At the recently held 2024 American Association for Cancer Research (AACR) Annual Meeting, positive Phase II trial results of the combination of Immunogen’s antibody-drug conjugate (ADC) Elahere and Merck & Co’s immune checkpoint inhibitor (ICI) Keytruda in the treatment of folate receptor-alpha (FR-α) positive recurrent microsatellite stable / mismatch repair proficient serous endometrial cancer were presented. With continued success, Elahere will not only infiltrate the endometrial cancer market but also pave the way for future treatment strategies with an ADC and immunotherapy combination, says GlobalData, a leading data and analytics company.

GlobalData’s patient-based forecast reveals that the endometrial cancer market is projected to reach $7.9 billion in 2030 in the US.

Following these positive results, an exploratory molecular analysis was performed to identify biomarkers as potential predictors of response. Although the response did not appear to be driven by FR-α expression, the analysis may be limited by the small sample size.

Jasminemay Barcelon, Oncology & Hematology Analyst at GlobalData, comments: “If synergism between these two classes is confirmed, the novel combination could be utilized for other indications with overexpressed FR-α. A continued expansion study is indicated to assess whether the responses were dependent on or driven by FR-α expression. Additionally, increasing the duration of response should be a continued focus.”

Keytruda already boasts approvals for two advanced endometrial cancer indications and in 13 other oncology indications with projected sales of $22.7 billion by 2030 based on GlobalData’s analyst consensus forecast.

Elahere recently obtained full approval as the first and only ADC for platinum-resistant ovarian cancer. Elahere’s sales in ovarian cancer across the seven major markets (the US, France, Germany, Italy, Spain, the UK, and Japan) are predicted to reach $602 million by 2030, based on GlobalData’s patient-based forecast.

Elahere holds a potential label expansion within ovarian cancer and other indications, such as non-small cell lung cancer and triple-negative breast cancer with high FR-a expression. The success of Elahere in ovarian cancer with its approved companion diagnostic, VENTANA FOLR1 assay, can serve as a model for patient stratification by biomarker.

Barcelon concludes: “In terms of commercial success, Keytruda maintains its blockbuster status in the immune checkpoint inhibitor class despite it being oversaturated. Elahere holds a potential first-to-market advantage in endometrial cancer but will face competition from other pipeline ADC agents that may have a lower threshold for FR-α expression, increasing the treatable patient population or lower lung or ocular toxicities.

“While continued positive clinical results may lead to additional Elahere approvals and address the unmet need of the undeserved FR-α -positive patient population with an aggressive subtype of endometrial cancer, this will capture only a small patient share within this indication. However, it demonstrates the potential of combining ADCs and immunotherapies as a promising strategy to sidestep the ICI resistance and improve patients’ outcomes in solid tumors.”