Margaret K. Callahan

Nivolumab plus Ipilimumab in Advanced Melanoma

BACKGROUND In patients with melanoma, ipilimumab (an antibody against cytotoxic T-lymphocyte-associated antigen 4 [CTLA-4]) prolongs overall survival, and nivolumab (an antibody against the programmed death 1 [PD-1] receptor) produced durable tumor regression in a phase 1 trial. On the basis of their distinct immunologic mechanisms of action and supportive preclinical data, we conducted a phase 1 trial of nivolumab combined with ipilimumab in patients with advanced melanoma. METHODS We administered intravenous doses of nivolumab and ipilimumab in patients every 3 weeks for 4 doses, followed by nivolumab alone every 3 weeks for 4 doses (concurrent regimen). The combined treatment was subsequently administered every 12 weeks for up to 8 doses. In a sequenced regimen, patients previously treated with ipilimumab received nivolumab every 2 weeks for up to 48 doses. RESULTS A total of 53 patients received concurrent therapy with nivolumab and ipilimumab, and 33 received sequenced treatment. The objective-response rate (according to modified World Health Organization criteria) for all patients in the concurrent-regimen group was 40%. Evidence of clinical activity (conventional, unconfirmed, or immune-related response or stable disease for ≥24 weeks) was observed in 65% of patients. At the maximum doses that were associated with an acceptable level of adverse events (nivolumab at a dose of 1 mg per kilogram of body weight and ipilimumab at a dose of 3 mg per kilogram), 53% of patients had an objective response, all with tumor reduction of 80% or more. Grade 3 or 4 adverse events related to therapy occurred in 53% of patients in the concurrent-regimen group but were qualitatively similar to previous experience with monotherapy and were generally reversible. Among patients in the sequenced-regimen group, 18% had grade 3 or 4 adverse events related to therapy and the objective-response rate was 20%. CONCLUSIONS Concurrent therapy with nivolumab and ipilimumab had a manageable safety profile and provided clinical activity that appears to be distinct from that in published data on monotherapy, with rapid and deep tumor regression in a substantial proportion of patients. (Funded by Bristol-Myers Squibb and Ono Pharmaceutical; ClinicalTrials.gov number, NCT01024231.).

Immunologic Correlates of the Abscopal Effect in a Patient with Melanoma

The abscopal effect is a phenomenon in which local radiotherapy is associated with the regression of metastatic cancer at a distance from the irradiated site. The abscopal effect may be mediated by activation of the immune system. Ipilimumab is a monoclonal antibody that inhibits an immunologic checkpoint on T cells, cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4). We report a case of the abscopal effect in a patient with melanoma treated with ipilimumab and radiotherapy. Temporal associations were noted: tumor shrinkage with antibody responses to the cancer-testis antigen NY-ESO-1, changes in peripheral-blood immune cells, and increases in antibody responses to other antigens after radiotherapy. (Funded by the National Institutes of Health and others.).

Immune Checkpoint Blockade in Cancer Therapy

Immunologic checkpoint blockade with antibodies that target cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) and the programmed cell death protein 1 pathway (PD-1/PD-L1) have demonstrated promise in a variety of malignancies. Ipilimumab (CTLA-4) and pembrolizumab (PD-1) are approved by the US Food and Drug Administration for the treatment of advanced melanoma, and additional regulatory approvals are expected across the oncologic spectrum for a variety of other agents that target these pathways. Treatment with both CTLA-4 and PD-1/PD-L1 blockade is associated with a unique pattern of adverse events called immune-related adverse events, and occasionally, unusual kinetics of tumor response are seen. Combination approaches involving CTLA-4 and PD-1/PD-L1 blockade are being investigated to determine whether they enhance the efficacy of either approach alone. Principles learned during the development of CTLA-4 and PD-1/PD-L1 approaches will likely be used as new immunologic checkpoint blocking antibodies begin clinical investigation.

Hepatotoxicity with combination of vemurafenib and ipilimumab.

The independent mechanisms of action and largely nonoverlapping toxicity profiles of vemurafenib and ipilimumab made it logical to test them together in a study of patients with melanoma. An unexpected level of hepatic toxicity caused the early termination of the study.

