On July 19, 2024, GRO Biosciences Inc. ("GRObio"), a biotechnology firm utilizing synthetic biology to enhance the amino acid alphabet and advance protein therapeutics, announced the successful closure of an oversubscribed $60.3 million Series B financing round. The funds will be allocated to advance the Company’s leading program into clinical trials for treating refractory gout, expand the GRObio pipeline, and grow its genomically recoded organism (GRO) platform for scalable production of therapeutics with multiple non-standard amino acids (NSAAs).

The Series B financing boosts GRObio’s total capital raised to over $90 million and was co-led by new investors Atlas Venture and Access Biotechnology. Existing investors, such as Leaps by Bayer, Redmile Group, Digitalis Ventures, and Innovation Endeavors, also participated. As part of the financing, Kevin Bitterman, PhD, Partner at Atlas Venture, and Dan Becker, MD, PhD, Managing Director at Access Biotechnology, have joined the Company’s Board of Directors.

GRObio’s lead program, ProGly-Uricase, is designed to treat severe, refractory gout, a form of arthritis characterized by painful joint inflammation caused by an excess of uric acid. For patients who do not respond to first-line treatments, the only available therapy is a uricase enzyme that dissolves uric acid crystals and lowers uric acid levels in the blood. However, many patients develop anti-drug antibodies (ADAs) that rapidly remove the enzyme from their system, reducing its safety and effectiveness and leaving them with few treatment alternatives.

ProGly-Uricase is a proprietary uricase enzyme that utilizes the Company’s ProGly NSAAs to prevent the formation of anti-drug antibodies (ADAs) and help patients with severe, refractory gout achieve long-term effective control of serum uric acid levels. The Series B financing will allow the Company to quickly establish proof of concept for ProGly-Uricase through a clinical study involving human subjects with elevated uric acid levels.

ProGly NSAAs include sugar molecules known as glycans, which precisely regulate the immune response to proteins. These glycans help the immune system identify the therapy as a "self" protein rather than a foreign substance, thereby preventing an immune reaction. This technology is readily applicable to a broad range of immunogenic therapies beyond uricase. Additionally, ProGly therapies are being developed to address and prevent autoimmune diseases by inducing highly specific tolerance to disease-causing autoantigens, without broadly suppressing the immune system.

“We are thrilled to partner with new investors Atlas Venture and Access Biotechnology, whose backing, combined with that of our existing investors, strengthens our capabilities,” said Dan Mandell, PhD, Chief Executive Officer of GRObio. “With our therapeutic approach validated preclinically and our GRO platform proven scalable, we now have the perfect team to advance GRObio into the clinical stage.” This financing will allow us to obtain crucial clinical efficacy data for gout and expand our platform to achieve the first scalable production of proteins incorporating multiple NSAAs, including the integration of drug, immune recruitment, and tissue-targeting payloads.”

Kevin Bitterman, PhD, Partner at Atlas Venture, remarked, “GRObio has developed a leading platform for discovering and producing therapeutics with non-standard amino acids. The Company has a distinct and promising pathway to various commercial opportunities, beginning with the urgent need in severe, refractory gout. Atlas Venture is thrilled to collaborate with this exceptional team and advance this groundbreaking technology into clinical applications.”

Dan Becker, MD, PhD, Managing Director at Access Biotechnology, stated, “GRObio’s ProGly programs provide innovative solutions for patients who have limited or no effective treatment options. By collaborating with GRObio, we are excited to enhance the quality of life for patients across various conditions served by the GRO platform.”