Chemotherapeutic Assay Selects Effective Treatments for Ovarian Cancer

At 6 months, the arm receiving chemotherapy selected by ChemoID had an ORR of 55%, compared with 5% in the physician choice arm.

A chemotherapeutic assay (ChemoID) designed to to select targeted treatments for patients with platinum-resistant ovarian cancer, based on the cytotoxicity profile of patients’ cancer stem cells, significantly improved objective response rates (ORRs), according to data from a phase 3 trial (NCT03949283) published in npj Precision Oncology.¹

In the multicenter trial 81 patients were randomized 1:1 to be treated with 1 of 13 preselected chemotherapy regimens that was either assigned by the ChemoID assay (n = 34) or by physician’s choice (n = 41). The primary end point was ORR as determined by CT scans using RECIST 1.1 criteria at 6 months. The ChemoID arm experienced an ORR of 55% (95% CI, 39%-73%) vs 5% (95% CI, 0%-11%) in the physician choice arm (odds ratio [OR], 0.044; P < .0001).

The purpose of the assay is to identify effective chemotherapy that will kill the majority of tumor cells, thereby reducing tumor size and to identify which treatment will decrease cancer stem cell count to curb the risk of disease recurrence.

“The thought is that by testing the tumor for chemosensitivity in not only the tumor cells, but also the cancer stem cells, one can eradicate the cancer stem cells that would repopulate the tumor,” commented Pier Paolo Claudio, MD, a codeveloper of the clinical test, in a news release.²

Additional Efficacy Data

Duration of response (DOR) and progression-free survival (PFS) were secondary end points. In those treated with chemotherapy guided by the assay, median DOR was 8 months, compared with 5.5 months (P < .0001) in the physician choice arm.¹

PFS was favored with the use of the assay over physician’s choice, as well, with medians of 11.0 months (95% CI, 8.0-not available [NA]) vs 3.0 months (95% CI, 2.0-3.5), respectively, reducing the risk for disease progression by 73% (HR, 0.27; 95% CI, 0.15-0.49; P < .0001).

Clinical benefit rates (CBR) were higher among the assay-guided arm at 85% (95% CI, 73%-97%), compared with 24% (95% CI, 11%-38%) in the physician choice arm.

“Overall response rate, median progression-free survival and median duration of response were statistically and clinically significantly improved when patients were treated using the ChemoID assay versus physician’s choice therapy in a randomized trial of patients with recurrent ovarian cancer,” added Herzog, a Cancer Center physician researcher, the Paul and Carolyn Flory Professor in Gynecologic Oncology in the UC College of Medicine and director of UC Health’s Gynecologic Cancer Disease Center in the release.² “This is partly due to the selection and reactivation of cancer stem cells that rebuild and repair the tumor from the damage received from chemotherapy.”

Patient Characteristics

Patients were adult females who had received at most 5 prior lines of therapy including at least 1 platinum-based treatment. While the trial was open to patients with multiple histotypes, all patients enrolled had recurrent high-grade serous carcinoma.¹

About half of patients in the assay-guided group responded to treatment, with 18 partial responses and 2 complete responses; 13 had stable disease; and 7 had progressive disease. Likewise, most patients in the physician choice arm had progressive disease (n = 32), 8 subjects had stable disease, 1 had partial response, and 1 had complete response.¹

The median ages of patients in assay-guided and physician choice arms were 55.3 and 54.6 years, respectively.¹

Investigators noted that significant adverse effects are associated with nonplatinum chemotherapy for platinum-resistant ovarian cancer.

Reference

1. Herzog TJ, Krivak TC, Bush S 2nd, et al. ChemoID-guided therapy improves objective response rate in recurrent platinum-resistant ovarian cancer randomized clinical trial. NPJ Precis Oncol. 2025;9(1):86. Published 2025 Mar 25. doi:10.1038/s41698-025-00874-0
2. Device reduces risk of brain injury after heart valve replacement. News release. JAMA For the Media. August 4, 2016. Accessed August 18, 2016. https://media.jamanetwork.com/news-item/device-reduces-risk-of-braininjury-after-heart-valve-replacement/