Faculty Bibliography

Patients with resected, high-risk melanoma receive adjuvant immune checkpoint blockade (ICB), yet clinical benefit remains unpredictable, with 25%-40% of patients experiencing recurrence. To evaluate whether pre-treatment gut microbiome (GMB) features predict recurrence, we analyzed stool samples from 674 patients enrolled in a phase 3 clinical trial, CheckMate 915, which investigated the combination of nivolumab plus ipilimumab versus nivolumab as a single agent across five geographic regions. Region-specific and cross-region meta-analyses identified pre-treatment taxa associated with recurrence, including Eubacterium, Ruminococcus, Firmicutes, and Clostridium. Recurrence prediction was strongest when the validation cohort exhibited GMB profiles similar to those in the discovery cohort. Among closely matched individuals (Jensen-Shannon divergence [JSD] ≤ 0.11), the area under the curve (AUC) for recurrence prediction ranged from 0.78 to 0.94 across regions. GMB composition remained largely stable following treatment. These findings suggest that gut bacterial markers can predict recurrence after adjuvant ICB treatment in melanoma, supporting their potential as clinically actionable biomarkers to guide personalized therapy.

PURPOSE/UNASSIGNED:Cancer treatment has been revolutionized by immune checkpoint inhibitors (ICI). However, a subset of patients do not respond and/or they experience significant adverse events. Attempts to integrate reliable biomarkers of ICI response as part of standard care have been hampered by limited generalizability. We previously reported our supervised machine learning (ML) model in a retrospective cohort of metastatic melanoma. EXPERIMENTAL DESIGN/UNASSIGNED:In this study, we expanded our testing to include larger cohorts of patients with melanoma accrued at several sites, including patients enrolled in clinical trials in both adjuvant and metastatic settings. We examined pretreatment hematoxylin and eosin slides from 639 patients with stage III/IV melanoma treated with ICIs [anti-cytotoxic T-lymphocyte-associated protein 4 (n = 212), anti-programmed death 1 (n = 271), or the combination (n = 156)]. We tested the generalizability of our supervised ML algorithm to predict response to ICIs in the metastatic melanoma cohort and then developed a self-supervised ML model to identify the histologic morphologies associated with patients' survival following ICI use in adjuvant and metastatic melanoma cohorts. RESULTS/UNASSIGNED:We predicted the response to ICI treatment with an AUC of 0.72. The deep convolutional neural network classified patients into high and low risk based on their likelihood of progression-free survival (P < 0.0001). We uncovered a novel association of specific histomorphologic tumor features-epithelioid histology and a low tumor-stroma ratio-with survival following ICI treatment. CONCLUSIONS/UNASSIGNED:Our data support the generalizability of our developed ML algorithm in predicting response to ICI treatment in patients with metastatic unresectable melanoma. We also showed, for the first time, tumor features associated with patients' overall survival.

PURPOSE/OBJECTIVE:CheckMate 915 (NCT03068455) compared adjuvant nivolumab monotherapy versus combination nivolumab+ipilimumab in patients with resected stage III/IV melanoma. This exploratory analysis was performed to identify biomarkers that correlate with benefit from adjuvant immunotherapy. PATIENTS AND METHODS/METHODS:1,844 patients received nivolumab 480 mg every 4 weeks or nivolumab 240 mg every 2 weeks with ipilimumab 1 mg/kg every 6 weeks. Tumor and peripheral biomarkers were evaluated, including tumor-informed circulating tumor DNA (ctDNA) at postresection baseline and on-treatment, for their association with recurrence-free survival and distant metastases-free survival. RESULTS:Biomarker analyses were conducted in 60-96% of the intention-to-treat population. ctDNA positivity at baseline (seen in 16.2% of patients) and on-treatment was associated with higher risk of recurrence than ctDNA negativity (HR, 1.97; 95% CI, 1.57 to 2.46), with a high specificity (87%) and modest sensitivity (39%). ctDNA status, tumor mutational burden (TMB) status (TMB < or ≥350 mutations/tumor) and interferon gamma-RNA signature score (< or ≥median) evaluated together, as well as ctDNA status with tumor CD8 or cell programmed death ligand 1 expression, were more predictive of survival than ctDNA alone. Tumor bulk RNA-seq expression patterns identified gene expression at baseline associated with recurrence. CONCLUSIONS:This study represents the largest assessment of ctDNA and other baseline tumor and peripheral biomarkers for predicting recurrence-free survival in patients with resected melanoma receiving adjuvant immunotherapy. ctDNA alone and in combination with more established biomarkers predicted recurrence-free and distant metastasis-free survival and has potential utility for assessing and monitoring the risk of recurrence in patients with resected melanoma treated with immunotherapy in the adjuvant setting. TRIAL REGISTRATION NUMBER/BACKGROUND:NCT03068455.

Patients with advanced melanoma resistant to immune checkpoint or BRAF/MEK inhibitors have treatment options with relatively low efficacy. Lifileucel, a one-time autologous tumor-infiltrating lymphocyte cell therapy, was approved in the US based on the pivotal C-144-01 study. A 5-year follow-up of the C-144-01 trial assessed the long-term efficacy and safety of lifileucel. At the cutoff date (November 20, 2024), the ORR was 31.4% (complete response [CR], 5.9%; partial response [PR], 25.5%). Overall, 79.3% of patients had tumor burden reduction; 16 had deepened responses with 4 converting from PR to CR > 1 year after lifileucel infusion; 31.3% of responders completed the 5-year assessment with ongoing responses. The median duration of response was 36.5 months. Responders (n = 48) had lower tumor burden and fewer liver or brain metastases than the overall population. Median overall survival (OS) was 13.9 months, with 5-year OS of 19.7%. Adverse events were consistent with nonmyeloablative lymphodepletion and interleukin-2 safety profiles and declined rapidly within 2 weeks after lifileucel infusion. Most grade 3/4 cytopenias resolved to grade ≤ 2 by day 30. This 5-year analysis demonstrated long-term benefit and meaningful OS with one-time lifileucel therapy, with no additional long-term safety concerns.

