Nektar reports Phase 2 data on rezpegaldesleukin in lupus

Nektar (NKTR) announced topline data from a Phase 2 study of rezpegaldesleukin, or Rezpeg, in adults with moderately-to-severely active systemic lupus erythematosus – SLE – despite receiving standard-of-care treatment. Rezpeg is an investigational, potential first-in-class selective regulatory T-cell inducing IL-2 conjugate designed to treat select autoimmune diseases. The primary endpoint of the Phase 2 study was a 4-point reduction in the SLEDAI-2K score in pre-defined study populations. Although the mid-dose level demonstrated a numeric improvement in SLEDAI-2K score as compared to placebo, the primary endpoint was not met. The placebo-adjusted responses for the low- and high-doses were less than those of the mid-dose for both populations. The mid-dose level in the study also demonstrated consistent and potentially clinically meaningful improvements for the majority of secondary clinical endpoints in patients treated with Rezpeg compared with placebo. The placebo-adjusted responses for BICLA and LLDAS for the low and high doses were less than those of the mid-dose for both populations. Biomarker data demonstrated Rezpeg led to dose-dependent proliferation of T regulatory cells, which was consistent with prior studies. Lilly (LLY) has notified Nektar that they do not intend to advance Rezpeg to Phase 3 development for SLE. Nektar and Lilly plan to work together to determine next steps for the planned Phase 2b study in atopic dermatitis. Most adverse events reported were mild or moderate in severity. A dose dependent increase was observed in adverse events reported. The frequency of infections and infestations across placebo and all dose levels of Rezpeg was similar. At the high dose, discontinuations were due primarily to a higher rate of adverse events for this dose level in these patients with moderate-to-severe active lupus. Nektar entered a strategic collaboration with Lilly in 2017 to develop and potentially commercialize Rezpeg.