Phase 1b study of cobimetinib plus atezolizumab in patients with advanced BRAFV600 wild-type melanoma progressing on prior anti-programmed death-1 therapy

OBJECTIVE

To evaluate the efficacy and safety of cobimetinib plus atezolizumab in the treatment of patients with advanced BRAF^V600 wild-type melanoma who had progressed on prior anti‒programmed death-1 (PD-1) therapy.

PATIENTS AND METHODS

This phase 1b, open-label, international multicentre study enrolled 3 cohorts. Herein, we report on patients in cohorts A and B who had progressed on prior anti‒PD-1 therapy. Patients in cohort A received cobimetinib 60 mg once daily for 21 days followed by a 7-day break and concurrent intravenous atezolizumab 840 mg every 2 weeks. Patients in cohort B received the same dosing regimen as cohort A except for cycle 1 in which patients received cobimetinib only for the first 14 days prior to initiation of atezolizumab on cycle 1 day 15. Coprimary end-points were objective response rate and disease control rate. Secondary end-points were duration of response, progression free survival and overall survival.

RESULTS

Between 19th June 2017 and 12th December 2018, 103 patients were enrolled. Median follow-up was 6.9 months (interquartile range, 4.8-10.1 months); objective response rate was 14.6% and disease control rate was 38.8% (95% confidence interval, 29.39-48.94). The median duration of response, progression-free survival and overall survival was 12.7 months, 3.8 months and 14.7 months, respectively. The most common adverse events were diarrhoea (75/103; 72.8%), dermatitis acneiform (57/103; 55.3%) and nausea (52/103; 50.5%). Thirty-four patients (33.0%) died: 33 (91.7%) due to progressive disease and one (1%) due to treatment-related oesophagitis.

CONCLUSIONS

Combination therapy with cobimetinib and atezolizumab in patients with advanced BRAF^V600 wild-type melanoma with disease progression on or after prior anti‒PD-1 therapy demonstrated limited activity.

CLINICAL TRIAL REGISTRATION

This study is registered with ClinicalTrials.gov; NCT03178851.

Clinical Models to Define Response and Survival With Anti-PD-1 Antibodies Alone or Combined With Ipilimumab in Metastatic Melanoma

PURPOSE

Currently, there are no robust biomarkers that predict immunotherapy outcomes in metastatic melanoma. We sought to build multivariable predictive models for response and survival to anti-programmed cell death protein 1 (anti-PD-1) monotherapy or in combination with anticytotoxic T-cell lymphocyte-4 (ipilimumab [IPI]; anti-PD-1 ± IPI) by including routine clinical data available at the point of treatment initiation.

METHODS

One thousand six hundred forty-four patients with metastatic melanoma treated with anti-PD-1 ± IPI at 16 centers from Australia, the United States, and Europe were included. Demographics, disease characteristics, and baseline blood parameters were analyzed. The end points of this study were objective response rate (ORR), progression-free survival (PFS), and overall survival (OS). The final predictive models for ORR, PFS, and OS were determined through penalized regression methodology (least absolute shrinkage and selection operator method) to select the most significant predictors for all three outcomes (discovery cohort, N = 633). Each model was validated internally and externally in two independent cohorts (validation-1 [N = 419] and validation-2 [N = 592]) and nomograms were created.

RESULTS

The final model for predicting ORR (area under the curve [AUC] = 0.71) in immunotherapy-treated patients included the following clinical parameters: Eastern Cooperative Oncology Group Performance Status, presence/absence of liver and lung metastases, serum lactate dehydrogenase, blood neutrophil-lymphocyte ratio, therapy (monotherapy/combination), and line of treatment. The final predictive models for PFS (AUC = 0.68) and OS (AUC = 0.77) included the same variables as those in the ORR model (except for presence/absence of lung metastases), and included presence/absence of brain metastases and blood hemoglobin. Nomogram calculators were developed from the clinical models to predict outcomes for patients with metastatic melanoma treated with anti-PD-1 ± IPI.

CONCLUSION

Newly developed combinations of routinely collected baseline clinical factors predict the response and survival outcomes of patients with metastatic melanoma treated with immunotherapy and may serve as valuable tools for clinical decision making.

