American clinical-stage biopharmaceutical company Galera Therapeutics, Inc. (OTC: GRTX) announced on Wednesday that it has entered into an Asset Purchase Agreement with Toronto-based Biossil Inc., a privately held biotechnology company.

The deal covers Galera's dismutase mimetics portfolio, including all formulations and indications of avasopasem and rucosopasem. Under the agreement, Biossil will make an upfront payment of USD3.5m and may pay up to USD105m in future regulatory milestones, commercial milestones, and contingent value rights.

Biossil will also assume all obligations to Blackstone Life Sciences under the existing 2018 Royalty Agreement, including a 4% royalty on potential commercialisation of either avasopasem or rucosopasem.

In a 407-patient Phase 3 study, avasopasem showed statistically significant reductions in severe oral mucositis incidence and duration in patients receiving chemoradiotherapy for head and neck cancer, with results due to appear in the November 2025 edition of eClinical Medicine. The US Food and Drug Administration has also granted Fast Track and Breakthrough Therapy designations to avasopasem for the reduction of radiotherapy-induced severe oral mucositis.

Galera's lead program will continue to be its pan-inhibitor of Nitric Oxide Synthase (NOS), known as L-NMMA or tilarginine. The candidate is in a multicentre Phase 2 trial in metaplastic breast cancer, in combination with alpelisib and nab-paclitaxel.