Totus Medicines Announces Successful Phase 1 Study and Expansion Trial for TOS-358

Totus Medicines, a leader in small molecule drug discovery and development, has announced the successful completion of a Phase 1 dose-escalation study for TOS-358, the first covalent PI3Kα inhibitor in clinical development. The study demonstrated pan-mutant clinical activity, 95% target engagement, and no grade 3 or 4 toxicities at doses as low as 5 mg BID. Following this success, Totus is initiating an expansion trial in breast, endometrial, urothelial, and head and neck cancers at 5 & 8 mg BID.

Nassim Usman, Ph.D., President & CEO of Totus Medicines, highlighted the significance of the Phase 1 study results, noting the high target engagement, initial clinical activity, and low toxicity profile at low doses. These findings suggest a promising future for TOS-358 in combination with CDK4/6 and SERDs.

In addition to these clinical advancements, Totus Medicines has appointed Zelanna Goldberg, M.D., M.A.S., as Chief Medical Officer. Dr. Goldberg brings extensive experience in oncology drug development, having held leadership positions at several companies, including Alpine Immune Sciences, Iovance Biotherapeutics, Inc., Pfizer, and Sunesis Pharmaceuticals. Her expertise is expected to be invaluable as Totus advances its clinical-stage programs.

Dr. Goldberg expressed her enthusiasm about joining Totus Medicines, particularly at a time when TOS-358 has demonstrated a best-in-class profile in the PI3Kα space. She looks forward to contributing her drug development expertise to support the progress of the company's pipeline in areas of unmet medical need.

Totus Medicines is leveraging a novel DNA-encoded covalent library technology combined with artificial intelligence/machine learning (AI/ML) to discover and develop small molecule medicines. This innovative approach allows the company to screen hundreds of millions of drug candidates against multiple targets simultaneously, leading to the discovery of superior drug candidates for currently undrugged and difficult to drug targets.