Weber, Jeffrey S.

Abstract Background In BRAF-mutated high-risk melanoma, targeted therapy (BRAF/MEK inhibitors) and checkpoint inhibitor (CPI) immunotherapy have durable benefits as first-line (1L) adjuvant therapy. Based on differing action mechanisms of BRAF/MEK inhibitors and CPI immunotherapies, there is interest in evaluating the activity of 2L adjuvant targeted therapy in decreasing the risk of subsequent recurrence after repeat resection following relapse on/after 1L adjuvant CPI. Patients and methods This was a retrospective review of BRAF V600-mutated resected stage III/IV melanoma patients in the United States, Australia, and The Netherlands who received 1L adjuvant CPI immunotherapy, relapsed locoregionally/distantly, were again resected to no evidence of disease, and received dabrafenib/trametinib (dab/tram) as 2L adjuvant therapy. The primary endpoint was relapse-free survival (RFS) from initiation of 2L adjuvant dab/tram (RFS-2), analyzed via Kaplan-Meier methods. Results Thirty-eight patients were included (median age 50 years, 63% male, 87% stage III, median follow-up 19 months from 2L dab/tram initiation). Median dab/tram duration was 10.1 months (range: 1 day–22.7 months), with half discontinuing due to progression or adverse events. Median (95% CI) RFS-2 was 18.9 (14.9–28.1) months, with 91%, 81%, and 58% remaining relapse-free at 6, 12, and 18 months, respectively. Most patients remained distant metastasis-free at 6, 12, and 18 months (97%, 85%, and 71%, respectively). Two patients were deceased at the last follow-up, with 97% alive at 18 months. Conclusions Over 80% of patients remained relapse- and metastasis-free at 12 months after 2L dab/tram initiation, with only 2 deaths observed. Dab/tram appears to have activity in the 2L adjuvant setting, although more follow-up is required.

Background Management of immune-related adverse events (irAEs) is important as they cause treatment interruption or discontinuation, more often seen with combination immune checkpoint inhibitor (ICI) therapy. Here, we retrospectively evaluated the safety and effectiveness of anti-interleukin-6 receptor (anti-IL-6R) as therapy for irAEs. Methods We performed a retrospective multicenter study evaluating patients diagnosed with de novo irAEs or flare of pre-existing autoimmune disease following ICI and were treated with anti-IL-6R. Our objectives were to assess the improvement of irAEs as well as the overall tumor response rate (ORR) before and after anti-IL-6R treatment. Results We identified a total of 92 patients who received therapeutic anti-IL-6R antibodies (tocilizumab or sarilumab). Median age was 61 years, 63% were men, 69% received anti-programmed cell death protein-1 (PD-1) antibodies alone, and 26% patients were treated with the combination of anti-cytotoxic T lymphocyte antigen-4 and anti-PD-1 antibodies. Cancer types were primarily melanoma (46%), genitourinary cancer (35%), and lung cancer (8%). Indications for using anti-IL-6R antibodies included inflammatory arthritis (73%), hepatitis/cholangitis (7%), myositis/myocarditis/myasthenia gravis (5%), polymyalgia rheumatica (4%), and one patient each with autoimmune scleroderma, nephritis, colitis, pneumonitis and central nervous system vasculitis. Notably, 88% of patients had received corticosteroids, and 36% received other disease-modifying antirheumatic drugs (DMARDs) as first-line therapies, but without adequate improvement. After initiation of anti-IL-6R (as first-line or post-corticosteroids and DMARDs), 73% of patients showed resolution or change to ≤grade 1 of irAEs after a median of 2.0 months from initiation of anti-IL-6R therapy. Six patients (7%) stopped anti-IL-6R due to adverse events. Of 70 evaluable patients by RECIST (Response Evaluation Criteria in Solid Tumors) V.1.1 criteria; the ORR was 66% prior versus 66% after anti-IL-6R (95% CI, 54% to 77%), with 8% higher complete response rate. Of 34 evaluable patients with melanoma, the ORR was 56% prior and increased to 68% after anti-IL-6R (p=0.04). Conclusion Targeting IL-6R could be an effective approach to treat several irAE types without hindering antitumor immunity. This study supports ongoing clinical trials evaluating the safety and efficacy of tocilizumab (anti-IL-6R antibody) in combination with ICIs ( NCT04940299 , NCT03999749 ).

