On December 4, 2024 Sonnet BioTherapeutics Holdings, Inc. (the "Company" or "Sonnet") (NASDAQ: SONN), a clinical-stage company developing innovative targeted immunotherapeutic drugs, reported the publication of extensive discovery, development and preclinical data on SON-1010 demonstrating its mechanism of action in Frontiers in Immunology (Press release, Sonnet BioTherapeutics, DEC 4, 2024, View Source [SID1234648794]). SON-1010, Sonnet’s lead proprietary drug candidate, combines the Company’s fully human albumin-binding (FHAB) construct with a native single-chain IL-12 sequence to simplify delivery of the cytokine systemically. The paper entitled "SON-1010: An Albumin-binding IL-12 Fusion Protein with Improved Cytokine Half-life Targets Tumors and Enhances Therapeutic Efficacy," details the identification of single-chain variable fragments (scFv) from a human phage display library that bound human, mouse, and cynomolgus macaque serum albumin, both at physiologic and acidic conditions. The composition of matter patent claims on the FHAB domain and SON-1010 fusion protein have been issued in a number of major markets, including but not limited to the U.S., China, Japan, Russia and New Zealand, and expire between 2038 and 2039. Additionally, the Company announced the release of a "What This Means" segment to discuss the publication which is now available here.
Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:
Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing
Schedule Your 30 min Free Demo!
The extensive discovery program included putting the scFv domains through a series of steps to identify strongly binding molecules that bind tightly over a 5.8 to 7.2 pH range and do not interfere with the normal physiology of albumin to bind the neonatal Fc receptor (FcRn). This resulted in having prolonged half-life in serum and binding to SPARC/GP60, which allows albumin to target the tumor microenvironment (TME). A final molecule was selected and a single mutation was introduced that minimizes the potential for immunogenicity. This FHAB domain was characterized, and manufacturing processes were developed to prepare Sonnet’s first drug candidate for the clinic. Once identified, the murine form of mIL12-FHAB was shown to be much more efficient at blocking tumor growth compared to murine IL-12, while stimulating significant and prolonged IFNγ production with minimal toxicity. Biodistribution studies in mice confirmed tumor delivery and toxicological studies in non-human primates allowed the initiation of the clinical trials.
"We are pleased to share these findings, which is the first time we have fully described the extensive research that was required to discover and develop our signature FHAB platform," said Pankaj Mohan, Ph.D., Founder and CEO of Sonnet. "This work lays the foundation for all of the products on our platform that are designed to safely extend the half-life of cytokines and deliver them to the tumor, where they can convert the immunological response from ‘cold’ to ‘hot’ and potentially realize the promise of immunotherapy."
"IL-12 and related compounds have been extensively studied in cancer and immunotherapy indications. However, recombinant interleukins have had limited clinical success owing to their short circulating half-life, inefficient TME targeting, and requirement for frequent dosing, often leading to substantial systemic toxicities," added John Cini, Ph.D. Co-Founder and CSO of Sonnet. "We believe we have addressed these issues with our discovered platform, having utilized a molecule that can be applied in any solid tumor type that concentrates albumin, such as sarcoma, gynecologic, and gastrointestinal cancers. We intend to explore new compounds as well, as funds become available."
The Company is currently conducting a Phase 1 clinical trial of SON-1010 (IL12-FHAB) as a monotherapy in adult patients with advanced solid tumors (SB101; NCT05352750). The Company expects to report safety data from this study in Q4 2024. SON-1010 is being evaluated in an ongoing Phase 1/2a study through a Master Clinical Trial and Supply Agreement, along with ancillary Quality and Safety Agreements, with Roche in combination with atezolizumab (Tecentriq) for the treatment of Platinum-Resistant Ovarian Cancer (PROC).