Sonnet BioTherapeutics Announces Updated Clinical Data for SON-1010 as Monotherapy or Combined with an anti-PD-L1, along with an Increase in the Dose-Escalation Target

• The SON-1010 studies have together enrolled 61 subjects, to date, as dose escalation continues in SB101 and SB221 at higher levels
• Patients have received up to 25 cycles of SON-1010 as monotherapy and 10 cycles of SON-1010 with atezolizumab (Tecentriq^®) without dose-limiting toxicity at any dose level
• Cytokine data reveals about 10-fold extended half-life for SON-1010 compared with rhIL-12 that induces prolonged and controlled IFNγ responses, with no evidence of cytokine release syndrome at any dose
• Clinical benefit was seen at four months post-initiation of dosing in 35% of evaluable patients (8/23) with advanced solid tumors

PRINCETON, NJ / ACCESSWIRE / May 20, 2024 / Sonnet BioTherapeutics Holdings, Inc. (NASDAQ:SONN) (the "Company" or "Sonnet"), a clinical-stage company developing targeted immunotherapeutic drugs, announced today that the safety of SON-1010 dosing has been formally reviewed in both of the current Phase 1 clinical trials and the Company is now increasing the target dose of SON-1010 during dose escalation. SON-1010 is a proprietary version of recombinant human interleukin-12 (rhIL-12), configured using Sonnet's Fully Human Albumin Binding (F_HAB) platform, which extends the half-life and activity of the IL-12 component due to binding native albumin in the serum and targets the tumor microenvironment (TME) by strongly binding gp60 and Secreted Protein Acidic and Rich in Cysteine (SPARC). SB101 is a Phase 1 multiple-ascending dose (MAD) trial in adult patients with advanced solid tumors (NCT05352750) that commenced in Q2 2022 and is currently enrolling the sixth dose cohort. SB221 is a Phase 1b/2a dose-escalation and proof-of-concept study of the combination of SON-1010 with atezolizumab (in collaboration with Genentech, a member of the Roche Group), in a study focused on platinum-resistant ovarian cancer (PROC) (NCT05756907) that started in Q4 2023, now enrolling the fourth dose cohort. In addition, SON-1010 was studied in SB102, which was a Phase 1 single-ascending dose (SAD) trial in healthy volunteers (NCT05408572) that started in Q3 2022; the results were recently published (Kenney, et al, Frontiers in Immunology, 2024).