 40 Gy in 5 fractions. Irradiated tumour sites were the following: 21 lung/pleural, 15 bone, 7 lymph node, 4 adrenal, 4 liver, 3 brain, 2 spleen, and 1 pancreas. At a median followup of 11.6 (1.8-53.5) months the median PFS from study entry was 9.6 months (95%CI 7.4-20.5) with the vast majority of progression occurring outside of the irradiated areas. The 2-year local control of the irradiated tumours was 96%. The 2-year OS from study entry was 77%. The cumulative incidence of changing systemic therapy was 47% at 1 year and 75% at 2 years, with a median time to a change in systemic therapy of 12.6 months. There were no grade 3-5 SRT related toxicities. Conclusions: To our knowledge, this is the first prospective evaluation of the use of SRT for oligoprogressive metastatic cancer. Local control of irradiated oligoprogressive mRCC tumours was high. After delivering SRT, mRCC patients did not need a change in their systemic therapy for a median of 1 year, effectively increasing the PFS of their TKI therapy. This novel approach should be studied in patients with oligoprogression on immunotherapy. Clinical trial information: NCT02019576 .

Characterizing sites of metastatic involvement in metastatic clear-cell, papillary, and chromophobe renal cell carcinoma

5071

Background: There exists considerable biological and clinical variability between histologic variants of metastatic renal-cell carcinoma (mRCC). Data reporting on sites of metastatic involvement in less common histologies of mRCC are sparse. We sought to characterize the frequency of metastatic site involvement across the three most common histologies of mRCC: clear-cell (ccRCC), papillary (pRCC), and chromophobe (chrRCC). Methods: Using the International mRCC Database Consortium (IMDC) database, patients with mRCC starting systemic therapy between 2002-2019 were identified and sites of metastases at the time of systemic therapy initiation were documented. Patients with multiple sites of metastatic involvement were included in analyses of all groups to which they had metastases. The primary outcomes were prevalence of metastatic site involvement and overall survival (OS). Patients with mixed histology were excluded. Results: 10,105 patients were eligible for analysis. Median age at diagnosis was 60, 72% were male and 79% underwent nephrectomy. 92%, 7% and 2% of patients had ccRCC, pRCC, and chrRCC, respectively. Frequency of metastatic site involvement across the histologic subtypes is shown in Table. Lung, adrenal, brain and pancreatic metastases were more frequent in ccRCC, lymph node involvement was most frequent in pRCC, and liver metastases were most frequent in chrRCC. Median OS for ccRCC varied by site of metastatic involvement, ranging between 16 months (brain/pleura) and 50 months (pancreas). OS by site of metastatic involvement was compared between histologies for the four most common sites of metastases (lung, lymph nodes, bone, liver). As compared to patients with ccRCC, patients with pRCC had lower OS regardless of site of metastasis (p < 0.05). Power was limited and thus differences in OS between ccRCC and chrRCC were not detectable. Conclusions: Sites of metastatic involvement differ based on histology in mRCC. These data highlight the clinical and biologic variability between histologic subtypes of mRCC and constitute the largest cohorts of patients with metastatic pRCC and chrRCC to report on sites of metastases. Sites of Metastatic Involvement by Histology. [Table: see text]

Application of IMDC criteria across first-line (1L) and second-line (2L) therapies in metastatic renal-cell carcinoma (mRCC): New and updated benchmarks of clinical outcomes