Overall Survival with Combined Nivolumab and Ipilimumab in Advanced Melanoma

BACKGROUND Nivolumab combined with ipilimumab resulted in longer progression‐free survival and a higher objective response rate than ipilimumab alone in a phase 3 trial involving patients with advanced melanoma. We now report 3‐year overall survival outcomes in this trial. METHODS We randomly assigned, in a 1:1:1 ratio, patients with previously untreated advanced melanoma to receive nivolumab at a dose of 1 mg per kilogram of body weight plus ipilimumab at a dose of 3 mg per kilogram every 3 weeks for four doses, followed by nivolumab at a dose of 3 mg per kilogram every 2 weeks; nivolumab at a dose of 3 mg per kilogram every 2 weeks plus placebo; or ipilimumab at a dose of 3 mg per kilogram every 3 weeks for four doses plus placebo, until progression, the occurrence of unacceptable toxic effects, or withdrawal of consent. Randomization was stratified according to programmed death ligand 1 (PD‐L1) status, BRAF mutation status, and metastasis stage. The two primary end points were progression‐free survival and overall survival in the nivolumab‐plus‐ipilimumab group and in the nivolumab group versus the ipilimumab group. RESULTS At a minimum follow‐up of 36 months, the median overall survival had not been reached in the nivolumab‐plus‐ipilimumab group and was 37.6 months in the nivolumab group, as compared with 19.9 months in the ipilimumab group (hazard ratio for death with nivolumab plus ipilimumab vs. ipilimumab, 0.55 [P<0.001]; hazard ratio for death with nivolumab vs. ipilimumab, 0.65 [P<0.001]). The overall survival rate at 3 years was 58% in the nivolumab‐plus‐ipilimumab group and 52% in the nivolumab group, as compared with 34% in the ipilimumab group. The safety profile was unchanged from the initial report. Treatment‐related adverse events of grade 3 or 4 occurred in 59% of the patients in the nivolumab‐plus‐ipilimumab group, in 21% of those in the nivolumab group, and in 28% of those in the ipilimumab group. CONCLUSIONS Among patients with advanced melanoma, significantly longer overall survival occurred with combination therapy with nivolumab plus ipilimumab or with nivolumab alone than with ipilimumab alone. (Funded by Bristol‐Myers Squibb and others; CheckMate 067 ClinicalTrials.gov number, NCT01844505.)

Relief of Profound Feedback Inhibition of Mitogenic Signaling by RAF Inhibitors Attenuates Their Activity in BRAFV600E Melanomas

BRAF(V600E) drives tumors by dysregulating ERK signaling. In these tumors, we show that high levels of ERK-dependent negative feedback potently suppress ligand-dependent mitogenic signaling and Ras function. BRAF(V600E) activation is Ras independent and it signals as a RAF-inhibitor-sensitive monomer. RAF inhibitors potently inhibit RAF monomers and ERK signaling, causing relief of ERK-dependent feedback, reactivation of ligand-dependent signal transduction, increased Ras-GTP, and generation of RAF-inhibitor-resistant RAF dimers. This results in a rebound in ERK activity and culminates in a new steady state, wherein ERK signaling is elevated compared to its initial nadir after RAF inhibition. In this state, ERK signaling is RAF inhibitor resistant, and MEK inhibitor sensitive, and combined inhibition results in enhancement of ERK pathway inhibition and antitumor activity.

Immune Modulation in Cancer with Antibodies

Ipilimumab is the prototypical immunomodulatory antibody, approved by the FDA in 2011 for advanced melanoma on the basis of survival benefit. Since that time, we have made significant strides in optimizing this therapy: we have characterized the spectrum of immune-related adverse events and learned how to mitigate them with treatment algorithms, discovered potential biomarkers of activity, and identified the potential synergy between checkpoint modulation and other therapeutic modalities. Recent phase I trials have established the efficacy and safety of next-generation checkpoint agents, including PD-1 and PD-L1 inhibitors, across multiple tumor types. Much work lies ahead in developing these next-generation checkpoint agents, testing them in combination, and determining how to integrate them into the treatment paradigms of various tumor types.

