BioPharma

Nektar’s bempeg shows encouraging Phase II data in first-line melanoma with BMS’ Opdivo

Only time will tell if a larger Phase III study will confirm data on a few dozen patients, but the two-drug combination appears to produce a higher complete response rate than than an existing doublet combination, without the associated toxicity.

Data on an investigational drug for treating a form of skin cancer indicate it is highly active when combined with a commonly used immunotherapy drug, according to a presentation over the weekend at the American Society of Clinical Oncology meeting in Chicago.

San Francisco-based Nektar Therapeutics showed data Saturday from its Phase II PIVOT-02 study of bempegaldesleukin with Bristol-Myers Squibb’s PD-1 checkpoint inhibitor Opdivo (nivolumab) in first-line, Stage III-IV metastatic melanoma. Bempegaldesleukin, also known as bempeg for short, is an IL-2 pathway agonist preferential to the antigen CD122.

Among 38 patients from the study, the overall response rate was 53 percent after a median 12.7-month followup, including a 34 percent complete response rate. Mild to moderate side effects occurring in more than 30 percent of 41 patients included fatigue, pyrexia, rash, pruritus, nausea, influenza-like illness, arthralgia, chills and myalgia. Serious or worse side effects occurred in less than 15 percent of patients, with 9.8 percent of patients discontinuing treatment due to treatment-related side effects.

Shares of Nektar were up 13 percent on the Nasdaq Monday morning following the news.

Bempeg is currently undergoing a Phase III trial, comparing the two-drug combination against Opdivo alone. If that trial can show results equivalent or better than a combination of Opdivo with another BMS immunotherapy drug, the CTLA-4 inhibitor Yervoy (ipilimumab), then bempeg and Opdivo will become widely used, wrote Dr. Adi Diab, a melanoma specialist at The University of Texas MD Anderson Cancer Center and PIVOT-2 investigator, in an email. “Given that bempeg plus [Opdivo] is well-tolerated, and coupled with the high CR rate, this doublet could easily become the first-line standard of care of melanoma,” Diab wrote. That would allow for Yervoy to be used in second-line treatment instead, he wrote, adding that most melanoma patients are treated with single-agent PD-1 inhibitors. In addition to Opdivo, Merck & Co.’s Keytruda (pembrolizumab) also has Food and Drug Administration approval for melanoma.

Whether overall response rate data from a few dozen patients with melanoma can be extrapolated to a randomized Phase III trial of 764 patients, only time will tell. The trial is using overall response rate, progression-free survival and overall survival as co-primary endpoints. Diab wrote that as a two-arm study, the Phase III bempeg and Opdivo trial is appropriately powered with the 764-patient enrollment target.

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For comparison’s sake, according to four-year follow-up data published in The Lancet in October 2018 on CheckMate 067 – a three-arm, 1,296-patient Phase III trial in a similar melanoma population that tested Opdivo and Yervoy against Opdivo or Yervoy alone – the overall response rate for the combination was 58 percent, similar to the one in PIVOT-2. However, the complete response rate was 21 percent for Opdivo with Yervoy, 18 percent for Opdivo alone and 5 percent for Yervoy alone. Median overall survival for the two-drug combination was not reached, while for the two drugs by themselves it was 36.9 months and 19.9 months, respectively. Median progression-free survival was 11.5 months for Opdivo with Yervoy, 6.9 months for Opdivo and 2.9 months for Yervoy.

Photo: Alaric DeArment, MedCity News