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BACKGROUNDDespite the success of immune checkpoint and targeted therapy, many patients with melanoma ultimately require further treatment. The combination of carboplatin, paclitaxel, and bevacizumab (CPB) has demonstrated promising activity in a single‐arm study. In the current study, the authors performed a randomized phase 2 study to confirm efficacy and to determine whether adding everolimus would increase the activity of the combination.METHODSThrough the North Central Cancer Treatment Group, a total of 149 patients with unresectable AJCC 6th edition stage IV melanoma were randomized from May 2010 to May 2014 to either CPB or CPB with everolimus (CPBE). The primary endpoint was progression‐free survival (PFS), with secondary endpoints of overall survival (OS), response rate, and tolerability.RESULTSThe CPB and CPBE treatment arms were balanced with regard to age (median age: 59 years vs 58 years) and high lactate dehydrogenase (48% vs 51%), but were unbalanced with regard to sex (male sex: 72% vs 55%; P = .03). Overall, there was no difference noted with regard to PFS, with a median PFS of 5.6 months for CPB versus 5.1 months for CPBE (hazard ratio [HR], 1.14; 95% confidence interval [95% CI], 0.81‐1.62 [P = .44]), or for OS, with a median OS of 14.5 months for CPB versus 10.8 months for CPBE (HR, 1.16; 95% CI, 0.84‐1.84). The confirmed response rate was 13% for CPB and 23% for CPBE (P = .13). Toxicity was higher for CPBE compared with CPB (83% for grade 3 + and 14% for grade 4 + vs 63% for grade 3 + and 11% for grade 4+, respectively) (toxicities were graded using the Cancer Therapy Evaluation Program of the National Cancer Institute Common Terminology Criteria for Adverse Events [version 4.0]). Common grade 3 + toxicities were neutropenia, leukopenia, and fatigue, which occurred in both treatment arms with comparable frequency.CONCLUSIONSBoth experimental arms demonstrated activity, with a PFS of >5 months. However, the addition of everolimus to CPB failed to improve outcomes, with increased toxicity noted. These findings replicate the moderate antitumor activity of CPB, with future development possibly in combination with targeted or immunotherapy. Cancer 2018;124:537‐45. © 2017 American Cancer Society.

KEYNOTE-030 (ClinicalTrials.gov ID, NCT02083484) was a global expanded access program that allowed access to pembrolizumab, an antiprogrammed death 1 antibody, for patients with advanced melanoma before its regulatory approval. Patients with unresectable stage III/IV melanoma that progressed after standard-of-care therapy, including ipilimumab and, if BRAF V600 mutant, a BRAF inhibitor, were eligible to receive pembrolizumab 2 mg/kg every 3 weeks. Response was assessed by immune-related response criteria by investigator review. Adverse events (AEs) were graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events, version 4.0. In the United States, 979 patients enrolled between April and September 2014. Of the 947 evaluable patients, 621 (65.6%) remained on treatment and transitioned to receive commercial pembrolizumab following approval by the Food and Drug Administration, whereas 326 (34.4%) discontinued, most commonly for disease progression (39.6%) or death (26.4%). Objective response rate was 14.5% (95% confidence interval, 12.2%–16.8%) in the treated population (n=947) and 22.1% (95% confidence interval, 18.8%–25.5%) in patients who had ≥1 response assessment reported (n=619). Twelve patients achieved complete response. One hundred eighty-one (19.1%) patients experienced ≥1 treatment-related AE, most commonly general disorders (8.0%), skin/subcutaneous tissue disorders (7.3%), and gastrointestinal disorders (6.4%); 29 (3.1%) patients experienced ≥1 grade 3/4 treatment-related AE. Immune-mediated AEs were also reported. There were no treatment-related deaths. The safety and efficacy observed in this expanded access program were consistent with those previously reported for similar populations and support the use of pembrolizumab for patients with advanced melanoma.

