Clinical-stage biopharmaceutical company OrsoBio has secured $67m in an oversubscribed Series B financing round to expedite the development of its mitochondrial protonophore portfolio for obesity and associated metabolic disorders.

The funding round was led jointly by Ascenta Capital and Woodline Partners, with substantial contributions from current stakeholders including Samsara Biocapital, Enavate Sciences and Longitude Capital.

Ascenta Capital co-founder and managing partner Evan Rachlin has joined the board of directors of OrsoBio.

The capital injection will be channelled towards advancing the company's mitochondrial protonophore portfolio for obesity which has shown promising results in preclinical studies.

Mitochondrial protonophores have demonstrated the ability to directly increase energy expenditure, making them a potentially ideal complement to the metabolic benefits of glucagon-like peptide-1 receptor agonists (GLP-1 RAs).

Mitochondrial protonophores, developed by OrsoBio, have led to weight loss, preserved lean body mass and enhanced insulin sensitivity in preclinical trials.

OrsoBio is conducting a 12-week Phase I clinical trial for TLC-6740, an oral, liver-targeted mitochondrial protonophore, in patients with obesity.

The trial follows a successful Phase I study in healthy subjects, in which TLC-6740 was found to be safe and well-tolerated. It induced dose-dependent increases in energy expenditure and improvements in lipid profiles and insulin resistance markers.

Phase Ib and Phase IIa studies for TLC-6740 are now set to begin targeting patients with obesity and type 2 diabetes, including those undergoing GLP-1 RA therapy.

In 2025, OrsoBio plans to complete IND-enabling studies for two additional novel protonophores, TLC-1180 and TLC-1235.

TLC-1180 is a potent mitochondrial protonophore suitable for weekly oral or subcutaneous administration, while TLC-1235 is a controlled-release mitochondrial protonophore that has demonstrated metabolic benefits across various models and species.

OrsoBio founder and CEO Mani Subramanian stated: “We welcome Ascenta Capital and Woodline Partners to OrsoBio and appreciate their support and that of our existing investors. These resources enable us to continue advancing our portfolio of mitochondrial protonophores and other potential therapies to address the burden of obesity and obesity-associated diseases.

“We believe that the future of obesity treatment will include GLP-1 RA-based combinations; this financing will enable us to build the scientific and clinical foundations to support our protonophores as components of these regimens.”