5063

Background: In patients with mRCC, the International mRCC Database Consortium (IMDC) criteria have been validated as a prognostic tool in patients treated with targeted therapy in the 1-4L settings and with 2L Nivolumab (Nivo). However, it is unknown whether the IMDC criteria can be used to risk stratify in recently approved 1L IO combination therapies, including Ipilimumab + Nivolumab (IOIO) and Axitinib + Pembrolizumab/Avelumab (IOVE). We sought to assess the ability of the IMDC criteria to risk stratify with the use of novel 1L IO combinations and provide updated benchmarks for older 1L and 2L treatments. Methods: Patients with mRCC starting systemic therapy between 2010-2019 were identified through the IMDC. IMDC risk score was calculated at the time of starting the line of therapy of interest. The primary endpoint was overall survival (OS) from time of initiating the treatment of interest. Results: From a total of 6596 unique patients, 5043 treated in the 1L setting and 2498 treated in the 2L setting were included in the analysis. Across the entire cohort, median age was 61, 73% were male, 16% had sarcomatoid features, 79% underwent nephrectomy and 88% had clear-cell histology. IMDC risk groups for 1L and 2L treatment were 17%, 57%, 27% and 10%, 60%, 30% for favourable-, intermediate- and poor-risk disease, respectively. IMDC criteria appropriately risk stratified into 3 prognostic groups in 1L IOIO and 1L IOVE combinations, in addition to older treatments: 1L VEGF TT, 2L VEGF TT, 2L Nivo and 2L Everolimus. Results are displayed in Table. Due to the novelty of 1L IO combinations, median follow up time was shorter and thus landmark OS values are presented. Conclusions: IMDC criteria may be used to risk stratify in recently approved 1L IO combination therapies in addition to older 1L and 2L treatments. These data provide contemporary benchmarks for OS that may be used for patient counseling and trial design. [Table: see text]

SAVOIR: A phase III study of savolitinib versus sunitinib in pts with MET-driven papillary renal cell carcinoma (PRCC)

5002

Background: PRCC is the most common type of non-clear cell RCC, accounting for 10–15% of renal malignancies. As a subset of PRCC cases are MET-driven, MET inhibition may be an appropriate targeted treatment approach. In a single-arm Phase II study, savolitinib (AZD6094, HMPL‐504, volitinib), a highly selective MET-tyrosine kinase inhibitor, demonstrated antitumor activity in pts with MET-driven PRCC (Choueiri et al. JCO 2017). The Phase III SAVOIR study (NCT03091192) further assessed savolitinib vs standard of care sunitinib in pts with MET-driven PRCC. Methods: In this open-label (sponsor blinded), randomized study, pts with centrally confirmed MET-driven ( MET and/or HGF amplification, chromosome 7 gain and/or MET kinase domain mutations), metastatic PRCC were randomized to savolitinib 600 mg once daily (QD), or sunitinib 50 mg QD 4 weeks on / 2 weeks off. Primary objective was progression-free survival (PFS; RECIST 1.1 by blinded independent central review). Secondary objectives included overall survival (OS), objective response rate (ORR), and safety and tolerability. Results: After external data on predicted PFS with sunitinib in pts with MET-driven disease became available, study enrollment was closed. At data cutoff (Aug 2019), only 60 of the planned 180 pts were randomized (savolitinib n = 33; sunitinib n = 27). Most had chromosome 7 gain (savolitinib 91%; sunitinib 96%) and no prior therapy (savolitinib 85%; sunitinib 93%). PFS, OS, and ORR were numerically improved with savolitinib vs sunitinib (Table). CTCAE grade ≥3 adverse events (AEs) were reported in 42% and 81% of pts; dose modifications were related to AEs in 30% and 74% of pts with savolitinib and sunitinib respectively. After discontinuation, 36% of all savolitinib and 19% of all sunitinib pts received subsequent anticancer therapy. Conclusions: Although pt numbers and follow-up were limited, savolitinib demonstrated encouraging efficacy and an improved safety profile vs sunitinib, with fewer grade ≥3 AEs and fewer dose modifications required. Sunitinib performance was poorer than expected based on external retrospective data. Further investigation of savolitinib as a treatment option for MET-driven PRCC is warranted. Clinical trial information: NCT03091192 . [Table: see text]

PROSPER: Phase III randomized study comparing perioperative nivolumab versus observation in patients with renal cell carcinoma (RCC) undergoing nephrectomy (ECOG-ACRIN EA8143)

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 .

