Neoadjuvant-Intent Immunotherapy in Advanced, Resectable Cutaneous Squamous Cell Carcinoma

Importance

In clinical trials, preoperative immune checkpoint inhibitors (ICIs) have shown clinical activity in advanced cutaneous squamous cell carcinoma (cSCC). However, these studies excluded patients with relevant comorbidities.

Objective

To evaluate radiologic and pathologic response rates to neoadjuvant-intent programed cell death protein 1 (PD-1) ICIs in a clinical population.

Design, Setting, and Participants

This cohort study of patients who were treated with neoadjuvant cemiplimab or pembrolizumab for advanced cSCC from January 2018 to January 2023 was conducted at 2 academic institutions in Boston, Massachusetts. Median follow-up was 9.5 months (range, 1.2-40.5).

Exposures

Cemiplimab or pembrolizumab.

Main Outcomes and Measures

Primary outcomes were radiologic and pathologic response rates. Secondary outcomes were 1-year recurrence-free survival, progression-free survival, disease-specific survival, and overall survival.

Results

This cohort study included 27 patients (including 9 patients [33.3%] with a history of lymphoma). Most patients were male (18 of 27 [66.7%]), with a median age of 72 years (range, 53-87 years). Most primary tumors were located on the head/neck (21 of 27 [77.8%]). There were no unexpected delays in surgery. The median number of doses before surgery was 3.5 (range, 1.0-10.0). Five patients (18.5%) ultimately declined to undergo planned surgery due to clinical responses or stability, and 1 (3.7%) did not undergo surgery due to progressive disease. The overall pathologic response rate (pathological complete response [pCR] or major pathological response) was 47.4% (9 of 19), and the overall radiologic response rate (radiologic complete response or partial response) was 50.0% (8 of 16). The pCR rate (7 of 19 [36.8%]) was higher than the radiologic complete response rate (2 of 16 [12.5%]). The pCR rate among patients with cSCC and concomitant lymphoma was 25.0%. The 1-year recurrence-free survival rate was 90.9% (95% CI, 50.8%-98.7%), progression-free survival was 83.3% (95% CI, 27.3%-97.5%), disease-specific survival was 91.7% (95% CI, 53.9%-98.8%), and overall survival was 84.6% (95% CI, 51.2%-95.9%).

Conclusions and Relevance

The results of this cohort study support the reproducibility of neoadjuvant-intent immunotherapy for cSCC in the clinical setting, including for patients with a history of lymphoma. Outside of clinical trials, it is not infrequent for patients to opt out of surgery for regressing tumors. The inclusion of higher-risk patients and preference for nonsurgical treatment are 2 factors that might explain the numerically lower pathologic response rate in this institutional experience.

Cemiplimab for Kidney Transplant Recipients With Advanced Cutaneous Squamous Cell Carcinoma

PURPOSE

Cemiplimab is approved for treating locally advanced or metastatic cutaneous squamous cell carcinoma (CSCC). Solid organ transplant recipients have been excluded from immunotherapy trials, given concern for allograft rejection despite their increased risk of skin cancers. Chronic immunosuppression is necessary to prevent organ rejection but may attenuate antitumor response with PD-1 inhibitors.

METHODS

We report a phase I study of cemiplimab for kidney transplant recipients (KTRs) with advanced CSCC. After cross-taper to a mammalian target of rapamycin (mTOR) inhibitor and pulsed dose corticosteroids (prednisone 40 mg once daily, the day before and on days 1-3 of each cycle, followed by 20 mg once daily on days 4-6, then 10 mg once daily until the day before each subsequent cycle), patients received cemiplimab 350 mg intravenously once every 3 weeks for up to 2 years and were assessed for response every 8 weeks. The primary end point was the rate of kidney rejection, with key secondary end points including rate and duration of response, and survival.

RESULTS

Twelve patients were treated. No kidney rejection or loss was observed. A response to cemiplimab was observed in five of 11 evaluable patients (46%; 90% CI, 22 to 73), including two with durable responses beyond a year. Median follow-up was 6.8 months (range, 0.7-29.8). Treatment-related grade 3 or greater adverse events occurred in five patients (42%), including diarrhea, infection, and metabolic disturbances. One patient died of angioedema and anaphylaxis attributed to mTOR inhibitor cross-taper.

CONCLUSION

mTOR inhibitor and corticosteroids represent a favorable immunosuppressive regimen for KTRs with advanced CSCC receiving immunotherapy. This combination resulted in durable antitumor responses with no kidney rejection events (funded by Regeneron Pharmaceuticals [ClinicalTrials.gov identifier: NCT04339062]).

Patterns of initial distant metastases in 151 patients undergoing surveillance for treated Merkel cell carcinoma

BACKGROUND

Merkel cell carcinoma (MCC) is associated with high rates of recurrence and distant metastatic progression. Current guidelines for surveillance imaging are not evidence based. Better characterization of the pattern of distant metastatic spread will better inform surveillance and facilitate earlier detection of metastases.

OBJECTIVES

This retrospective study aimed to assess potential relationships between primary tumour site and site of initial distant metastasis, time to distant metastasis, overall survival (OS) and MCC-specific death (MSD).

METHODS

Patients with local or regional (Stage I-III) disease who were treated with curative intent and progressed to Stage IV were included in this study (n = 151). Fisher's exact test was used to assess differences in patterns of initial distant metastases based on primary tumour site. Time to initial distant metastasis was calculated from date of MCC diagnosis. OS and MSD were calculated from date of initial distant metastasis to date of death from any or MCC-related causes, respectively.

RESULTS

Of 151 patients included in analysis, 89 (58.9%) had a single initial distant metastatic site, and 62 (41.1%) had multiple sites. Patients with upper limb primary tumours were significantly less likely to develop distant lymph node or liver metastases (p = 0.02 and 0.04, respectively). Median time to distant metastasis was 11 months (IQR 6.7-17.9 months). Median OS was 15.3 months, and was shorter for patients with liver (7.0 months, p = 0.0004) or bone metastases (8.9 months, p < 0.0001). Using skin/soft tissue metastasis as a reference group, patients with multiple metastatic sites had significantly higher hazards of MSD (HR = 3.46 univariate, 3.77 multivariate analysis). Time to distant metastasis, OS and MSD did not differ by viral status.

CONCLUSION

Sites of initial distant metastasis are related to primary tumour sites and survival outcomes. Because patients often have multiple initial metastases, full-body cross-sectional rather than region-specific imaging may facilitate earlier detection of metastatic disease.

Assessing Longitudinal Treatment Efficacies and Alterations in Molecular Markers Associated with Glutamatergic Signaling and Immune Checkpoint Inhibitors in a Spontaneous Melanoma Mouse Model

Previous work done by our laboratory described the use of an immunocompetent spontaneous melanoma-prone mouse model, TGS (TG-3/SKH-1), to evaluate treatment outcomes using inhibitors of glutamatergic signaling and immune checkpoint for 18 weeks. We showed a significant therapeutic efficacy with a notable sex-biased response in male mice. In this follow-up 18-week study, the dose of the glutamatergic signaling inhibitor was increased (from 1.7 mg/kg to 25 mg/kg), which resulted in improved responses in female mice but not male mice. The greatest reduction in tumor progression was observed in male mice treated with single-agent troriluzole and anti-PD-1. Furthermore, a randomly selected group of mice was removed from treatment after 18 weeks and maintained for up to an additional 48 weeks demonstrating the utility of the TGS mouse model to perform a ≥1-year preclinical therapeutic study in a physiologically relevant tumor-host environment. Digital spatial imaging analyses were performed in tumors and tumor microenvironments across treatment modalities using antibody panels for immune cell types and immune cell activation. The results suggest that immune cell populations and cytotoxic activities of T cells play critical roles in treatment responses in these mice. Examination of a group of molecular protein markers based on the proposed mechanisms of action of inhibitors of glutamatergic signaling and immune checkpoint showed that alterations in expression levels of xCT, γ-H2AX, EAAT2, PD-L1, and PD-1 are likely associated with the loss of treatment responses. These results suggest the importance of tracking changes in molecular markers associated with the mechanism of action of therapeutics over the course of a longitudinal preclinical therapeutic study in spatial and temporal manners.

A multicenter real-world analysis of risk factors, therapeutics, and outcomes of patients with metastatic basal cell carcinoma

BACKGROUND

Metastatic basal cell carcinoma (mBCC) is rare and there are limited data regarding patient and tumor risk factors, optimal treatments, and disease prognosis.

OBJECTIVE

To assess patient and tumor characteristics, therapeutics, and outcomes of mBCC stratified by location of metastasis.

METHODS

Retrospective cohort study of 53 patients with mBCC treated at 4 large academic centers in Boston, Massachusetts; Philadelphia, Pennsylvania; and Cleveland, Ohio between January 1, 2005 and December 31, 2021.

RESULTS

A total of 53 patients with mBCC were identified across 4 centers, 22 (42%) of whom had mBCC with spread limited to lymph nodes and 31 (58%) patients with distant organ spread (with or without lymph node involvement). Overall, half (n = 11) of patients with nodal metastasis achieved complete remission of disease, compared with just 1 (3%) patient with distant metastasis. The 5-year survival for nodal and distant metastatic patients was 89.3% and 61.0%, respectively.

LIMITATIONS

Small sample size due to disease rarity.

CONCLUSIONS AND RELEVANCE

Patients with nodal disease are more likely to have disease remission whereas patients with distant metastasis are more likely to have persistent disease and die from their disease. However, 5-year survival rates exceed 50%, even for stage IV disease.

