Unraveling the Therapeutic Benefit of Sequenced Chemo-immunotherapy

Combination immune-checkpoint inhibition with chemotherapy is a clinical standard, yet concurrent administration may limit the full benefit of immunotherapy by blunting the proliferation and differentiation of CD8 T cells. Identifying patients in whom sequential chemo-immunotherapy or immunotherapy alone is feasible should be a priority to optimize long-term outcomes. See related article by Mariniello et al., p. 1833.

Facts and Hopes in Using Omics to Advance Combined Immunotherapy Strategies

The field of oncology has been transformed by immune checkpoint inhibitors (ICI) and other immune-based agents; however, many patients do not receive a durable benefit. While biomarker assessments from pivotal ICI trials have uncovered certain mechanisms of resistance, results thus far have only scraped the surface. Mechanisms of resistance are as complex as the tumor microenvironment (TME) itself, and the development of effective therapeutic strategies will only be possible by building accurate models of the tumor-immune interface. With advancement of multi-omic technologies, high-resolution characterization of the TME is now possible. In addition to sequencing of bulk tumor, single-cell transcriptomic, proteomic, and epigenomic data as well as T-cell receptor profiling can now be simultaneously measured and compared between responders and nonresponders to ICI. Spatial sequencing and imaging platforms have further expanded the dimensionality of existing technologies. Rapid advancements in computation and data sharing strategies enable development of biologically interpretable machine learning models to integrate data from high-resolution, multi-omic platforms. These models catalyze the identification of resistance mechanisms and predictors of benefit in ICI-treated patients, providing scientific foundation for novel clinical trials. Moving forward, we propose a framework by which in silico screening, functional validation, and clinical trial biomarker assessment can be used for the advancement of combined immunotherapy strategies.

Rapidly Evolving Pre- and Post-surgical Systemic Treatment of Melanoma

With the development of effective BRAF-targeted and immune-checkpoint immunotherapies for metastatic melanoma, clinical trials are moving these treatments into earlier adjuvant and perioperative settings. BRAF-targeted therapy is a standard of care in resected stage III-IV melanoma, while anti-programmed death-1 (PD1) immunotherapy is now a standard of care option in resected stage IIB through IV disease. With both modalities, recurrence-free survival and distant-metastasis-free survival are improved by a relative 35-50%, yet no improvement in overall survival has been demonstrated. Neoadjuvant anti-PD1 therapy improves event-free survival by approximately an absolute 23%, although improvements in overall survival have yet to be demonstrated. Understanding which patients are most likely to recur and which are most likely to benefit from treatment is now the highest priority question in the field. Biomarker analyses, such as gene expression profiling of the primary lesion and circulating DNA, are preliminarily exciting as potential biomarkers, though each has drawbacks. As in the setting of metastatic disease, markers that inform positive outcomes include interferon-γ gene expression, PD-L1, and high tumor mutational burden, while negative predictors of outcome include circulating factors such as lactate dehydrogenase, interleukin-8, and C-reactive protein. Integrating and validating these markers into clinically relevant models is thus a high priority. Melanoma therapeutics continues to advance with combination adjuvant approaches now investigating anti-PD1 with lymphocyte activation gene 3 (LAG3), T-cell immunoreceptor with Ig and ITIM domains (TIGIT), and individualized neoantigen therapies. How this progress will be integrated into the management of a unique patient to reduce recurrence, limit toxicity, and avoid over-treatment will dominate clinical research and patient care over the next decade.

Top advances of the year: Melanoma

The field of melanoma therapeutics is moving quickly with the first approval of adoptive cell transfer in solid tumors. Moreover, individualized neoantigen therapies, PRAME‐targeting strategies, oncolytic viruses, and more are rapidly emerging.

Radiomic analysis of patient and inter-organ heterogeneity in response to immunotherapies and BRAF targeted therapy in metastatic melanoma

Background

Variability in treatment response may be attributable to organ-level heterogeneity in tumor lesions. Radiomic analysis of medical images can elucidate non-invasive biomarkers of clinical outcome. Organ-specific radiomic comparison across immunotherapies and targeted therapies has not been previously reported.

Methods

We queried UPMC Hillman Cancer Center registry for patients with metastatic melanoma (MEL) treated with immune checkpoint inhibitors (ICI) (anti-PD1/CTLA4 [ipilimumab+nivolumab; I+N] or anti-PD1 monotherapy) or BRAF targeted therapy. Best overall response was measured using RECIST v1.1. Lesions were segmented into discrete volume-of-interest with 400 radiomics features extracted. Overall and organ-specific machine-learning models were constructed to predict disease control (DC) versus progressive disease (PD) using XGBoost.

Results

291 MEL patients were identified, including 242 ICI (91 I+N, 151 PD1) and 49 BRAF. 667 metastases were analyzed, including 541 ICI (236 I+N, 305 PD1) and 126 BRAF. Across cohorts, baseline demographics included 39-47% female, 24-29% M1C, 24-46% M1D, and 61-80% with elevated LDH. Among patients experiencing DC, the organs with the greatest reduction were liver (-88%±12%, I+N; mean±S.E.M.) and lung (-72%±8%, I+N). For patients with multiple same-organ target lesions, the highest inter-lesion heterogeneity was observed in brain among patients who received ICI while no intra-organ heterogeneity was observed in BRAF. 267 patients were kept for radiomic modeling, including 221 ICI (86 I+N, 135 PD1) and 46 BRAF. Models consisting of optimized radiomic signatures classified DC/PD across I+N (AUC=0.85) and PD1 (0.71) and within individual organ sites (AUC=0.72∼0.94). Integration of clinical variables improved the models' performance. Comparison of models between treatments and across organ sites suggested mostly non-overlapping DC or PD features. Skewness, kurtosis, and informational measure of correlation (IMC) were among the radiomic features shared between overall response models. Kurtosis and IMC were also utilized by multiple organ-site models.

Conclusions

Differential organ-specific response was observed across BRAF and ICI with within organ heterogeneity observed for ICI but not for BRAF. Radiomic features of organ-specific response demonstrated little overlap. Integrating clinical factors with radiomics improves the prediction of disease course outcome and prediction of tumor heterogeneity.

Th2 Cells Are Associated with Tumor Recurrence Following Radiation

The curative treatment of multiple solid tumors, including head and neck squamous cell carcinoma (HNSCC), utilizes radiation. The outcomes for HPV/p16-negative HNSCC are significantly worse than HPV/p16-positive tumors, with increased radiation resistance leading to worse locoregional recurrence (LRR) and ultimately death. This study analyzed the relationship between immune function and outcomes following radiation in HPV/p16-negative tumors to identify mechanisms of radiation resistance and prognostic immune biomarkers. A discovery cohort of 94 patients with HNSCC treated uniformly with surgery and adjuvant radiation and a validation cohort of 97 similarly treated patients were utilized. Tumor immune infiltrates were derived from RNAseq gene expression. The immune cell types significantly associated with outcomes in the discovery cohort were examined in the independent validation cohort. A positive association between high Th2 infiltration and LRR was identified in the discovery cohort and validated in the validation cohort. Tumor mutations in CREBBP/EP300 and CASP8 were significantly associated with Th2 infiltration. A pathway analysis of genes correlated with Th2 cells revealed the potential repression of the antitumor immune response and the activation of BRCA1-associated DNA damage repair in multiple cohorts. The Th2 infiltrates were enriched in the HPV/p16-negative HNSCC tumors and associated with LRR and mutations in CASP8, CREBBP/EP300, and pathways previously shown to impact the response to radiation.

Pharmacokinetic study of capivasertib and the CYP3A4 substrate midazolam in patients with advanced solid tumors

PURPOSE

Capivasertib, a potent, selective inhibitor of all three AKT serine/threonine kinase (AKT) isoforms, is being evaluated in phase 3 trials in advanced breast and prostate cancer. This study evaluated the drug-drug interaction risk of capivasertib with the cytochrome P450 3A substrate midazolam in previously treated adults with advanced solid tumors.

