FLORENCE, Italy and NEW YORK, May 28, 2026
Menarini Group and its wholly owned subsidiary Stemline Therapeutics have announced the presentation of encouraging new clinical data from the Phase 1b/2 ELEVATE study evaluating elacestrant in combination with capivasertib in patients with estrogen receptor-positive (ER+), HER2-negative (HER2-) metastatic breast cancer (mBC) at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting. The findings highlight the potential of the combination therapy to address critical resistance mechanisms that continue to challenge treatment outcomes in advanced breast cancer, particularly among patients harboring co-existing ESR1 and PIK3CA mutations. The latest results further strengthen Menarini’s expanding oncology portfolio and reinforce elacestrant’s potential role as a foundational endocrine therapy across multiple breast cancer treatment settings.
ELEVATE Study Demonstrates Encouraging Clinical Activity
The Phase 1b portion of the ELEVATE study evaluated multiple dose levels of elacestrant combined with capivasertib in patients with advanced or metastatic ER+/HER2- breast cancer. The trial was specifically designed to investigate whether combining endocrine therapy with targeted inhibition of the PI3K/AKT/mTOR signaling pathway could overcome common mechanisms of endocrine resistance and improve long-term patient outcomes.
Despite these challenges, TECVAYLI demonstrated exceptional efficacy. The treatment achieved a 71% reduction in the risk of disease progression or death, corresponding to a hazard ratio of 0.29, while also reducing the risk of death by 40% compared with standard therapies. These improvements in both progression-free survival and overall survival represent a significant advance for patients facing limited treatment options after relapse. Researchers also reported statistically significant improvements across all major secondary endpoints, reinforcing the robustness of the clinical benefit observed in the study.
Deep and Durable Responses Strengthen Clinical Profile
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One of the most compelling findings from MajesTEC-9 was the depth and durability of responses achieved with TECVAYLI. Nearly two-thirds of treated patients (65.9%) achieved a complete response or better, compared with only 16.8% in the standard-of-care group. These findings suggest that TECVAYLI not only delays disease progression but also delivers profound disease control capable of driving long-term clinical benefit.
Data presented at ASCO 2026 demonstrated promising efficacy within the recommended Phase 2 dose cohort consisting of elacestrant 345 mg plus capivasertib 320 mg twice daily. Investigators reported an impressive 88.9% disease control rate (DCR), a 66.7% clinical benefit rate at 24 weeks, and a 33.3% objective response rate (ORR). Notably, all patients achieving objective responses carried both ESR1 and PIK3CA mutations, suggesting the combination may offer a highly targeted therapeutic strategy for a genetically defined patient population. Researchers also reported that the median duration of response had not yet been reached, indicating the potential for durable and sustained treatment benefits.
Addressing Resistance Mechanisms in Metastatic Breast Cancer
Resistance to endocrine therapy remains one of the most significant challenges in the management of ER+/HER2- metastatic breast cancer. Mutations in the ESR1 gene frequently drive resistance to standard hormone therapies, while alterations in the PIK3CA pathway contribute to tumor growth and treatment escape. Patients carrying both mutations often face limited treatment options and poorer clinical outcomes.
The ELEVATE findings suggest that simultaneous targeting of these resistance pathways may provide a more effective treatment strategy than sequential therapies directed at individual molecular alterations. Preliminary analyses showed a median progression-free survival (mPFS) of 11.3 months within the recommended Phase 2 dose population and 10.9 months among patients with co-existing ESR1 and PIK3CA mutations, highlighting the potential for clinically meaningful disease control. Importantly, investigators reported that the combination maintained a safety profile generally consistent with the known characteristics of each individual therapy, supporting continued development and further clinical evaluation.
Expanding Elacestrant’s Role Across Breast Cancer Treatment
Beyond the ELEVATE study, Menarini also presented updates from its broader elacestrant clinical development program, demonstrating the company’s commitment to expanding treatment options for breast cancer patients. Multiple ongoing studies are evaluating elacestrant in combination with targeted therapies, CDK4/6 inhibitors, and other treatment modalities across both metastatic and early-stage disease settings.
These include the ADELA Phase 3 trial, assessing elacestrant plus everolimus in ESR1-mutated metastatic breast cancer, the ELECTRA study evaluating elacestrant with abemaciclib in patients with brain metastases, and the ELEGANT Phase 3 trial investigating elacestrant in high-risk early breast cancer. Collectively, these programs position elacestrant as a potentially transformative endocrine therapy backbone capable of addressing multiple disease stages and resistance profiles. As precision oncology continues to advance, the encouraging ELEVATE data underscore the growing importance of biomarker-driven treatment strategies and reinforce Menarini’s leadership in developing innovative therapies for patients with advanced breast cancer.
Source: Menarini Group press release
