BOSTON, June 1, 2026
Servier has announced encouraging new clinical findings for Emiltatug Ledadotin (Emi-Le), an investigational B7-H4-targeted antibody-drug conjugate (ADC), during an oral presentation at the American Society of Clinical Oncology (ASCO) 2026 Annual Meeting. The Phase 1 data demonstrated promising anti-tumor activity and a favorable safety profile in patients with advanced, recurrent, or metastatic adenoid cystic carcinoma (ACC), a rare and difficult-to-treat cancer with no approved systemic therapies. The results come shortly after the U.S. Food and Drug Administration (FDA) granted Breakthrough Therapy Designation to Emi-Le for patients with locally advanced, recurrent, or metastatic ACC characterized by solid histology or high-grade transformation. The latest findings reinforce the potential of targeted antibody-drug conjugates to transform treatment options for rare cancers with significant unmet medical needs and position Emi-Le as one of the most promising emerging therapies in ACC research.
Phase 1 Trial Demonstrates Encouraging Clinical Activity
The ongoing Phase 1 clinical study evaluated Emi-Le in patients with advanced or metastatic solid tumors, including 48 patients with adenoid cystic carcinoma, a malignancy often associated with poor long-term outcomes and limited therapeutic options. Among 45 evaluable ACC patients, the investigational therapy achieved an objective response rate (ORR) of 35.6%, including one complete response, while delivering an impressive disease control rate (DCR) of 82.2%. These findings indicate meaningful anti-tumor activity in a disease where treatment advances have historically been limited.
Particularly notable were results from a post-hoc analysis focusing on patients with aggressive ACC subtypes characterized by solid histology or high-grade transformation. In this higher-risk population, Emi-Le demonstrated an ORR of 46.9%, a DCR of 81.3%, and a median progression-free survival (PFS) of 7.8 months, suggesting the therapy may offer substantial clinical benefit for patients with the greatest unmet need. Researchers highlighted the consistency of tumor shrinkage across participants as a key indicator supporting further development.
Targeted ADC Technology Expands Precision Oncology Opportunities
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Emi-Le represents an advanced generation of antibody-drug conjugate technology, combining targeted tumor recognition with highly potent anti-cancer payload delivery. The therapy is designed to selectively target B7-H4, an immune checkpoint protein highly expressed in ACC and multiple other tumor types, while minimizing exposure to healthy tissues. The ADC incorporates a target-optimized drug-to-antibody ratio and a proprietary auristatin-based payload engineered to maximize anti-tumor activity while maintaining a manageable safety profile.
The growing success of ADCs across oncology has fueled significant interest in the development of next-generation targeted therapies capable of delivering improved efficacy with reduced toxicity. Servier’s latest findings provide additional evidence supporting B7-H4 as an important therapeutic target and further validate ADC technology as a critical component of future precision medicine strategies.
Favorable Safety Profile Supports Continued Development
In addition to encouraging efficacy signals, Emi-Le demonstrated a favorable and potentially differentiated safety profile. Most treatment-related adverse events were transient, manageable, and primarily laboratory-based or low-grade in severity. The most frequently reported treatment-related adverse events included transient increases in liver enzymes, reversible proteinuria, fatigue, and nausea. Importantly, no Grade 4 or Grade 5 treatment-related adverse events were reported, and treatment discontinuation due to adverse events occurred in only 3.9% of patients. No treatment-related deaths were observed during the study.
These findings are particularly significant given the challenges often associated with developing therapies for rare cancers, where balancing efficacy and tolerability remains critical. Building on these positive results, Servier plans to advance Emi-Le into a pivotal Phase 2 study designed to further evaluate efficacy and safety in a larger ACC patient population. With FDA Breakthrough Therapy Designation already secured and growing clinical momentum, Emi-Le could emerge as a transformative treatment option for patients with advanced adenoid cystic carcinoma and potentially establish a new standard of care in this underserved oncology setting.
Source: Servier press release
