ROCKVILLE, MD, July 23, 2026
MacroGenics, Inc. announced a significant clinical update from its ongoing Phase 1 study of MGC026, an investigational B7-H3-targeted antibody-drug conjugate (ADC) being developed for patients with advanced solid tumors. The company confirmed that the trial achieved the pre-specified Stage 1 response threshold in patients with recurrent or metastatic squamous cell carcinoma of the head and neck (SCCHN), allowing progression into Stage 2 under the Simon’s two-stage design. The interim findings have also been accepted for poster presentation at the European Society for Medical Oncology (ESMO) Congress 2026, highlighting the growing clinical interest in MGC026 as a potential treatment for multiple difficult-to-treat cancers. The study continues to evaluate the therapy across several tumor types while expanding patient enrollment globally.
Phase 1 Trial Shows Encouraging Clinical Activity
The dose-escalation phase of the trial evaluated MGC026 at doses ranging from 1 mg/kg to 9 mg/kg every three weeks (q3W) and was successfully completed during the fourth quarter of 2025. Based on the safety and activity observed, 7.5 mg/kg every three weeks was selected for further evaluation in four tumor-specific expansion cohorts, including SCCHN, endometrial cancer, melanoma, and soft tissue sarcoma. As of July 8, 2026, a total of 74 patients had been enrolled across both the dose-escalation and cohort-expansion stages at clinical sites in the United States, Australia, and the United Kingdom. Importantly, investigators reported no cases of interstitial lung disease or ocular toxicity, while evidence of anti-tumor activity was observed across multiple cancer indications, supporting the continued advancement of the investigational ADC.
ESMO 2026 Presentation Highlights Development Progress
MacroGenics announced that the interim clinical data will be presented during the ESMO Congress 2026, scheduled for October 23–27, 2026, in Madrid, Spain. The featured poster will present the first-in-human Phase 1 study evaluating the safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary anti-tumor activity of MGC026 in patients with advanced solid tumors. The company will also present clinical data from its Phase 2 LINNET study evaluating lorigerlimab, an investigational PD-1 × CTLA-4 bispecific DART molecule, in patients with advanced gynecologic cancers. According to Eric Risser, President and Chief Executive Officer of MacroGenics, the company believes the upcoming ESMO presentation represents an important opportunity to demonstrate the clinical potential of MGC026 as development continues across multiple solid tumor indications.
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MGC026 Designed to Target B7-H3 Across Multiple Solid Tumors
MGC026 is a novel B7-H3-directed ADC that utilizes Synaffix’s proprietary ADC technology combined with the SYNtecan E™ exatecan-based topoisomerase I inhibitor payload. The therapy is specifically designed to selectively deliver a potent cytotoxic agent to B7-H3-expressing tumors, a target commonly found on tumor cells, tumor-associated stroma, and tumor-associated vasculature. By combining targeted delivery with a drug-to-antibody ratio (DAR) of 4, MacroGenics aims to maximize anti-cancer activity while limiting off-target toxicity. The encouraging interim Phase 1 results, successful advancement into Stage 2 of the SCCHN cohort, and continued enrollment across additional cancer types reinforce the company’s commitment to expanding innovative ADC therapies for patients with advanced cancers and support the ongoing clinical development of MGC026 as a potential future treatment option.
Source: MacroGenics press release
