Engage Bio Acquired by Lilly
In a recent conversation with Leah Makley, COO of MBC, Will Olsen traced the five-year journey behind Engage Bio – a story of sustained scientific conviction and a lean team that rebuilt its technical foundation more than once to solve some of genetic medicine’s trickiest challenges.
Will founded Engage in 2021 with a clear ambition: getting genetic medicines into patients. Before Engage, he spent two years at Stanford spinout Rejuvenation Tech working on mRNA for longevity applications, and early experiments in mice informed his instincts for the potential of genetic medicine.
Engage’s initial platform relied on mRNA, but required dosing too frequently to be clinically viable. That realization forced a full rebuild and a pivot to DNA. Transitioning to DNA improved durability, but posed two new problems: low expression and high DNA-dependent toxicity. Will made resolving these issues the center of the company’s scientific work.
Through trial and error (and a little luck), Engage arrived at its Tethosome platform: a non-viral DNA delivery system designed to address the core tradeoffs that have long limited genetic medicine: potency, tolerability, and redosability. The system combines modified DNA payloads with lipid nanoparticles and a proprietary mRNA-encoded helper protein that shuttles the construct into the nucleus. The result, in Will’s words: the best expression he’d ever seen.
From shortly after its founding, Engage was based at MBC BioLabs with a small, incredibly hardworking and passionate team. The company raised a modest seed round from SciFounders, Pioneer Fund, the Cal Innovation Fund, Y Combinator, and the Cystic Fibrosis Foundation, plus non-dilutive funding from the Gates Foundation and NIH-NCATS. Early capital came from investors willing to back the team and an idea, rather than a validated dataset. Later, the Gates Foundation and CFF brought credibility and validation alongside capital.
Engage was in conversations with multiple strategic partners when Lilly entered the picture. What distinguished Lilly was its ambition and speed: armed with compelling results from pilot studies, the deal came together quickly. The fit made sense: Lilly’s platform discovery and technology groups offered the scientific depth and development scale to take the platform where it needed to go. The acquisition folded Engage’s team and technology into one of the largest drug-making organizations in the world, with multiple groups inside Lilly already lining up to work with it. The team is now navigating the transition and moving toward development candidates, the next step for a small, driven team that bet everything on a hard problem and won.