Promising Phase 1 Data for Servier's Emiltatug Ledadotin (Emi-Le) in Adenoid Cystic Carcinoma (ACC) Presented at ASCO 2026

• Emi-Le recently received Breakthrough Designation from the U.S. Food and Drug Administration (FDA) for the proposed treatment of patients with locally advanced, recurrent or metastatic ACC with solid histology or high-grade transformation
• Oral presentation shows Emi-Le was well tolerated and showed promising signals of efficacy among 45 evaluable participants with ACC

BOSTON, June 1, 2026 /PRNewswire/ -- Servier today announced promising new Phase 1 clinical data for Emi-Le, an investigational antibody drug conjugate (ADC) directed against B7-H4, during an oral session at the American Society of Clinical Oncology (ASCO) 2026 Annual Meeting in Chicago, Illinois.

Emi-Le is an advanced engineered ADC that is directed against B7-H4, an immune checkpoint protein that is highly expressed in ACC along with several other cancers. As part of an ongoing Phase 1 trial, a dose escalation and backfill cohort enrolled adult patients with advanced or metastatic solid tumors (n=180), including those with ACC (n=48) defined by an aggressive clinicopathologic phenotype and/or molecular features consistent with poor prognosis.

"Emi-Le represents a novel, targeted therapeutic approach for patients who suffer from recurrent, advanced or metastatic ACC. The recent FDA Breakthrough Designation further validates the critical unmet need for a targeted systemic therapy to address the challenging effects of this disease for affected individuals," said Elly Barry, MD, Chief Medical Officer, Day One Biopharmaceuticals, now part of Servier Group. "These encouraging data at ASCO indicate strong promise to support a population distinctly in need of effective therapies and will help inform the pivotal Phase 2 study we will undertake in a larger set of participants."

The analysis presented at ASCO found:

• Emi-Le was well-tolerated demonstrating a distinct and potentially differentiated emerging safety profile:
  • Most treatment-related adverse events (TRAEs) were transient laboratory-based and/or low-grade. The most common TRAEs were transient AST increase (56%) generally asymptomatic and reversible proteinuria (54%), predominantly low-grade fatigue (42%) and nausea (33%).
  • The only Grade 3 TRAEs in ≥10% of pts were transient AST increase (20%) and proteinuria (23%). No Grade 4 or 5 TRAEs reported.
  • TRAEs leading to treatment discontinuation occurred in 3.9% of patients and no treatment-related deaths were reported.
• Promising signals of efficacy among 45 evaluable participants with ACC.
  • Objective response rate (ORR) was 35.6%, including one complete response.
  • Disease control rate was 82.2%.
  • Further, a post-hoc analysis was conducted in a more clearly defined aggressive ACC subtype reflecting clinical features used in practice by clinicians and pathologists, including solid histology or high-grade transformation. This analysis (n=32 evaluable participants) reported promising signals:
    • Consistent tumor shrinkage, with an ORR of 46.9%, DCR of 81.3% and median PFS of 7.8 months.

"These data provide important insights into the use of a targeted ADC for the difficult-to-treat rare cancer ACC, most notably demonstrating favorable tolerability and a potentially differentiated safety profile," said Glenn J. Hanna, M.D., study investigator and Director, Center for Cancer Therapeutic Innovation at Dana Farber Cancer Institute. "The encouraging anti-tumor activity observed to date supports continued investigation of this program, particularly given the poor prognosis for patients with ACC and the lack of approved or preferred systemic therapies in the advanced or metastatic setting. If confirmed in further studies, this profile could potentially represent a paradigm shift in treatment."

Media Contact
Kenneth DiCienzo: [email protected]

About Emi-Le
Emi-Le is a B7-H4-directed Dolasynthen ADC with a precise, target-optimized drug-to-antibody ratio (DAR 6) and a proprietary auristatin-F HPA payload with controlled bystander effect. This candidate is under evaluation in an ongoing Phase 1 clinical trial (previously with Mersana Therapeutics). The U.S. Food and Drug Administration has granted Fast Track designations to Emi-Le for the treatment of 1) adult patients with advanced or metastatic triple-negative breast cancer, and 2) advanced or metastatic HER2 low / HER2 negative breast cancer post-topo-1 ADC (including TNBC and certain HR+ breast cancers). It has also received Breakthrough Designation from the FDA for the treatment of patients with locally advanced, recurrent or metastatic adenoid cystic carcinoma with solid histology or high-grade transformation. For more information about the trial, visit clinicaltrials.gov (NCT05377996).

About Adenoid Cystic Carcinoma
Adenoid cystic carcinoma (ACC) occurs in the secretory glands, typically in the head and neck, but also in other areas of the body. Globally, more than 200,000 people have ACC. It is diagnosed in roughly four per one million people annually, and does not discriminate by ethnicity or lifestyle factors. Today there are no approved or preferred systemic therapies to treat advanced or metastatic ACC; most people are treated with surgery or radiation, but the disease recurs in 50 percent of cases, often becoming more aggressive with metastases in distant areas of the body.¹

About Servier in Oncology
Servier is a global leader in oncology, governed by a non-profit foundation. Servier approaches innovation with a long-term vision, free of influence from fiduciary responsibilities.

Servier invests close to 20% of revenue from brand-name medicines in R&D each year. Servier aspires to advance more targeted therapies by identifying mutations and understanding how these mutations impact cancer and its progression. Servier believes we can serve more people by helping the right patients find the right treatment, at the right time.

Servier takes a One Innovation Engine approach to R&D and is actively seeking alliances, partnerships and acquisitions at various stages of the portfolio.

For more information about working with Servier to bring the promise of tomorrow to the patients it serves, visit Servier.com and Servier.us.

¹ Adenoid Cystic Carcinoma Research Foundation. Accessed May 2026.

SOURCE Servier Pharmaceuticals