The combination of two mAb drugs eradicated a large tumor, but also sparked new toxicity concerns associated with immunotherapies.
A case report published on Apr. 20, 2015 in the New England Journal of Medicine (NEJM) investigating the use of monoclonal antibodies Yervoy (ipilumumab) and Opdivo (nivolumab) found that the combination of drugs reduced the tumors by 80% in more than half of melanoma patients. Even though there were only 13 patients in the Phase I trial, the researchers observed a “remarkable” tumor response in one patient whose large chest-wall melanoma almost completely disappeared in three weeks after only one dose of the drug combination.
While the results of the immunotherapy treatment are impressive, the study investigators warn that they have concerns about the “overly vigorous antimelanoma” response they observed and say that “such an antitumor effect occurring in a transmural metastasis in the small bowel or myocardium, common sites for metastatic melanoma, could have grave consequences.” Despite these warnings and a treatment delay due to a rash, the patient in question who had remarkable results has resumed treatment.
The results of the case study were published alongside a larger double-blind study involving 142 patients with metastatic melanoma with BRAF V600 wild-type tumors. In that study, 61% (44 of 72) patients receiving the drug combination of Yervoy and Opdivo responded to the drug, and 22% (16 patients) reported a complete response. Eleven percent (4 of 37 patients) in the group that received Yervoy and placebo showed a response of some kind, indicating that the combination of drugs is more efficacious than Yervoy alone. Progression-free survival was also significantly higher in the Yervoy/Opdivo group than in the Yervoy group alone.
The success of the drug combination of Yervoy and Opdivo comes at a price, however, as serious drug-related adverse events were reported in more than half of patients in this arm (54%), which is significantly more than the 24% of those on Yervoy plus placebo who experienced side effects.
Source: NEJM