Immune-Related Adverse Events, Need for Systemic Immunosuppression, and Effects on Survival and Time to Treatment Failure in Patients With Melanoma Treated With Ipilimumab at Memorial Sloan Kettering Cancer Center

PURPOSE Ipilimumab is a standard treatment for metastatic melanoma, but immune-related adverse events (irAEs) are common and can be severe. We reviewed our large, contemporary experience with ipilimumab treatment outside of clinical trials to determine the frequency of use of systemic corticosteroid or anti-tumor necrosis factor α (anti-TNFα) therapy and the effect of these therapies on overall survival (OS) and time to treatment failure (TTF). PATIENTS AND METHODS We reviewed retrospectively the medical records of patients with melanoma who had received treatment between April 2011 and July 2013 with ipilimumab at the standard dose of 3 mg/kg. We collected data on patient demographics, previous and subsequent treatments, number of ipilimumab doses, irAEs and how they were treated, and overall survival. RESULTS Of the 298 patients, 254 (85%) experienced an irAE of any grade. Fifty-six patients (19%) discontinued therapy because of an irAE, most commonly diarrhea. Overall, 103 patients (35%) required systemic corticosteroid treatment for an irAE; 29 (10%) also required anti-TNFα therapy. Defining TTF as either starting a new treatment or death, estimated median TTF was 5.7 months. Twelve percent of patients experienced long-term disease control without receiving additional antimelanoma therapy. OS and TTF were not affected by the occurrence of irAEs or the need for systemic corticosteroids. CONCLUSION IrAEs are common in patients treated with ipilimumab. In our experience, approximately one-third of ipilimumab-treated patients required systemic corticosteroids, and almost one-third of those required further immune suppression with anti-TNFα therapy. Practitioners and patients should be prepared to treat irAEs and should understand that such treatment does not affect OS or TTF.

At the Bedside: CTLA-4- and PD-1-blocking antibodies in cancer immunotherapy

It is increasingly appreciated that cancers are recognized by the immune system, and under some circumstances, the immune system may control or even eliminate tumors. The modulation of signaling via coinhibitory or costimulatory receptors expressed on T cells has proven to be a potent way to amplify antitumor immune responses. This approach has been exploited successfully for the generation of a new class of anticancer therapies, “checkpoint‐blocking” antibodies, exemplified by the recently FDA‐approved agent, ipilimumab, an antibody that blocks the coinhibitory receptor CTLA‐4. Capitalizing on the success of ipilimumab, agents that target a second coinhibitory receptor, PD‐1, or its ligand, PD‐L1, are in clinical development. Lessons learned from treating patients with CTLA‐4 and PD‐1 pathway‐blocking antibodies will be reviewed, with a focus on concepts likely to inform the clinical development and application of agents in earlier stages of development. See related review At the bench: Preclinical rationale for CTLA‐4 and PD‐1 blockade as cancer immunotherapy.

Nivolumab monotherapy in recurrent metastatic urothelial carcinoma (CheckMate 032): a multicentre, open-label, two-stage, multi-arm, phase 1/2 trial

Summary Background There are few effective treatments for advanced urothelial carcinoma after progression following platinum-based chemotherapy. We assessed the activity and safety of nivolumab in patients with locally advanced or metastatic urothelial carcinoma who progressed after prior platinum-based therapy. Methods This phase 1/2 multicentre open-label study enrolled patients aged ≥18 years with urothelial carcinoma of the renal pelvis, ureter, bladder, or urethra unselected by programmed death ligand-1 (PD-L1). Tumour PD-L1 membrane expression was assessed. Patients received nivolumab 3 mg/kg intravenously every 2 weeks until disease progression or study treatment discontinuation, whichever occurred later. The primary endpoint was objective response rate by investigator assessment. All patients who received at least one dose of any study medication were analysed. Here we report an interim analysis of this ongoing trial. CheckMate 032 is registered with ClinicalTrials.gov, NCT01928394. Findings Between June 2014 and April 2015, 86 patients with metastatic urothelial carcinoma were enrolled and 78 were treated with nivolumab monotherapy. At data cutoff (March 24, 2016), minimum follow-up was 9 months. A confirmed investigator-assessed objective response was achieved in 19 (24·4%) of 78 patients (95% CI 15·3–35·4). Grade 3/4 treatment-related adverse events occurred in 17 (21·8%) of 78 patients, the most common being laboratory abnormalities: asymptomatic elevated lipase in four (5·1%) and asymptomatic elevated amylase three (3·8%) patients. Serious adverse events were reported in 36 (46·2%) of 78 patients. Two (2·6%) of 78 patients discontinued due to treatment-related adverse events (pneumonitis and thrombocytopenia) and subsequently died. Interpretation Nivolumab monotherapy was associated with significant and durable clinical responses and a manageable safety profile in previously treated patients with locally advanced or metastatic urothelial carcinoma. These data indicate a favourable benefit:risk profile for nivolumab and support further investigation of nivolumab monotherapy in advanced urothelial carcinoma.