METHODS

Patients received oral capivasertib 400 mg twice daily (BID) on an intermittent schedule (4 days on/3 days off) starting on day 2 of cycle 1 (29 days) and on day 1 of each 28-day cycle thereafter. In cycle 1 only, patients received oral midazolam (1 mg) on day 1 (alone), and days 8 and 12 (3rd day off and 4th day on capivasertib, respectively). Midazolam pharmacokinetics on days 8 and 12 were analyzed versus day 1. Capivasertib, with or without standard-of-care treatment, was continued in patients deemed likely to benefit. Safety and exploratory efficacy analyses were conducted.

RESULTS

Capivasertib-midazolam coadministration increased midazolam exposure (n = 21): geometric mean ratio (90% confidence interval) AUCinf and Cmax was 1.13 (0.97-1.32) and 1.15 (0.99-1.33) for day 8 versus day 1, and 1.75 (1.50-2.05) and 1.25 (1.08-1.46) for day 12 versus day 1. The capivasertib safety profile was manageable when administered with or without midazolam. Two patients had partial responses to treatment.

CONCLUSION

The up to 1.75-fold increase in midazolam exposure indicates capivasertib is a weak CYP3A inhibitor at 400 mg BID on an intermittent schedule. Capivasertib was well tolerated; exploratory efficacy analysis demonstrated evidence of clinical activity in this heavily pre-treated population.

CLINICALTRIALS

gov: NCT04958226.

Society for Immunotherapy of Cancer (SITC) recommendations on intratumoral immunotherapy clinical trials (IICT): from premalignant to metastatic disease

BACKGROUND

Intratumorally delivered immunotherapies have the potential to favorably alter the local tumor microenvironment and may stimulate systemic host immunity, offering an alternative or adjunct to other local and systemic treatments. Despite their potential, these therapies have had limited success in late-phase trials for advanced cancer resulting in few formal approvals. The Society for Immunotherapy of Cancer (SITC) convened a panel of experts to determine how to design clinical trials with the greatest chance of demonstrating the benefits of intratumoral immunotherapy for patients with cancers across all stages of pathogenesis.

METHODS

An Intratumoral Immunotherapy Clinical Trials Expert Panel composed of international key stakeholders from academia and industry was assembled. A multiple choice/free response survey was distributed to the panel, and the results of this survey were discussed during a half-day consensus meeting. Key discussion points are summarized in the following manuscript.

RESULTS

The panel determined unique clinical trial designs tailored to different stages of cancer development-from premalignant to unresectable/metastatic-that can maximize the chance of capturing the effect of intratumoral immunotherapies. Design elements discussed included study type, patient stratification and exclusion criteria, indications of randomization, study arm determination, endpoints, biological sample collection, and response assessment with biomarkers and imaging. Populations to prioritize for the study of intratumoral immunotherapy, including stage, type of cancer and line of treatment, were also discussed along with common barriers to the development of these local treatments.

CONCLUSIONS

The SITC Intratumoral Immunotherapy Clinical Trials Expert Panel has identified key considerations for the design and implementation of studies that have the greatest potential to capture the effect of intratumorally delivered immunotherapies. With more effective and standardized trial designs, the potential of intratumoral immunotherapy can be realized and lead to regulatory approvals that will extend the benefit of these local treatments to the patients who need them the most.

US physician perspective on the use of biomarker and ctDNA testing in patients with melanoma

New treatments have increased survival of patients with melanoma, and methods to monitor patients throughout the disease process are needed. Circulating tumor DNA (ctDNA) is a predictive and prognostic biomarker that may allow routine, real-time monitoring of disease status. We surveyed 44 US physicians to understand their preferences and practice patterns for biomarker and ctDNA testing in their patients with melanoma. Tumor biomarker testing was often ordered in stage IIIA-IV patients. Barriers to biomarker testing include insufficient tissue (60%) and lack of insurance coverage (54%). ctDNA testing was ordered by 16-18% of physicians for stages II-IV. Reasons for not using ctDNA testing included lack of prospective data (41%), ctDNA testing used for research only (18%), and others. Physicians (≥74%) believed that ctDNA assays could help with monitoring and treatment selection throughout the disease process. Physicians consider ctDNA testing potentially valuable for clinical decision-making but cited concerns that should be addressed.

Nivolumab + Tacrolimus + Prednisone ± Ipilimumab for Kidney Transplant Recipients With Advanced Cutaneous Cancers

PURPOSE

Cancer-related mortality rates among kidney transplant recipients (KTR) are high, but these patients have largely been excluded from trials of immune checkpoint inhibitors because of immunosuppression and risk of treatment-related allograft loss (TRAL). We conducted a prospective clinical trial testing nivolumab (NIVO) + tacrolimus (TACRO) + prednisone (PRED) ± ipilimumab (IPI) in KTR with advanced cutaneous cancers.

METHODS

Adult KTR with advanced melanoma or basal, cutaneous squamous, or Merkel cell carcinomas were eligible. Immunosuppression was standardized to TACRO (serum trough 2-5 ng/mL) + PRED 5 mg once daily. Patients then received NIVO 480 mg IV once every 4 weeks. The primary composite end point was partial or complete (tumor) response (CR) or stable disease per RECIST v1.1 without allograft loss at 16W. Patients with progressive disease (PD) could receive IPI 1 mg/kg IV + NIVO 3 mg/kg once every 3 weeks × 4 followed by NIVO. Donor-derived cell-free DNA (dd-cfDNA) levels were measured approximately once every 2 weeks as a potential predictor of allograft rejection.

RESULTS

Among eight evaluable patients, none met the trial's primary end point. All eight patients experienced PD on NIVO + TACRO + PRED; TRAL occurred in one patient. Six patients then received IPI + NIVO + TACRO + PRED. Best overall responses: two CR (one with TRAL) and four PD (one with TRAL). In total, 7 of 8 pre-NIVO tumor biopsies contained a paucity of infiltrating immune cells. In total, 2 of 5 on-NIVO biopsies demonstrated moderate immune infiltrates; both patients later experienced a CR to IPI + NIVO. In 2 of 3 patients with TRAL, dd-cfDNA elevations occurred 10 and 15 days before increases in serum creatinine.

CONCLUSION

In most KTR with advanced skin cancer, TACRO + PRED provides insufficient allograft protection and compromises immune-mediated tumor regression after administration of NIVO ± IPI. Elevated dd-cfDNA levels can signal treatment-related allograft rejection earlier than rises in serum creatinine.

Pembrolizumab Versus Placebo as Adjuvant Therapy in Resected Stage IIB or IIC Melanoma: Final Analysis of Distant Metastasis-Free Survival in the Phase III KEYNOTE-716 Study

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.Pembrolizumab adjuvant therapy was shown to significantly improve recurrence-free survival (RFS) and distant metastasis-free survival (DMFS) in patients with resected stage IIB or IIC melanoma in earlier analyses of the randomized, double-blind, phase III KEYNOTE-716 study (ClinicalTrials.gov identifier: NCT03553836). We report results of the protocol-specified final analysis of DMFS for KEYNOTE-716. Overall, 976 patients were randomly allocated to pembrolizumab (n = 487) or placebo (n = 489). As of January 4, 2023, median follow-up was 39.4 months (range, 26.0-51.4 months). The median DMFS was not reached in either treatment group, and the estimated 36-month DMFS was 84.4% for pembrolizumab and 74.7% for placebo (hazard ratio [HR], 0.59 [95% CI, 0.44 to 0.79]). The median RFS was not reached in either treatment group, and the estimated 36-month RFS was 76.2% for pembrolizumab and 63.4% for placebo (HR, 0.62 [95% CI, 0.49 to 0.79]). DMFS and RFS results were consistent across most prespecified subgroups, including stage IIB and stage IIC melanoma. The safety profile of pembrolizumab was manageable and consistent with previous reports. These results continue to support the use of pembrolizumab adjuvant therapy in patients with resected stage IIB or IIC melanoma.

