Cambridge-based startup Mersana Therapeutics said today that it raised $75 million in an initial public offering.
The company sold 5 million shares of common stock at $15 apiece. Mersana, which debuted on the Nasdaq exchange listed under “MRSN”, also gave underwriters a 30-day option to buy up to 750,000 more shares at $15 per share.
J.P. Morgan, Cowen and Leerink Partners were book-running managers and Wedbush PacGrow was co-manager for the offering, the company said.
Mersana’s lead platform, Dolaflexin, is designed to boost the efficacy of antibody-drug conjugates. Its Dolaflexin platform uses a biodegradable, biocompatible polymer, Fleximer, which attaches to its auristatin drug payload using a linker designed for use with the polymer.
The polymer surrounds the payload and stops it from aggregating in circulation, according to Mersana. Multiple molecules of the polymer-drug conjugate is then attached to an antibody, thereby boosting the payload capacity of the final antibody-drug conjugate.
The company said on its website that using its Dolaflexin platform, it has generated antibody-drug conjugates with drug-to-antibody ratios of 12 to 15, all while demonstrating acceptable pharmacokinetics in animal models.
