Mocertatug Rezetecan Shows 62% Response in Ovarian Cancer
Updated phase 1 BEHOLD-1 data reports a confirmed objective response rate in platinum-resistant ovarian cancer patients.
Updated on Nov. 9, 2026 in Cancer
Updated data from the phase 1 BEHOLD-1 study showed a 62% confirmed objective response rate for mocertatug rezetecan at 5.8 mg/kg in platinum-resistant ovarian cancer, presented at the ESMO Congress in 2026. The results cover 136 patients with a median follow-up of 13.4 months.
Why it matters
Platinum-resistant ovarian cancer has limited treatment options once standard therapy stops working, so a B7-H4-directed antibody-drug conjugate with high response rates could matter for this patient group. The findings remain early and depend on confirmation in larger trials.
The confirmed objective response rate of 62% at 5.8 mg/kg, with a 95% confidence interval of 46.5% to 76.2% across 45 patients, compares with 36% at the 2.8 mg/kg dose. Neutropenia occurred in 87% of patients at the highest dose, with grade 3 or higher events in 60%, and the phase 3 comparison against standard care has not yet reported.
The players
Floor Backes
Floor Backes is a gynecologic oncologist and principal investigator associated with the BEHOLD-1 study at The Ohio State University Wexner Medical Center.
The Ohio State University Wexner Medical Center
The Ohio State University Wexner Medical Center is a major academic cancer center in Columbus, Ohio, that participated in the BEHOLD-1 trial.
The details
In the BEHOLD-1 trial, 97% of evaluable tumors were B7-H4 positive, and the drug is given every three weeks at 5.8, 4.8, or 2.8 mg/kg. Granulocyte colony-stimulating factor prophylaxis is strongly recommended across the BEHOLD program to manage myelosuppression.
Timeline
2026: Updated BEHOLD-1 data presented at the ESMO Congress
Phase 3 BEHOLD-Ovarian01 trial is ongoing
Health Landscape
Mocertatug rezetecan belongs to the BEHOLD program's effort to target B7-H4, a protein found on most tumors in this study, with antibody-drug conjugates. Its results sit alongside earlier antibody-drug conjugates approved for ovarian cancer, and phase 3 data will determine whether it changes standard treatment.
For people with platinum-resistant ovarian cancer, a treatment that reaches tumor response rates in this range could offer a new option if confirmed. Patients receiving the drug would need growth-factor support to manage neutropenia, which affected most participants at the highest dose.
The takeaway
Early response data are promising, but confirmation in phase 3 trials will determine whether this antibody-drug conjugate becomes part of standard care for platinum-resistant ovarian cancer.
What happens next
Results from the phase 3 BEHOLD-Ovarian01 trial comparing mocertatug rezetecan with standard of care are still pending.
Further reading
Explore more on Cancer for context on how targeted therapies are reshaping treatment options.
Source note: This article includes information reported by OncLive.
