GRO Biosciences (GRObio), a US-based biotechnology company, has raised $60.3m in a Series B financing round co-led by new investors Atlas Venture and Access Biotechnology.

The company is engaged in utilising synthetic biology to broaden the amino acid building blocks and advance protein therapeutics.

Its Series B round also saw participation from previous investors including Leaps by Bayer, Redmile Group, Innovation Endeavors, and Digitalis Ventures.

With the Series B financing, GRO Biosciences’ total capital raised now exceeds $90m.

The company, lead programme is ProGly-Uricase, which is being developed for the treatment for severe, refractory gout, a form of arthritis that leads to painful joint inflammation.

ProGly-Uricase is a proprietary uricase enzyme that incorporates the company’s ProGly non-standard amino acids (NSAAs). This formulation helps prevent the development of anti-drug antibodies (ADAs) and enables patients with severe, refractory gout to maintain long-term effective control of serum uric acid levels.

Access Biotechnology managing director Dan Becker said: “GRObio’s ProGly programmes offer novel solutions to patients with few, if any, viable treatment options.

“By partnering with GRObio we look forward to bringing significant improvements in quality of life to patients in need across the full range of indications accessible to the GRO platform.”

The Series B financing for GRO Biosciences will support a clinical study to validate the proof of concept for ProGly-Uricase as a treatment for refractory gout in patients with elevated uric acid levels.

In addition, the proceeds will be used to expand GRO Biosciences’ genomically recoded organism (GRO) platform for scalable production of therapeutics incorporating various NSAAs.

GRO Biosciences CEO Dan Mandell said: “Having proved our therapeutic approach preclinically and demonstrated scalability of our GRO platform, we have assembled the ideal team to advance GRObio to a clinical-stage company.

“This financing enables us to acquire valuable clinical efficacy data in gout, while expanding our platform to demonstrate the first scalable production of proteins with multiple NSAAs, including simultaneous incorporation of drug, immune recruitment, and tissue-targeting payloads.”