Purpose Enhancer of zeste homolog 2 (EZH2), a chromatin remodeler, is implicated in the pathogenesis of clear cell renal cell carcinoma (ccRCC). However, the effect of EZH2 on outcomes in localized ccRCC is unclear, and molecular biomarkers are not currently integrated into prognostic models or adjuvant therapy trials. Methods We performed Cox regression to evaluate the association of tumor-based EZH2 gene and protein expression with survival in three independent cohorts: a cohort from The Cancer Genome Atlas (n = 532), a cohort from University of Texas Southwestern Medical Center (n = 122), and a cohort from Mayo Clinic (n = 1,338). Analyses were adjusted for the prognostic stage, size, grade, and necrosis (SSIGN) score as well as within low-, intermediate-, and high-risk SSIGN groups. Results Patients in The Cancer Genome Atlas cohort with EZH2-high gene expression were 1.5 times more likely to experience overall death than patients with EZH2-low expression (95% CI, 1.1 to 2.3; P = .028). Patients in the University of Texas Southwestern Medical Center cohort with EZH2-high protein expression were two times more likely to experience overall death than patients with EZH2-low expression (95% CI, 1.1 to 4.4; P = .034). Similarly, patients in the Mayo Clinic cohort with EZH2-high protein expression were 1.4 times more likely to experience overall death (95% CI, 1.2 to 1.7; P < .001). Patients in the Mayo Clinic cohort with EZH2-high protein expression were nearly two times more likely to experience RCC-specific death (95% CI, 1.5 to 2.6; P < .001); EZH2 protein expression was particularly prognostic among patients with low-risk SSIGN tumors (HR, 6.1; 95% CI, 3.4 to 11.1; P < .001). Conclusion EZH2 expression accurately predicts risk of RCC death beyond existing clinicopathologic models, particularly in low- and intermediate-risk SSIGN tumors. Further studies are required to incorporate molecular biomarkers into surveillance guidelines and adjuvant clinical trials.

We previously reported an extremely rare case of follicular dendritic cell sarcoma (FDCS) presented as a thyroid mass. Given the rarity of this disease, there are no personalized and molecularly targeted treatment options due to the lack of knowledge in the genomic makeup of the tumor. A 44-year-old white woman was diagnosed with an extranodal FDCS in thyroid. The patient underwent a total thyroidectomy, central compartment dissection, parathyroid re-implantation, and adjuvant radiation therapy. Tumor DNA sequencing of 236 genes by FoundationOne panel found truncating mutations in PTEN and missense mutations in RET and TP53. However, patient-matched germline DNA was not sequenced which is critical for identification of true somatic mutations. Furthermore, the FoundationOne panel doesn't measure genomic rearrangements which have been shown to be abundant in sarcomas and are associated with sarcoma tumorigenesis and progression. In the current study, we carried out comprehensive genomic sequencing of the tumor, adjacent normal tissues, and patient-matched blood, in an effort to understand the genomic makeup of this rare extranodal FDCS and to identify potential therapeutic targets. Eighty-one somatic point mutations were identified in tumor but not in adjacent normal tissues or blood. A clonal truncating mutation in the CLTCL1 gene, which stabilizes the mitotic spindle, was likely a driver mutation of tumorigenesis and could explain the extensive copy number aberrations (CNAs) and genomic rearrangements in the tumor including a chr15/chr17 local chromothripsis resulted in 6 expressed fusion genes. The fusion gene HDGFRP3→SHC4 led to a 200-fold increase in the expression of oncogene SHC4 which is a potential target of the commercial drug Dasatinib. Missense mutations in ATM and splice-site mutation in VEGFR1 were also detected in addition to the TP53 missense mutation reported by FoundationOne.