Efficacy of immune-checkpoint inhibitors (ICI) in the treatment of older adults with metastatic renal cell carcinoma (mRCC): An international mRCC database consortium (IMDC) analysis

5068

Background: Anti-PD-1/PD-L1 immune-checkpoint inhibitors (ICI) are now a standard of care in metastatic renal cell carcinoma (mRCC). Older adults were underrepresented in registration trials and given that immunological senescence may affect the anti-tumor activity of ICIs, there is uncertainty about the efficacy of ICIs in this population. Here we provide real world data on outcomes of older adults with mRCC treated with ICIs. Methods: Patients with mRCC treated with a PD-1/PD-L1 ICI either as monotherapy or as a combination treatment from 2000 to 2019 were included. Older adult was defined as ≥ 70-years at the time of ICI treatment. Descriptive statistics were summarized in means, medians and proportions. Efficacy was assessed by survival analysis, including overall survival (OS), time to treatment failure (TTF), and overall response rate (ORR). Multivariate analyses adjusted for imbalances in IMDC risk factors. P < 0.05 was considered statistically significant. Results: Of 1427 patients, 397 (28%) were older adults. Mean age of older vs. younger adults was 74 (70-92) vs. 60 (22-69) years. Groups were comparable in terms of gender (Female 28.5% vs. 26.1%, p = 0.36), rates of nephrectomy (21% vs. 18.3%, p = 0.24) and presence of sarcomatoid features (12.3% vs. 17.8%, p = 0.14). Proportion of IMDC risk-groups between older vs. younger adults were as follows: 15.4% vs. 18.2% for favorable, 61.2% vs. 59.1% for intermediate, and 23.4% vs. 22.7% for poor; there was no statistical difference (p = 0.55). ICI was used as 1st line in 40%, 2nd line in 48.5% and 3rd line in 11.5% patients; older adults were less likely to be treated with ICI in 1st line (32.2% vs. 43%, p < 0.01). In terms of survival, older adults had poorer median OS (25.1m vs. 30.8m, p < 0.01) but similar median TTF (6.9m vs. 6.9m, p = 0.40) compared to younger adults. In multivariate analyses, older age was not a predictor of either worse OS (aHR = 1.02, p = 0.86) or TTF (aHR = 0.95, p = 0.59). Older adults had a lower ORR compared to younger (24% vs. 31%, p = 0.01), which was mainly driven by responses in 1st line (31% vs. 44%, p = 0.02) and not observed in 2nd/3rd line (20% vs. 20%, p = 0.86). Conclusions: On multivariate analyses, older adults with mRCC treated with ICI had no difference in OS and TTF when compared to younger adults, despite having lower ORR in 1st line. Our data supports that older age is not an independent risk factor for survival; thus, treatment selection should not be based solely on chronological age.

Outcomes of patients with metastatic renal cell carcinoma (mRCC) treated with first-line Immuno-oncology (IO) agents who do not meet eligibility criteria for clinical trials

