Semma Therapeutics

Semma Therapeutics was a biopharmaceutical company developing regenerative, cell-based therapies for type 1 diabetes (T1D). Its approach combined proprietary human stem cell-derived islet cells ("SC-islets"), including glucose-responsive insulin-producing beta cells generated in the laboratory, with a cell delivery and encapsulation device intended to shield the implanted cells from the patient's immune system. The stated goal was a functional cure — durable, physiological glucose control without exogenous insulin and without continuous systemic immunosuppression.

The underlying technology originated in the Harvard laboratory of Professor Douglas Melton, whose team developed methods to generate billions of functional insulin-producing beta cells in vitro; that technology was exclusively licensed to Semma. Preclinical work reported that transplanted human stem cell-derived beta cells produced high levels of human insulin after glucose challenge in mice and controlled diabetes in animal models, and later that the cell/device system produced positive c-peptide release and glycemic control in non-human primates and pigs. The company operated two sites: a Cambridge/Boston headquarters focused on beta cell manufacturing and purification, and a Rhode Island (Providence) site, formerly CytoSolv's headquarters and referred to as "Semma South," focused on the delivery system.

Sources differ on the founding year (2014 per the JDRF T1D Fund announcement, 2015 per other aggregators). Semma was acquired by Vertex Pharmaceuticals for $950 million in cash under an agreement announced in September 2019, and continued as a separate Vertex subsidiary.

Founding story

The company was founded to commercialize beta-cell differentiation research from Douglas Melton's laboratory at Harvard and the Harvard Stem Cell Institute, where Melton and colleagues, including scientific co-founder Felicia Pagliuca, generated functional beta cells in vitro. Melton's two decades of T1D-focused stem cell research followed the diagnosis of two of his children, Sam and Emma, with type 1 diabetes; the company name was formed from their names. Robert Millman, previously IP counsel to companies including Epizyme, iPierian and Verastem and founder and first president of CoStim Pharmaceuticals, co-founded Semma and served as its initial CEO. Sources give the founding year as 2014 (JDRF T1D Fund) or 2015 (aggregator listings), with initial financing led by MPM Capital and F-Prime Capital alongside strategic investors Novartis and Medtronic.

Business model

Semma was a venture-backed, pre-commercial biotechnology developer of a combination cell-plus-device product, funded by equity financings from institutional and strategic investors, venture philanthropy and public research grants, and pursuing strategic partnerships with pharmaceutical and medical device companies. It became a wholly owned operating subsidiary of Vertex Pharmaceuticals after the 2019 acquisition.

Traction

Preclinical milestones included in vitro and in vivo demonstration that stem cell-derived beta cells mimic endogenous human beta cell function, high human insulin levels and diabetes control in transplanted mice, a May 2019 Nature publication on advances in regenerative cell therapy for T1D, and July 2019 preclinical proof-of-concept in two lead T1D programs, with cell/device data in non-human primates and pigs showing c-peptide release and glycemic control. The company reported 27 employees across two sites in late 2015; aggregator data lists roughly 88 employees and a 51-200 headcount band. Total disclosed funding was $163M across three rounds.

Latest developments

The most recent substantive developments in the sources are the September 2019 announcement of Vertex Pharmaceuticals' $950 million all-cash acquisition of Semma, its completion in the fourth quarter of 2019 (reported as October 2019), and Semma's continuation as a separate Vertex subsidiary with Bastiano Sanna as president and Douglas Melton as chair of the scientific advisory board.