Final results of urelumab, an anti-CD137 agonist monoclonal antibody, in combination with cetuximab or nivolumab in patients with advanced solid tumors

BACKGROUND

Resistance to immune checkpoint inhibitors and targeted treatments for cancer is common; thus, novel immunotherapy agents are needed. Urelumab is a monoclonal antibody agonist that binds to CD137 receptors expressed on T cells. Here, we report two studies that evaluated urelumab in combination with cetuximab or nivolumab in patients with select, advanced solid tumors.

METHODS

CA186-018: Patients with metastatic colorectal cancer or metastatic squamous cell carcinoma of the head and neck (SCCHN) were treated in a dose-evaluation phase with urelumab 0.1 mg/kg (urelumab-0.1) every 3 weeks (Q3W)+cetuximab 250 mg/m2 (cetuximab-250) weekly; and in a dose-expansion phase with urelumab 8 mg flat dose (urelumab-8) Q3W+cetuximab-250 weekly. CA186-107: The dose-escalation phase included patients with previously treated advanced solid tumors (or treated or treatment-naive melanoma); patients received urelumab 3 mg flat dose (urelumab-3) or urelumab-8 every 4 weeks+nivolumab 3 mg/kg (nivolumab-3) or 240 mg (nivolumab-240) every 2 weeks. In the expansion phase, patients with melanoma, non-small cell lung cancer, or SCCHN were treated with urelumab-8+nivolumab-240. Primary endpoints were safety and tolerability, and the secondary endpoint included efficacy assessments.

RESULTS

CA186-018: 66 patients received study treatment. The most frequent treatment-related adverse events (TRAEs) were fatigue (75%; n=3) with urelumab-0.1+cetuximab-250 and dermatitis (45%; n=28) with urelumab-8+cetuximab-250. Three patients (5%) discontinued due to TRAE(s) (with urelumab-8+cetuximab-250). One patient with SCCHN had a partial response (objective response rate (ORR) 5%, with urelumab-8+cetuximab-250).CA186-107: 134 patients received study treatment. Fatigue was the most common TRAE (32%; n=2 with urelumab-3+nivolumab-3; n=1 with urelumab-8+nivolumab-3; n=40 with urelumab-8+nivolumab-240). Nine patients (7%) discontinued due to TRAE(s) (n=1 with urelumab-3+nivolumab-3; n=8 with urelumab-8+nivolumab-240). Patients with melanoma naive to anti-PD-1 therapy exhibited the highest ORR (49%; n=21 with urelumab-8+nivolumab-240). Intratumoral gene expression in immune-related pathways (CD3, CD8, CXCL9, GZMB) increased on treatment with urelumab+nivolumab.

CONCLUSIONS

Although the addition of urelumab at these doses was tolerable, preliminary response rates did not indicate an evident additive benefit. Nevertheless, the positive pharmacodynamics effects observed with urelumab and the high response rate in treatment-naive patients with melanoma warrant further investigation of other anti-CD137 agonist agents for treatment of cancer.

TRIAL REGISTRATION NUMBERS

NCT02110082; NCT02253992.

Individualised neoantigen therapy mRNA-4157 (V940) plus pembrolizumab versus pembrolizumab monotherapy in resected melanoma (KEYNOTE-942): a randomised, phase 2b study

BACKGROUND

Checkpoint inhibitors are standard adjuvant treatment for stage IIB-IV resected melanoma, but many patients recur. Our study aimed to evaluate whether mRNA-4157 (V940), a novel mRNA-based individualised neoantigen therapy, combined with pembrolizumab, improved recurrence-free survival and distant metastasis-free survival versus pembrolizumab monotherapy in resected high-risk melanoma.

METHODS

We did an open-label, randomised, phase 2b, adjuvant study of mRNA-4157 plus pembrolizumab versus pembrolizumab monotherapy in patients, enrolled from sites in the USA and Australia, with completely resected high-risk cutaneous melanoma. Patients with completely resected melanoma (stage IIIB-IV) were assigned 2:1 to receive open-label mRNA-4157 plus pembrolizumab or pembrolizumab monotherapy. mRNA-4157 was administered intramuscularly (maximum nine doses) and pembrolizumab intravenously (maximum 18 doses) in 3-week cycles. The primary endpoint was recurrence-free survival in the intention-to-treat population. This ongoing trial is registered at ClinicalTrials.gov, NCT03897881.

FINDINGS

From July 18, 2019, to Sept 30, 2021, 157 patients were assigned to mRNA-4157 plus pembrolizumab combination therapy (n=107) or pembrolizumab monotherapy (n=50); median follow-up was 23 months and 24 months, respectively. Recurrence-free survival was longer with combination versus monotherapy (hazard ratio [HR] for recurrence or death, 0·561 [95% CI 0·309-1·017]; two-sided p=0·053), with lower recurrence or death event rate (24 [22%] of 107 vs 20 [40%] of 50); 18-month recurrence-free survival was 79% (95% CI 69·0-85·6) versus 62% (46·9-74·3). Most treatment-related adverse events were grade 1-2. Grade ≥3 treatment-related adverse events occurred in 25% of patients in the combination group and 18% of patients in the monotherapy group, with no mRNA-4157-related grade 4-5 events. Immune-mediated adverse event frequency was similar for the combination (37 [36%]) and monotherapy (18 [36%]) groups.

INTERPRETATION

Adjuvant mRNA-4157 plus pembrolizumab prolonged recurrence-free survival versus pembrolizumab monotherapy in patients with resected high-risk melanoma and showed a manageable safety profile. These results provide evidence that an mRNA-based individualised neoantigen therapy might be beneficial in the adjuvant setting.

FUNDING

Moderna in collaboration with Merck Sharp & Dohme, a subsidiary of Merck & Co, Rahway, NJ, USA.

Phase I study of peposertib and avelumab with or without palliative radiotherapy in patients with advanced solid tumors

INTRODUCTION

We report results from a phase I, three-part, dose-escalation study of peposertib, a DNA-dependent protein kinase inhibitor, in combination with avelumab, an immune checkpoint inhibitor, with or without radiotherapy in patients with advanced solid tumors.

MATERIALS AND METHODS

Peposertib 100-400 mg twice daily (b.i.d.) or 100-250 mg once daily (q.d.) was administered in combination with avelumab 800 mg every 2 weeks in Part A or avelumab plus radiotherapy (3 Gy/fraction × 10 days) in Part B. Part FE assessed the effect of food on the pharmacokinetics of peposertib plus avelumab. The primary endpoint in Parts A and B was dose-limiting toxicity (DLT). Secondary endpoints were safety, best overall response per RECIST version 1.1, and pharmacokinetics. The recommended phase II dose (RP2D) and maximum tolerated dose (MTD) were determined in Parts A and B.

RESULTS

In Part A, peposertib doses administered were 100 mg (n = 4), 200 mg (n = 11), 250 mg (n = 4), 300 mg (n = 6), and 400 mg (n = 4) b.i.d. Of DLT-evaluable patients, one each had DLT at the 250-mg and 300-mg dose levels and three had DLT at the 400-mg b.i.d. dose level. In Part B, peposertib doses administered were 100 mg (n = 3), 150 mg (n = 3), 200 mg (n = 4), and 250 mg (n = 9) q.d.; no DLT was reported in evaluable patients. Peposertib 200 mg b.i.d. plus avelumab and peposertib 250 mg q.d. plus avelumab and radiotherapy were declared as the RP2D/MTD. No objective responses were observed in Part A or B; one patient had a partial response in Part FE. Peposertib exposure was generally dose proportional.

CONCLUSIONS

Peposertib doses up to 200 mg b.i.d. in combination with avelumab and up to 250 mg q.d. in combination with avelumab and radiotherapy were tolerable in patients with advanced solid tumors; however, antitumor activity was limited.

CLINICALTRIALS

GOV IDENTIFIER

NCT03724890.

Uncovering the Potential of CD40 Agonism to Enhance Immune Checkpoint Blockade

In this CCR Translations, we discuss the therapeutic potential of CD40 agonism, which stimulates antigen-presenting cells (APC) to activate effector T and NK cells. CD40 agonism may lead to development of an interferon-activated, T cell-inflamed tumor microenvironment and has the potential to facilitate long-term response with immune checkpoint blockade. See related article by Weiss et al., p. 74.