LBA4500 Background: Cisplatin-based chemo is a standard 1L treatment (tx) for mUC and the only tx that prolongs OS; however, age or comorbidities render many pts ineligible, and 30-50% receive no tx. Atezo (MPDL3280A) is active and well tolerated in platinum-treated mUC, justifying testing atezo as 1L tx in cisplatin-ineligible pts. Methods: Pts were chemo naive in the metastatic setting and cisplatin ineligible (renal [GFR > 30 but < 60 mL/min]/hearing impairment, ≥ G2 peripheral neuropathy [PN] or ≥ ECOG PS2). Atezo 1200 mg was given IV q3w until PD (RECIST v1.1). Centrally assessed PD-L1 on tumor infiltrating immune cells (IC; SP142 IHC assay) was scored IC2/3, 1 or 0. The primary efficacy endpoint was confirmed ORR assessed per RECIST v1.1 (central independent review facility) using a data cutoff of Sep 14, 2015. Results: 119 efficacy/safety-evaluable pts of any PD-L1 IC had a median age of 73 y: 21% ≥ 80 y. 18% had prior systemic tx (21% [neo]adjuvant); 10% had radiotherapy. 66% had visceral mets. 71% had CrCl < 60 mL/min; 13% had hearing loss ≥ 25 dB; 6% had prior PN ≥ G2; 20% had ECOG PS2. ORR was 19% (95% CI 13-28; 5% CR), and responses occurred in all IC subgroups (Table; includes DCR/PFS/OS) and in pts with poor prognostic factors. 22/23 responses were ongoing with mDOR not reached. Median follow-up was 8.5 mo (range 0.2-14.3); median tx duration was 15 wk. Atezo was generally well tolerated. Tx-related all-G and G3-4 AEs were seen in 64% and 12% of pts, respectively. Related all-G AEs ≥ 10% included fatigue, pruritus, diarrhea. 1 G5 related AE occurred (sepsis). 3% had a G3-4 immune-mediated AE. Conclusions: Atezo has clinically meaningful activity in 1L cisplatin-ineligible mUC pts, and preliminary OS is encouraging. The durable nature of response and favorable AE profile makes this an attractive alternative to chemo. NCT02108652. Clinical trial information: NCT02108652. [Table: see text]

Abstract Anti–PD-1 therapy has improved clinical outcomes in advanced melanoma, but most patients experience intrinsic resistance. Responding patients can develop acquired resistance to anti–PD-1. We retrospectively reviewed 488 patients treated with anti–PD-1 from three academic centers and identified 36 patients with acquired resistance, defined as disease progression following objective response. The incidence, timing, disease sites, post-progression survival (PPS), and outcomes were evaluated descriptively. The acquired resistance cohort consisted of 67% with more than 1 feature of poor prognosis (stage M1c, elevated LDH, or brain metastasis), and 67% had previously received ipilimumab. Partial and complete responses were achieved in 89% (n = 32) and 11% (n = 4) of patients, respectively, and median time to resistance (progression-free survival; PFS) was 11.1 months (range 4.3–32.8 months). Most progression was isolated (78% of patients, n = 28) and occurred while receiving therapy (78%, n = 28). The median PPS was 12.8 months (range 0.1–51.8 months), and the median overall survival was 33.7 months. Among isolated progressors, 15 received localized therapy (12 with surgery, 3 with radiation). Patients with isolated versus systemic progression exhibited a trend for improved PPS (P = 0.081), and patients with an initial PFS ≥ 15 months showed significant PPS improvement (P = 0.036). Two patients experienced subsequent responses to anti–PD-1 resumption. In conclusion, acquired resistance to anti–PD-1 was frequently associated with excellent clinical outcomes and often presented as isolated progression amenable to localized therapy (surgery or radiation) or systemic progression sensitive to therapy resumption. Cancer Immunol Res; 5(5); 357–62. ©2017 AACR.

431 Background: While targeting VEGF improves outcomes for mRCC pts, resistance invariably develops, often within the first year. Here, we describe the efficacy and safety of atezo (anti-PD-L1) with bev (anti-VEGF) and atezo monotherapy vs sun (TKI) in first-line mRCC. Methods: Treatment-naïve mRCC pts were enrolled in a hypothesis generating Ph II study (IMmotion150; NCT01984242) and randomized to atezo 1200 mg IV q3w + bev 15 mg/kg IV q3w, atezo alone or sun 50 mg PO QD 4 wk on/2 wk off. Crossover to atezo + bev after disease progression was allowed for pts receiving atezo or sun. PD-L1 expression was scored on tumor-infiltrating immune cells (IC, SP142 IHC assay). Coprimary endpoints were PFS (RECIST v1.1 by independent review [IRF]) in ITT pts and pts with PD-L1 expression on ≥ 1% of IC (PD-L1+). Results: Baseline characteristics were comparable across arms and between ITT and PD-L1+ pts. The majority of sun and atezo pts subsequently received atezo + bev. Median survival follow up was 20.7 mo. The PFS HR in ITT pts for atezo + bev vs sun was 1.00 and 1.19 for atezo vs sun. In PD-L1+ pts, the PFS HR for atezo + bev vs sun was 0.64 and 1.03 for atezo vs sun (table). Tx-related Gr 3-4 AEs were seen in 40%, 16% and 57% of pts in the atezo + bev, atezo and sun arms, respectively. AEs leading to death occurred in 3%, 2% and 2% of pts, respectively. Conclusion: Atezo + bev resulted in encouraging antitumor activity in the PD-L1+ subgroup of first-line RCC pts. Atezo + bev safety is consistent with the known profile of atezo and bev individually. The clinical benefit of atezo + bev vs sun will be evaluated in the ongoing Ph III study IMmotion151 (NCT02420821). Clinical trial information: NCT01984242. [Table: see text]