Tumor-Associated Macrophages in Merkel Cell Carcinoma: Old Balances, New Checks

A recent report sheds light on the tumor-associated macrophages (TAM) in Merkel cell carcinoma (MCC), and the association of S100A8-expressing TAMs with resistance to anti-PD-(L)1 inhibitors. These data improve our understanding about why some tumors with brisk tumor-infiltrating lymphocytes do not respond to immunotherapy and provide a compelling rationale to target myeloid checkpoints in MCC. See related article by Tabachnick-Cherny et al., p. xxxx.

A Challenging Diagnosis of Merkel Cell Carcinoma Occurring in the Lymph Nodes and Skin of a Patient with Mantle Cell Lymphoma: A Case Report

Abstract is missing (Short communication)

A Spontaneous Melanoma Mouse Model Applicable for a Longitudinal Chemotherapy and Immunotherapy Study

Mouse models that reflect human disorders provide invaluable tools for the translation of basic science discoveries to clinical therapies. However, many of these in vivo therapeutic studies are short term and do not accurately mimic patient conditions. In this study, we used a fully immunocompetent, transgenic mouse model, TGS, in which the spontaneous development of metastatic melanoma is driven by the ectopic expression of a normal neuronal receptor, mGluR1, as a model to assess longitudinal treatment response (up to 8 months) with an inhibitor of glutamatergic signaling, troriluzole, which is a prodrug of riluzole, plus an antibody against PD-1, an immune checkpoint inhibitor. Our results reveal a sex-biased treatment response that led to improved survival in troriluzole and/or anti-PD-1-treated male mice that correlated with differential CD8+ T cells and CD11b+ myeloid cell populations in the tumor-stromal interface, supporting the notion that this model is a responsive and tractable system for evaluating therapeutic regimens for melanoma in an immunocompetent setting.

Combination oncolytic virus, radiation therapy, and immune checkpoint inhibitor treatment in anti-PD-1-refractory cancer

BACKGROUND

Immunotherapies are becoming front-line treatments for many advanced cancers, and combinations of two or more therapies are beginning to be investigated. Based on their individual antitumor capabilities, we sought to determine whether combination oncolytic virus (OV) and radiation therapy (RT) may improve cancer outcomes.

METHODS

To investigate the activity of this combination therapy, we used in vitro mouse and human cancer cell lines as well as a mouse model of skin cancer. After initial results, we further included immune checkpoint blockade, whose addition constituted a triple combination immunotherapy.

RESULTS

Our findings demonstrate that OV and RT reduce tumor growth via conversion of immunologically 'cold' tumors to 'hot', via a CD8+ T cell-dependent and IL-1α-dependent mechanism that is associated with increased PD-1/PD-L1 expression, and the triple combination of OV, RT, and PD-1 checkpoint inhibition impedes tumor growth and prolongs survival. Further, we describe the response of a PD-1-refractory patient with cutaneous squamous cell carcinoma who received the triple combination of OV, RT, and immune checkpoint inhibitor (ICI), and went on to experience unexpected, prolonged control and survival. He remains off-treatment and is without evidence of progression for >44 months since study entry.

CONCLUSIONS

Effective systemic antitumor immune response is rarely elicited by a single therapy. In a skin cancer mouse model, we demonstrate improved outcomes with combination OV, RT, and ICI treatment, which is associated with mechanisms involving augmented CD8+ T cell infiltration and IL-1α expression. We report tumor reduction and prolonged survival of a patient with skin cancer treated with combination OV, RT, and ICI. Overall, our data provide strong rationale for combining OV, RT, and ICI for treatment of patients with ICI-refractory skin and potentially other cancers.

A phase I trial of riluzole and sorafenib in patients with advanced solid tumors: CTEP #8850

BACKGROUND

Overexpression of metabotropic glutamate receptor 1 (GRM1) has been implicated in the pathogenesis of multiple cancers. Riluzole, an inhibitor of glutamate release, showed synergistic antitumor activity in combination with the multi-kinase inhibitor sorafenib in preclinical models. This phase I trial identified the toxicity profile, dose-limiting toxicities, maximum tolerated dose (MTD), and pharmacokinetic and pharmacodynamic properties of riluzole combined with sorafenib in patients with advanced cancers.

PATIENTS AND METHODS

Patients with refractory solid tumors were enrolled utilizing a 3+3 dose-escalation design. Riluzole was given at 100 mg PO BID in combination with sorafenib, beginning at 200 mg PO daily and escalating in 200 mg increments per level in 28-day cycles. Restaging evaluations were performed every 2 cycles.

RESULTS

35 patients were enrolled over 4 dose levels. The MTD was declared at dose level 3 (riluzole: 100 mg PO BID; sorafenib: 400 mg AM/200 mg PM). Pharmacokinetic analyses did not reveal definitive evidence of drug-drug interactions. Consistent decreases in phospho-forms of ERK and AKT in tumor tissue analyses with accompanying decrease in GRM1 expression and increase in pro-apoptotic BIM suggest target engagement by the combination. Best responses included a partial response in 1 (2.9%) patient with pancreatic acinar cell carcinoma with a KANK4-RAF1 fusion, and stable disease in 11 (36%) patients.

CONCLUSION

Combination therapy with riluzole and sorafenib was safe and tolerable in patients with advanced solid tumors. The partial response in a patient with a RAF1 fusion suggests that further exploration in a genomically selected cohort may be warranted.

Abstract 3275: Combination of talimogene laherparepvec (T-VEC) with pembrolizumab (pembro) in advanced melanoma patients following progression on a prior PD-1 inhibitor: SWOG S1607

We hypothesize that a significant number of patients do not respond to PD-1/L1 blockade because there are no pre-existing tumor antigen-specific T-cells, and this can be addressed by combination therapy with an oncolytic virus such as T-VEC. S1607 is a single arm Phase 2 study of T-VEC plus pembro in patients with advanced melanoma after PD-1/L1 inhibitor progression. The primary endpoint is ORR by modified RECIST (progression at the first follow-up disease assessment had to be confirmed). Secondary endpoints include durable response rate (response ≥ 6 months), ORR in injected, non-visceral non-injected, and visceral lesions, PFS, OS and toxicity. In Cohort A patients must have at least one measurable visceral lesion; in Cohort B patients must not have any visceral lesions. Each cohort had an independent accrual goal with a 2-stage design. All received intratumoral T-VEC and pembro 200mg IV every 21 days. Tumor biopsy and research blood are taken at baseline and on Day 28 (both injected and non-injected lesions). Tumor assessments are performed every 12 weeks for up to 2 years. 38 evaluable patients were enrolled. As of July 26, 2022, the median follow up was 28 months. Treatment was well tolerated, with 5/38 (13%) grade 3 AE (no grade 4/5) including injection site reactions, lymphocyte count decrease, and hypoxia. Cohort A was closed after stage I (n=11) with no confirmed responses. In Cohort B (n=27), there were 7 confirmed responses (26%; 2 CR, 5 PR; this rejected H0: ORR = 10%, p=0.01). Clinical outcomes are summarized in Table 1. Baseline tumor mutational burden from 17 patients in Cohort B were not different between responder vs non-responders (p=0.96). Translational study is ongoing for pharmacodynamic confirmation. T-VEC plus pembro in melanoma patients who have progressed on prior anti-PD1/L1 therapy has efficacy in the subset of melanoma patients who have non-visceral metastases.

Table 1 Cohort A (Visceral) Cohort B(Non-Visceral) N (%; 95% CI) 11 27 Confirmed PR + CR 0 (0%; 0%-28%) 7 (26%; 11%-46%) Confirmed + Unconfirmed 1 (9%; 0%-41%) 9 (33%; 17%-54%) Durable response 0 (0%; 0%-28%) 4 (15%; 4%-34%) Median PFS in months 2.1 (0.7-5.5) 2.3 (1.9-6.2) INJECTED LESIONS 11 27 Confirmed PR + CR 0 (0%; 0%-28%) 6 (22%; 9%-42%) Confirmed + Unconfirmed, PR + CR 1 (9%; 0%-41%) 8 (30%; 14%-50%) NON-INJECTED, NON-VISCERAL LESIONS 8 19 Confirmed PR + CR 0 (0%; 0%-37%) 3 (16%; 3%-40%) Confirmed + Unconfirmed, PR + CR 0 (0%; 0%-37%) 5 (26%; 9%-51%) VISCERAL LESIONS 11 Confirmed PR + CR 0 (0%; 0%-28%) Confirmed + Unconfirmed, PR + CR 1 (9%; 0%-41%) ACQUIRED RESISTANCE 3 2 Confirmed PR + CR 0 (0%; 0%-71%) 2 (100%; 16%-100%) Confirmed + Unconfirmed, PR + CR 0 (0%; 0%-71%) 2 (100%; 16%-100%) Median PFS in months 2.1 (2.0-4.1) NR (8.0-∞) PRIMARY RESISTANCE 8 25 Confirmed PR + CR 0 (0%; 0%-37%) 5 (20%; 7%-41%) Confirmed + Unconfirmed, PR + CR 1 (13%; 0%-53%) 7 (28%; 12%-49%) Median PFS in months 1.8 (0.3-6.2) 2.1 (1.9-3.3)

Citation Format: Siwen Hu-Lieskovan, James Moon, John Hyngstrom, Katie M. Campbell, Gino K. In, Theodore F. Logan, Kari L. Kendra, Ding M. Wang, Douglas B. Johnson, Gary C. Doolittle, Alan Tan, Ann W. Silk, Kenneth F. Grossmann, Christopher W. Ryan, Sapna P. Patel, Shay Bellasea, Michael C. Wu, John M. Kirkwood, Helen X. Chen, Antoni Ribas. Combination of talimogene laherparepvec (T-VEC) with pembrolizumab (pembro) in advanced melanoma patients following progression on a prior PD-1 inhibitor: SWOG S1607 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3275.