Immunotherapy for Melanoma

Melanoma is the leading cause of death from skin cancer and is responsible for over 7000 deaths in the USA each year alone. For many decades, limited treatment options were available for patients with metastatic melanoma; however, over the last decade, a new era in treatment dawned for oncologists and their patients. Targeted therapy with BRAF and MEK inhibitors represents an important cornerstone in the treatment of metastatic melanoma; however, this chapter carefully reviews the past and current therapy options available, with a significant focus on immunotherapy-based approaches. In addition, we provide an overview of the results of recent advances in the adjuvant setting for patients with resected stage III and stage IV melanoma, as well as in patients with melanoma brain metastases. Finally, we provide a brief overview of the current research efforts in the field of immuno-oncology for melanoma.

Association Between Sex and Immune Checkpoint Inhibitor Outcomes for Patients With Melanoma

IMPORTANCE

Immune checkpoint inhibitors (ICIs) have revolutionized melanoma treatment and are now standard of care. Although sex is associated with immune function and immune-related diseases, the interaction between sex and ICIs is understudied.

OBJECTIVE

To examine whether cancer immunotherapy effectiveness varies between female and male patients with advanced melanoma treated with either nivolumab plus ipilimumab combination therapy or anti-programmed cell death protein 1 (PD-1) therapy (namely, pembrolizumab or nivolumab).

DESIGN, SETTING, AND PARTICIPANTS

The study population consisted of 1369 older adults (aged ≥65 years) with a record of melanoma diagnosis from January 1, 1991, to December 31, 2015, in the Surveillance, Epidemiology, and End Results-Medicare linked database. Patients with a diagnosis of stage III or stage IV melanoma and a claims record showing nivolumab plus ipilimumab combination therapy or anti-PD-1 therapy (ie, pembrolizumab or nivolumab) as their last type of ICI prescribed were included in the analyses. Patients were followed up through December 31, 2017, for the overall survival analysis. Statistical analysis was performed from September 19, 2019, to February 20, 2021.

EXPOSURES

Sex, last prescribed ICI, and prior use of ipilimumab.

MAIN OUTCOMES AND MEASURES

The primary outcome was overall survival, defined as time from the index date until death from any cause, with patients censored at the end of the study (December 31, 2017). Cox proportional hazards regression modeling was used to examine the association of sex with ICI outcomes while adjusting for prior use of ipilimumab, age at ICI initiation, Charlson Comorbidity Index, cancer stage at the time of diagnosis, and autoimmune disease diagnosis.

RESULTS

Among the 1369 patients in the study (982 men [71.7%]; median age, 75 years [IQR, 69-82 years]), the outcome of nivolumab plus ipilimumab combination therapy depended on sex (Wald χ2 = 9.48; P = .009 for interaction). The mortality hazard ratio (HR) for women with prior ipilimumab use receiving combination therapy was 2.06 times (95% CI, 1.28-3.32; P = .003) higher than their male counterparts. No significant difference was observed between women and men receiving anti-PD-1 therapy with (HR, 0.97 [95% CI, 0.68-1.38]; P = .85) or without prior ipilimumab use (HR, 0.85 [95% CI, 0.67-1.07]; P = .16). For women with prior ipilimumab use, combination therapy was associated with 2.82 times higher mortality hazards than anti-PD-1 therapy (95% CI, 1.73-4.60). No statistically significant difference was seen in mortality risk between anti-PD-1 therapy and combination therapy for men.

CONCLUSIONS AND RELEVANCE

This cohort study suggests that female patients with advanced melanoma may not benefit as much from combination ICIs as male patients would. Tumor mutation burden or estrogen level may serve as an important biomarker associated with ICI response in metastatic melanoma.

Therapeutic Advancements Across Clinical Stages in Melanoma, With a Focus on Targeted Immunotherapy

Melanoma is the most fatal skin cancer. In the early stages, it can be safely treated with surgery alone. However, since 2011, there has been an important revolution in the treatment of melanoma with new effective treatments. Targeted therapy and immunotherapy with checkpoint inhibitors have changed the history of this disease. To date, more than half of advanced melanoma patients are alive at 5 years; despite this breakthrough, approximately half of the patients still do not respond to treatment. For these reasons, new therapeutic strategies are required to expand the number of patients who can benefit from immunotherapy or combination with targeted therapy. Current research aims at preventing primary and acquired resistance, which are both responsible for treatment failure in about 50% of patients. This could increase the effectiveness of available drugs and allow for the evaluation of new combinations and new targets. The main pathways and molecules under study are the IDO inhibitor, TLR9 agonist, STING, LAG-3, TIM-3, HDAC inhibitors, pegylated IL-2 (NKTR-214), GITR, and adenosine pathway inhibitors, among others (there are currently about 3000 trials that are evaluating immunotherapeutic combinations in different tumors). Other promising strategies are cancer vaccines and oncolytic viruses. Another approach is to isolate and remove immune cells (DCs, T cells, and NK cells) from the patient's blood or tumor infiltrates, add specific gene fragments, expand them in culture with growth factors, and re-inoculate into the same patient. TILs, TCR gene transfer, and CAR-T therapy follow this approach. In this article, we give an overview over the current status of melanoma therapies, the clinical rationale for choosing treatments, and the new immunotherapy approaches.

