Faculty Bibliography

The mechanisms underlying the efficacy of anti-programmed cell death protein 1 (PD-1) and anti-cytotoxic T lymphocyte-associated protein 4 (CTLA-4) therapy are incompletely understood. Here, by immune profiling responding PD-1⁺CD8⁺ T (T_Resp) cell populations from patients with advanced melanoma, we identified differential programming of T_Resp cells in response to combination therapy, from an exhausted toward a more cytotoxic effector program. This effect does not occur with anti-PD-1 monotherapy. Single-cell transcriptome and T cell receptor repertoire analysis was used to identify altered effector programming of expanding PD-1⁺CD8⁺ T cell clones with distinct regulon usage, STAT1 and STAT3 utilization and antitumor specificity connected to interleukin (IL)-21 signaling in combination and anti-CTLA-4 monotherapy. Therapeutic efficacy of CTLA-4 blockade was lost in B16F10 melanoma models with either Il21r^- deficiency or anti-IL-21 receptor blockade. Together, these results show how IL-21 signaling to T_Resp is critical for anti-CTLA-4-based checkpoint therapies and highlight major signaling differences to anti-PD-1 monotherapy.

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/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.

mRNA-4157 (V940) is an individualized neoantigen therapy (INT) targeting up to 34 patient-specific tumor neoantigens to induce T cell responses and potentiate anti-tumor activity. We report mechanistic insights into the immunogenicity of mRNA-4157 via characterization of T cell responses to neoantigens from the first-in-human phase 1, KEYNOTE-603 study (NCT03313778) in patients with resected non-small cell lung cancer (Part A: 1mg mRNA-4157, n = 4) or resected cutaneous melanoma (Part D: 1mg mRNA-4157 + 200mg pembrolizumab, n = 12). Safety, tolerability, and immunogenicity were assessed. All patients experienced ≥1 treatment-emergent adverse event (AE); there were no grade 4/5 AEs or dose-limiting toxicities. mRNA-4157 alone induced consistent de novo, and strengthened pre-existing, T cell responses to targeted neoantigens. Following combination therapy, sustained mRNA-4157-induced neoantigen-specific T cell responses and expansion of cytotoxic CD8 and CD4 T cells were observed. These findings show the potential of a novel mRNA INT approach in oncology.

PURPOSE/UNASSIGNED:Immune checkpoint inhibition (ICI) shows benefits in adjuvant (AT) and neoadjuvant melanoma treatments. However, ICI frequently induces severe immune-related adverse events (irAE). Unlike metastatic disease, in which irAEs are a clinical trade-off for treatment that improves survival, the toxicity burden from ICI in the AT setting is a substantial clinical problem urging for irAE-predictive biomarkers. EXPERIMENTAL DESIGN/UNASSIGNED:We assessed postsurgical, pre-ICI treatment peripheral CD4+ and CD8+ T cells from clinical trial patients (CheckMate 915) treated with AT nivolumab (n = 130) or ipilimumab/nivolumab (COMBO, n = 82). Performing RNA sequencing differential gene expression analysis, we tested baseline differences associated with severe (grades 3-5) irAEs and constructed an irAE-predictive model using least absolute shrinkage and selection operator-regularized logistic regression. RESULTS/UNASSIGNED:The analysis of predicted protein-protein interactions among differentially expressed genes in peripheral CD4+ cells revealed significant enrichment of the spleen tyrosine kinase (SYK) pathway, associated with severe irAEs in COMBO-treated patients. This gene expression signature predicted severe-irAE COMBO patients (χ2P value = 0.001) with 73% accuracy and was independent of disease recurrence (P = 0.79). The irAE-predictive model incorporating this gene expression signature demonstrated 82% accuracy (χ2P value = 8.91E-06). CONCLUSIONS/UNASSIGNED:We identified baseline gene expression differences in key immune pathways of peripheral blood T cells from COMBO-treated patients with grades 3 to 5 irAEs and defined a SYK-related gene signature correctly identifying ∼60% of COMBO-treated patients with grades 3 to 5 irAEs. This finding aligns with our previous work linking anti-CTLA4 irAEs with a germline variant associated with high SYK expression. This gene signature may serve as a baseline biomarker of severe grade 3 to 5 irAE risk, which is especially important in AT treatment.