Radiation dose, schedule, and novel systemic targets for radio-immunotherapy combinations

Immunotherapy combinations are being investigated to expand the benefit of immune checkpoint blockade across many cancer types. Radiation combinations, in particular using stereotactic body radiotherapy, are of keen interest because of underlying mechanistic rationale, safety, and availability as a standard of care in certain cancers. In addition to direct tumor cytotoxicity, radiation therapy has immunomodulatory effects such as induction of immunogenic cell death, enhancement of antigen presentation, and expansion of the T-cell receptor repertoire as well as recruitment and increased activity of tumor-specific effector CD8+ cells. Combinations of radiation with cytokines and/or chemokines and anti-programmed death 1 and anticytotoxic T-lymphocyte antigen 4 therapies have demonstrated safety and feasibility, as well as the potential to improve long-term outcomes and possibly induce out of irradiated field or abscopal responses. Novel immunoradiotherapy combinations represent a promising therapeutic approach to overcome radioresistance and further enhance systemic immunotherapy. Potential benefits include reversing CD8+ T-cell exhaustion, inhibiting myeloid-derived suppressor cells, and reversing M2 macrophage polarization as well as decreasing levels of colony-stimulating factor-1 and transforming growth factor-β. Here, we discuss current data and mechanistic rationale for combining novel immunotherapy agents with radiation therapy.

The PD-1- and LAG-3-targeting bispecific molecule tebotelimab in solid tumors and hematologic cancers: a phase 1 trial

Tebotelimab, a bispecific PD-1×LAG-3 DART molecule that blocks both PD-1 and LAG-3, was investigated for clinical safety and activity in a phase 1 dose-escalation and cohort-expansion clinical trial in patients with solid tumors or hematologic malignancies and disease progression on previous treatment. Primary endpoints were safety and maximum tolerated dose of tebotelimab when administered as a single agent (n = 269) or in combination with the anti-HER2 antibody margetuximab (n = 84). Secondary endpoints included anti-tumor activity. In patients with advanced cancer treated with tebotelimab monotherapy, 68% (184/269) experienced treatment-related adverse events (TRAEs; 22% were grade ≥3). No maximum tolerated dose was defined; the recommended phase 2 dose (RP2D) was 600 mg once every 2 weeks. There were tumor decreases in 34% (59/172) of response-evaluable patients in the dose-escalation cohorts, with objective responses in multiple solid tumor types, including PD-1-refractory disease, and in LAG-3+ non-Hodgkin lymphomas, including CAR-T refractory disease. To enhance potential anti-tumor responses, we tested margetuximab plus tebotelimab. In patients with HER2+ tumors treated with tebotelimab plus margetuximab, 74% (62/84) had TRAEs (17% were grade ≥3). The RP2D was 600 mg once every 3 weeks. The confirmed objective response rate in these patients was 19% (14/72), including responses in patients typically not responsive to anti-HER2/anti-PD-1 combination therapy. ClinicalTrials.gov identifier: NCT03219268 .

CD4+ TIL to the Rescue of Anti-PD-1 Failure by Targeting MHC-II

In this CCR Translations, we discuss the potential for tumor-infiltrating lymphocyte therapy to overcome immune checkpoint inhibitor resistance through CD4+-mediated and MHC-II-dependent killing. Validating these results from human tumors has potential to improve the clinical application of adoptive cellular transfer in advanced cancers. See related article by Draghi et al., p. 3937.

Society for Immunotherapy of Cancer (SITC) clinical practice guideline on immunotherapy for the treatment of melanoma, version 3.0

Since the first approval for immune checkpoint inhibitors (ICIs) for the treatment of cutaneous melanoma more than a decade ago, immunotherapy has completely transformed the treatment landscape of this chemotherapy-resistant disease. Combination regimens including ICIs directed against programmed cell death protein 1 (PD-1) with anti-cytotoxic T lymphocyte antigen-4 (CTLA-4) agents or, more recently, anti-lymphocyte-activation gene 3 (LAG-3) agents, have gained regulatory approvals for the treatment of metastatic cutaneous melanoma, with long-term follow-up data suggesting the possibility of cure for some patients with advanced disease. In the resectable setting, adjuvant ICIs prolong recurrence-free survival, and neoadjuvant strategies are an active area of investigation. Other immunotherapy strategies, such as oncolytic virotherapy for injectable cutaneous melanoma and bispecific T-cell engager therapy for HLA-A*02:01 genotype-positive uveal melanoma, are also available to patients. Despite the remarkable efficacy of these regimens for many patients with cutaneous melanoma, traditional immunotherapy biomarkers (ie, programmed death-ligand 1 expression, tumor mutational burden, T-cell infiltrate and/or microsatellite stability) have failed to reliably predict response. Furthermore, ICIs are associated with unique toxicity profiles, particularly for the highly active combination of anti-PD-1 plus anti-CTLA-4 agents. The Society for Immunotherapy of Cancer (SITC) convened a panel of experts to develop this clinical practice guideline on immunotherapy for the treatment of melanoma, including rare subtypes of the disease (eg, uveal, mucosal), with the goal of improving patient care by providing guidance to the oncology community. Drawing from published data and clinical experience, the Expert Panel developed evidence- and consensus-based recommendations for healthcare professionals using immunotherapy to treat melanoma, with topics including therapy selection in the advanced and perioperative settings, intratumoral immunotherapy, when to use immunotherapy for patients with BRAFV600-mutated disease, management of patients with brain metastases, evaluation of treatment response, special patient populations, patient education, quality of life, and survivorship, among others.

Debating Sentinel Lymph Node Biopsy for Melanoma in the Modern Adjuvant Era

With the activity of adjuvant immunotherapy, is sentinel lymph node biopsy still needed in melanoma?

PD-1 Monotherapy Reigns Supreme in Adjuvant Melanoma…But for How Long?

The results of CheckMate-238 led to the original FDA approval of anti-PD-1 therapy in high-risk, resectable melanoma. In this CCR Translations, we discuss the 5-year update of this pivotal trial and contextualize its results in the face of limited survival data, neoadjuvant therapy, next-generation biomarkers, and novel immunotherapy combinations. See related article by Larkin et al., p. 3352.

Identification of tumor-intrinsic drivers of immune exclusion in acral melanoma

Background

Acral melanoma (AM) has distinct characteristics as compared to cutaneous melanoma and exhibits poor response to immune checkpoint inhibitors (ICI). Tumor-intrinsic mechanisms of immune exclusion have been identified in many cancers but less studied in AM.

Methods

We characterized clinically annotated tumors from patients diagnosed with AM at our institution in correlation with ICI response using whole transcriptome RNAseq, whole exome sequencing, CD8 immunohistochemistry, and multispectral immunofluorescence imaging. A defined interferon-γ-associated T cell-inflamed gene signature was used to categorize tumors into non-T cell-inflamed and T cell-inflamed phenotypes. In combination with AM tumors from two published studies, we systematically assessed the immune landscape of AM and detected differential gene expression and pathway activation in a non-T cell-inflamed tumor microenvironment (TME). Two single-cell(sc) RNAseq AM cohorts and 11 bulk RNAseq cohorts of various tumor types were used for independent validation on pathways associated with lack of ICI response. In total, 892 specimens were included in this study.

Results

72.5% of AM tumors showed low expression of the T cell-inflamed gene signature, with 23.9% of total tumors categorized as the non-T cell-inflamed phenotype. Patients of low CD3 + CD8 + PD1 + intratumoral T cell density showed poor prognosis. We identified 11 oncogenic pathways significantly upregulated in non-T cell-inflamed relative to T cell-inflamed TME shared across all three acral cohorts (MYC, HGF, MITF, VEGF, EGFR, SP1, ERBB2, TFEB, SREBF1, SOX2, and CCND1). scRNAseq analysis revealed that tumor cell-expressing pathway scores were significantly higher in low vs high T cell-infiltrated AM tumors. We further demonstrated that the 11 pathways were enriched in ICI non-responders compared to responders across cancers, including acral melanoma, cutaneous melanoma, triple-negative breast cancer, and non-small cell lung cancer. Pathway activation was associated with low expression of interferon stimulated genes, suggesting suppression of antigen presentation. Across the 11 pathways, fatty acid synthase and CXCL8 were unifying downstream target molecules suggesting potential nodes for therapeutic intervention.

