Endometriosis: Momentum in Early-Phase Research

Rising activity in early-stage clinical trials (Phases I and II) reflects renewed momentum in the search for better therapies for endometriosis.

March is recognized globally as Endometriosis Awareness Month, bringing increased attention to a condition that affects millions of women worldwide but often remains underdiagnosed and undertreated. For the clinical research industry, this is not only an important awareness topic, but also a reminder of the significant unmet need that still exists in women’s health. Despite increasing recognition of disease burden, treatment options remain limited and there is continued need for better therapies supported by well-designed clinical development programs.

Within women’s health, endometriosis sits at the intersection of chronic pelvic pain, infertility, and broader reproductive health challenges. As a result, it has become an increasingly important focus area not only for improving disease management, but also for advancing understanding of women’s reproductive health more broadly.

A Common Chronic Disease with Significant Impact

Endometriosis is one of the most common chronic diseases affecting women of reproductive age. Globally, it is estimated that around 10% of women are diagnosed with endometriosis during their lifetime.

The disease occurs when tissue similar to the lining of the uterus grows outside the uterine cavity. These lesions respond to hormonal cycles and can cause inflammation, internal bleeding and the formation of scar tissue.

Patients frequently experience symptoms such as:🔹Dysmenorrhea (painful menstruation)🔹Chronic pelvic pain 🔹Dyspareunia (pain during sexual intercourse)

The impact, however, extends well beyond symptoms alone. Endometriosis can substantially affect fertility, daily functioning, quality of life, and overall well-being. It also places a meaningful burden on healthcare systems and society through repeated medical visits, delayed diagnosis, long-term management needs, and lost productivity.

Disease Burden and Diagnostic Challenges

Although widely recognized, the true prevalence of endometriosis remains difficult to estimate due to diagnostic delays and variability in study methodologies. Current evidence suggests that approximately 10% of women worldwide are affected, while a substantial proportion of cases remain undiagnosed for years.

For many women, the journey to diagnosis can take years, leaving patients to navigate persistent symptoms before receiving a clear clinical explanation. Symptoms may be normalized, disease severity does not always correlate with symptom intensity, and some patients remain asymptomatic.

Laparoscopy has historically been considered the gold standard for diagnosis, although it is invasive and resource intensive. Increasingly, clinicians rely on combinations of patient history, clinical examination, and imaging techniques such as transvaginal ultrasound to support earlier detection.

From a research and development perspective, these diagnostic challenges are important. Delayed diagnosis, heterogeneous presentation, and variability in symptom burden all contribute to the complexity of trial design, patient identification, and endpoint selection in endometriosis studies.

Treatment: Long-Term Management Without a Cure

Endometriosis is considered a chronic and recurrent disease, requiring long-term management strategies. Current treatment approaches focus primarily on hormonal suppression and symptom control, while surgery remains an important option for selected patients, particularly for lesion removal, symptom relief, and fertility-related management.

Typical treatment pathways include:

First-line therapies: 🔹Combined oral contraceptive pills 🔹Progestogens

Second-line therapies: 🔹Gonadotropin-releasing hormone (GnRH) agonists 🔹GnRH antagonists

These approaches can provide meaningful symptom relief for many patients, but they are not curative. They may also be associated with recurrence, tolerability limitations, or side effects such as hot flushes or reduced bone density. Surgery can also play an important role in management, yet recurrence and the need for ongoing follow-up continue to highlight the need for better and more durable treatment options.

This gap between disease burden and available treatment options is one of the key reasons endometriosis remains such an important area for clinical research.

Clinical Trials and Emerging Therapeutic Approaches

The rising number of early-phase clinical trials highlights growing scientific interest in developing new treatment options for endometriosis.

Several investigational approaches are currently under evaluation, including:

🔹Selective progesterone receptor modulators

🔹Selective estrogen receptor modulators

🔹Aromatase inhibitors

🔹Non-hormonal approaches targeting pain pathways and inflammatory mechanisms

Hormonal therapies, particularly GnRH antagonists, continue to play a major role in clinical research. At the same time, there is clear interest in identifying alternatives that may offer improved tolerability, broader applicability, or a different mechanism of action.

China and the United States currently lead global research activity, while other regions remain underrepresented in clinical trial participation. At the same time, several reviews of randomized clinical trials have highlighted limited transparency and incomplete methodological reporting, which can complicate the interpretation and replication of study results.

The field combines high unmet need with growing scientific momentum, but it also requires careful study planning, reliable patient follow-up, and strong operational execution.

Why Sponsors Partner with SanaClis in Endometriosis Research

Endometriosis trials present distinct scientific and operational challenges. Consistent data collection, patient retention, site engagement, and alignment between clinical operations and investigational product management can all have a meaningful impact on study delivery.

SanaClis supports sponsors conducting endometriosis research through:

• Experience supporting complex therapeutic programs, including early-phase clinical development
• Established site relationships capable of managing specialized gynecology patient populations
• Clinical teams experienced in studies requiring long-term patient monitoring and symptom assessment
• Dedicated project teams (maximum 1–2 studies per Project Manager)
• Our 93% on-time and on-budget delivery
• An integrated CRO and clinical supply chain model under one roof, ensuring alignment between clinical operations and investigational product management, particularly in studies involving long treatment timelines, hormonal therapies and complex site coordination.

In therapeutic areas such as endometriosis, where patient experience and long-term disease management are central to study design, this type of operational coordination becomes especially important.

Looking Ahead

Endometriosis remains a widespread and burdensome chronic disease affecting millions of women worldwide. Despite increasing awareness and expanding research activity, important gaps remain in diagnosis, treatment, and long-term disease management.

At the same time, the field is seeing growing momentum in therapeutic innovation. As research continues to explore new hormonal and non-hormonal strategies, there is a clear opportunity to advance therapies that go beyond symptom suppression and better address long-term patient needs.

For the clinical research industry, endometriosis represents both a challenge and an opportunity: a challenging disease area with complex study requirements, but also an important space for innovation in women’s health where unmet need remains high.

Continued progress in disease understanding, earlier diagnosis and the development of more effective and better-tolerated therapies will be essential to improving outcomes for patients living with this complex condition.