5070

Background: IO combination therapies [including IOIO and IO/vascular endothelial growth factor inhibitor (IOVE) combinations] in mRCC have been approved based on registration clinical trials that have strict eligibility criteria. The clinical outcomes of trial ineligible patients who are treated with first-line IOIO or IOVE combinations are unknown. Methods: Metastatic RCC patients treated with first-line IOIO or IOVE were retrospectively deemed ineligible for clinical trials (according to commonly used inclusion/exclusion criteria in IO trials) if they had a Karnofsky performance status (KPS) < 70%, no clear-cell component, brain metastases, hemoglobin (Hb) < 9 g/dL, eGFR < 40 mL/min, platelet count of < 100,000/mm3, and/or neutrophil count < 1500/mm3. Time to treatment failure (TTF) and overall survival (OS) were calculated from time of starting first-line IO therapy. Results: Overall, 26% (155/592) of patients in the International mRCC Database Consortium (IMDC) were deemed ineligible for clinical trials by the above criteria. Baseline characteristics are listed in Table. The reasons for ineligibility were: no clear-cell component (34%, 53/155), Hb < 9g/dL (28%, 44/155), eGFR < 40 mL/min (19%, 30/155), brain metastases (19%, 29/155), KPS < 70% (14%, 21/155), platelet < 100,000/mm3 (3%, 4/155) and neutrophil count < 1500/mm3 (0%, 0/155). Between ineligible versus eligible patients, the response rate, median TTF and median OS of first-line IOIO or IOVE was 34% vs 46% (p = 0.02), 4.2 vs 9.7 months (p < 0.01), and 25.3 vs 44.4 months (p < 0.01), respectively. When adjusted by the IMDC prognostic categories, the HR for death between trial ineligible and trial eligible patients was 1.50 (95% CI 1.05-2.14). Conclusions: The number of patients that are ineligible for clinical trials is substantial and their outcomes are inferior. These data may guide patient counselling and specific trials addressing the unmet needs of protocol ineligible patients are warranted. [Table: see text]

Impact of value frameworks on the magnitude of clinical benefit: Evaluating a decade of randomized trials for systemic therapy in solid malignancies

e19410

Background: In the era of rapid development of new, expensive cancer therapies, value frameworks were developed to quantify clinical benefit. We assessed the evolution of the magnitude of clinical benefit since the 2015 introduction of the ASCO and ESMO value frameworks. Methods: Randomized phase II and III clinical trials assessing systemic therapies for solid malignancies from January 2010 to July 2019 were evaluated. Study characteristics were recorded, and magnitude of clinical benefit (Δ) was calculated for the endpoints overall survival (OS), progression-free survival (PFS), response rate (RR), and quality of life (QoL). Multivariable analyses compared ΔOS, ΔPFS, and ΔRR in 2010-2014 [pre-value frameworks (PRE)] to 2015-2019 [post-value frameworks (POST)]. Results: In the 290 studies analyzed [60 (21%) PRE and 230 (79%) POST], the most common primary endpoint was PFS (46%), followed by OS (20%), RR (16%), and QoL (8%), with a non-significant increase in OS and decrease in RR as a primary endpoint in the POST era (Table). Studies evaluating immunotherapy and palliative therapy significantly increased POST [0 (0%) v 39 (17%), Fisher’s exact p<0.01 and 25 (42%) v 142 (62%), Chi squared p=0.01, respectively]. Studies reporting improvement in QoL doubled POST [3 (5%) v 22 (10%) Fisher’s exact p=0.56], however not statistically significant. Median ΔOS was significantly greater POST (N= 140 evaluable studies, 1.3 v -0.2 months, Wilcoxon p=0.005) but there was no significant difference in median ΔPFS or ΔRR. Multivariable analyses revealed significant improvement in ΔOS POST (OR 3.08, 95% CI 0.54-5.62, p=0.02) while adjusting for drug mechanism of action, line of therapy, disease setting, and primary endpoint. Conclusions: After the development of value frameworks, median OS improved minimally. The impact of value frameworks has yet to be fully realized in randomized clinical trials. Efforts to include endpoints shown to impact value, such as QoL, into clinical trials are warranted. [Table: see text]

MET status and treatment outcomes in papillary renal cell carcinoma (PRCC): Pooled analysis of historical data