10006 Background: Treatment options are limited for patients with advanced melanoma who have progressed on checkpoint inhibitors and targeted therapies. Adoptive cell therapy using tumor-infiltrating lymphocytes (TIL) leverages and enhances the body’s natural defense against cancer and has shown durable responses in heavily pretreated melanoma patients. Methods: C-144-01 is a global Phase 2 open-label, multicenter study of efficacy & safety of lifileucel in patients with unresectable metastatic melanoma who have progressed on checkpoint inhibitors and BRAF/MEK inhibitors, if BRAFv600 mutant. We report on Cohort 2 (N = 66) patients who have received TIL. Tumors were resected at local institutions, processed in central GMP facilities for TIL production, manufactured, cryopreserved & shipped back to sites in a 22-day process. Therapy consisted of one week of lymphodepletion, a single lifileucel infusion, and up to 6 IL-2 doses. ORR was based on RECIST v1.1 by investigator assessment. Data cutoff was Feb 2, 2020. Results: Baseline characteristics: 3.3 mean prior therapies (anti-PD1 100%; anti-CTLA-4 80%; BRAF/MEK inhibitor 23%), high baseline tumor burden (106 mm mean target lesion sum of diameters), 44% liver/brain lesions, 40.9% LDH > ULN. ORR by investigator was 36.4% (2 CR, 22 PR) and DCR was 80.3%. Mean time to response was 1.9 months (range: 1.3-5.6). After a median study follow-up of 17.0 months, median DOR (mDOR) was still not reached. Six responders have progressed, 2 have died and 2 started other anti-cancer therapy without progression. The adverse event profile was consistent with the underlying advanced disease and the lymphodepletion and IL-2 regimens. Additional follow-up data will be available for presentation. Conclusions: Lifileucel treatment results in a 36.4% ORR and mDOR was not reached at 17.0 months of median study follow up in a heavily pretreated metastatic melanoma patients with high baseline disease burden who progressed on multiple prior therapies, including anti-PD1 and BRAF/MEK inhibitors, if BRAFv600 mutant. Clinical trial information: NCT02360579.

9016 Background: The MAP kinase (MAPK) pathway is of critical importance for keratinocyte proliferation and maturation and is essential for epidermal homeostasis. Occurrence of hyperproliferative skin lesions including keratoacanthomas (KA) and cuSCC are considered a class effect of BRAFi [Anforth 2012, Chu 2012, Mattei 2012]. These effects, as well as promotion of pre-existing RAS-driven malignancies, may be caused by paradoxical activation of the MAPK pathway downstream of BRAF in wild-type BRAF cells. As MEK inhibition blocks downstream MAPK signaling, it was hypothesized that addition of a MEKi to a BRAFi would abrogate these effects [Su, 2012]. Methods: This 4-part phase I/II study enrolled 365 BRAFV600E/Kmutated MM pts in Parts B-D. In part C, 162 pts (BRAFi and MEKi treatment-naïve, ≥ 18 yrs; ECOG PS <2; RECIST measurable disease) were randomized to D monotherapy 150mg BID (D mono) vs. the combination of D (150 mg BID) and T (1 mg or 2 mg QD). Primary endpoints included safety and efficacy. Occurrence of cuSCC (including KA) across three arms in Part C and secondary malignancies with D+T across all Parts are provided below. Results: The difference in incidence of cuSCC between D mono and the D+T (150/1) was statistically significant, whereas the difference in incidence between D mono and D+T (150/2) was not. The median time to onset of cuSCC was 30 days in D mono compared to 282 and 152 days with D+T (150/1 and 150/2, respectively). Of 365 pts who received D+T, 2 (<1%) cases of new cancers (colorectal and gliobastoma) and 2 (<1%) cases of new primary malignant melanoma were reported. Conclusions: These data support the experimental hypothesis that the occurrence of cuSCC (including KA) can be substantially reduced and delayed by the addition of a MEKi to BRAFi therapy. Clinical trial information: NCT01072175. [Table: see text]

9009 Background: Programmed death-1 (PD-1) is an inhibitory T-cell co-receptor that may lead to suppression of antitumor immunity. Lambrolizumab is a humanized monoclonal IgG4 antibody against PD-1. This study explored the safety and clinical activity of lambrolizumab in patients (pts) with advanced melanoma (MEL). Methods: In this ongoing phase 1b expansion study of MEL pts with or without previous ipilimumab (IPI) treatment, lambrolizumab was administered IV every 2 or 3 weeks until disease progression or unacceptable toxicity. Tumor response was assessed every 12 weeks by independent, central, blinded radiographic review per immune-related response criteria and RECIST 1.1. Results: As of December 1, 2012, 294 pts with MEL were enrolled, including 179 IPI-naive and 115 IPI-pretreated. Pts received lambrolizumab 10 mg/kg (n = 183) or 2 mg/kg (n = 111). Preliminary data from the first 85 consecutive pts dosed before April 25, 2012, who had independent radiologic review available as of December 3, 2012, indicate a confirmed overall response rate per RECIST 1.1 of greater than 35%, pooled across all doses and schedules and including both IPI-naive and IPI-pretreated patients. The median duration of response has not been reached as only 2 pts who had initial response discontinued due to disease progression, but the duration of confirmed responses range from 28+ to 240+ days (up to 8+ months). Among 133 pts who were dosed with lambrolizumab before July 31, 2012, and evaluable for adverse events (AEs) as of September 28, 2012, fatigue (22%), rash (18%), and pruritus (14%) were the most common drug-related AEs (mostly grade 1/2). The incidence of drug-related grade 3/4 AEs was 10% (24% regardless of attribution). Four drug-related cases of pneumonitis were reported, all of grade 1/2. Grade 3/4 drug-related hypothyroidism (n = 1) and hyperthyroidism (n = 1) were noted. Conclusions: Preliminary data suggest that lambrolizumab has significant antitumor activity and is well tolerated with manageable side effects in both IPI-naive and IPI-pretreated MEL pts. These data have led to an ongoing, international, randomized study of lambrolizumab versus chemotherapy in IPI-pretreated MEL. Clinical trial information: NCT01295827.

