In the earnings call yesterday after the close, Nektar Therapeutics (NASDAQ:NKTR) President & CEO Howard Robin mentioned a "softening in response rates" in the Phase 1/2 PIVOT-02 study evaluating NKTR-214 (bempegaldesleukin), combined with Bristol-Myers Squibb's (NYSE:BMY) Opdivo (nivolumab) or Opdivo + Yervoy (ipilimumab) between the first and second Fleming cohorts in melanoma (the issue was first raised at ASCO in early June).

Apparently two of the earliest production batches of product were different than the other 20 batches produced. Specifically, there was a single "suboptimal" batch of in-process intermediate that was used to produce the two lots, most of which were used in the study. All subsequent product has been produced within specifications.

To address the issue, the company has developed a "comprehensive control strategy" to limit variances in raw materials, intermediates and final product that is currently being validated for commercial-scale manufacturing. It has also revamped the structure of its CMC organization with supply chain and manufacturing now reporting to SVP of Manufacturing Kevin Brodbeck, Ph.D. Biologics Process Sciences is now reporting to Chief Scientific Officer Jonathan Zalevsky, Ph.D.