e19321

Background: PRCC accounts for 10–15% of RCCs, but there are limited biomarker-based data to inform targeted treatment. Treatments for patients (pts) with advanced/metastatic PRCC include those approved for clear cell RCC such as sunitinib or everolimus, however their activity in PRCC can be limited. A subset of PRCCs are MET-driven, and it has been suggested that this may be a negative prognostic factor, although the role of MET activation in advanced/metastatic disease is unclear. We explored the prevalance of MET status in pts with advanced/metastatic PRCC treated with targeted therapies and impact on clinical outcomes. Methods: This large, international, retrospective, observational study included pts with previously treated, locally advanced/metastatic PRCC. MET status was determined retrospectively by NGS of archival tissue. MET-driven disease was defined as MET and/or HGF amplification, chromosome 7 gain (requiring > 30% tumor content) and/or MET kinase domain mutations. Study objectives included progression-free survival (PFS), time to treatment failure (TTF) and overall survival (OS) by MET status. Results: 305/308 pts (International Metastatic RCC Database Consortium, n = 72; The Asan Genito-Urinary Cancer Center, n = 40; Groupe Français d’Etude des Tumeurs Uro-Génitales, n = 196) received first-line (1L) treatment; sunitinib was most common (68%). 214 (69%) pts received 2L therapy; everolimus was most common (20%). Of 179 pts with valid NGS results, 38%, 49% and 13% had MET-driven, MET-independent (ind) tumors and chromosome 7 ploidy unevaluable, respectively. Baseline demographics were mostly balanced among groups. In sunitinib-treated pts, PFS and TTF were numerically longer in pts with MET-driven tumors vs pts with MET-ind tumors, but OS was similar (Table). In everolimus-treated pts, PFS and TTF were similar for both MET groups; however the sample size was small. Conclusions: MET alterations are frequent in advanced/metastatic PRCC and have potential to impact PFS and TTF, although our results show limited effect on OS. These data show that MET-driven tumours may not predict for poorer outcome vs MET-ind tumours and there is a need for suitable therapies for MET-driven PRCC. [Table: see text]

Integrative molecular characterization of sarcomatoid and rhabdoid renal cell carcinoma (S/R RCC) to reveal potential determinants of poor prognosis and response to immune checkpoint inhibitors (ICI)

715

Background: S/R RCC are highly aggressive tumors but recent pilot clinical data have suggested that these tumors respond well to ICI. Our aim was to perform integrative molecular characterization of S/R RCC tumors in order to characterize potential features that underlie their poor prognosis and responses to ICI. Methods: We compared genomic (1), transcriptomic (2) and immune microenvironment (3) data between S/R and non-S/R tumors. (1) S/R patients from 3 cohorts [N = 209]: The Cancer Genome Atlas [TCGA], CheckMate 010/025 & panel sequencing from Dana-Farber/Harvard Cancer Center [DF/HCC]. (2) RNA-seq on S/R from 2 cohorts [N = 98]: TCGA & CheckMate 010/025. (3) Immunofluorescence for CD8+ T cells [N = 17] & Immunohistochemistry for PD-L1 expression on tumor cells [N = 118] from CheckMate 010/025. Overall Response Rate (ORR), Progression Free Survival (PFS), and Overall Survival (OS) in S/R RCC was compared between ICI and non-ICI in clinical cohorts (Table). Results: S/R tumors were significantly enriched in mutations in BAP1, NF2, RELN, and MUTYH, deletions of CDKN2A/B & amplifications of EZH2 (q < 0.05) compared to non-S/R tumors. Gene Set Enrichment Analysis showed upregulation of epithelial-mesenchymal transition, immune pathways, and proliferation programs compared to non-S/R tumors in both RNA-seq cohorts independently (q < 0.25). S/R tumors exhibited greater infiltration by CD8+ T cells at the tumor margin (p = 0.048) and PD-L1 expression on tumor cells (43.2% vs 21.0%, p < 0.01) compared to non-S/R. S/R had improved ORR, PFS, and OS on ICI vs. non-ICI (Table). Conclusions: S/R RCC tumors have distinctive molecular features that may account for their association with poor prognosis and outcomes on ICI.[Table: see text]

Clinical outcomes of abiraterone acetate + prednisone (AA) + bone resorption inhibitors (BRI) versus AA alone as first-line therapy for castration-resistant prostate cancer (CRPC) with bone metastases (BM) in an international multicenter database