A phase Ib study of interleukin-2 plus pembrolizumab for patients with advanced melanoma

Introduction

High-dose interleukin-2 (HD IL-2) and pembrolizumab are each approved as single agents by the U.S. F.D.A. for the treatment of metastatic melanoma. There is limited data using the agents concurrently. The objectives of this study were to characterize the safety profile of IL-2 in combination with pembrolizumab in patients with unresectable or metastatic melanoma.

Methods

In this Phase Ib study, patients received pembrolizumab (200 mg IV every 3 weeks) and escalating doses of IL-2 (6,000 or 60,000 or 600,000 IU/kg IV bolus every 8 hours up to 14 doses per cycle) in cohorts of 3 patients. Prior treatment with a PD-1 blocking antibody was allowed. The primary endpoint was the maximum tolerated dose (MTD) of IL-2 when co-administered with pembrolizumab.

Results

Ten participants were enrolled, and 9 participants were evaluable for safety and efficacy. The majority of the evaluable participants (8/9) had been treated with PD-1 blocking antibody prior to enrollment. Patients received a median of 42, 22, and 9 doses of IL-2 in the low, intermediate, and high dose cohorts, respectively. Adverse events were more frequent with increasing doses of IL-2. No dose limiting toxicities were observed. The MTD of IL-2 was not reached. One partial response occurred in 9 patients (11%). The responding patient, who had received treatment with an anti-PD-1 prior to study entry, was treated in the HD IL-2 cohort.

Discussion

Although the sample size was small, HD IL-2 therapy in combination with pembrolizumab appears feasible and tolerable.

Clinical trial registration

ClinicalTrials.gov, identifier NCT02748564.

A phase 1b single-arm trial of intratumoral oncolytic virus V937 in combination with pembrolizumab in patients with advanced melanoma: results from the CAPRA study

Background

CAPRA (NCT02565992) evaluated Coxsackievirus A21 (V937) + pembrolizumab for metastatic/unresectable stage IIIB–IV melanoma.

Methods

Patients received intratumoral V937 on days 1, 3, 5, and 8 (then every 3 weeks [Q3W]) and intravenous pembrolizumab 2 mg/kg Q3W from day 8. Primary endpoint was safety.

Results

Median time from first dose to data cutoff was 32.0 months. No dose-limiting toxicities occurred; 14% (5/36) of patients experienced grade 3‒5 treatment-related adverse events. Objective response rate was 47% (complete response, 22%). Among 17 responders, 14 (82%) had responses ≥ 6 months. Among 8 patients previously treated with immunotherapy, 3 responded (1 complete, 2 partial). Responses were associated with increased serum CXCL10 and CCL22, suggesting viral replication contributes to antitumor immunity. For responders versus nonresponders, there was no difference in baseline tumor PD-L1 expression, ICAM1 expression, or CD3+ infiltrates. Surprisingly, the baseline cell density of CD3+CD8− T cells in the tumor microenvironment was significantly lower in responders compared with nonresponders (P = 0.0179).

Conclusions

These findings suggest responses to this combination may be seen even in patients without a typical “immune-active” microenvironment.

Trial registration number

NCT02565992.

A Retrospective Study of Ipilimumab Plus Nivolumab in Anti-PD-L1/PD-1 Refractory Merkel Cell Carcinoma

Merkel cell carcinoma (MCC) is a very rare but highly aggressive cutaneous neuroendocrine carcinoma and is associated with chronic exposure to ultraviolet light and the Merkel cell polyoma virus. The incidence rate of MCC is increasing and MCC is associated with high rates of recurrence and mortality. Immune checkpoint inhibitors (ICIs) offer durable responses and significant clinical benefit with 2 agents-avelumab (anti-PD-L1) and pembrolizumab (anti-PD-1)-currently approved by the U.S. Food and Drug Administration for the treatment of advanced MCC. Despite the advances in systemic therapy options for MCC, ~50% of patients with advanced MCC treated with ICI progress on therapy. There is a paucity of studies assessing second-line systemic therapy following primary/acquired resistance to ICIs. Current management in this setting remains a clinical challenge especially in trial ineligible patients. We evaluated objective response to ipilimumab plus nivolumab in metastatic MCC refractory to anti-PD-(L)1 therapy. Thirty-one percent of patients experienced a grade III or grade IV immune-related adverse event (irAE) due to ipilimumab plus nivolumab. No patients (0/13) achieved a complete or partial response via RECISTv1.1/irRECIST. Twenty-three percent (3/13) of patients achieved stable disease as the best overall response but progressed shortly thereafter. The median progression-free survival was 1.3 months (90% CI 1.1-1.5) from the initiation of ipi-nivo. The median overall survival was 4.7 months (95% CI 3-17). This study suggests limited, if any, clinical benefit of ipi-nivo in patients with advanced anti-PD-L1/anti-PD-1 refractory MCC.

A phase Ib dose-escalation study of troriluzole (BHV-4157), an oral glutamatergic signaling modulator, in combination with nivolumab in patients with advanced solid tumors

BACKGROUND

Glutamate signaling activates MAPK and PI3K/AKT pathways in tumor cells. Treatment with riluzole, a glutamate release inhibitor, has been previously shown to be safe in melanoma patients and produced biologic effects, but did not lead to radiographic responses, possibly due to poor pharmacokinetic properties. Therefore, we conducted a phase Ib trial to determine the safety and tolerability of the combination of the riluzole prodrug troriluzole (BHV-4157, trigriluzole) and the PD-1 antibody nivolumab in patients with advanced solid tumors.

METHODS

Patients with advanced or refractory solid tumors and measurable disease per RECIST 1.1 were treated with increasing doses of troriluzole using a semi-Bayesian modified toxicity probability interval dose escalation procedure. Troriluzole monotherapy was orally self-administered for a 14-day lead-in period followed by continuation of troriluzole in combination with nivolumab 240 mg IV every 2 weeks. Endpoints included safety, pharmacokinetics (PK) and efficacy.

RESULTS

We enrolled 14 patients with advanced solid tumors (melanoma = 3, NSCLC = 3, renal cell carcinoma = 2, bladder/urothelial = 2, ovarian cancer = 1, adenoid cystic carcinoma = 1, pleural mesothelial = 1, head and neck cancer = 1). Eleven patients had cancer progression on prior therapy with PD-1 or PD-L1 agent. Patients received troriluzole total daily doses from 140 to 560 mg (divided). The most common treatment-related adverse events (TRAE) occurring in ≥ 5 patients (> 35%) were transaminitis and increased lipase. DLT (dose-limiting toxicity) occurred in 3 patients: (1) grade 3 anorexia, (2) grade 3 fatigue and, (3) grade 3 atrial fibrillation. Six patients were treated at the MTD (maximum tolerated dose). No subjects discontinued treatment due to AEs. One response occurred (7%), which was a partial response in a subject who had PD-1 refractory disease. The 6-month PFS rate was 21%. PK data showed that the prodrug troriluzole was efficiently cleaved into riluzole by 2-h post-dosing in all dose cohorts tested.

CONCLUSION

The combination of troriluzole and nivolumab was safe and well-tolerated. The MTD of troriluzole was determined to be 420 mg total daily dose. The observed antitumor activity, primarily disease stabilization, is of interest in patients with PD-1 resistant tumors. Trial Registration ClinicalTrials.gov Identifier NCT03229278.

Society for Immunotherapy of Cancer (SITC) clinical practice guideline on immunotherapy for the treatment of nonmelanoma skin cancer

Nonmelanoma skin cancers (NMSCs) are some of the most commonly diagnosed malignancies. In general, early-stage NMSCs have favorable outcomes; however, a small subset of patients develop resistant, advanced, or metastatic disease, or aggressive subtypes that are more challenging to treat successfully. Recently, immune checkpoint inhibitors (ICIs) have been approved by the US Food and Drug Administration (FDA) for the treatment of Merkel cell carcinoma (MCC), cutaneous squamous cell carcinoma (CSCC), and basal cell carcinoma (BCC). Although ICIs have demonstrated activity against NMSCs, the routine clinical use of these agents may be more challenging due to a number of factors including the lack of predictive biomarkers, the need to consider special patient populations, the management of toxicity, and the assessment of atypical responses. With the goal of improving patient care by providing expert guidance to the oncology community, the Society for Immunotherapy of Cancer (SITC) convened a multidisciplinary panel of experts to develop a clinical practice guideline (CPG). The expert panel drew on the published literature as well as their own clinical experience to develop recommendations for healthcare professionals on important aspects of immunotherapeutic treatment for NMSCs, including staging, biomarker testing, patient selection, therapy selection, post-treatment response evaluation and surveillance, and patient quality of life (QOL) considerations, among others. The evidence- and consensus-based recommendations in this CPG are intended to provide guidance to cancer care professionals treating patients with NMSCs.