Current Challenges in Access to Melanoma Care: A Multidisciplinary Perspective

A diagnosis of melanoma requires multidisciplinary specialized care across all stages of disease. Although many important advances have been made for the treatment of melanoma for local and advanced disease, barriers to optimal care remain for many patients who live in areas without ready access to the expertise of a specialized melanoma center. In this article, we review some of the recent advances in the treatment of melanoma and the persistent challenges around the world that prevent the delivery of the best standard of care to patients living in the community. With the therapeutic landscape continuing to evolve and newer more complex drug therapies soon to be approved, it is important to recognize the many challenges that patients face and attempt to identify tools and policies that will help to improve treatment outcomes for their melanoma.

Adverse events during immunotherapy in Slovenian patients with metastatic melanoma reveal a positive correlation with better treatment outcomes

BACKGROUND

Immunotherapy with CTLA-4 inhibitors and PD1 checkpoint inhibitors has initiated a breakthrough in the treatment and prognosis of patients with metastatic melanoma. The survival of these patients has increased from the expected survival time of less than 12 months to at least forty months. However, immunotherapy with either anti-CTLA-4 antibodies or PD1 inhibitors alone or in combination has a broad palette of significant immune-related adverse events. The aim of the study was to assess the correlation of immune-related adverse events with treatment outcomes defined as significant differences in the overall response rate (ORR) and progression-free survival (PFS) of patients, who developed immune-related adverse events during immunotherapy.

PATIENTS AND METHODS

A retrospective analysis of patients with metastatic melanoma treated with immunotherapy in 2020 at the Oncology Institute of Ljubljana was performed. Only patients with radiological evaluation of the immunotherapy response were included. The patients were divided into two cohorts: a cohort of patients with immune-related adverse events (irAE group) and a cohort of patients with no immune-related adverse events (NirAE group). Significantly better overall response and progression-free survival in the irAE cohort defined the primary aim of our study. To investigate the differences in progression-free survival between the irAE cohort and NirAE cohort, we used survival analysis. In particular, a Cox proportional hazards model with covariates of time to progression and adverse events was used for survival analysis. The Kruskal-Wallis H-test was applied, and a p-value of p <= 0.05 was considered the cut-off point for a statistically significant difference between the groups.

RESULTS

Among the 120 patients treated with immunotherapy, radiological response evaluation was performed for 99 patients: 38 patients in the irAE cohort and 61 patients in the NirAE cohort. The ORRs for the irAE and NirAE cohorts were 57% and 37%, respectively. The PFS was significantly better for the irAE cohort (301.6 days) than for the NirAE cohort (247.29 days). The results of the survival regression analysis showed a significant increase in the survival probability from less than 60% for the NirAE cohort to almost 80% for the irAE cohort.

CONCLUSIONS

Patients with metastatic melanoma treated with immunotherapy who developed immune-related adverse events showed better treatment outcomes with longer times to disease progression and better overall response rates than patients treated with immunotherapy who did not develop immune-related adverse events, with a significant increase in the survival probability from less than 60% for the NirAE cohort to almost 80% for the irAE cohort.

Combining anti-cytotoxic T-lymphocyte antigen 4 (CTLA-4) and -programmed cell death protein 1 (PD-1) agents for cancer immunotherapy

