Just more than a week after the FDA cleared Orgovyx (relugolix), Myovant Sciences GmbH and Pfizer Inc. disclosed a deal worth as much as $4.2 billion to develop the compound in oncology and women’s health in the U.S. and Canada.

The FDA gave its go-ahead to Basel, Switzerland-based Myovant’s Orgovyx on Dec. 18 for adults with advanced prostate cancer (PC) – the first and only, once-daily oral GnRH antagonist for the disease. U.S. regulators are reviewing a relugolix combination tablet (relugolix 40 mg, estradiol 1.0 mg, and norethindrone acetate 0.5 mg) for uterine fibroids, and have set the PDUFA date as June 1, 2021. The combo pill is in the works for endometriosis as well, with an NDA expected in the first half of 2021.

Myovant is collecting $650 million up front from Pfizer Inc., of New York. Regulatory and sales milestone payments could bring the value to $4.2 billion, including $200 million in potential regulatory rewards for FDA approvals of the relugolix combo tablet in women’s health, and tiered sales milestones upon reaching certain thresholds up to $2.5 billion in net sales for PC, as well as for achievements in the combined women’s health indications. Pfizer also gets an exclusive option to commercialize relugolix in cancer outside the U.S. and Canada, excluding certain Asian countries. If that option is exercised, Myovant will bank $50 million and stands to reap double-digit royalties.

The two firms will jointly develop and sell Orgovyx in PC and, if approved, the combo tablet in women’s health in the U.S. and Canada. Early next year, they will begin co-promoting Orgovyx for PC – a nice fit with Pfizer’s already available Xtandi (enzalutamide), the androgen receptor inhibitor partnered with Tokyo-based Astellas Pharma Inc. that was first green-lighted by the FDA in the summer of 2012 for late-stage, castration-resistant PC. Myovant and Pfizer will split profits and certain expenses for Orgovyx and the combo tablet, with Myovant recording revenues. Continuing to lead clinical development for the combo product, Myovant also remains responsible for regulatory interactions and drug supply.

Doctors will diagnose more than 190,000 cases of PC in the U.S. this year, estimates the American Cancer Society. Specifically, Orgovyx works by blocking the pituitary gland from making luteinizing hormone and follicle-stimulating hormone, thereby knocking down testosterone. PC treatments largely have involved androgen deprivation therapy (ADT); it’s injected or placed as small implants under the skin. The reduction of clinic visits with the Myovant drug could be particularly important during the COVID-19 pandemic, officials have noted. In his Dec. 21 report, J.P. Morgan analyst Eric Joseph said his firm sees Orgovyx “becoming the preferred ADT backbone therapy in the hormone-sensitive segment over the longer term.”

Shares of Myovant (NASDAQ:MYOV) were trading pre-market at $29.58, up $6.83, or 30%.