Navtemadlin (KRT-232) activity after failure of anti-PD-1/L1 therapy in patients (pts) with TP53WT Merkel cell carcinoma (MCC)

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Background: MCC is a rare, aggressive, neuroendocrine skin cancer with a high risk of recurrence and metastases. A median survival of about 4 mo for pts with metastatic MCC who failed anti-PD-1/L1 therapy highlights an urgent need for novel therapies. In TP53WT MCC, oncoproteins from the Merkel cell polyomavirus (MCPyV) inhibit p53 tumor suppressor functions by activating murine double minute 2 (MDM2). Navtemadlin is a potent, selective, orally available MDM2 inhibitor that overcomes MDM2 dysregulation by restoring p53 activity and inducing apoptosis of TP53WT tumors. Methods: The dose-finding, phase 1b/2 KRT-232-103 study (NCT03787602) evaluated navtemadlin in adult TP53WT MCC pts who failed anti-PD-1/L1 therapy. Pts were randomly assigned to oral navtemadlin once daily in 21- or 28-day cycles: 240 mg 7 days (D) on/14D off or 5D on/23D off, 180 mg 5D on/23 D off or 7D on/21D off, or 120 mg 7D on/14D off, until disease progression or unacceptable toxicity. The primary endpoint was Recommended Phase 2 Dose (RP2D); objective response rate (ORR) was assessed per RECIST v1.1. Results: As of Nov 30, 2021, 31 pts were enrolled with median age 66 y (range, 25-82); 52% had visceral disease and 71% had received ≥2 lines of prior therapy. Baseline tumor profiling of available samples showed low tumor mutation burden, MCPyV-positivity, and nonamplified MDM2 gene in 100%, 92%, and 100% of pts, respectively. Treatment-emergent adverse events (TEAEs) were observed in 100% (68% grade 3/4) of pts. The most common Grade 3/4 TEAEs were hematologic: 32% anemia, 32% lymphopenia, and 19% thrombocytopenia. Navtemadlin doses ≤180 mg were well tolerated with fewer dose reductions and longer treatment durations; subsequently the 240 mg arms were closed to further enrollment. Evaluable pts receiving 180 mg 5D on/23D off showed a 25% confirmed ORR, a 38% unconfirmed + confirmed ORR, and a 63% disease control rate (Table); median duration of response was not reached (range, 6-16.2+ mo) and median time to treatment response was 4.1 mo (range, 1.2-7). Notably, one responder, following a prolonged partial response, achieved complete metabolic remission by PET/CT after 2 y on treatment. The 120 mg arm was closed due to a low response rate. The 180 mg dose has been selected for further evaluation. Conclusions: Navtemadlin is the first targeted agent to show promising single-agent activity in heavily pretreated MCC pts who failed anti-PD-1/L1 therapy. This study demonstrates that upregulation of the p53 pathway is a viable therapeutic strategy in MCC. Clinical trial information: NCT03787602. [Table: see text]

A phase 1b/2a study of safety and efficacy of NT-I7 in combination with anti-PD-L1 (atezolizumab) in patients with anti-PD-1/PD-L1 naïve or relapsed/refractory (R/R) high-risk skin cancers: The phase 1b report

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Background: Novel immunotherapy approaches have changed the treatment landscape of patients (pts) with high-risk cancers like melanoma, Merkel cell carcinoma (MCC) and cutaneous squamous cell carcinoma (cSCC). However, despite the widespread use of checkpoint inhibitors (CPI) in these indications, most pts either fail to respond or eventually have progressed. NT-I7 (efineptakin alfa) is a long-acting human IL-7 that can increase the number and functionality of T-cells in peripheral blood and within the tumors. NT-I7 in combination with atezolizumab (atezo), may augment the efficacy in high-risk skin cancers. Methods: This is a phase 1b/2a study to evaluate the safety and efficacy of NT-I7 in combination with atezo in pts with CPI- naïve or relapsed/refractory (R/R) high-risk skin cancers. Phase 1b dose escalation followed a 3+3 design, in which pts who received NT-I7 IM every 3 weeks (Q3W) at 3 dose levels (DL1-3): 120, 360, and 840 µg/kg or Q6W at DL4 1200 µg/kg, and atezo IV 1200 mg Q3W. The objectives of the phase 1b were to evaluate dose-limiting toxicity (DLT), determine the MTD and the recommended phase 2 dose (RP2D), pharmacokinetics (PK), pharmacodynamics and preliminary antitumor activity. Results: As of January 14, 2022, 16 pts were enrolled in phase 1b: DL1 (n = 3), DL2 (n = 3), DL3 (n = 7), and DL4 (n = 3). The median age was 66 years [46-86], with ECOG PS 0 in 6 (37%), 1 in 7 (44%) and 2 in 3 (19%), and median number of prior therapies 1 [1-2]. One pt had a DLT at DL3 [Grade (G)3 confusion and G3 increased AST] but no DLTs were reported at DL4 and MTD was not reached. The RP2D was 1200 µg/kg Q6W of NT-I7 plus atezo 1200 mg Q3W. All pts had drug related AEs. Most AEs were G 1- 2 in 11(69%) pts; 5 (31%) in G3. There were no related G4/G5 AEs. Eleven pts had stable disease and the disease control rate was 69% (11/16). Preliminary PK analysis of DL1- 3 showed dose dependent Cmax, with Tmax at ̃24hr and T½ ranging ̃75hr to 125hr. NT-I7 dose-dependent expansion of the absolute lymphocyte count, CD3+, CD4+ and CD8+ T-cells peaked after one dose and the increase was maintained by repeat dosing until the end of treatment. Immunophenotyping of memory T-cell subsets showed a 5-fold expansion in most T-cell subsets and a 30-fold expansion of the stem cell memory CD8+ T-cell subset (Tscm) at DL4. Conclusions: This trial is the first time an IL-7 cytokine-based therapy and CPI has been assessed in UV induced high-risk skin cancers including in IO refractory pts. The combination of NT-I7 and atezo showed favorable safety and anticancer activity. NT-I7 significantly increased total lymphocyte and the T-cell compartment, with a greatest expansion of the CD8+ Tscm, a vital population for eliciting antitumor activity. Additional safety and efficacy updates will be provided by the ongoing phase 2a trial in CPI-naïve cSCC and MCC and CPI R/R MCC, cSCC and melanoma. Clinical trial information: NCT03901573.

A randomized, controlled, open-label, phase 2 study of cemiplimab ± RP1 in patients with advanced cutaneous squamous cell carcinoma (CERPASS)

TPS9593

Background: RP1 is an oncolytic virus (HSV-1) that expresses a fusogenic glycoprotein (GALV-GP R-) and granulocyte macrophage colony stimulating factor (GM-CSF). In preclinical studies, RP1 induced immunogenic tumor cell death and provided potent systemic anti-tumor activity, which is further improved by combining anti-PD-1 therapy. The prognosis for advanced and metastatic cutaneous squamous cell carcinoma (CSCC) remains poor for many patients despite the adoption of cemiplimab and pembrolizumab as a standard treatment. Preliminary results from IGNYTE, a phase I/II clinical study of RP1 in combination with nivolumab showed a high rate of deep and durable responses in patients (pts) with CSCC. This study is evaluating the efficacy and safety of cemiplimab ± RP1 versus cemiplimab alone in advanced CSCC. Methods: This global, multicenter, randomized phase 2 study is enrolling pts with metastatic or unresectable, locally advanced CSCC who are not candidates for/refuse surgery and/or radiation therapy. Key eligibility criteria include no prior treatment with anti-PD1/PD-L1 antibodies or oncolytic viruses. The clinical trial is enrolling approximately 180 pts from centers in the EU, Australia, Canada, and USA. Pts are randomized in a 2:1 ratio to receive combination therapy or monotherapy respectively. Pts receive 350 mg of cemiplimab intravenously (IV) Q3W for up to 108 weeks. In the RP1 + cemiplimab arm, RP1 is injected intratumorally at a starting RP1 dose of 1 × 106 plaque-forming units (PFU)/mL alone, followed by up to 7 doses of RP1 at 1 × 107 PFU/mL Q3W together with the same dose of cemiplimab. Pts in the combination arm may receive up to 8 additional RP1 doses if protocol specific criteria are met. No crossover is allowed. Pts are stratified by disease status (nodal or distant metastatic or locally advanced CSCC) and prior systemic therapy. Tumor assessments are performed every 9 weeks. The dual independent primary endpoints are overall response rate and complete response rate, both by a blinded independent review. Secondary endpoints include safety, progression-free survival, duration of response, and overall survival. Exploratory endpoints include quality of life, and immune biomarker analyses. This trial is currently enrolling pts. Clinical trial information: NCT04050436.

Characterization of clinical outcomes after shorter course hypofractionated and standard-course radiotherapy for stage I-III curatively-treated Merkel cell carcinoma

BACKGROUND

Limited data exists regarding the efficacy of curative hypofractionated radiotherapy (hypo-RT) regimens compared to conventionally-fractionated radiotherapy (conv-RT) for Merkel cell carcinoma (MCC).

METHODS

A retrospective analysis of 241 patients diagnosed with non-metastatic MCC from 2005-2021 and who received RT at Dana-Farber/Brigham & Women's Cancer Center. The primary outcome was cumulative incidence of in-field locoregional relapse using Gray's test with competing risks of death and isolated out-of-field recurrence. Secondary outcomes included overall survival (OS) and MCC-specific survival using log-rank tests, and risk factors of recurrence using Cox-proportional hazards regression.

RESULTS

There were 50 (20.6%) and 193 (79.4%) courses of hypo-RT and conv-RT, respectively. The hypo-RT cohort was older (≥73 years at diagnosis: 78.0% vs. 41.5%, p<0.01), and received a lower equivalent total RT dose in 2 Gy per fraction (<50 Gy: 58.0% vs. 5.2%, p<0.01). Median follow-up was 65.1 months (range: 1.2-194.5) for conv-RT and 25.0 months (range: 1.6-131.3) for hypo-RT cohorts. Two-year cumulative incidence of in-field locoregional relapse was low in both groups (1.1% conv-RT vs. 4.1% hypo-RT, p=0.114). While two-year OS was lower for the hypo-RT group (62.6% vs. 84.4%, p=0.0008), two-year MCC-specific survival was similar (84.7 vs. 86.6%, p=0.743). On multivariable analysis, immunosuppression, clinical stage III disease, and lymphovascular invasion were associated with any-recurrence when controlling for sex, age, and hypo-RT.