Introduction: Cytotoxic T-lymphocyte antigen 4 (CTLA-4) and programmed cell death protein 1 (PD-1) represent inhibitory immune checkpoints. Combination immune checkpoint inhibitor (ICI) therapy with anti-CTLA-4 plus anti-PD-1 antibodies in preclinical models demonstrated greater anti-tumor effect than therapy with either antibody alone. Based upon this anti-tumor effect, anti-CTLA-4 plus anti-PD-1 antibodies have since been tested in a patients, across tumor types, with advanced malignancies.Areas covered: Herein we describe the biologic rationale for combining anti-CTLA-4 plus anti-PD-1 antibodies, the early studies which established different treatment schedules of the ICI combination in melanoma, the definitive studies which established the role for anti-CTLA-4 plus anti-PD-1 antibodies in patients with advanced malignancies and the toxicity profiles of these agents. We also discuss several experimental disease settings where combined CTLA-4 and PD-1 blockade is being explored.Expert opinion: We anticipate that combination therapy with anti-CTLA-4 plus anti-PD-1 antibodies will become a treatment standard for patients with cancers both responsive and unresponsive to single agent ICI therapy. Given the toxicity profile, we expect that most patients will be treated with lower doses of anti-CTLA-4 and full doses of anti-PD-1 antibodies, however, there may be instances in which a higher dose of anti-CTLA-4 is preferred.

The "Great Debate" at Immunotherapy Bridge 2020, December 3rd, 2020

As part of the 2020 Immunotherapy Bridge virtual congress (December 2nd–3rd, Italy), the Great Debate session featured counterpoint views from leading experts on three clinical questions in immunotherapy today. The first of these was whether antitumoral vaccination is still a treatment option. The second topic debated whether anti-programmed death (PD)-1/PD-ligand (L)1 blockade should be the backbone for immunotherapy combination. Finally, the use of innovative study designs and surrogate endpoints was considered from both an academic and industry perspective. For each topic, two experts presented the argument and counter-argument in support of two different points of view. As with previous Bridge congresses, the debates were assigned by meeting Chairs and positions taken by experts during the debates may not have necessarily reflected their respective personal view. The views summarised in this article are based on available evidence but may reflect personal interpretation of these data, clinical experience and subjective opinion of the speaker.

Systemic Therapy of Metastatic Melanoma: On the Road to Cure

This decade has brought significant survival improvement in patients with metastatic melanoma with targeted therapies and immunotherapies. As our understanding of the mechanisms of action of these therapeutics evolves, even more impressive therapeutic success is being achieved through various combination strategies, including combinations of different immunotherapies as well as with other modalities. This review summarizes prospectively and retrospectively generated clinical evidence on modern melanoma therapy, focusing on immunotherapy and targeted therapy with BRAF kinase inhibitors and MEK kinase inhibitors (BRAF/MEK inhibitors), including recent data presented at major conference meetings. The combination of the anti-PD-1 directed monoclonal antibody nivolumab and of the CTLA-4 antagonist ipilimumab achieves unprecedented 5-year overall survival (OS) rates above 50%; however, toxicity is high. For PD-1 monotherapy (nivolumab or pembrolizumab), toxicities are in general well manageable. Today, novel combinations of such immune checkpoint inhibitors (ICIs) are under investigation, for example with cytokines and oncolytic viruses (i.e., pegylated interleukin-2, talimogene laherparepvec). Furthermore, current studies investigate the combined or sequential use of ICIs plus BRAF/MEK inhibitors. Several studies focus particularly on poor prognosis patients, as e.g., on anti-PD-1 refractory melanoma, patients with brain metastases, or uveal melanoma. It is hoped, on the road to cure, that these new approaches further improve long term survival in patients with advanced or metastatic melanoma.

Emerging PD-1/PD-L1 antagonists for the treatment of malignant melanoma

INTRODUCTION

Increased understanding of the interactive mechanisms between tumors and the immune system led to the development of immune checkpoint inhibitors, which have revolutioned the treatment of metastatic melanoma and subsequently many other tumors. In 2014, nivolumab and pembrolizumab, two checkpoint inhibitors binding to PD-1, were approved for the treatment of metastatic melanoma. Since then, a plethora of new molecules have enriched the armamentarium against melanoma.

AREAS COVERED

This review summarizes the last updates about treatment with nivolumab and pembrolizumab, data on other PD-1/PDL-1 agents such as spartalizumab and atezolizumab and emerging compounds, new combinations with NKTR-214, anti LAG-3, anti IDO-1 and TVEC, new checkpoint inhibitors (e.g. TIM-3 or TIGIT) and other new molecules for the treatment of metastatic melanoma.

EXPERT OPINION

Currently, several ongoing clinical trials are investigating novel molecules, or immunotherapy combinations, in order to achieve even better survival outcomes for patients, overcoming resistance mechanisms and improving toxicity profiles. The challenge in the near future will be to select the most appropriate treatments according to the specific characteristics of the patients.