Conclusions

A unique set of pathways is associated with immune exclusion and ICI resistance in AM. These data may inform immunotherapy combinations for immediate clinical translation.

Tumor cell p38 inhibition to overcome immunotherapy resistance

Patients with tumors that do not respond to immune-checkpoint inhibition often harbor a non-T cell-inflamed tumor microenvironment, characterized by the absence of IFN-γ-associated CD8+ T cell and dendritic cell activation. Understanding the molecular mechanisms underlying immune exclusion in non-responding patients may enable the development of novel combination therapies. p38 MAPK is a known regulator of dendritic and myeloid cells however a tumor-intrinsic immunomodulatory role has not been previously described. Here we identify tumor cell p38 signaling as a therapeutic target to potentiate anti-tumor immunity and overcome resistance to immune-checkpoint inhibitors (ICI). Molecular analysis of tumor tissues from patients with human papillomavirus-negative head and neck squamous carcinoma reveals a p38-centered network enriched in non-T cell-inflamed tumors. Pan-cancer single-cell RNA analysis suggests that p38 activation may be an immune-exclusion mechanism across multiple tumor types. P38 knockdown in cancer cell lines increases T cell migration, and p38 inhibition plus ICI in preclinical models shows greater efficacy compared to monotherapies. In a clinical trial of patients refractory to PD1/L1 therapy, pexmetinib, a p38 inhibitor, plus nivolumab demonstrated deep and durable clinical responses. Targeting of p38 with anti-PD1 has the potential to induce the T cell-inflamed phenotype and overcome immunotherapy resistance.

Germline immunomodulatory expression quantitative trait loci (ieQTLs) associated with immune-related toxicity from checkpoint inhibition

BACKGROUND

Immune checkpoint inhibition (ICI) has improved clinical outcomes for metastatic melanoma patients; however, 65-80% of patients treated with ICI experience immune-related adverse events (irAEs). Given the plausible link of irAEs with underlying host immunity, we explored whether germline genetic variants controlling the expression of 42 immunomodulatory genes were associated with the risk of irAEs in melanoma patients treated with the single-agent anti-CTLA-4 antibody ipilimumab (IPI).

METHODS

We identified 42 immunomodulatory expression quantitative trait loci (ieQTLs) most significantly associated with the expression of 382 immune-related genes. These germline variants were genotyped in IPI-treated melanoma patients, collected as part of a multi-institutional collaboration. We tested the association of ieQTLs with irAEs in a discovery cohort of 95 patients, followed by validation in an additional 97 patients.

RESULTS

We found that the alternate allele of rs7036417, a variant linked to increased expression of SYK, was strongly associated with an increased risk of grade 3-4 toxicity [odds ratio (OR) = 7.46; 95% confidence interval (CI) = 2.65-21.03; p = 1.43E-04]. This variant was not associated with response (OR = 0.90; 95% CI = 0.37-2.21; p = 0.82).

CONCLUSION

We report that rs7036417 is associated with increased risk of severe irAEs, independent of IPI efficacy. SYK plays an important role in B-cell/T-cell expansion, and increased pSYK has been reported in patients with autoimmune disease. The association between rs7036417 and IPI irAEs in our data suggests a role of SYK overexpression in irAE development. These findings support the hypothesis that inherited variation in immune-related pathways modulates ICI toxicity and suggests SYK as a possible future target for therapies to reduce irAEs.

Phase I Study of SYNB1891, an Engineered E. coli Nissle Strain Expressing STING Agonist, with and without Atezolizumab in Advanced Malignancies

PURPOSE

SYNB1891 is a live, modified strain of the probiotic Escherichia coli Nissle 1917 (EcN) engineered to produce cyclic dinucleotides under hypoxia, leading to STimulator of INterferon Genes (STING) activation in phagocytic antigen-presenting cells in tumors and activating complementary innate immune pathways.

PATIENTS AND METHODS

This first-in-human study (NCT04167137) enrolled participants with refractory advanced cancers to receive repeat intratumoral injections of SYNB1891 either alone or in combination with atezolizumab, with the primary objective of evaluating the safety and tolerability of both regimens.

RESULTS

Twenty-four participants received monotherapy across six cohorts, and 8 participants received combination therapy in two cohorts. Five cytokine release syndrome events occurred with monotherapy, including one that met the criteria for dose-limiting toxicity at the highest dose; no other SYNB1891-related serious adverse events occurred, and no SYNB1891-related infections were observed. SYNB1891 was not detected in the blood at 6 or 24 hours after the first intratumoral dose or in tumor tissue 7 days following the first dose. Treatment with SYNB1891 resulted in activation of the STING pathway and target engagement as assessed by upregulation of IFN-stimulated genes, chemokines/cytokines, and T-cell response genes in core biopsies obtained predose and 7 days following the third weekly dose. In addition, a dose-related increase in serum cytokines was observed, as well as stable disease in 4 participants refractory to prior PD-1/L1 antibodies.

CONCLUSIONS

Repeat intratumoral injection of SYNB1891 as monotherapy and in combination with atezolizumab was safe and well tolerated, and evidence of STING pathway target engagement was observed.

CD16+ Macrophages: An Emerging Biomarker for Combined CTLA-4 and PD-1 Blockade

In a retrospective analysis of patients with unresectable melanoma, higher pretreatment tissue densities of CD16+ macrophages were associated with clinical benefit from combined CTLA-4 and PD-1 blockade. With further validation, this biomarker could serve as a tool in selecting between immune checkpoint inhibitor regimens. See related article by Lee et al., p. 2513.

Expression of lymphoid structure-associated cytokine/chemokine gene transcripts in tumor and protein in serum are prognostic of melanoma patient outcomes

Background

Proinflammatory chemokines/cytokines support development and maturation of tertiary lymphoid structures (TLS) within the tumor microenvironment (TME). In the current study, we sought to investigate the prognostic value of TLS-associated chemokines/cytokines (TLS-kines) expression levels in melanoma patients by performing serum protein and tissue transcriptomic analyses, and to then correlate these data with patients clinicopathological and TME characteristics.

Methods

Levels of TLS-kines in patients' sera were quantitated using a custom Luminex Multiplex Assay. The Cancer Genomic Atlas melanoma cohort (TCGA-SKCM) and a Moffitt Melanoma cohort were used for tissue transcriptomic analyses. Associations between target analytes and survival outcomes, clinicopathological variables, and correlations between TLS-kines were statistically analyzed.

Results

Serum of 95 patients with melanoma were evaluated; 48 (50%) female, median age of 63, IQR 51-70 years. Serum levels of APRIL/TNFSF13 were positively correlated with levels of both CXCL10 and CXCL13. In multivariate analyses, high levels of serum APRIL/TNFSF13 were associated with improved event-free survival after adjusting for age and stage (HR = 0.64, 95% CI 0.43-0.95; p = 0.03). High expression of APRIL/TNFSF13 tumor transcripts was significantly associated with improved OS in TCGA-SKCM (HR = 0.69, 95% CI 0.52-0.93; p = 0.01) and in Moffitt Melanoma patients (HR = 0.51, 95% CI: 0.32-0.82; p = 0.006). Further incorporation of CXCL13 and CXCL10 tumor transcript levels in a 3-gene index revealed that high APRIL/CXCL10/CXCL13 expression was associated with improved OS in the TCGA SKCM cohort (HR = 0.42, 95% CI 0.19-0.94; p = 0.035). Melanoma differentially expressed genes positively associated with high APRIL/CXCL10/CXCL13 tumor expression were linked to tumor infiltration by a diverse array of proinflammatory immune cell types.

