Turn on cookies to sign in
Signing in saves your progress to your Curie account. We can only do that with cookies on — turn them on to continue.
A promising antibody-drug conjugate called mocertatug rezetecan (Mo-Rez) is showing impressive results in platinum-resistant ovarian cancer — one of the toughest cancers to treat. Updated BEHOLD-1 trial data show a 62% response rate at the top dose, with responses lasting over a year. Biomarker analysis reveals the drug works across a wide range of tumor profiles, suggesting it could help a broad patient population.
Mo-Rez (mocertatug rezetecan), an investigational antibody-drug conjugate (ADC) targeting the B7-H4 protein, is delivering striking results in platinum-resistant ovarian cancer (PROC) — a disease with historically limited treatment options. Updated data from the phase 1 BEHOLD-1 trial, presented at the 2026 ESMO Congress, show that at the recommended dose of 5.8 mg/kg every 3 weeks, Mo-Rez achieved a 62% confirmed response rate after more than 13 months of median follow-up, with responses lasting a median of 12.2 months.
A companion biomarker analysis adds important nuance: nearly all patients (96–97%) had B7-H4–positive tumors, and responses were seen across all levels of B7-H4 expression — meaning the drug isn't limited to patients with the highest protein levels. Researchers also found that higher expression of the enzyme CTSB and a "matrix remodeling" gene signature were linked to better responses, hinting that composite biomarker profiles — not just B7-H4 alone — may be needed to predict who benefits most.
By the Numbers:
Why it matters: PROC is notoriously difficult to treat, and durable responses of this magnitude are rare. Mo-Rez is now being tested in five global phase 3 trials across ovarian and endometrial cancers, signaling its potential to reshape treatment for gynecologic cancers.