CONCLUSIONS AND RELEVANCE

There was no difference in cumulative incidence of in-field locoregional relapse or MCC-specific survival between hypo-RT and conv-RT. Prospective studies are needed to confirm hypo-RT as an efficacious treatment option for MCC.

BAMM (BRAF Autophagy and MEK Inhibition in Melanoma): A Phase I/II Trial of Dabrafenib, Trametinib, and Hydroxychloroquine in Advanced BRAFV600-mutant Melanoma

PURPOSE

Autophagy is a resistance mechanism to BRAF/MEK inhibition in BRAFV600-mutant melanoma. Here we used hydroxychloroquine (HCQ) to inhibit autophagy in combination with dabrafenib 150 mg twice daily and trametinib 2 mg every day (D+T).

PATIENTS AND METHODS

We conducted a phase I/II clinical trial in four centers of HCQ + D+T in patients with advanced BRAFV600-mutant melanoma. The primary objectives were the recommended phase II dose (RP2D) and the one-year progression-free survival (PFS) rate of >53%.

RESULTS

Thirty-four patients were evaluable for one-year PFS rate. Patient demographics were as follows: elevated lactate dehydrogenase: 47%; stage IV M1c/M1d: 52%; prior immunotherapy: 50%. In phase I, there was no dose-limiting toxicity. HCQ 600 mg orally twice daily with D+T was the RP2D. The one-year PFS rate was 48.2% [95% confidence interval (CI), 31.0%-65.5%], median PFS was 11.2 months (95% CI, 5.4-16.9 months), and response rate (RR) was 85% (95% CI, 64%-95%). The complete RR was 41% and median overall survival (OS) was 26.5 months. In a patient with elevated LDH (n = 16), the RR was 88% and median PFS and OS were 7.3 and 22 months, respectively.

CONCLUSIONS

HCQ + D+T was well tolerated and produced a high RR but did not meet criteria for success for the one-year PFS rate. There was a high proportion of patients with pretreated and elevated LDH, an increasingly common demographic in patients receiving targeted therapy. In this difficult-to-treat population, the RR and PFS were encouraging. A randomized trial of D+T + HCQ or placebo in patients with BRAFV600-mutant melanoma with elevated LDH and previous immunotherapy is being conducted.

Abstract CT139: Intratumoral oncolytic virus V937 in combination with pembrolizumab (pembro) in patients (pts) with advanced melanoma: Updated results from the phase 1b CAPRA study

Background: Coxsackievirus A21 (V937) is an RNA oncolytic virus targeting ICAM-1 receptors. Pharmacodynamic effects of oncolytic viruses in the tumor microenvironment (TME), including increased CD8+ T cells and PD-L1 expression, support their use in combination with checkpoint inhibitors. We present updated clinical and correlative data from the multicenter phase 1b CAPRA study (NCT02565992) of V937 + pembro in pts with advanced melanoma. Methods: Eligible pts had metastatic/unresectable stage IIIB-IV melanoma and ≥1 cutaneous/subcutaneous tumor or lymph node amenable to V937 intratumoral injection. Pts received V937 on days 1, 3, 5, and 8; then Q3W for up to 19 injections (maximum dose, 3 × 108 50% TCID50). Pts received IV pembro 2 mg/kg Q3W on day 8, continuing for up to 2 y. Primary endpoints were incidence of AEs, serious AEs (SAEs), and dose-limiting toxicities (DLTs). Secondary endpoints were ORR, duration of response (DOR), PFS, and OS. Biomarkers were an exploratory endpoint. Results: 36 pts were enrolled (mean age, 68.5 y; 75% male; 22% had prior immunotherapy). As of 4 Nov 2019, median (range) time from first dose to data cutoff was 32.0 (10.7−45.3) mo. No DLTs occurred. Grade 3-5 treatment-related AEs occurred in 5 (14%) pts. 3 (8%) pts had treatment-related SAEs (autoimmune encephalitis and septic shock in 1 pt, keratoacanthoma, autoimmune hepatitis); 1 died from septic shock. Efficacy results included ORR of 47% (CR, 22%; PR, 25%; Table 1). In comparing responders vs nonresponders, baseline tumor samples showed no difference in PD-L1 expression and lower CD3+CD8- infiltrate in responders. Conclusions: V937 + pembro had manageable safety and promising efficacy in pts with advanced melanoma. Response was not associated with an inflamed TME at baseline, indicating that V937 may induce an immune responsive TME. The combination is being studied in the neoadjuvant setting in pts with stage III melanoma (KEYMAKER-U02).

Table 1.Efficacy OutcomesV937 + Pembro (N = 36)ORR,a % (95% CI)b47 (30-65)- CR22 (10-39)- PR25 (12-42)DOR,c median (range), moNR (1.4+ to 22.0+)PFS,c,d median (95% CI), mo11.9 (3.4-NR)12-mo PFS,c % (95% CI)45 (28-60)OS,c median (95% CI), mo30.9 (20.3-40.5)12-mo OS,c % (95% CI)85 (68-94)+ indicates no PD by the time of last disease assessment. NR, not reached.aBest overall response with confirmation based on investigator assessment per immune-related response criteria; imaging was performed Q6W.bBased on the exact method for binomial data.cKaplan-Meier estimate.dBased on investigator assessment per immune-related response criteria.

Citation Format: Ann W. Silk, Steven J. O'Day, Howard L. Kaufman, Jennifer Bryan, Jacqueline T. Norrell, Casey Imbergamo, Daniella Portal, Edwin Zambrano-Acosta, Marisa Palmeri, Seymour Fein, Cai Wu, Leslie Guerreiro, Daniel Medina, Praveen K. Bommareddy, Andrew Zloza, Bernard A. Fox, Carmen Ballesteros-Merino, Darren Shafren, Mark Grose, Joshua A. Vieth, Janice M. Mehnert. Intratumoral oncolytic virus V937 in combination with pembrolizumab (pembro) in patients (pts) with advanced melanoma: Updated results from the phase 1b CAPRA study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT139.

Abstract 2846: Stereotypic patterns and genomic correlates of organotropism in metastatic melanoma

Despite the major role that metastasis plays in the morbidity and mortality of melanoma, stereotyped patterns of metastasis and drivers of its organotropism in melanoma are still not well characterized, limited by a dearth of sequencing data in well-annotated clinical melanoma samples. To address these open questions, we performed an integrative analysis of clinical and genomic features from 243 patients with metastatic melanoma treated at Dana Farber Cancer Institute (DFCI). Tumor biopsies were sequenced with OncoPanel, a next-generation sequencing panel that identifies mutations in 331 cancer genes. Presence of site metastases was evaluated radiographically pre-treatment for each patient; sites include lymph node (64% of cohort), soft tissue (59%), lung (57%), liver (32%), brain (24%), bone (22%), mesentery (12%), adrenal gland (9%), spleen (7%), and other metastatic sites (13%).

Metastases showed significant co-occurrences (e.g. bone and lung, OR 2.8, 95% CI = [2.3, 3.3], p &lt; 0.01; adrenal and mesentery, OR 4.4, 95% CI = [3.8, 5.0], p &lt; 0.01) and exclusions (lymph node and brain, OR 0.5, 95% CI = [0.2, 0.8], p = 0.02). We performed unsupervised hierarchical clustering of patients with cutaneous melanoma (n = 203) by metastatic site pattern using a Euclidean distance metric weighted to favor uncommon metastatic sites, yielding five stereotypic patterns of metastasis, characterized by: (1) co-occurrence of adrenal, mesenteric, and abdominal metastases (n=19); (2) liver metastases (n=33); (3) low metastatic burden (n=80); (4) co-occurrence of lung, brain, and mesentery metastases (n=42); and (5) co-occurrence of bone and lung metastases (n=29). Clustering is stable, with highly concordant cluster assignments in repeated subsampling of the data.

Patients with cutaneous melanoma (n=203) exhibited both site-specific and pattern-specific genomic correlates of metastatic organotropism that persist after correction for mutational burden. Tumors from patients with liver metastases showed significantly higher prevalence (p &lt; 0.05) of mutation compared to patients without liver metastases in KMT2D (56% vs 18%), BCL6 (22% vs 0%), TMPRSS2 (22% vs 0%), ARID1B (33% vs 4%), MET (33% vs 4%), and AXL (44% vs 11%), with similar enrichment in the liver met-predominant metastatic cluster, implicating dysregulation of histone and protein deacetylation pathways in liver metastatic organotropism (p &lt; 0.01). Numerous additional mutational correlates were found for the remaining nine metastatic sites and all five metastatic patterns, and validation in an orthogonal dataset is ongoing.

We present robust stereotypic patterns of metastasis and both site- and pattern-specific genomic correlates of organotropism in metastatic melanoma. By leveraging a valuable clinical/genomic data set, we nominate genetic correlates of organotropism for functional validation and potential therapeutic targets.

Citation Format: William H. Ge, Giuseppe Tarantino, Emily Robitschek, Michael P. Manos, Lauren Eastman, Olivia Ouyang, Patrick Ott, Ann W. Silk, Osama E. Rahma, Alexander Gusev, Rizwan Haq, Elizabeth I. Buchbinder, Megan L. Insco, Stephen Hodi, Eliezer Van Allen, David Liu. Stereotypic patterns and genomic correlates of organotropism in metastatic melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2846.