Conclusion

Serum protein and tumor transcript levels of APRIL/TNFSF13 are associated with improved survival outcomes. Patients exhibiting high coordinate expression of APRIL/CXCL10/CXCL13 transcripts in their tumors displayed superior OS. Further investigation of TLS-kine expression profiles related to clinical outcomes in larger cohort studies is warranted.

Potential of circulating tumor DNA to refine immunotherapy

Circulating tumor DNA (ctDNA) is a noninvasive strategy to disease assessment of minimal residual disease and treatment response for advanced cancer. ctDNA is emerging as a tool for use in clinical practice and informing novel clinical trial designs in melanoma.

Phase I/II sequencing study of azacitidine, epacadostat, and pembrolizumab in advanced solid tumors

BACKGROUND

Indoleamine 2,3-dioxygenase 1 (IDO1), an interferon-inducible enzyme, contributes to tumor immune intolerance. Immune checkpoint inhibition may increase interferon levels; combining IDO1 inhibition with immune checkpoint blockade represents an attractive strategy. Epigenetic agents trigger interferon responses and may serve as an immunotherapy priming method. We evaluated whether epigenetic therapy plus IDO1 inhibition and immune checkpoint blockade confers clinical benefit to patients with advanced solid tumors.

METHODS

ECHO-206 was a Phase I/II study where treatment-experienced patients with advanced solid tumors (N = 70) received azacitidine plus an immunotherapy doublet (epacadostat [IDO1 inhibitor] and pembrolizumab). Sequencing of treatment was also assessed. Primary endpoints were safety/tolerability (Phase I), maximum tolerated dose (MTD) or pharmacologically active dose (PAD; Phase I), and investigator-assessed objective response rate (ORR; Phase II).

RESULTS

In Phase I, no dose-limiting toxicities were reported, the MTD was not reached; a PAD was not determined. ORR was 5.7%, with four partial responses. The most common treatment-related adverse events (AEs) were fatigue (42.9%) and nausea (42.9%). Twelve (17.1%) patients experienced ≥1 fatal AE, one of which (asthenia) was treatment-related.

CONCLUSIONS

Although the azacitidine-epacadostat-pembrolizumab regimen was well tolerated, it was not associated with substantial clinical response in patients with advanced solid tumors previously exposed to immunotherapy.

Partial tumor irradiation plus pembrolizumab in treating large advanced solid tumor metastases

BACKGROUNDWe previously demonstrated the safety of stereotactic body radiotherapy followed by pembrolizumab (SBRT+P) in patients with advanced solid tumors. This phase I clinical trial was expanded to study the safety of partial tumor irradiation (partial-Rx). We assessed irradiated local failure (LF) and clinical outcomes with correlations to biomarkers including CD8+ T cell radiomics score (RS) and circulating cytokines.METHODSPatients received SBRT to 2-4 metastases and pembrolizumab for up to 7 days after SBRT. Tumors measuring up to 65 cc received the full radiation dose (complete-Rx), whereas tumors measuring more than 65 cc received partial-Rx. Landmark analysis was used to assess the relationship between tumor response and overall survival (OS). Multivariable analysis was performed for RS and circulating cytokines.RESULTSIn the combined (expansion plus original) cohort, 97 patients (219 metastases) were analyzed and received SBRT+P. Forty-six (47%) patients received at least 1 partial-Rx treatment. There were 7 (7.2%)dose-limiting toxicities (DLTs). 1-year LF was 7.6% overall, and 13.3% and 5.4% for partial-Rx and complete-Rx tumors, respectively (HR 2.32, 95% CI 0.90-5.97, P = 0.08). The overall, unirradiated, and irradiated objective response rates were 22%, 12%, and 34%, respectively. Irradiated tumor response to SBRT+P was associated with prolonged OS; 1-year OS was 71% (responders), 42% (mixed-responders), and 0% (nonresponders) (P < 0.01). High-RS was significantly associated with improved LF, progression-free survival (PFS), and OS. Elevated circulating IL-8 was independently associated with inferior PFS and OS.CONCLUSIONSBRT+P is safe in patients with large, advanced solid tumors. Additional studies are warranted to assess noninferiority of complete versus partial irradiation of tumors in the setting of immunotherapy.TRIAL REGISTRATIONClinicaltrials.gov NCT02608385FUNDINGMerck Investigator Studies Program; Hillman Fellows for Innovative Cancer Research Program; NIH grants UM1CA186690-06, P50CA254865-01A1, P30CA047904-32, and R01DE031729-01A1.

The "Great Debate" at Melanoma Bridge 2022, Naples, December 1st-3rd, 2022

The Great Debate session at the 2022 Melanoma Bridge congress (December 1-3) featured counterpoint views from leading experts on five contemporary topics of debate in the management of melanoma. The debates considered the choice of anti-lymphocyte-activation gene (LAG)-3 therapy or ipilimumab in combination with anti-programmed death (PD)-1 therapy, whether anti-PD-1 monotherapy is still acceptable as a comparator arm in clinical trials, whether adjuvant treatment of melanoma is still a useful treatment option, the role of adjuvant therapy in stage II melanoma, what role surgery will continue to have in the treatment of melanoma. As is customary in the Melanoma Bridge Great Debates, the speakers are invited by the meeting Chairs to express one side of the assigned debate and the opinions given may not fully reflect personal views. Audiences voted in favour of either side of the argument both before and after each debate.

Myeloid Maturity: ATRA to Enhance Anti-PD-1?

Myeloid-derived suppressor cells (MDSC) are associated with resistance to anti-PD-1 therapies. All-trans retinoic acid (ATRA) may induce maturation of MDSCs and alter their immunosuppressive effects. Adding ATRA to pembrolizumab may target this resistance mechanism to enhance the overall impact of anti-PD-1-based immunotherapy. See related article by Tobin et al., p. 1209.

Trametinib in Patients With NF1-, GNAQ-, or GNA11-Mutant Tumors: Results From the NCI-MATCH ECOG-ACRIN Trial (EAY131) Subprotocols S1 and S2

PURPOSE

NCI-MATCH is a precision medicine trial using genomic testing to allocate patients with advanced malignancies to targeted treatment subprotocols. This report combines two subprotocols evaluating trametinib, a MEK1/2 inhibitor, in patients with Neurofibromatosis 1 (NF1[S1] or GNA11/Q [S2]) altered tumors.

METHODS

Eligible patients had tumors with deleterious inactivating NF1 or GNA11/Q mutations by the customized Oncomine AmpliSeq panel. Prior MEK inhibitor treatment was excluded. Glioblastomas (GBMs) were permitted, including malignancies associated with germline NF1 mutations (S1 only). Trametinib was administered at 2 mg once daily over 28-day cycles until toxicity or disease progression. Primary end point was objective response rate (ORR). Secondary end points included progression-free survival (PFS) at 6 months, PFS, and overall survival. Exploratory analyses included co-occurring genomic alterations and PTEN loss.

RESULTS

Fifty patients were eligible and started therapy: 46 with NF1 mutations (S1) and four with GNA11 mutations (S2). In the NF1 cohort, nonsense single-nucleotide variants were identified in 29 and frameshift deletions in 17 tumors. All in S2 had nonuveal melanoma and GNA11 Q209L variant. Two partial responses (PR) were noted in S1, one patient each with advanced lung cancer and GBM for an ORR of 4.3% (90% CI, 0.8 to 13.1). One patient with melanoma in S2 had a PR (ORR, 25%; 90% CI, 1.3 to 75.1). Prolonged stable disease (SD) was also noted in five patients (four in S1 and one in S2) with additional rare histologies. Adverse events were as previously described with trametinib. Comutations in TP53 and PIK3CA were common.

CONCLUSION

Although these subprotocols did not meet the primary end point for ORR, significant responses or prolonged SD noted in some disease subtypes warrants further investigation.

