These 7 biotechs are shaping the next generation of endometriosis care

Endometriosis is a debilitating condition where tissue similar to the lining of the uterus grows outside the uterus, causing pain, inflammation, and increasing the risk of infertility as well as ovarian and endometrial cancers.

It affects around 190 million women and girls globally, according to the World Health Organization. The standard of care involves a combination of treatments that include pain management medicines, hormone therapy, and sometimes even surgery to remove the harmful tissue. However, a cure is yet to be found. Moreover, a review in the American Journal of Obstetrics and Gynecology (AJOG) explained that diagnosing the condition is hard as endometriosis research remains underfunded and understudied, despite its high prevalence.

Still, as the knowledge of drug targets implicated in the disease progression expands, more and more biotechs are enthusiastic about taking on the condition. As we observe Endometriosis Awareness Month in March, let us take a look at seven companies advancing promising candidates in the clinic.

Ananda Pharma

• Location: U.K.
• Drug candidate: MRX1
• Technology: cannabidiol

U.K.-based company Ananda Pharma is conducting a pilot randomized controlled trial ENDOCAN-1 to test the efficacy of an oral cannabinoid drug to help manage the pain associated with endometriosis. The cannabinoid in question is MRX1, which will be tested in 100 women with pelvic pain caused by endometriosis along with a placebo for 12 weeks.

Currently being evaluated in the phase 1 study, MRX1 contains cannabidiol (CBD), a compound that has shown promise in addressing both the symptoms and underlying mechanisms of endometriosis. It has anti-inflammatory, pain relief, and antidepressant therapeutic effects as it interacts with more than 65 different receptors and mechanisms in the body, some of which involve the endocannabinoid system (ECS). This system plays a critical role in maintaining balance in the body, influencing functions such as memory, neurogenesis, mood regulation, appetite, metabolism, stress response, immune function, reproduction, pain management, temperature regulation, and sleep.

By influencing pain perception and inflammation and modulating other receptor systems involved in pain signaling, MRX1 aims to mitigate endometriosis-related pain in patients.

In December 2024, it secured £100,000 ($129,169) in funding.

Kissei Pharmaceutical

• Location: Japan
• Drug candidate: Linzagolix
• Technology: GnRH antagonist

Japanese company Kissei Pharmaceutical has drug candidates in its pipeline to address different kinds of diseases, including Parkinson’s disease and non-muscle-invasive bladder cancer. But the biotech company’s most advanced drug in the mix is Linzagolix, which is in the clinic to treat uterine fibroids – non-cancerous growths that develop in the uterus – and endometriosis.

Linzagolix is a GnRH receptor antagonist that binds and blocks the GnRH receptor in the pituitary gland in the brain. This way, GnRH is prevented from stimulating the release of the follicle-stimulating hormone (FSH) and luteinizing hormone (LH), decreasing their production and thereby reducing the amount of estrogen in the ovaries. By reducing estrogen levels, linzagolix could help deter the growth of endometriosis tissue.

Kissei licensed linzagolix to U.K.-based Theramex to further develop the drug, and it was approved in the European Union under the name YSELTY to treat the condition in December 2024. The company seeks to snag approvals from regulators across the world, and is evaluating the drug in phase 3 studies.

A study found that 200 mg of linzagolix along with add-back therapy (ABT) – a treatment often paired with GnRH agonists to combat low estrogen levels in order to mitigate side effects – significantly reduced dysmenorrhea – painful cramping during periods – and non-menstrual pelvic pain after three months of therapy. Meanwhile, a daily dose of 75 mg of linzagolix yielded a significant decrease only in dysmenorrhea after three months.

Hope Medicine

• Location: China
• Drug candidate: HMI-115
• Technology: monoclonal antibody

China-based Hope Medicine is building a pipeline focused on endocrine, cardiovascular and metabolic diseases as well as women’s health. 

The most advanced in the company’s pipeline is HMI-115 for endometriosis. HMI-115 is a monoclonal antibody that works by blocking the prolactin receptor (PRLR). The endometrium has this receptor, which produces the hormone prolactin. Elevated levels of this hormone are often observed in people with endometriosis, particularly patients who experience infertility. These high levels are also said to contribute to pain and can impact endometriosis progression.

In a phase 2 trial, the drug demonstrated statistically significant improvement in endometriosis pain. There was a 42% reduction in the dysmenorrhea pain score and a 50% decline in the non-menstrual pelvic pain score across 142 patients with endometriosis in the U.S., Poland, and China. Most of the patients also reported normal menstrual periods.

The drug is also being tested in a phase 2 study in patients with androgenic alopecia, a common form of hair loss.

Gesynta Pharma

• Location: Sweden
• Drug candidate: vipoglanstat
• Technology: small molecule

Most endometriosis treatments that are meant to offer pain relief to patients do not provide enough benefit and tend to cause intolerable side effects. Ongoing scientific research suggests that there are several drug targets to address the condition. The enzyme microsomal prostaglandin E synthase (mPGES-1) is one such drug target. While it is present only at low levels in humans, in inflamed tissues as seen in endometriosis lesions, the levels of this enzyme are heightened, which ultimately leads to more production of proinflammatory prostaglandin E2 (PGE2), a potent biological mediator of pain and inflammation. To combat this uptick in the amount of mPGES-1, Swedish company Gesynta Pharma is developing the candidate vipoglanstat in the clinic.

