With less than a month to go before a scheduled regulatory decision on its lead asset, clinical-stage biotech ImmunoGen said its SVP/chief commercial officer, Kristen Harrington-Smith, will step down from her post.

The company is developing mirvetuximab soravtansine, an antibody drug conjugate, in ovarian cancer patients who express high levels of folate receptor alpha (FRα) and who are resistant to chemotherapy. The agent is under priority review at the Food and Drug Administration and has a PDUFA date of November 28.

Harrington-Smith is set to depart on November 16 “for personal reasons to pursue a new opportunity closer to her home,” ImmunoGen said in a statement this week. 

In the company’s third-quarter earnings announcement Friday, president and CEO Mark Enyedy reassured investors that preparations to launch mirvetuximab this month were complete. The CEO used an analyst call Friday morning to put a finer point on those activities. 

“Our highly experienced field team is fully staffed and out engaging with customers; our distribution, market access and patient support infrastructure is in place; and we have vials of commercial-ready drug product in inventory awaiting labeling and packaging,” he said on the call. “We are ready to rapidly deliver mirv’ to patients upon approval.”

About 4,300 doctors treat ovarian cancer in the U.S. ImmunoGen plans to focus initially on the 400 or so who treat roughly a third of all patients, said Enyedy, before expanding to the broader market.

ImmunoGen estimates that there are 19,500 drug-treatable, second- through fourth-line ovarian cancer patients in the U.S. each year. Roughly 35% to 40% of those express high levels of FRα and 75% currently receive single-agent chemo or a non-bevacizumab regimen. 

“This gives us a market opportunity of roughly 5,200 patients for our anticipated initial label,” Enyedy said. 

Upon approval, the firm plans to pursue a label expansion to market mirvetuximab for another 1,800 FRα-high patients, giving it a total opportunity of 7,000 patients in the platinum-resistant setting. Further studies could move the drug into platinum-sensitive disease, expanding the market above 11,000 patients. The MIRASOL trial, set to read out in early 2023, is designed to support a conversion from accelerated approval to full US approval.

While Harrington-Smith will play a role in the transition process, VP of market access Todd Talarico will serve as interim leader of the commercial organization during the search to identify a new permanent commercial chief, ImmunoGen said.

The company’s statement noted that Harrington-Smith’s departure is “unrelated to the company’s business performance,” including expectations relating to the potential approval of mirvetuximab.

ImmunoGen reported third-quarter revenue of $15.4 million, up 14.4% versus the year-ago quarter. Selling, general and administrative (SG&A) expenses came in at $33.6 million, a 32.6% increase versus the same quarter last year. That was due primarily to building those commercial capabilities, including hiring of personnel, in preparation for the potential U.S. launch. 

Ovarian cancer is the leading cause of death from gynecological cancers, claiming the lives of roughly 13,000 women each year in the U.S., according to the National Institutes of Health.