GRO Biosciences (GRObio), a biotechnology company pioneering the expansion of the amino acid alphabet through synthetic biology, has announced the successful closure of a $60.3 million Series B financing round. This funding will propel the company's lead program, ProGly-Uricase, into clinical trials for refractory gout, expand GRObio's therapeutic pipeline, and enhance its genomically recoded organism (GRO) platform for scalable production of therapeutics using multiple non-standard amino acids (NSAAs).

The Series B financing, co-led by new investors Atlas Venture and Access Biotechnology, brings GRObio’s total capital raised to over $90 million. Previous investors Leaps by Bayer, Redmile Group, Digitalis Ventures, and Innovation Endeavors also contributed to the round. Following this investment, Kevin Bitterman, PhD, Partner at Atlas Venture, and Dan Becker, MD, PhD, Managing Director at Access Biotechnology, will join GRObio’s Board of Directors.

GRObio’s flagship program, ProGly-Uricase, targets severe refractory gout, a debilitating form of arthritis caused by excessive uric acid accumulation in joints. Current uricase enzyme therapies for this condition often fail as patients develop anti-drug antibodies (ADAs) that reduce the enzyme’s efficacy. ProGly-Uricase, enhanced with GRObio’s proprietary ProGly NSAAs, aims to prevent ADA formation, allowing sustained control of uric acid levels.

ProGly NSAAs incorporate glycans—sugar molecules that modulate immune responses—to educate the immune system to recognize therapeutic proteins as “self” rather than foreign, reducing immune rejection. This technology can be applied to various immunogenic therapies, extending its potential beyond uricase to other treatments, including those for autoimmune diseases.

Dan Mandell, PhD, Chief Executive Officer of GRObio, expressed excitement about the new funding and partnerships: “We are thrilled to partner with new investors Atlas Venture and Access Biotechnology, whose participation complements the continued support of our existing investors. 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.”

Kevin Bitterman, PhD, highlighted GRObio's pioneering platform: “GRObio has built the industry-leading platform for discovery and production of therapeutics with non-standard amino acids. The Company has a clear and differentiated path to multiple commercial opportunities, starting with the pressing unmet need in severe, refractory gout. Atlas Venture is excited to partner with this outstanding team and to bring this revolutionary technology to the clinic.”

Dan Becker, MD, PhD, added, “GRObio’s ProGly programs 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.”

With this new influx of capital, GRObio is well-positioned to advance its innovative protein therapeutics and demonstrate the potential of its GRO platform in transforming the treatment landscape for various diseases.

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