Vipoglanstat specifically targets mPGES-1 to curb inflammation. Currently in phase 2 trials, the drug has been shown to inhibit mPGES-1. Preclinical data have shown a marked reduction of endometriotic lesions and pain with vipoglanstat. Moreover, in a phase 2 study testing the candidate in patients with systemic sclerosis (SS) who have Raynaud’s phenomenon –  a condition where blood vessels narrow because of low blood flow and occurs in 95% of those with (SS) – the drug spurred a 57% reduction of PGE2 – a promising biomarker for endometriosis.

The biotech company kicked off the year with a SEK 304 million ($30.09 million) series B funding round to move the endometriosis drug further up the clinic.

TiumBio

• Location: South Korea
• Drug candidate: TU2670
• Technology: GnRH antagonist

South Korean company TiumBio is progressing its lead candidate TU2670 to address endometriosis and uterine fibroids. 

TU2670 is a GnRH antagonist that can bind to pituitary receptors to suppress estradiol hormone. According to the company, existing GnRH agonists tend to be in an injection form, and they inhibit sex hormones to the level of menopause, resulting in serious side effects such as bone loss. Unlike these traditional GnRH agonists, TU2670 is an oral GnRH antagonist that only suppresses hormone levels to the level of efficacy, thereby circumventing certain side effects and improving ease of delivery. 

As the candidate works by controlling sex hormone levels, it allows for the drug to potentially be tested to treat conditions like precocious puberty and infertility.

It is being investigated in a phase 2a clinical trial in five European countries. TiumBio signed an exclusive licensing agreement with fellow South Korean biotech Deawon Pharma for the development and commercialization of TU2670 in South Korea in 2019, and Deawon is currently conducting a phase 2 clinical trial in South Korea in uterine fibroids. The company also penned a $170 million licensing agreement with Chinese company Hansoh Pharma to develop and commercialize TU2670 in Greater China in 2022. Currently, Hansoh is carrying out clinical trials for TU2670 in China.

Two years ago, the company bagged KRW 38.5 billion ($26.19 million) in funding to boost its pipeline. 

Viramal

• Location: U.K. and Sweden
• Drug candidate: VML-0501
• Technology: synthetic steroid

Women’s healthcare company based in the U.K. and Sweden, Viramal specializes in developing medicines that treat a range of debilitating conditions commonly experienced by women.

Its portfolio consists of drugs that have targeted delivery. They are administered to the pelvic cavity to optimize drug concentration and aim to avoid any systemic side effects – those adverse effects that affect the entire body, rather than a specific organ or area.

To address endometriosis and infertility, the company has developed VML-0501, which is given trans-vaginally to patients. If approved, the candidate could be the first treatment to preserve hormone balance, reach the pelvic cavity and target tissue through vaginal administration, and rejuvenate ovarian tissue and improve fertility, according to the company.

The candidate is a formulation of danazol, which is a synthetic steroid and pituitary gonadotropin inhibitor that works to treat endometriosis by shrinking the displaced tissue of the uterus. VML-0501 is currently being studied in phase 2b trials.

Endometriosis treatments: preclinical R&D on a high 

There are different kinds of drug candidates in preclinical stages of development for endometriosis at the moment. For instance, American biotech Temple Therapeutics’ TTX334Dx is in early stages, and it acts by killing fibrotic cells – attacking the root cause of the condition instead of only mitigating symptoms. Its other candidate is a diagnostic one – TTX334Dx – which has shown its ability in detecting endometriosis with the help of biomarkers and other molecules in the blood.

Another U.S.-based biotech conducting endometriosis preclinical studies is Flightpath Biosciences. Its candidate FP-300 is an antibiotic against the bacteria Fusobacterium nucleatum. Recent studies have found a possible link between the bacterial infection and the development of endometriosis, as the pathogen has been found in a significant percentage of patients with endometriosis. 

Besides Flightpath, Celmatix in New York is pioneering an immunotherapy approach to cause the regression of endometriosis lesions by resetting immune cells. Its JNK inhibitor is designed to restore apoptotic sensitivity – a cell’s susceptibility to programmed cell death – to endometriotic lesions, shift innate immune cells to phagocytosis, and reduce pain and neuronal inflammation.

Meanwhile, in the U.K., ValiRx has come up with VAL-301, a reformulated version of its anti-cancer peptide small molecule drug VAL201, that is designed to inhibit the androgen activation of SRC kinase, a mechanism that drives hormone-dependent cell growth, to potentially lower endometrial lesions.

Swiss biotech Fimmcyte’s FMC2 and French company BCI Pharma’s undisclosed endometriosis candidate are both in lead optimization stages at present. Israeli company Gynica’s cannabinoid drugs have just entered the clinic to alleviate symptoms of endometriosis.

The global endometriosis treatment market size was estimated at $1.76 billion in 2024 and is expected to grow at a 12.25% compound annual growth rate (CAGR) in the next five years, according to a report by Grand View Research. While challenges to therapeutic research still exist, the ongoing preclinical and clinical development of treatments for endometriosis could pave the way for change.