Interferon Biology and LAG-3 Shedding in PD-(L)1 plus LAG-3 Immunotherapy

Targeting coinhibitory receptors on dysfunctional T cells may improve response to anti-PD-(L)1 in the IFNγ associated T-cell-inflamed tumor microenvironment. The bispecific lymphocyte activation gene 3 (LAG-3) and PD-L1 blocking antibody FS118, potentially through LAG-3 shedding, represents a promising strategy to improve immune checkpoint blockade. Soluble LAG-3 is an intriguing biomarker for LAG-3 drug activity. See related article by Yap et al., p. 888.

Lorigerlimab, a bispecific PD-1×CTLA-4 DART molecule in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC): A phase 1 expansion (exp) cohort

155

Background: Lorigerlimab (MGD019) is an investigational, bispecific Fc-bearing (IgG4) DART molecule designed to enhance CTLA-4 blockade on dual expressing, tumor infiltrating lymphocytes, while maintaining maximal PD-1 blockade on PD-1 expressing cells. Lorigerlimab has approximate dose proportional PK across 1–10 mg/kg IV dosing Q3W, with sustained PD-1 receptor occupancy evident at doses ≥1 mg/kg Q3W. MGD019-01 is a global first-in-human dose finding and activity estimating study of lorigerlimab in advanced solid tumors (AST). Methods: The exp phase of MGD019-01 evaluates single agent safety, PK, and antitumor effects of lorigerlimab at the recommended dose for exp of 6 mg/kg IV Q3W in 4 tumor specific cohorts. Confirmed responses were noted in each cohort. Preliminary results of the mCRPC cohort are reported here. Response evaluable pts received ≥1 dose and had ≥1 postbaseline imaging evaluation. Measurable lesions were evaluated per RECIST v1.1 and skeletal metastases assessed by bone scan. Prostate specific antigen (PSA) response was defined as a ≥50% (PSA50) or ≥90% (PSA90) PSA decline from baseline with confirmation ≥3 weeks later. Expression of proliferation marker, Ki67, and inducible costimulator (ICOS) by peripheral T cells was assessed by flow cytometry. Results: At data cutoff (9/10/22), 127 pts with AST received ≥1 dose of lorigerlimab 6 mg/kg. Median exposure was 10 weeks (range, 0.1, 94.4) with median of 4 infusions. 6 pts remain on therapy; 36 discontinued for PD (n=13), AEs (n=17), or patient/physician decision (n=6). Treatment related adverse events (TRAE) occurred in 109/127 (85.8%) pts. TRAEs occurring in ≥15% of pts were fatigue, pruritus, hypothyroidism, pyrexia. Rates of grade ≥3 TRAEs and immune-related AEs were 32.3% and 7.9%, respectively. AEs leading to drug discontinuation occurred in 22.8% of pts. There were no fatal AEs related to lorigerlimab. In the mCRPC exp cohort (n=42), pts had a median of 2 prior lines of therapy for CRPC, >80% received prior ART or taxanes; 88% had visceral (liver, 26%; lung, 26%) or nodal disease and 95% had bone metastases. 42 pts were PSA response evaluable; 35 were RECIST evaluable. ORR was 25.7% (9/35; 9 confirmed PRs). Median duration of response was 16.1 weeks (range 6–25+ weeks). 5 responders remain on study, 4 discontinued for unrelated fatal AEs: COVID-19 (2) cardiac arrest (1) C. difficile infection (1). Confirmed PSA50 and PSA90 response rates were 28.6% (12/42) and 21.4% (9/42), respectively. Increased frequencies of Ki67+ and ICOS+ T cells were observed on day 8 posttreatment compared to pretherapy per the flow cytometry analyses from 35 pts. Conclusions: Lorigerlimab demonstrates a manageable safety profile with evidence of encouraging and durable antitumor activity in a chemotherapy refractory mCRPC population. Randomized evaluation of lorigerlimab in mCRPC is warranted. Clinical trial information: NCT03761017 .

Old Dog, New Trick: A Tumor-Intrinsic Role for PD-1 in Chemoresistant Tumor Subclones

SUMMARY

Programmed cell death protein 1 (PD-1) is a well-known driver of immunosuppression and lymphocyte-associated disease progression. Increasing evidence suggests a tumor-intrinsic role for PD-1 in promoting chemoresistance via stem-like features. Moving forward, a recent study implies a novel antitumor mechanism for PD-1 inhibition. See related article by Rotolo et al., p. 621.

Targeting Cbl-b in cancer immunotherapy

Cancer immunotherapy with immune-checkpoint blockade has improved the outcomes of patients with various malignancies, yet a majority do not benefit or develop resistance. To address this unmet need, efforts across the field are targeting additional coinhibitory receptors, costimulatory proteins, and intracellular mediators that could prevent or bypass anti-PD1 resistance mechanisms. The CD28 costimulatory pathway is necessary for antigen-specific T cell activation, though prior CD28 agonists did not translate successfully to clinic due to toxicity. Casitas B lymphoma-b (Cbl-b) is a downstream, master regulator of both CD28 and CTLA-4 signaling. This E3 ubiquitin ligase regulates both innate and adaptive immune cells, ultimately promoting an immunosuppressive tumor microenvironment (TME) in the absence of CD28 costimulation. Recent advances in pharmaceutical screening and computational biology have enabled the development of novel platforms to target this once 'undruggable' protein. These platforms include DNA encoded library screening, allosteric drug targeting, small-interfering RNA inhibition, CRISPR genome editing, and adoptive cell therapy. Both genetic knock-out models and Cbl-b inhibitors have been shown to reverse immunosuppression in the TME, stimulate cytotoxic T cell activity, and promote tumor regression, findings augmented with PD1 blockade in experimental models. In translating Cbl-b inhibitors to clinic, we propose specific gene expression profiles that may identify patient populations most likely to benefit. Overall, novel Cbl-b inhibitors provide antigen-specific immune stimulation and are a promising therapeutic tool in the field of immuno-oncology.

Combination of the STING Agonist MIW815 (ADU-S100) and PD-1 Inhibitor Spartalizumab in Advanced/Metastatic Solid Tumors or Lymphomas: An Open-Label, Multicenter, Phase Ib Study

PURPOSE

The stimulator of IFN genes (STING) is a transmembrane protein that plays a role in the immune response to tumors. Single-agent STING agonist MIW815 (ADU-S100) has demonstrated immune activation but limited antitumor activity. This phase Ib, multicenter, dose-escalation study assessed the safety and tolerability of MIW815 plus spartalizumab (PDR001), a humanized IgG4 antibody against PD-1, in 106 patients with advanced solid tumors or lymphomas.

PATIENTS AND METHODS

Patients were treated with weekly intratumoral injections of MIW815 (50-3,200 μg) on a 3-weeks-on/1-week-off schedule or once every 4 weeks, plus a fixed dose of spartalizumab (400 mg) intravenously every 4 weeks.

RESULTS

Common adverse events were pyrexia (n = 23; 22%), injection site pain (n = 21; 20%), and diarrhea (n = 12; 11%). Overall response rate was 10.4%. The MTD was not reached. Pharmacodynamic biomarker analysis demonstrated on-target activity.

CONCLUSIONS

The combination of MIW815 and spartalizumab was well tolerated in patients with advanced/metastatic cancers, including in patients with anti-PD-1 refractory disease. Minimal antitumor responses were seen.

Quantitative Spatial Profiling of TILs as the Next Step beyond PD-L1 Testing for Immune Checkpoint Blockade

SUMMARY

Analysis of tumor-infiltrating lymphocyte (TIL) functional states, particularly tumor-reactive PD-1T TILs, within specific spatial context, can serve as a biologically informed predictive marker of immunotherapy that may be superior to standard clinical biomarkers. High-plex quantitative immune cell phenotyping within their spatial context has tremendous potential in immuno-oncology. See related article by Hummelink et al., p. 4893.

Prognosis of Patients With Primary Melanoma Stage I and II According to American Joint Committee on Cancer Version 8 Validated in Two Independent Cohorts: Implications for Adjuvant Treatment

PURPOSE

The first randomized trial of adjuvant treatment with checkpoint inhibitor in stage II melanoma reported a significant reduction in risk of tumor recurrence. This study evaluates two independent data sets to further document survival probabilities for patients with primary stage I and II melanoma.