30

Background: BM in patients (pts) with CRPC are associated with shorter overall survival (OS) and higher costs. BRI zoledronic acid and denosumab are frequently used to prevent skeletal-related events (SRE) in pts with CRPC and BM. AA is the most common 1st line therapy for men with metastatic CRPC. We aimed to assess the impact of BRI on OS and time to first SRE (ttSRE) of pts receiving 1st line treatment AA for CRPC with BM. Methods: A retrospective cohort of pts starting AA as 1st line therapy for CRPC with BM between 2013-2016 was identified through 8 hospitals’ IRB approved registries. Pts were classified by use of concomitant BRI and subgrouped by volume of disease (per E3805 definition) at AA start. Kaplan-Meier method and Cox models were used to assess OS and ttSRE with hazard ratio (HR) estimates (95% CI). Results: Of the 745 pts included (543 deaths), 529 (71.0%) had AA alone and 216 (29.0%) AA+BRI. Median follow-up was 23.5 months. Pts receiving concomitant BRI showed a significantly longer OS and a 35% reduced risk of death compared to AA alone (HR=0.65; 95% CI, 0.54-0.79; P<.0001). The OS benefit with BRI was greater for the subgroup with high volume disease (HV) (HR=0.51; 95% CI, 0.38-0.68; P<.0001). The cohort with AA+BRI had a significantly shorter ttSRE (HR=1.27; 95% CI; 1.0-1.60; P=.0439) and, notably, the risk of first SRE was more than doubled for the subgroup with LV (HR=2.29; 95% CI, 1.57-3.35; P<.0001). On MVA, BRI vs. no BRI, prior local therapy (PLT) vs. no PLT, LV vs. HV, baseline VAS pain ≤3 vs. >5, PS 0 vs. ≥1, and PSA are independently associated with longer OS. Conclusions: The addition of BRI to 1st line AA for CRPC men with BM was associated with improved OS, particularly in HV, and worsened ttSRE, more evident in LV. These data suggest a potentially different impact of concomitant BRI on HV vs. LV, which could affect clinical decision making.[Table: see text]

Second-line VEGF TKI after IO combination therapy: Results from the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC)

684

Background: Immuno-Oncology (IO) combinations are standard of care first-line treatment for metastatic renal cell carcinoma (mRCC). Data on therapy with vascular endothelial growth factor (VEGF) tyrosine kinase inhibitors (TKI) post-progression on IO-combination therapy are limited. Methods: Using the IMDC, a retrospective analysis was done on mRCC patients treated with second-line VEGF TKIs after receiving IO combination therapy. Patients received first-line ipilimumab+nivolumab (IOIO) or anti-PD(L)1+anti-VEGF (IOVE). Baseline variables and second-line IMDC risk factors were collected. Overall response rates (ORR), time to treatment failure (TTF) and overall survival (OS) were determined. Multivariable Cox regression analysis was performed. Results: 142 patients were included. 75 patients received IOIO and 67 received IOVE pretreatment. The ORR of 2nd line therapy was 17/46 (37%) and 7/57 (12%) in the IOIO and IOVE pretreated groups, respectively (p<0.01). 2nd-line TTF was 5.4 months (95% CI 4.1-8.3) for the IOIO- and 4.6 months (95% CI 3.7-5.8) for the IOVE-pretreated group (p=0.37). 2nd-line median OS was 17.2 months (95% CI 10.8-35.1) and 11.8 months (95% CI 9.9-21.3) for the prior IOIO and IOVE groups, respectively (p=0.13). The hazard ratio adjusted by IMDC for IOVE vs IOIO pretreatment was 1.22 (95% CI 0.73-2.07, p=0.45) for 2nd line TTF and 1.43 (95% CI 0.74-2.8, p=0.29) for 2nd line OS. Conclusions: VEGF TKIs show activity after combination IO therapy. Response rates are higher in patients treated with VEGF TKIs after first-line IOIO compared to after IOVE. In patients with VEGF TKI after IOIO or IOVE, no difference in OS and TTF was observed.[Table: see text]