Sonnet BioTherapeutics Holdings, Inc. announced a clinical collaboration agreement with Roche. A clinical trial (SB221) will be conducted to assess the safety and preliminary efficacy of SON-1010 (IL12-FHAB) in combination with Roche's atezolizumab in patients with platinum-resistant ovarian cancer (PROC). Interleukin-12 (IL-12) is a cytokine, or an immune cell-signaling protein, that enhances the activity of natural killer (NK) cells and T cells.

SON-1010 is a proprietary version of native human IL-12, configured using Sonnet's fully human albumin binding (FHAB®) platform, which targets the tumor microenvironment (TME) and extends the pharmacokinetics (PK) and subsequent pharmacodynamics (PD) of the molecule. Atezolizumab is an immune checkpoint inhibitor approved for the treatment of some of the most aggressive and difficult-to-treat forms of cancer. The characteristics of ovarian cancer present a unique opportunity to assess the combination of these two agents in an indication that persists as a large unmet medical need.

Sonnet and Roche have entered into a Master Clinical Trial and Supply Agreement (MCSA), along with ancillary Quality and Safety Agreements, to study the safety and efficacy of the combination of SON-1010 and atezolizumab in a platinum-resistant ovarian cancer (PROC) patient setting. Further, the companies would provide SON-1010 and atezolizumab, respectively, for use in the Phase 1b/Phase 2a safety and efficacy study. SB221 is a global Phase 1b/2a multicenter, dose-escalation and randomized proof-of-concept study to assess the safety, tolerability, PK, PD, and efficacy of SON-1010 administered subcutaneously (SC), either alone or in combination with atezolizumab given intravenously (IV).

The study is designed in Part 1 to rapidly establish the maximum tolerated dose (MTD) of the combination in patients with advanced solid tumors in small dose-escalation groups and to expand the dataset at the recommended Phase 2 dose (RP2D). This would be followed in Part 2 by an assessment in patients with PROC of the potential for improved efficacy of the combination over SON-1010 alone or the standard of care. Both companies look forward to this collaboration as an opportunity to improve outcomes for patients with ovarian cancer.