BACKGROUND:edition (AJCC v8) stage IIIA melanoma have been under-represented in clinical trials of adjuvant drug therapy. The benefit of adjuvant targeted therapy and immunotherapy in this population is unclear. PATIENTS AND METHODS/METHODS:In this multicenter, retrospective study, patients with stage IIIA melanoma (AJCC v8) who received adjuvant pembrolizumab or nivolumab (anti-PD1), BRAF/MEK-targeted therapy dabrafenib + trametinib (TT), or no adjuvant treatment (OBS) were included. Recurrence-free survival (RFS), distant metastasis-free survival (DMFS), and toxicity rates were examined. RESULTS:A total of 628 patients from 34 centers across Australia, Europe and USA were identified - 256 in anti-PD1, 80 in TT and 292 in OBS. The median follow-up was 2.6 years (IQR, 1.6-3.4 years). The presence of some key poor prognostic variables was significantly higher in anti-PD1 compared to OBS. The two-year RFS was 79.3% (95% CI, 74.1-84.8) for anti-PD1, 98.6% (95% CI, 96.0-100) for TT and 84.3% (95% CI, 79.9-89.0) for OBS. The two-year DMFS was 88.4% (95% CI, 84.3-92.8) in anti-PD1, 100% in TT and 91.1% (95% CI, 87.7-94.7) in OBS. Higher Breslow thickness and higher mitotic rate were associated with higher risk of recurrence in the anti-PD1 and OBS (P<0.05). Rates of ≥ Grade 3 toxicities were 10.9% with anti-PD1 and 17.5% with TT; discontinuation due to toxicity occurred in 13.3% and 21.2%, respectively. Rates of unresolved toxicity at last follow-up were 26.9% in anti-PD1 and 12.5% in TT groups. CONCLUSIONS:Stage IIIA melanoma has a modest risk of recurrence. Adjuvant anti-PD1 did not significantly improve RFS or DMFS compared to OBS alone. Adjuvant TT appears promising over anti-PD1 or OBS. Outcomes after adjuvant therapy in this population needs further study in larger datasets with longer follow up or prospective randomised trials.

BACKGROUND:In the phase 3 CheckMate 76 K trial, adjuvant nivolumab significantly improved recurrence-free survival and distant metastasis-free survival versus placebo in patients with resected stage IIB/C melanoma. We report patient-reported outcomes from CheckMate 76 K. METHODS:Change from baseline to week 53 in health-related quality of life (HRQoL), as measured using the EORTC QLQ-C30 and EQ-5D-5L utility index and visual analog scale (VAS), was compared between treatment groups using linear mixed-effect models. Time to confirmed deterioration (TTCD) in HRQoL was assessed using Cox regression. Bother from side effects, as measured by the FACIT-GP5, was descriptively compared between treatment groups. RESULTS:There were no clinically meaningful differences in change from baseline between treatment groups in EORTC QLQ-C30 subscales, including global health status (GHS)/quality of life (QoL; least squares mean [LSM] difference: -1.3; 95 % confidence interval [CI]: -2.9, 0.4), and EQ-5D-5L utility index (LSM difference: -0.011; 95 % CI: -0.025, 0.004) and VAS (LSM difference: -1.3; 95 % CI: -2.6, 0.0). There was no difference in TTCD for nivolumab versus placebo in EORTC QLQ-C30 GHS/QoL (hazard ratio [HR]: 1.10; 95 % CI: 0.88, 1.36) or EQ-5D-5L utility index (HR: 1.10; 95 % CI: 0.86, 1.42); however, TTCD in EQ-5D-5L VAS was longer with placebo (HR: 1.92; 95 % CI: 1.39, 2.64). Proportions of patients reporting severe side effect bother ("quite a bit"/"very much") were minimal (nivolumab: 1 %-4 %; placebo: 0 %-2 %). CONCLUSIONS:Patients with resected stage IIB/C melanoma treated with adjuvant nivolumab demonstrated stable HRQoL and minimal bother from side effects. CLINICAL TRIAL INFORMATION/BACKGROUND:NCT04099251.

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.

The gut microbiome (GMB) has been associated with outcomes of immune checkpoint blockade therapy in melanoma, but there is limited consensus on the specific taxa involved, particularly across different geographic regions. We analyzed pre-treatment stool samples from 674 melanoma patients participating in a phase-III trial of adjuvant nivolumab plus ipilimumab versus nivolumab, across three continents and five regions. Longitudinal analysis revealed that GMB was largely unchanged following treatment, offering promise for lasting GMB-based interventions. In region-specific and cross-region meta-analyses, we identified pre-treatment taxonomic markers associated with recurrence, including Eubacterium, Ruminococcus, Firmicutes, and Clostridium. Recurrence prediction by these markers was best achieved across regions by matching participants on GMB compositional similarity between the intra-regional discovery and external validation sets. AUCs for prediction ranged from 0.83-0.94 (depending on the initial discovery region) for patients closely matched on GMB composition (e.g., JSD ≤0.11). This evidence indicates that taxonomic markers for prediction of recurrence are generalizable across regions, for individuals of similar GMB composition.