$30 million. The bulk of the capital came in the $21 million first closing of its Series B round of venture capital, from Fidelity Biosciences in Cambridge and ProQuest Investments, of San Diego, Princeton, NJ, and Montreal, in November 2005. The company’s other investors include Rho Ventures, PureTech Ventures, Harris & Harris Group, the Cape Family Fund, and Lansing Brown Investments. Olson said that the company has since added more than $10 million to the second-round financing in the form of follow-on investments from existing backers.
PureTech, of Boston, was the venture firm that initially helped Mikhail Papisov, a bioengineer at Massachusetts General Hospital, to found Mersana (fka Nanopharma) and license his drug-delivery technology from MGH. Olson, a former vice president of licensing at Pfizer, joined Mersana as chief executive after learning about the startup from PureTech. She said that the startup’s drug-delivery molecules interest her because of their versatility and utility in medicine.
Mersana says it can attach all manner of drugs—including small molecules, proteins, and nucleic acids—to its polymers, and that multiple drugs can be linked to a single polymer molecule. The polymers are designed to hold tightly to the drugs and release them at the optimal time such as inside of target cells, reducing the amount of the unlinked drugs that circulate in the bloodstream, where they could reach healthy tissues and cause side effects.
The firm is studying its molecules’ ability to deliver RNA-interference (RNAi) drugs, which show great promise to mute disease-causing genes but are tricky to get into cells before they are broken down in the body. Olson said that her firm is researching ways to link RNAi drugs to Fleximer molecules along with a compound designed to target specific cells. She hopes that her firm will be able to partner with an RNAi company within the next year to year and a half.
Olson said that her firm is already in touch with developer of RNAi therapies but declined to provide specifics of those discussions. In our other reporting, we’ve covered how Cambridge, MA-based Alnylam Pharmaceuticals (NASDAQ:[[ticker:ALNY]]) has sought partnerships with other biotech firms and academics to overcome the challenges of delivering its RNAi treatments into cells.