478 Background: Resistance invariably develops in all patients with metastatic ccRCC treated with mTOR inhibitors. Previously we demonstrated that dual inhibition of Hsp90 and the mTOR pathway in lung cancer models leads to synergistic reductions in tumor growth. Herein, we tested the efficacy of ganetespib as a single agent and in combination with mTOR inhibition using in vitro and in vivoccRCC models. Methods: For the in vitro work we utilized the following seven ccRCC cell lines: Caki-1, Caki-2, A-498, A-704, 769-P, 786-O, ACHN. For the in vivo work we used A498 xenografts. In vitro, we determined the single agent EC50 of everolimus and ganetespib at 72 hours by assessing percent viability of A498 cells compared to vehicle using the MTS assay. We then performed combinations of ganetespib and everolimus at EC20, EC30, and EC50 in A498 cells. Translating these studies in vivo, we compared the combinatorial activity of ganetespib and temsirolimus to monotherapy in mice bearing A498 tumor xenografts. Results: As a single agent, all ccRCC cell lines tested were sensitive to ganetespib at nanomolar concentration (EC50 15 – 75 nm) and to everolimus at micromolar concentrations (EC50 4 – 54 mm). In vitro, the combination of ganetespib and everolimus also decreased cell viability in an additive fashion. In vivo, ganetespib and temsirolimus demonstrated comparable single agent activity at sub-MTD doses (T/C = 63 and 60, respectively). Combining ganetespib with temsirolimus improved tumor growth suppression by ~30% (T/C = 43). Conclusions: Given the broad in vitro sensitivity of ccRCC cell lines to single agent ganetespib as well as the in vivo activity of the combination of ganetespib and temsirolimus, we believe ganetespib warrants further study in ccRCC. Updated results will be presented at the conference including the in vivo activity of the combination of ganetespib and antivascular endothelial growth factor agents.

464 Background: Although the von Hippel-Lindau (VHL) tumor suppressor gene is mutated in 60% of ccRCC, deletion of VHL in mice is insufficient for tumorigenesis. Sequencing of ccRCC tumors identified mutations in SETD2, a histone H3 lysine 36 (H3K36) trimethyltransferase. We hypothesize that loss of SETD2 methyltransferase activity alters the genome wide pattern of H3K36 trimethylation (H3K36me3) in ccRCC, and contributes to the cancer phenotype. Methods: To generate a genome-wide profile of H3K36me3 in frozen nephrectomy samples and RCC cell lines, we optimized a chromatin immunoprecipitation (ChIP) protocol for the isolation of DNA associated with H3K36me3. H3K36me3 is associated with open chromatin and an H3K36me3-specific antibody was used for immunoprecipitation of endogenous H3K36me3-bound DNA. ChIP PCR primers were optimized for active genes, such as actin, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and a “gene desert” on chromosome 12 (negative control). ChIP libraries were then generated from 3 paired uninvolved kidney and RCC and 2 RCC cell lines. In order to identify H3K36Me3 upregulated regions in uninvolved kidney and RCC, reads from the ChIP sequencing were mapped to the human genome using Burrows-Wheeler Aligner and SICER algorithms. Results: Using ChIP PCR, we found that active genomic regions were enriched 15-30 fold over the negative controls indicating that the quality and yield of immunoprecipitated DNA/chromatin complexes from frozen tissue was sufficient for ChIP sequencing. A preliminary ChIP sequencing analysis of RCC cell lines and frozen ccRCC tissue indicates that H3K36me3 enriched DNA sequences were mapped to exons (31.3%) compared to introns (13.5%, p<0.001), consistent with the role of H3K36me3 in transcription. Conclusions: Genomic regions enriched for H3K36Me3 binding were identified from patient-derived tissue and RCC cell lines. Current efforts are focused on comparing the H3K36me3 profiles between matched tumor and uninvolved kidney ChIP libraries to generate a genome wide map of dysregulated H3K36me3 modifications.