By Fineline Cube 
Sino-US biotech Phanes Therapeutics Inc. announced the first patient dosing in a clinical study for its internally developed CD73 antibody, mavrostobart (PT199). The study evaluates the drug in combination with chemotherapy, marking a significant step in the development of innovative cancer therapies.
Mavrostobart Mechanism and Innovation
Mavrostobart is designed as a differentiated, best-in-class anti-CD73 antibody. It targets the immunosuppressive tumor microenvironment by counteracting CD73-catalyzed adenosine production. Unlike other CD73 antibodies, mavrostobart demonstrates full suppression of both soluble and membrane-bound CD73, underscoring its unique mechanism of action.
Clinical Trial Details
The multi-center Phase I/II clinical trial, known as the MORNINGSTAR study (NCT05431270), is assessing the safety, tolerability, pharmacokinetics, and preliminary efficacy of mavrostobart. The trial is evaluating the drug both as a monotherapy and in combination with a PD-1 inhibitor or chemotherapy. Additionally, a Phase I clinical trial of mavrostobart is underway in China (CTR20242381).-Fineline Info & Tech