PATIENTS AND METHODS

The Central Malignant Melanoma Registry (CMMR) in Germany evaluated 17,544 patients with a primary diagnosis of stage I and II melanoma from 2000 to 2015. The exploratory cohort consisted of 6,725 patients from the Center for Dermato-Oncology at the University of Tübingen, and the confirmatory cohort consisted of 10,819 patients from 11 other German centers. Survival outcomes were compared with published American Joint Committee on Cancer version 8 (AJCCv8) stage I and II survival data.

RESULTS

For the two CMMR cohorts in stage IA compared with the AJCCv8 cohort, melanoma-specific survival rates at 10 years were 95.1%-95.6% versus 98%; 89.7%-90.9% versus 94% in stage IB; 80.7%-83.1% versus 88% in stage IIA; 72.0%-79.9% versus 82% in stage IIB; and 57.6%-64.7% versus 75% in stage IIC, respectively. Recurrence rates were approximately twice as high as melanoma-specific mortality rates in stages IA-IIA.

CONCLUSION

The melanoma-specific survival rates in the two CMMR cohorts across stages I and II are less favorable than published in AJCCv8. This has important implications for the consideration of adjuvant treatment in this population.

Pembrolizumab versus placebo as adjuvant therapy in resected stage IIB or IIC melanoma (KEYNOTE-716): distant metastasis-free survival results of a multicentre, double-blind, randomised, phase 3 trial

BACKGROUND

Patients with stage IIB or IIC melanoma who undergo surgery alone are at a substantial risk for disease recurrence. Adjuvant pembrolizumab significantly improved recurrence-free survival versus placebo in stage IIB or IIC melanoma in the first interim analysis of the KEYNOTE-716 trial. Here, we report results from the secondary endpoint of distant metastasis-free survival (prespecified third interim analysis), and recurrence-free survival with longer follow-up.

METHODS

KEYNOTE-716 is a multicentre, double-blind, placebo-controlled, crossover or rechallenge, randomised, phase 3 trial done at 160 academic medical centres and hospitals across 16 countries. Eligible patients were aged 12 years and older with newly-diagnosed, completely resected, and histologically confirmed stage IIB (T3b or T4a) or IIC (T4b) cutaneous melanoma; negative sentinel lymph node biopsy; and an Eastern Cooperative Oncology Group performance status of 0-1. Patients were randomly assigned (1:1) to receive either 200 mg of pembrolizumab (2 mg/kg up to a maximum of 200 mg in paediatric patients) or placebo, both intravenously, every 3 weeks for 17 cycles (part 1) or until disease recurrence or unacceptable toxicity. Eligible patients with disease recurrence could receive further treatment with pembrolizumab in the part 2 crossover or rechallenge phase. Randomisation was done using an interactive response technology system and stratified by T category and paediatric status. The primary endpoint was investigator-assessed recurrence-free survival (assessed here with longer follow-up), and we report the prespecified third interim analysis of distant metastasis-free survival (secondary endpoint). Efficacy analyses were done in the intention-to-treat population (all patients who were randomly assigned, according to assigned group) and safety was assessed in all patients who were randomly assigned and received at least one dose of trial treatment, according to the treatment received. KEYNOTE-716 is registered at ClinicalTrials.gov, NCT03553836, and has completed recruitment.

FINDINGS

Between Sept 23, 2018, and Nov 4, 2020, 976 patients were randomly assigned to receive pembrolizumab (n=487) or placebo (n=489). At a median follow-up of 27·4 months (IQR 23·1-31·7), median distant metastasis-free survival was not reached (95% CI not reached [NR]-NR) in either group. Pembrolizumab significantly improved distant metastasis-free survival (hazard ratio [HR] 0·64, 95% CI 0·47-0·88, p=0·0029) versus placebo. Median recurrence-free survival was 37·2 months (95% CI NR-NR) in the pembrolizumab group and not reached in the placebo group (95% CI NR-NR). The risk of recurrence remained lower with pembrolizumab versus placebo (HR 0·64, 95% CI 0·50-0·84). The most common grade 3 or worse adverse events were hypertension (16 [3%] of 483 patients in the pembrolizumab group vs 17 [4%] of 486 patients in the placebo group), diarrhoea (eight [2%] vs one [<1%]), rash (seven [1%] vs two [<1%]), autoimmune hepatitis (seven [1%] vs two [<1%]), and increased lipase (six [1%] vs eight [2%]). Treatment-related serious adverse events occurred in 49 (10%) patients in the pembrolizumab group and 11 (2%) patients in the placebo group. No treatment-related deaths were reported.

INTERPRETATION

Adjuvant pembrolizumab is an efficacious treatment option for resected stage IIB and IIC melanoma, with significant improvement in distant-metastasis free survival versus placebo and continued reduction in the risk of recurrence with an adverse event profile consistent with previous studies of pembrolizumab. The overall benefit-risk of pembrolizumab continues to be positive in the adjuvant setting.

FUNDING

Merck Sharp & Dohme, a subsidiary of Merck & Co.

Adjuvant pembrolizumab versus placebo in resected high-risk stage II melanoma: Health-related quality of life from the randomized phase 3 KEYNOTE-716 study

BACKGROUND

Adjuvant pembrolizumab significantly improved recurrence-free survival (RFS) versus placebo in resected stage IIB and IIC melanoma in the phase 3 KEYNOTE-716 study. Health-related quality of life (HRQoL) results are reported.

METHODS

Patients were randomly assigned 1:1 to pembrolizumab 200 mg (2 mg/kg, patients ≥12 to <18 years) Q3W or placebo for ≤17 cycles or until disease recurrence, unacceptable toxicity, or withdrawal. Change from baseline in EORTC QLQ-C30 global health status (GHS)/quality of life (QoL) was a prespecified exploratory end point. Change in EORTC QLQ-C30 functioning, symptom, and single-item scales, and EQ-5D-5L visual analog scale (VAS) were also summarized. Primary analyses were performed at week 48 to ensure adequate completion/compliance. The HRQoL population comprised patients who received ≥1 dose of treatment and completed ≥1 assessment.

RESULTS

The HRQoL population included 969 patients (pembrolizumab, n = 483; placebo, n = 486). Compliance at week 48 was ≥80% for both instruments. EORTC QLQ-C30 GHS/QoL, physical functioning, role functioning, and EQ-5D-5L VAS scores were stable from baseline to week 48 in both arms, with no clinically meaningful decline observed. Scores did not differ significantly between pembrolizumab and placebo. EORTC QLQ-C30 GHS/QoL, physical functioning, role functioning, and EQ-5D-5L VAS scores remained stable through week 96 in both arms.

CONCLUSIONS

HRQoL was stable with adjuvant pembrolizumab, with no clinically meaningful decline observed. Change from baseline in HRQoL was similar between arms. These results, in conjunction with the improved RFS and manageable safety previously reported, support the use of adjuvant pembrolizumab for high-risk stage II melanoma.

Progression/Recurrence-Free Survival 2 in Adjuvant Melanoma

The long-term outcome of patients with stage III melanoma - that is, melanoma that has spread to nearby lymph nodes, lymphatics, or skin - who have received treatment with immune checkpoint inhibitors is of substantial interest. The article by Eggermont et al.1 published in this issue of NEJM Evidence reports 5-year outcomes from the stage III melanoma trial, KEYNOTE-054, which compared pembrolizumab (anti-programmed cell death protein 1 [PD-1]) with placebo. The data show durable recurrence-free survival (RFS) and distant metastasis-free survival (DMFS).

Autoantibodies as Predictors for Clinical Outcome and Toxicity for Immunotherapy

Peripheral blood autoantibody signatures might be useful biomarkers of immunotherapy outcome. Signatures predicting melanoma recurrence and toxicity during adjuvant immunotherapy were recently presented. Whether autoantibodies are bystanders or have a pathophysiologic role is unknown, and further efforts are needed to investigate potential mechanisms and determine causation. See related article by Johannet et al., p. 4121.