Evaluating clinical responses to BRAF inhibition in BRAF/TERT promoter mutated melanoma

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Background: Combined BRAF/MEK inhibition results in improved progression free and overall survival in BRAF mutated melanoma, but significant response is not universally observed. TERT promoter activating mutations often co-occur with BRAF mutations and have been associated with aggressive features and poorer prognosis. The TERT promotor inhibits apoptosis via a mechanism dependent upon BRAF mutant MAPK activation. Preclinical data in mouse models suggests that BRAF/TERT genetic duet melanomas are associated with improved response to BRAF/MEK inhibition as compared with BRAF mutant/TERT-WT melanomas. Methods: We performed a single center retrospective analysis of adults with melanoma with confirmed BRAF mutations +/- TERT promoter mutations. Responses and progression free survival in response to BRAF/MEK inhibition was assessed. Differences in RR and PFS were compared using Kaplan-Meier and Log-Rank. Results: 52 cases of BRAF/TERT genetic duet and BRAF mutated/TERT-WT melanomas were assessed. A total of 24 patients received BRAF/MEK inhibitors over the course of treatment meeting criteria for study inclusion; 9 (37.5%) BRAF/TERT genetic duet and 15 (62.5%) BRAF mutated/TERT-WT. BRAF V600E was present in 19/24 (79.2%) and V600K in 5/24 (20.8%). In the genetic duets, TERT -146C > T was present in 4/9 (44.4%), -124C > T in 2/9 (22.2%), -139_-138CC > TT in 2/9 (22.2%), and a SNV in 1/9 (11.1%). Mean age at diagnosis was 56 ± 13.5 years and 62.5% were male. ECOG PFS was 0-1 in 15/24 (62.5%), 2-3 in 6/24 (25%), and unreported in 3/24 (12.5%). Mean LDH at start of therapy was 391 (range 81-1664). At initial diagnosis 20.8% were Stage I, 25% Stage II, 37.5% Stage III, and 16.7% Stage IV. Two or more sites of disease were present in 10/24 (41.7%) and 2/24 (8.3%) had CNS metastases. BRAF/MEK directed therapy was first line in 6/24 (25%) of patients, others received prior immunotherapy. No significant differences between groups were observed in baseline demographics, disease state at diagnosis, or treatment history. In BRAF/TERT genetic duet melanomas CR was observed in 1/9 (11.1%), PR in 7/9 (77.8%), and NR in 1/9 (11.1%). In BRAF mutated/TERT-WT CR was observed in 3/15 (20%), PR in 11/15 (73.3%), and NR in 1/15 (6.7%). BRAF/TERT genetic duets were observed to initially have somewhat better PFS on first exposure to BRAF/MEK directed therapy but the PFS curves crossed at about 5 months with no significant difference observed overall (p = 0.40). Conclusions: This study is the first to report on outcomes of BRAF/MEK directed therapy in BRAF/TERT genetic duet vs BRAF mutated/TERT-WT melanomas in humans. While preclinical data from mouse models observed an improved response to BRAF/MEK inhibition in genetic duet tumors, no significant difference was observed. Our study is limited by small sample size. A multicenter analysis may be of interest to better understand the effects of BRAF inhibition in patients with BRAF/TERT genetic duet melanoma.

Predictors of immunotherapy benefit in Merkel cell carcinoma

Merkel cell carcinoma is a rare cancer for which immune checkpoint blockade is standard-of-care for recurrent/metastatic disease. However, not all patients benefit from immunotherapy. A greater understanding of molecular mechanisms and predictive biomarkers are unmet needs. We retrospectively analyzed electronic health records and next-generation sequencing data of 45 patients treated at our institution from 2013 to 2020 to understand clinical and genomic correlates of benefit from immunotherapy. Our cohort predominantly included individuals with stage III disease at primary disease diagnosis and individuals with stage IV disease at recurrent/metastatic disease diagnosis. Most received immunotherapy as first-line treatment. 43% experienced objective response (median duration of response 24.2 months, 95% confidence interval 8.8-not reached). Median overall survival was 15.5 months (95% confidence interval 9.0–28.7) (median follow-up 25.2 months). Less advanced stage at primary disease diagnosis and shorter disease-free interval between completion of initial treatment and recurrence were each associated with greater odds of response (odds ratio of 0.06, p = 0.04 for stage; odds ratio 0.75, p = 0.05 for disease-free interval). Single-nucleotide variants in ARID2 and NTRK1 were associated with response (p = 0.05, without Bonferroni correction), while none of Merkel cell polyomavirus status, total mutational burden, ultraviolet mutational signatures, and copy-number alterations predicted outcomes. Patients with shorter disease-free interval may be particularly suitable immunotherapy candidates. Our molecular findings point to ARID2 and NTRK1 as potential predictive markers and/or therapeutic targets (e.g., with Trk inhibitors), although this association needs to be confirmed in a larger sample.

Immunologic Characteristics of Nonmelanoma Skin Cancers: Implications for Immunotherapy

In this review, we summarize the immunology of nonmelanoma skin cancers (NMSCs) and the clinical data with immunotherapy in this heterogeneous group of cancers that include basal cell carcinoma (BCC), cutaneous squamous cell carcinoma (CSCC), and Merkel cell carcinoma (MCC). NMSCs are exceedingly common, and their treatment consumes substantial health care resources. Annual global mortality from NMSCs is comparable to that from malignant melanoma. Although the majority of NMSCs are localized at diagnosis and are treated effectively with surgery, metastases (nodal and distant) can sometimes arise and require systemic therapy. Given the success of immunotherapy in treating cutaneous melanoma, there has been an increasing interest in studying the immunology of NMSCs. Immunocompromised patients have a substantially higher risk of developing NMSCs (particularly CSCC and MCC), suggesting a role of the immune system in the pathogenesis of these cancers. Similar to cutaneous melanoma, the pathogenesis of BCC, CSCC, and virus-negative MCC is related to DNA damage from ultraviolet radiation exposure, and these cancers have a very high tumor mutational burden, which likely results in higher levels of tumor neoantigens that may be targets for the immune system. Viral antigens in virus-positive MCC are also strongly immunogenic. Emerging data from clinical trials of immune checkpoint inhibitors in NMSCs look very promising and are rapidly changing the treatment landscape of these cancers. Specifically, pembrolizumab and avelumab are U.S. Food and Drug Administration-approved for treatment of metastatic MCC and cemiplimab for metastatic CSCC. Several ongoing trials are investigating novel immunotherapies (monotherapies as well as combination) for treatment of NMSCs.

Effect of cyclo-oxygenase inhibitor use during checkpoint blockade immunotherapy in patients with metastatic melanoma and non-small cell lung cancer

Background

Immune checkpoint inhibitors (ICIs) improve survival outcomes in metastatic melanoma and non-small cell lung cancer (NSCLC). Preclinical evidence suggests that overexpression of cyclo-oxygenase-2 (COX2) in tumors facilitates immune evasion through prostaglandin E2 production and that COX inhibition synergizes with ICIs to promote antitumor T-cell activation. This study investigates whether concurrent COX inhibitor (COXi) use during ICI treatment compared with ICI alone is associated with improved time-to-progression (TTP), objective response rate (ORR) and overall survival (OS) in patients with metastatic melanoma and NSCLC.

Methods

We retrospectively reviewed 90 metastatic melanoma and 37 metastatic NSCLC patients, treated with ICI between 2011 and 2019. Differences in TTP and OS by ICI+COXi versus ICI alone were compared using Kaplan-Meier and Cox regression. Interaction between ICI+COXi versus ICI alone and pretreatment neutrophil–lymphocyte ratio (NLR) was examined. Independent radiology review per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 was performed.

Results

For patients with melanoma, median TTP was significantly prolonged in ICI+COXi versus ICI alone (245 vs 100.5 days, p=0.002). On multivariate analysis, ICI+COXi associated with increased TTP (HR 0.36, 95% CI 0.2 to 0.66, p=0.001), adjusted for age, pretreatment NLR, and gender. For NSCLC patients, ICI+COXi also associated with increased TTP compared with ICI alone on multivariate analysis (HR 0.45; 95% CI 0.21 to 0.97; p=0.042) adjusted for age. ORR at 6 months was significantly higher in patients who received ICI+COXi compared with ICI alone in both melanoma (58.6% vs 19.2%, p=0.0005) and NSCLC (73.7% vs 33.3%, p=0.036) cohorts. In the melanoma cohort, high pretreatment NLR (>5) associated with decreased TTP (HR 3.21, 95% CI 1.64 to 6.3; p=0.0007); however, ICI+COXi significantly associated with increased TTP in high NLR (>5) patients (HR 0.08, 95% CI 0.03 to 0.25), but not in low NLR (≤5) patients (HR 0.65, 95% CI 0.32 to 1.32). Similar outcomes were found in an adjusted melanoma cohort after RECIST review.

Conclusions

Our study suggests that COXi use concurrently with ICI significantly associated with longer TTP and improved ORR at 6 months in patients with metastatic melanoma and NSCLC compared with ICI alone. Furthermore, COXi use appears to reverse the negative prognostic effect of a high NLR by prolonging TTP in patients with melanoma.

The Association of Radiation Dose-Fractionation and Immunotherapy Use With Overall Survival in Metastatic Melanoma Patients

Objective

Metastatic melanoma patients often receive palliative radiotherapy (RT) and immunotherapy (IT). However, the immunological interplay between RT dose-fractionation and IT is uncertain, and the optimal treatment strategy using RT and IT in metastatic melanoma remains unclear. Our main objective was to examine the effect of RT dose-fractionation on overall survival (OS).

Methods

Using the National Cancer Database (NCDB), we classified metastatic melanoma patients who received palliative RT into two dose-fractionation groups - conventionally fractionated RT (CFRT; <5 Gy/fraction) and hypofractionated RT (HFRT: ≥5 Gy/fraction) - with or without IT. Survival analysis was performed using the Cox regression model, Kaplan-Meier method, and propensity-score matching (PSM).

