Sonnet completes two IND-enabling toxicology studies with SON-1210

Sonnet BioTherapeutics Holdings announced that two IND-enabling toxicology studies have been completed in non-human primates using its lead bifunctional therapeutic candidate. SON-1210 is a proprietary, bispecific version of human Interleukins 12 and 15, configured using Sonnet’s Fully Human Albumin Binding platform. The first of two studies, a non-GLP toxicology study, was designed to elucidate the maximum tolerated dose of SON-1210 in a dose-escalation format in four cohorts of NHPs. The second study was a GLP repeat-dose toxicology study that employed three dose levels of SON-1210 or a vehicle control, each dosed three times every two weeks. The GLP study included a six-week recovery period for the high dose and vehicle control groups following the completion of the dosing phase. There were no SON-1210-related increases in toxicity, including liver enzymes, in the GLP study apart from the expected, and mild, on-target changes in hematology and clinical chemistry parameters that resolved completely within 14 to 21 days post-dosing. A significant increase in interferon gamma, which was transient in nature, was noted as early as one day following administration, with no apparent increase in other proinflammatory cytokines. IFNg is a well-known pharmacodynamic biomarker that is required for anti-tumor efficacy in preclinical models. Other signs of cytokine imbalance, or uncontrolled increase of pro-inflammatory cytokines were notably absent from all dose levels tested in the study.