Ipilimumab and Radiation in Patients with High-risk Resected or Regionally Advanced Melanoma

PURPOSE

In this prospective trial, we sought to assess the feasibility of concurrent administration of ipilimumab and radiation as adjuvant, neoadjuvant, or definitive therapy in patients with regionally advanced melanoma.

PATIENTS AND METHODS

Twenty-four patients in two cohorts were enrolled and received ipilimumab at 3 mg/kg every 3 weeks for four doses in conjunction with radiation; median dose was 4,000 cGy (interquartile range, 3,550-4,800 cGy). Patients in cohort 1 were treated adjuvantly; patients in cohort 2 were treated either neoadjuvantly or as definitive therapy.

RESULTS

Adverse event profiles were consistent with those previously reported with checkpoint inhibition and radiation. For the neoadjuvant/definitive cohort, the objective response rate was 64% (80% confidence interval, 40%-83%), with 4 of 10 evaluable patients achieving a radiographic complete response. An additional 3 patients in this cohort had a partial response and went on to surgical resection. With 2 years of follow-up, the 6-, 12-, and 24-month relapse-free survival for the adjuvant cohort was 85%, 69%, and 62%, respectively. At 2 years, all patients in the neoadjuvant/definitive cohort and 10/13 patients in the adjuvant cohort were still alive. Correlative studies suggested that response in some patients were associated with specific CD4+ T-cell subsets.

CONCLUSIONS

Overall, concurrent administration of ipilimumab and radiation was feasible, and resulted in a high response rate, converting some patients with unresectable disease into surgical candidates. Additional studies to investigate the combination of radiation and checkpoint inhibitor therapy are warranted.

Current Melanoma Treatments: Where Do We Stand?

Groundbreaking research in immunology and cancer biology in the last few decades has led to the discovery and development of novel therapeutics, such as immune checkpoint inhibitors and targeted therapies, which have revolutionized the clinical care of patients with metastatic melanoma. Updated data from the largest clinical trials continue to support the use of these treatment modalities, both in the metastatic and in adjuvant settings, with studies showing the predicted plateau effect on survival curves. However, with growing evidence that neoadjuvant therapy is also associated with high rates of recurrence-free survival, the question about whether patients should receive adjuvant or neoadjuvant treatment raises new questions about therapeutic options. Finally, management after resistance and intervention with novel immunotherapies are newer challenges, particularly in the field of non-cutaneous melanoma.

Real World Outcomes of Ipilimumab and Nivolumab in Patients with Metastatic Melanoma

Background: Immunotherapy has drastically changed the outlook for melanoma patients over the past decade. Specifically, the dual blockade of immune checkpoints using ipilimumab and nivolumab has shown unprecedented response rates and survival outcomes. This immense achievement, though, is at the cost of toxicity, with 60% of the patients experiencing high-grade adverse events (AEs). Our study aims to report the efficacy and toxicity outcomes of an out-of-trial, real-life population. Methods: Data on metastatic melanoma patients treated with ipilimumab and nivolumab were retrieved from our melanoma database—a single-center prospectively updated, medical-records based oncologic registry. Data included demographics, clinical and pathological information, as well as tumor responses and survival. Associations between patient or treatment characteristics and outcomes were also evaluated. Results: We identified 172 metastatic melanoma patients, of whom 64% were treatment-naïve. The median follow-up was 12 months. The response rates for treatment-naïve and previously-treated patients were 61% and 25%, respectively; median progression-free survival (PFS) were 12.2 and 2.6 months, and median overall survival (OS) were not-reached (NR) and 6.1 months, respectively. The estimated three-year OS for treatment-naïve patients was 58% (95% CI 42–65). At data cutoff, 22% were still on-treatment. Grade 3–4 adverse events (AEs) were reported in 60% of the patients, almost all of whom were exposed to steroid treatments (59%); AEs were fatal in 4 patients, and led to permanent treatment discontinuation in 31%. Factors significantly associated with outcome were cutaneous histology, low lactate dehydrogenase (LDH), low number of metastatic sites, performance status, first line of treatment and number of combinations administered during the induction phase. Conclusions: Despite the profoundly different baseline patient characteristics, the combination of ipilimumab and nivolumab is as effective in the real-world population as it was in clinical trials, including long-term outcomes. In addition to confirming the significance of baseline prognostic factors, our study reveals that the number of combinations effectively administered may also be correlated with good outcome.