Results

A total of 5,281 metastatic melanoma patients were included, with a median follow-up of 5.9 months. The three-year OS was highest in patients who received HFRT+IT [37.3% (95% CI: 31.1-43.5)] compared to those who received HFRT alone [19.0% (95% CI: 16.2-21.9)], CFRT+IT [17.6 (95%CI: 13.9-21.6)], or CFRT alone [8.6% (95%CI: 7.6-9.7); p<0.0001]. The magnitude of OS benefit with the use of IT was greater in those who received HFRT (18.3%) compared with those who received CFRT (9.0%) (p<0.0001). The addition of IT to HFRT, compared to CFRT, was associated with greater OS benefit in patients treated with RT to the brain and soft tissue/visceral (STV) sites. On PSM analysis, HFRT+IT was associated with improved three-year OS compared to other treatments.

Conclusion

Metastatic melanoma patients who received HFRT+IT was associated with the greatest OS benefit. Our findings warrant further prospective evaluation as to whether higher RT dose-per-fraction improves clinical outcomes in metastatic melanoma patients receiving IT.

Cyclooxygenase inhibitor use during checkpoint immunotherapy and effect on time to progression and overall survival for metastatic melanoma and non-small cell lung cancer patients

e22034

Background: Immune checkpoint inhibitors (ICIs) improve survival outcomes in metastatic melanoma and non-small cell lung cancer (NSCLC). Preclinical evidence suggests that overexpression of cyclooxygenase-2 (COX2) in tumors facilitates immune evasion through prostaglandin E2 production and that COX inhibition synergizes with ICIs to promote antitumor T-cell activation. This study investigates whether concurrent COX inhibitor (COXi) use during ICI treatment is associated with improved time-to-progression (TTP), objective response rate (ORR) and overall survival (OS) in metastatic melanoma and NSCLC patients. Methods: We retrospectively reviewed 90 metastatic melanoma and 37 metastatic NSCLC patients, treated only with ICI between 2011 and 2019. Differences in TTP and OS by COXi use were compared using Kaplan-Meier and Cox regression. Interaction between COXi use and neutrophil-lymphocyte ratio (NLR) was examined. Independent radiology review per RECIST v1.1 was performed. Results: For melanoma patients, median TTP was significantly prolonged in COXi users (245 v 100.5 days, p = .0002). On multivariate analysis (MVA), COXi use associated with increased TTP (HR 0.36, 95% CI: 0.2 – 0.66, p = 0.001) when adjusted for age, pretreatment NLR, and gender. For NSCLC patients, COXi use also associated with increased TTP on MVA (HR 0.45; 95% CI: 0.21 – 0.97; p = 0.042) adjusted for age. ORR at 6-months was significantly higher in patients who received concurrent COXi compared to those that did not in both melanoma (58.6% v 19.2%, p = 0.0005) and NSCLC (73.7% v 33.3%, p = 0.036) cohorts. COXi use was associated with improved OS in NSCLC patients on MVA (HR 0.3; 95% CI: 0.12 – 0.78; p = 0.013), but not in melanoma patients. In the melanoma cohort, high pretreatment NLR of > 5 associated with decreased TTP on MVA (HR 3.21, 95% CI: 1.64 – 6.3; p = 0.0007). However, for melanoma patients with high NLR > 5, COXi use significantly associated with increased TTP (HR 0.08, 95% CI: 0.03 – 0.25); but in melanoma patients with low NLR ≤5, there was no effect on TTP (HR 0.65, 95% CI: 0.32-1.32). Similar outcomes were found in an adjusted melanoma cohort after RECIST review. Conclusions: Our study suggests that use of COXi concurrent with ICI is significantly associated with longer TTP and improved ORR at 6-months in metastatic melanoma and NSCLC patients. NSCLC patients using COXi had prolonged OS. Furthermore, COXi use appears to reverse the negative prognostic effect of a high NLR by prolonging TTP in melanoma patients.

A phase Ib study of troriluzole (BHV-4157) in combination with nivolumab

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Background: The Metabotropic Glutamate Receptor 1 (GRM1) is overexpressed in many solid tumors. It activates MAPK and PI3K/AKT pathways and promotes an immune-suppressive tumor microenvironment. In an immunocompetent melanoma mouse model, GRM1 blockade using riluzole or its pro-drug troriluzole (BHV-4157) and PD-1 blockade inhibit tumor growth in an additive manner. We conducted a phase Ib trial of troriluzole and the PD-1 antibody nivolumab. Methods: Patients with advanced or refractory solid tumors were treated with increasing doses of troriluzole. Troriluzole monotherapy was given for a 14-day lead-in period and then patients received troriluzole in combination with nivolumab 240 mg IV every 2 weeks. Results: We enrolled 14 patients with advanced solid tumors (melanoma=3, NSCLC=3, renal cell cancer=2, NSCLC=2, head and neck cancer=2). Eleven patients had prior therapy with anti-PD-(L)1. PK sampling demonstrated that the prodrug was cleaved efficiently without regard to food (Table). The most common TEAEs (all grades) occurring in >40% of patients were transaminitis, increased lipase and nausea. DLT occurred in 3 patients: 1) grade 3 anorexia, 2) grade 3 fatigue and, 3) atrial fibrillation. The MTD was determined to be troriluzole 140 mg QAM + 280 mg PO QHS. The response rate was 7 % (1/14); this occurred in a PD-L1 treated patient. The 6-month PFS rate was 21%. Correlative studies will be presented. Conclusions: The combination of troriluzole and nivolumab was safe and well-tolerated in this highly PD-1 refractory population. Clinical trial information: NCT03229278. [Table: see text]

High-Dose Ipilimumab and High-Dose Interleukin-2 for Patients With Advanced Melanoma

High-dose ipilimumab (IPI) and high-dose interleukin-2 (IL-2) are approved agents for metastatic melanoma, but the efficacy and safety of the combination are unknown. The objective of this study was to evaluate the feasibility, safety, and efficacy of combination high-dose IPI and high-dose IL-2 in patients with histologically confirmed advanced unresectable stage III and IV melanoma. This Phase II, multicenter, open-label, single-arm trial was conducted in nine patients enrolled between 12/2014 and 12/2015. Subjects were treated with high-dose IPI 10 mg/kg intravenous (IV) every 3 weeks for four doses starting at week 1 and high-dose IL-2 (600,000 IU/kg IV bolus every 8 h for up to 14 doses) concurrently with IPI at weeks 4 and 7. After the first 12 weeks of combination therapy, maintenance IPI (10 mg/kg IV) monotherapy was administered every 12 weeks for up to 1 year. No patient had received prior PD-1 blockade, and only one received prior vemurafenib. Confirmed partial response was achieved in one (11%), stable disease in four (44%), and progressive disease in four (44%) of nine patients. Two patients achieved durable disease control of 44+ and 50+ months at the most recent follow-up without subsequent therapy. The median overall survival was not reached after a minimum 24 months of follow-up time. One-year and 2-year survival rates were 89 and 67%, respectively. Seven patients (78%) experienced grade 3 or 4 adverse events related to the study therapy, three of which were attributed to both agents. One patient discontinued the treatment due to liver and kidney toxicity. While toxicity was significant, all events were reversible, and there was no treatment-related mortality. In peripheral blood of patients with decreasing tumor burden, the ratio of the non-classical MHC-II proteins HLA-DM to HLA-DO increased 2-fold, raising the possibility of the ratio of HLA-DM:HLA-DO as a novel biomarker of response to treatment. Although the sample size was limited, combination therapy with high-dose IPI and high-dose IL-2 was feasible and associated with clinical benefit. IL-2-based compounds in combination with CTLA-4 blockade should be studied in advanced melanoma patients who fail to benefit from first-line PD-1 blockade.

Clinical Trial Registration:ClinicalTrials.gov, NCT02203604. Registered 30 July 2014, https://clinicaltrials.gov/ct2/show/NCT02203604.

Impact of the Oncology Care Model (OCM) on pain management: A retrospective cohort analysis

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Background: Pain is a common symptom among patients with cancer and impacts performance status and quality of life. The OCM was implemented at Rutgers Cancer Institute of New Jersey (RCINJ) in July 2016 with the goal of improving many quality metrics in cancer care including documentation of pain and a plan of care for pain. Hypothesis: Documentation of pain and a plan of care for pain improved after implementation of the OCM at RCINJ. Improved documentation would correlate with a decrease in reported quantitative pain scores. Methods: Data from patients enrolled in OCM during its first year of implementation (post OCM) was compared to data from a control cohort the preceding year (pre OCM). The initial progress note and EMR flowsheet in each year were reviewed to determine pain documentation. For patients reporting a pain score ≥ 1 on a 0-10 scale, the association between documentation of a plan of care and improvement in quantitative pain score on a subsequent visit was analyzed using Chi square testing. Results: A total of 260 patient charts were analyzed. A quantitative pain score was documented in 99% of patients in the pre OCM group and 100% in the post OCM group. For those with a pain score ≥ 1, documentation of a plan of care increased from 43% to 55% after OCM implementation. Patients whose charts contained documented plans of care for pain were less likely to have decreased pain scores at a subsequent visit (51% vs 76%). Conclusions: (1) Documentation of a quantitative pain score was completed in nearly all patients before and after the implementation of OCM. (2) There was a non-statistically significant increase in documentation of plan of care for pain after OCM implementation. (3) Documentation of a plan of care was not associated with a decreased pain score at a subsequent visit. This may be the result of small sample size or related to progressive cancer-related pain or inadequate pain intervention.

