Sonnet completes discovery phase of immuno-oncology program

PRINCETON, N.J.—Sonnet BioTherapeutics, a preclinical-stage biopharmaceutical company focused on enhanced cancer immunotherapies, announced recently the completion of the discovery phase for its proprietary immunotherapy platform. The company also announced that it has commenced chemistry, manufacturing and controls (CMC) development for up to four immuno-oncology assets with a “highly capable” New Jersey-based contract manufacturing partner.

Sonnet’s platform leverages a scaffold based on a proprietary albumin binding single-chain antibody fragment (scFv) for delivery of recombinant human-cytokines (rH-cytokines) and other validated targets. Cytokines—such as interleukin-12, 15, 18 and 2—have long been seen as important immune activators, the company notes; however, due to their short half-life, interleukins require high dosing, which results in higher likelihood of toxicity. Interleukins are also non-specific in that they disperse across all tissue, as opposed to seeking and accumulating in tumor tissue.

“Globally, cancer is responsible for about one in six deaths, and current immunotherapies are effective for only 20 percent of patients. The National Cancer Institute and other bodies believe interleukins are important tools in cancer immunotherapy,” said Dr. Pankaj Mohan, Sonnet founder and executive chairman. “We believe the Sonnet platform de-risks the use of interleukins by greatly extending their half-life within the body, while also improving their specificity to tumor tissue. Having concluded our discovery program with a multi-asset pipeline, we are excited to advance up to four lead therapeutic candidates (three of which have double targets) into CMC development and plan for primate data and IND.”

Dr. John Cini, co-founder and chief scientific officer at Sonnet, added: “The Sonnet platform involves a proprietary fully human ‘albumin binding domain’ (ABD) capable of accommodating one or two different interleukins (or scFv targets) without impacting binding efficiencies. Our platform has demonstrated in vivo a tenfold increase in pK and thirtyfold increase in efficacy as compared to recombinant interleukins without ABD in a mice melanoma model. This data was presented at the American Association for Cancer Research Annual Meeting (2017) and the Society for Immunotherapy of Cancer Annual Meeting (2017).”

Checkpoint inhibitors are the cornerstone of current cancer immunotherapy, Cini continued, noting: “These monoclonal antibodies can be very effective when the patient’s immune response to a tumor has been activated. However, adequate immune activation does not occur in the majority of patients. To reach their full potential, checkpoint inhibitors will need other agents to help the complete activation of the immune response. We believe our platform represents a promising strategy to unlock the potential of interleukins to activate this response and could improve overall survival rates. By addressing past challenges with interleukins, Sonnet promises to unleash the true potential of checkpoint inhibition treatments and other current cancer therapies.”