What happened

Myovant Sciences (NYSE:MYOV) stock is losing ground after the company reported earnings for its fiscal first quarter, the three-month period ended June 30, 2021. Investors upset about net product sales that weren't very impressive led the stock 12.5% lower this morning. The stock recovered some losses and was down just 9.1% as of  2:17 p.m. EDT on Wednesday.

So what 

Sales of products containing Myovant's gonadotropin-releasing hormone (GnRH) receptor antagonist, Orgovyx (relugolix), weren't as impressive as investors were expecting. Second-quarter sales of Orgovyx, the prostate cancer treatment the FDA approved last year, reached just $10.5 million.

Pharmaceutical sales representative speaking with a doctor.

Image source: Getty Images.

Investors have been watching the Orgovyx launch closely since it earned FDA approval to treat advanced prostate cancer patients last December. That's because last September, the company told investors its drug didn't significantly extend castration resistance-free survival compared to standard care.

Myovant also reported disappointing sales of more recently launched Myfembree. In May, the FDA approved this combination of relugolix, estrogen, and progesterone for the treatment of heavy menstrual bleeding associated with uterine fibroids.

As the first available treatment for this indication, investors expected more than just $1.1 million in top-line sales because the company has a big helping hand. Myovant is commercializing Myfembree jointly with Pfizer (NYSE:PFE), one of America's largest pharmaceutical companies.

Now what

The first approved treatments for conditions that affect millions of people usually go on to generate blockbuster drug sales. Unfortunately for Myovant, women's health is an unusually frustrating corner of the overall pharmaceutical industry.

Back in 2018, AbbVie (NYSE:ABBV) launched its own oral GnRH inhibitor called Orilissa to relieve pain associated with endometriosis. Even though endometriosis affects at least 6% of adult women in the U.S., sales of Orilissa remained flat in the second quarter of 2021 at just $30 million.

AbbVie's challenges with its GnRH inhibitor don't necessarily need to carry over to Myovant and Pfizer's launch of Myfembree. That said, it's probably best to avoid this stock until Myovant shows us relugolix can buck the trend.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.