9005 Background: Dual inhibition of the MAP kinase (MAPK) pathway with dabrafenib (D) and trametinib (T) in combination has demonstrated clinical benefit compared to D alone in a randomized Phase II trial in V600 BRAF-mutant MM pts, thus delaying the development of BRAFi resistance. Little is known about the efficacy of D + T after BRAFi resistance has been acquired. This analysis evaluates the ability of D + T combination to treat acquired resistance compared to the D + T combination as first-line treatment. Methods: These data from a phase I/II study include 1. BRAFi-resistant group: pts who received 150/2 D+T in Part B (n=26) and Part C (n=43) following progression on BRAFi monotherapy (mono); 2. BRAFi-naïve group: pts who received initial 150/2 D+T in Part B (n=24) and Part C (n=54). Results: Baseline characteristics (ECOG PS, M staging, LDH) were similar across all groups.In the Part B BRAFi-resistant group, 93% of pts previously received D or vemurafenib and all pts received D prior to D+T in Part C. In BRAFi-resistant group, prior best response of CR/PR (38%, 56%), SD (35%, 27%), PD (27%, 7%) was observed in Parts B and C respectively. In BRAFi-resistant group, the ORR and PFS with D+T was lower than initial D+T in BRAFi-naive group. Median duration of response (DoR) in BRAFi-resistant group cannot be calculated due to small no. of pts responding. Median DoR for BRAFi-naïve pts was 11.3 mo and 10.5 mo in Parts B and C respectively. In Part C, the 12-mo overall survival rates in BRAFi-naïve (150/2) pts was 79% vs 70% for pts initially on D mono, despite 80% pts crossing over to D+T combination. Conclusions: The clinical activity for 150/2 D+T combination is consistently superior in BRAFi-naive group vs BRAFi-resistant group in both Parts B and C. Dual MAPK blockade can delay clinical resistance to BRAF inhibition. However, once BRAFi resistance has occurred, the combination of BRAFi + MEKi is far less effective. Clinical trial information: NCT01072175. [Table: see text]

342 Background: Palliation of dysphagia (Dys) in patients with inoperable esophageal cancer (EC) can be challenging. The major goal of palliation therapy is to improve patient’s quality of life (QoL) and Dys and allow adequate caloric intake. The most commonly used palliative modalities for Dys are radiation therapy (RT) and esophageal stenting. However, RT is limited by total dose and adverse events (AE) in patients receiving systemic therapy (ST), and stenting suffers from a high rate of AE including reflux and chest pain. A relatively new modality of liquid nitrogen endoscopic spray cryotherapy (cryo) has been reported in retrospective studies to improve Dys in patients receiving systemic therapy. We prospectively evaluated Dys and QoL of patients with inoperable EC undergoing cryo in addition to ST for palliation. Methods: A prospective multicenter study of 24 adult inoperable EC patients undergoing cryo and ST for palliation at 4 specialized cancer centers from Sep 2017 to Aug 2019. QoL was assessed using a modified EORTC QLQ-OES18 questionnaire (score 18 to 72, with higher scores indicating worse QoL). Dys was measured using a 4-point Likert scale: 0, no Dys; 1, Dys to solids; 2, Dys to semi-solids; 3, Dys to liquids; 4, Dys to saliva. Paired t-test was used to evaluate change in QoL and Dys between pre- and post-cryo. Results: There were 19 males and 5 females (17 stage IV, 5 stage III, and 2 stage II at diagnosis). Among 24 patients, a total of 71 cryo were performed, with a mean of 2.9 treatments per patient. After a median follow-up of 2 months, the mean EORTC score improved significantly from 35.4 at baseline to 25.5 at last follow-up ( p < 0.001). Similarly, the Dys score improved significantly from 2.0 at baseline to 0.87 at last follow-up ( p < 0.001). Grade 3 or higher AE were seen in only one patient (4%) who had GI bleeding 2 weeks after cryo and was diagnosed with bleeding from severe reflux esophagitis related to gastric outlet obstruction. Conclusions: The analysis of this multicenter prospective study shows that cryo in addition to ST for palliation of EC is well tolerated with significant improvement in Dys and QoL.