INTRODUCTION/BACKGROUND:Approximately 50 % of resected stage II-IV melanoma patients develop recurrent disease by 5 years despite adjuvant anti-PD-1 therapy. Data to define best management of recurrences is lacking. METHODS:This was a multicentre, international, retrospective cohort study. Patients with resected stage II-IV melanoma who commenced adjuvant anti-PD-1-based therapy before January 2022 and later recurred were identified. Data on demographics, disease characteristics, recurrence patterns, management and outcomes were collected. RESULTS:711 patients from 17 sites were included. Median age was 60 [range 16-92], 64 % were male, 2 % stage II, 91 % were stage III, 7 % stage IV. Median time to recurrence was 6.2 months (0-68.5) and median follow up time from recurrence was 19.8 months (range 0.2-73.1). 63 % recurred on anti-PD-1 therapy, 36 % off therapy [3 % < 6 months, 33 % > 6 months]. Initial recurrences were locoregional (LR) alone in 44 %, distant alone (DR) in 43 %, and 11 % in both sites. LR recurrences were managed with local therapy, alone (62 %) or with "second adjuvant" anti-PD-1 (14 %) or BRAF/MEK therapy (23 %); 12 m RFS2 was 25 %, 29 % and 69 % respectively (p = 0.0045). Definitive systemic therapy at first recurrence was given in 16 % LR and 86 % DR, with best outcomes for anti-CTLA4 + anti-PD-1 and trial combinations (24 m PFS 63 % and 69 %, respectively). The 24 m OS for the entire cohort was 65 %. CONCLUSION/CONCLUSIONS:Most recurrences following adjuvant anti-PD-1 based therapy occur early and while still on drug. Outcomes are poor, regardless of site, timing of recurrence, and subsequent treatment.

Combination checkpoint blockade with anti-PD-1 and anti-CTLA-4 antibodies has shown promising efficacy in melanoma. However, the underlying mechanism in humans remains unclear. Here, we perform paired single-cell RNA and T cell receptor (TCR) sequencing across time in 36 patients with stage IV melanoma treated with anti-PD-1, anti-CTLA-4, or combination therapy. We develop the algorithm Cyclone to track temporal clonal dynamics and underlying cell states. Checkpoint blockade induces waves of clonal T cell responses that peak at distinct time points. Combination therapy results in greater magnitude of clonal responses at 6 and 9 weeks compared to single-agent therapies, including melanoma-specific CD8⁺ T cells and exhausted CD8⁺ T cell (T_EX) clones. Focused analyses of T_EX identify that anti-CTLA-4 induces robust expansion and proliferation of progenitor T_EX, which synergizes with anti-PD-1 to reinvigorate T_EX during combination therapy. These next generation immune profiling approaches can guide the selection of drugs, schedule, and dosing for novel combination strategies.

PURPOSE/OBJECTIVE:In phase III CheckMate 238, adjuvant nivolumab significantly improved recurrence-free survival compared with ipilimumab in patients with resected stage IIIB-C/IV melanoma without a significant difference in overall survival (OS). Here, we investigate progression-free survival (PFS) and OS after postrecurrence systemic therapy. PATIENTS AND METHODS/METHODS:>12 months [late] from initial therapy). RESULTS:73%). In response to subsequent therapy, patients on nivolumab with late versus early recurrence were more likely to benefit from anti-PD-1 monotherapy. Nivolumab-treated patients with either an early or late recurrence benefitted from an ipilimumab-based therapy or targeted therapy, each with similar OS. CONCLUSION/CONCLUSIONS:Postrecurrence survival was longer for patients who recurred >12 months. Patients on nivolumab who recurred early benefitted from SST but had better survival with ipilimumab-based regimens or targeted therapy compared with anti-PD-1 monotherapy.

