A pair of US$2 billion markets are gearing up for some new therapies over the next few years.

The drugs in development are to treat two major women's health conditions, endometriosis and uterine fibroids, which can cause a lot of pain for women and in some cases lead to infertility and surgical procedures.

An estimated 5 million Americans are living with endometriosis, a condition in which tissue from the uterus grows outside the uterus, leading to cysts, heavy bleeding, and scarring.

Another 3 million women have uterine fibroids, Myovant Sciences CEO Lynn Seely told Business Insider.

That condition involves benign tumours, called fibroids, growing in and around the uterus, causing heavy bleeding and pain in the women who do have symptoms.

"Everybody knows somebody with endometriosis but nobody's talking about it." Seely said.

Myovant is among the companies working on new treatments for the two conditions along with other women's health disorders. With the new developments, analysts anticipate both the endometriosis and uterine fibroid markets to hit US$2 billion over the next decade.

Potential new treatments in the works

Treating both endometriosis and uterine fibroids involves changing hormone levels in the body. Right now, there are a few drugs that can do this, including leuprolide, a hormone suppressant, and contraceptives are used as well, according to the Mayo Clinic.

Some of these treatments come with major side effects, including bone density loss and hot flashes.

The conditions can also be treated via surgery, but the hope is to come out with new treatments that have fewer side effects and are less invasive.

Here's what's in the works to treat uterine fibroids, endometriosis, and in some cases both:

  • Allergan is developing Esmya, a drug that's being investigated for use in uterine fibroids. The drug works by modulating progesterone, a key hormone for women relating to the uterus. It's a type of drug called a "selective progesterone receptor modulator." Bill Meury, Allergan's chief commercial officer told Business Insider he hopes to get results that can put the drug up for approval in 2018.
  • Bayer's drug, Vilaprisan, also works by modulating progesterone levels. Like Esmya, it's a "selective progesterone receptor modulator." In July, Bayer began a phase 3 trial studying the use of Vilaprisan to treat uterine fibroids. The trial's expected to take three years.
  • Myovant's drug, Relugolix, works by suppressing estrogen to low levels, and then reintroducing just enough so that it doesn't lead to bone density loss. That way, it won't be high enough to drive endometriosis and uterine fibroids, Seely said. It's a type of drug called "gonadotropin-releasing hormone receptor agonist." The US trials for Relugolix should wrap up in 2019, but a phase 3 trial conducted in Japan found that the drug wasn't inferior to leuprolide, one of the treatments currently available for uterine fibroids.
  • AbbVie, in partnership with Neurocrine Biosciences, is working on Elagolix, a drug that also works by altering hormone levels in women with uterine fibroids and endometriosis to reduce the pain associated with the conditions. Like Relugolix, Elagolix is a gonadotropin-releasing hormone receptor agonist. In September, AbbVie submitted the drug to the FDA for approval in endometriosis.

What still needs to be treated

But the treatments, while they will ideally be able to treat endometriosis and uterine fibroids with fewer side effects than what's currently available, won't be the end of the road. The hope is that this wave of new treatments will spark more, Seely said.

"When people see what a difference that we can make in the lives of women, others will follow," she said. But to get there, it will take more basic research into diseases related to women's health.

And there are still areas within women's health that need more attention. Allergan's also working on treatments to help with painful sexual intercourse, while Myovant's also working on a drug to treat infertility that's still in early stages.

There are also areas related to mental health and postpardum depression that still need some innovation, Meury said.

A version of this story was originally published in October 2017.

This article was originally published by Business Insider.