Dr Moore on the Phase 1/2 Study Investigating Ubamatamab in Ovarian Cancer

Kathleen N. Moore, MD, MS, associate director, Clinical Research, the Stephenson Cancer Center, director, Oklahoma TSET Phase I Program, professor, Section of Gynecologic Oncology, The University of Oklahoma College of Medicine, discusses the eligibility criteria for the ongoing, first-in-human, phase 1/2 study (NCT03564340) of ubamatamab (REGN4018), a MUC16- and CD3-targeted bispecific antibody, alone or in combination with cemiplimab-rwlc (Libtayo) in patients with recurrent ovarian cancer.

Patients who are eligible for the current trial investigating ubamatamab must have recurrent ovarian cancer, which must be classified as resistant to platinum, Moore says, adding that patients should have had recurrence within 6 months of the date of their last platinum treatment. Moreover, patients’ tumors must be measurable by RECIST v1.1 criteria, as response rate is one of the primary end points investigators will consider, Moore adds. Patients’ cancer antigen 125 plasma levels need to be at least 2 times the upper limit of normal (ULN) because the MUC16 protein has an extracellular tail of cancer antigen 125, which is why these levels are used as biomarkers of response to chemotherapy. Selecting for this elevated marker ensures that the patients enrolled in the study have cancer that expresses MUC16, Moore explains.

In the future, MUC16 may be detected on tumor specimens, and this translational work is ongoing among investigators, Moore continues. However, for now, cancer antigen 125 markers at least 2 times the ULN arerequired to indicate MUC16 expression in patients enrolling in this phase 1/2 trial, Moore says.

All other eligibility criteria are similar to those of most other studies in platinum-resistant ovarian cancer, Moore expands. Patients must have a generally good performance status, and their labwork results need to be within normal limits, she explains. Additionally, patients must have recovered from the adverse effects of other treatments, not including alopecia and low-grade neuropathy, prior to enrolling in this clinical trial, Moore concludes.