The origins of cancer vaccines date back to the 1800s. Since then, there have been significant efforts to generate vaccines against solid and hematologic malignancies using a variety of platforms. To date, these efforts have generally been met with minimal success. However, in the era of improved methods and technological advancements, supported by compelling preclinical and clinical data, a wave of renewed interest in the field offers the promise of discovering field-changing paradigms in the management of established and resected disease using cancer vaccines. These include novel approaches to personalized neoantigen vaccine development, as well as innovative immune-modulatory vaccines (IMVs) that facilitate activation of antiregulatory T cells to limit immunosuppression caused by regulatory immune cells. This article will introduce some of the limitations that have affected cancer vaccine development over the past several decades, followed by an introduction to the latest advancements in neoantigen vaccine and IMV therapy, and then conclude with a discussion of some of the newest technologies and progress that are occurring across the cancer vaccine space. Cancer vaccines are among the most promising frontiers for breakthrough innovations and strategies poised to make a measurable impact in the ongoing fight against cancer.

OBJECTIVES/OBJECTIVE:Nivolumab is approved as adjuvant therapy for resected stage III/IV melanoma based on the phase 3 CheckMate 238 trial. This analysis compared outcomes from CheckMate 238 with those from the real-world Flatiron Health electronic health record-derived de-identified database in patients with resected stage III melanoma (per AJCC-8) treated with adjuvant nivolumab. MATERIALS/METHODS:Outcomes included baseline characteristics, overall survival (OS) in the CheckMate 238 cohort (randomization until death or last known alive), and real-world overall survival (rwOS) in the Flatiron Health cohort (nivolumab initiation until death or data cutoff). rwOS was compared with OS using unadjusted and adjusted Cox proportional hazards models. Inverse probability of treatment weighting (IPTW) was combined with the adjusted model to reduce baseline discrepancies. RESULTS:The CheckMate 238 and real-world cohorts included 369 and 452 patients, respectively (median age, 56.0 and 63.0 years; median follow-up, 61.4 vs. 25.5 months). rwOS was not different from OS in the unadjusted (hazard ratio [HR] 1.27; 95% CI 0.92-1.74), adjusted (HR 1.01; 95% CI 0.67-1.54), and adjusted IPTW (HR 1.07; 95% CI 0.70-1.63) analyses. In the adjusted analysis, 2-year OS and rwOS rates were 84%. Median OS and rwOS were not reached. After IPTW, OS and rwOS were not different (HR 1.07; 95% CI 0.70-1.64). CONCLUSIONS:In this comparative analysis, OS in the CheckMate 238 trial was similar to rwOS in the Flatiron Health database after adjustments in patients with resected stage III melanoma (per AJCC-8) treated with adjuvant nivolumab, validating the trial results.

WHAT IS THIS SUMMARY ABOUT?/UNASSIGNED:in October 2023. The study goal was to learn whether nivolumab works as an adjuvant therapy (that is, helps to keep cancer from coming back when it is given after surgery) for stage 2 melanoma (skin cancer) that has not spread to other parts of the body. Nivolumab is an immunotherapy that activates a person's immune system so it can destroy cancer cells. In melanoma, staging describes the severity of the cancer. Melanoma staging ranges from 0 (very thin and confined to the upper layer of the skin) to 4 (spread to distant parts of the body), with earlier stages removed by surgery. The people in this study had stage 2 melanoma that had not spread to the lymph nodes or other organs in the body. HOW WAS THE STUDY DESIGNED?/UNASSIGNED:People 12 years and older with stage 2 melanoma that had not spread and had been removed by surgery were included in CheckMate 76K. People were randomly assigned to receive either nivolumab (526 patients) or placebo (264 patients). A placebo resembles the test medicine but does not contain any active medicines. The researchers assessed whether people who received nivolumab lived longer without their cancer returning and/or spreading to other parts of their bodies (compared with placebo) and if nivolumab was well tolerated. WHAT WERE THE RESULTS?/UNASSIGNED:Researchers found that people who received nivolumab were 58% less likely to have their cancer return and 53% less likely of having their cancer spread to distant parts of their body, compared with placebo. These reductions in risk with nivolumab were seen in different subgroups of people with a range of characteristics, and regardless of how deep the melanoma had gone into the skin. People taking nivolumab had more side effects than those taking placebo, but most were mild to moderate and manageable. WHAT DO THE RESULTS MEAN?/UNASSIGNED:Results from CheckMate 76K support the benefit of using nivolumab as a treatment option for people with stage 2 melanoma post-surgery.