[Table: see text]

Rescue therapy for patients with anti-PD-1-refractory Merkel cell carcinoma: a multicenter, retrospective case series

Merkel cell carcinoma (MCC) is a rare but clinically aggressive cancer with a high mortality rate. In recent years, antibodies blocking the interactions among PD-1 and its ligands have generated durable tumor regressions in patients with advanced MCC. However, there is a paucity of data regarding effective therapy for patients whose disease is refractory to PD-1 pathway blockade. This retrospective case series describes a heterogeneous group of patients treated with additional immune checkpoint blocking therapy after MCC progression through anti-PD-1. Among 13 patients treated with anti-CTLA-4, alone or in combination with anti-PD-1, objective responses were seen in 4 (31%). Additionally, one patient with MCC refractory to anti-PD-1 and anti-CTLA-4 experienced tumor regression with anti-PD-L1. Our report - the largest case series to date describing this patient population - provides evidence that sequentially-administered salvage immune checkpoint blocking therapy can potentially activate anti-tumor immunity in patients with advanced anti-PD-1-refractory MCC and provides a strong rationale for formally testing these agents in multicenter clinical trials. Additionally, to the best of our knowledge, our report is the first to demonstrate possible anti-tumor activity of second-line treatment with a PD-L1 antibody in a patient with anti-PD-1-refractory disease.

Safety and enhanced immunostimulatory activity of the DRD2 antagonist ONC201 in advanced solid tumor patients with weekly oral administration

Background

ONC201 is a small molecule antagonist of DRD2, a G protein-coupled receptor overexpressed in several malignancies, that has prolonged antitumor efficacy and immunomodulatory properties in preclinical models. The first-in-human trial of ONC201 previously established a recommended phase II dose (RP2D) of 625 mg once every three weeks. Here, we report the results of a phase I study that evaluated the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of weekly ONC201.

Methods

Patients ≥ 18 years old with an advanced solid tumor refractory to standard treatment were enrolled. Dose escalation proceeded with a 3 + 3 design from 375 mg to 625 mg of ONC201. One cycle, also the dose-limiting toxicity (DLT) window, was 21 days. The primary endpoint was to determine the RP2D of weekly ONC201, which was confirmed in an 11-patient dose expansion cohort.

Results

Twenty patients were enrolled: three at 375 mg and 17 at 625 mg of ONC201. The RP2D was defined as 625 mg with no DLT, treatment discontinuation, or dose modifications due to drug-related toxicity. PK profiles were consistent with every-three-week dosing and similar between the first and fourth dose. Serum prolactin and caspase-cleaved cytokeratin-18 induction were detected, along with intratumoral integrated stress response activation and infiltration of granzyme B+ Natural Killer cells. Induction of immune cytokines and effectors was higher in patients who received ONC201 once weekly versus once every three weeks. Stable disease of > 6 months was observed in several prostate and endometrial cancer patients.

Conclusions

Weekly, oral ONC201 is well-tolerated and results in enhanced immunostimulatory activity that warrants further investigation.

Trial registration

NCT02250781 (Oral ONC201 in Treating Patients With Advanced Solid Tumors), NCT02324621 (Continuation of Oral ONC201 in Treating Patients With Advanced Solid Tumors).

Electronic supplementary material

The online version of this article (10.1186/s40425-019-0599-8) contains supplementary material, which is available to authorized users.

Cyclooxygenase inhibitor use during checkpoint blockade immunotherapy and effect on time to progression for metastatic melanoma patients

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Background: In tumors, cyclooxygenase (COX) activity leads to biosynthesis of prostaglandin E2 which can inhibit T-cell and dendritic cell function, thereby allowing immune evasion. Preclinical models have shown therapeutic synergy between COX inhibitors (COXi) and anti-PD-1 inhibition (PD-1i) immunotherapy (IT). We hypothesized that patients (pts) treated with checkpoint blockade IT and concurrent COXi would have improved responses compared to those treated with IT and no COXi. Methods: We retrospectively analyzed 65 metastatic melanoma pts who received IT (PD-1i/PD-L1i/CTLA4i) between 5/2011-11/2017 on their 1st course of IT. Of these pts, 38.5% (N = 25) took concurrent COXi (aspirin, NSAIDs, or selective COX-2i) and 61.5% (N = 40) did not. We compared differences in baseline characteristics and time to progression (TTP) between IT-treated melanoma pts who did or did not receive COXi, using the Kaplan-Meier method and Cox regression. TTP was defined as time from IT start to progression of disease (POD) as determined by the treating physician based on CT or PET/CT scans, or last known alive. Results: Mean age was 66 yrs; male: 64.6%; BRAF mutant: 29.2%, ECOG 0/1/2: 60%/35.4%/4.6%; steroid use: 47.7% during IT; and prior non-checkpoint blockade IT: 13.8%. IT was stopped due to POD in 53.8% of pts, IT toxicity 6.2%, completed therapy 24.6%, and treatment holiday 15.4%. There were no significant differences in baseline characteristics between pts who did or did not receive COXi during IT, except for mean age (70 (COXi) versus 63 yrs (no COXi), p = 0.019). Pts that received COXi had longer TTP (median 245 days) vs without COXi (median 85 days, p = 0.0002). On multivariate analysis, COXi was associated with longer TTP (HR 0.34, p = 0.0004) after accounting for age, gender, steroid use, and ECOG PS ≥1. Immune-related toxicity was not significantly different with or without COXi (p = 0.73). Conclusions: Our findings suggest that in metastatic melanoma pts treated with IT, concurrent COXi use may result in a longer TTP, without increasing toxicity. These findings warrant further study to continue to augment outcomes for pts.

A phase I study of pazopanib with weekly paclitaxel and carboplatin in advanced solid tumors

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Background: Pazopanib (pazo) is an oral tyrosine kinase inhibitor of VEGFR, PDGFR and c-Kit. It is a weak inhibitor of CYP3A4 and CYP2C8 and may decrease paclitaxel (P) clearance. Daily pazo with P and carboplatin (C) every 21 days was not feasible on a previous study. We hypothesized that pazo dosed intermittently and on a different day from P and C may be tolerable. We sought to determine the maximum tolerated dose (MTD), dose-limiting toxicity (DLT), and pharmacokinetics (PK) of pazo with weekly P and C. Methods: Using a 3+3 standard design, a schedule of P 60-80 mg/m2 and C AUC2 on days 1, 8, and 15 with pazo 400-800 mg on days 2-5, 9-12, and 16-26 on a 28-day cycle was evaluated. Pazo alone could be continued if P and C were omitted due to maximal benefit or toxicity. PK was collected during cycles 1 and 2. Results: 34 patients (pts) were treated over 6 dose levels (Table). Mean age 57 (37-79). Tumor types: breast (22), lung (3) and other (9); 27 had prior platinum. Delay in starting cycle 2 due to grade 3 neutropenia was a DLT at dose level 2 and 5. Pts on 5A missed dosing during C1 and C2 due to neutropenia and required subsequent growth factor, and this was deemed unlikely to be sustainable long-term. All grade toxicities included anemia (62%), neutropenia (59%), and thrombocytopenia (56%). Protocol-defined MTD was not determined. PK analysis showed a dose proportional increase in pazo concentration, consistent with previous reports. Pazo did not alter the PK of C. Cmax of P was higher C2D1 vs C1D1; mean Cmax ratio between C2D1:C1D1 was 1.63 (95% CI:1.29-1.96). There were 11 objective responses (3 CRs, 8 PRs). Five breast pts were on pazo alone for a median of 9 cycles (2-52) with CR (2), PR (2) and SD (1); a squamous cell of unknown primary in CR received 22 cycles. Clinical trial information: NCT01407562. Conclusions: PK confirm that pazo is a weak inhibitor of CYP3A4 and CYP2C8. Myelosuppression was a major adverse event at all dose levels. MTD was not determined. Antitumor activity was achieved with this alternate combination schedule and sustained responses from sequential pazo monotherapy was observed.[Table: see text]

Therapy with high-dose Interleukin-2 (HD IL-2) in metastatic melanoma and renal cell carcinoma following PD1 or PDL1 inhibition

Background

Metastatic melanoma (mM) and renal cell carcinoma (mRCC) are often treated with anti-PD-1 based therapy, however not all patients respond and further therapies are needed. High dose interleukin-2 (HD IL-2) can lead to durable responses in a subset of mM and mRCC patients. The efficacy and toxicity of HD IL-2 therapy following anti-PD-1 or anti-PD-L1 therapy have not yet been explored.

Methods

Reports on mM and mRCC patients who had received HD IL-2 after PD-1 or PD-L1 inhibition were queried from the PROCLAIM^SM database. Patient characteristics, toxicity and efficacy were analyzed.

Results

A total of 57 patients (40 mM, 17 mRCC) were treated with high dose IL-2 after PD-1 or PD-L1 inhibition and had data recorded in the PROCLAIM database. The best overall response rate to HD IL-2 was 22.5% for mM (4 complete response (CR), 5 partial responses (PRs)) and 24% for mRCC (2 CRs, 2 PRs). The toxicity related to HD IL-2 observed in these patients was similar to that observed in patients treated with HD IL-2 without prior checkpoint blockade. One patient who had received prior PD-L1 blockade developed drug induced pneumonitis with HD IL-2 requiring steroid therapy.

Conclusion

In this retrospective analysis, HD IL-2 therapy displayed durable antitumor activity in mM and mRCC patients who progressed following treatment with PD-1 and PD-L1 inhibition. The toxicities were generally manageable and consistent with expectations from HD IL-2 but physicians should watch for immune related toxicities such as pneumonitis. This analysis supports the development of randomized prospective trials to assess the proper sequencing and combination of immune checkpoint blockade and cytokine therapy.

Electronic supplementary material

The online version of this article (10.1186/s40425-019-0522-3) contains supplementary material, which is available to authorized users.