Phase 3 Trial of TTFields and Paclitaxel Misses OS End Point in Ovarian Cancer

Update from the phase 3 ENGOT-ov50 / GOG-3029 / INNOVATE-3 clinical trial in patients with ovarian cancer treated with TTFields and paclitaxel. © reineg [stock.adobe.com]

Patients with platinum-resistant ovarian cancer given tumor treating fields (TTFields) therapy and paclitaxel did not have a benefit in overall survival (OS), failing to meet the primary end point of the phase 3 ENGOT-ov50 / GOG-3029 / INNOVATE-3 clinical trial at the final analysis (NCT03940196).¹

The trial randomized 280 patients who received TTFields therapy plus paclitaxel. Among those patients, the median OS was 12.2 months compared with 11.9 months for patients treated with paclitaxel alone (n = 278; HR, 1.008).

Consistent with what has previously been reported in other studies, treatment with TTFields was well-tolerated and no added systemic toxicities were observed.

“While the final results of the ENGOT-ov50 / GOG-3029 / INNOVATE-3 trial differ from our initial expectation, these data add important context to the treatment paradigm,” said David O’Malley, MD, professor of Obstetrics and Gynecology at The Ohio State University Wexner College of Medicine and Director of the Division of Gynecologic Oncology at The James Comprehensive Cancer Center, in the press release. “We see treatment exposure and number of prior therapies are relevant and can drive outcomes, and we will leverage these data as we explore and identify new opportunities to treat this deadly disease.”

The randomized, controlled, open-label phase 3 ENGOT-ov50 / GOG-3029 / INNOVATE-3 trial enrolled patients with recurrent ovarian cancer who had received a maximum of 5 total prior lines of systemic therapy.² Patients were required to be 18 years of age or older with an epithelial histology of ovarian or primary peritoneal or fallopian tube carcinoma at the time of diagnosis, a life expectancy of at least 12 weeks, an ECOG performance status of 0 or 1, evaluable measurable or non-measurable disease, and previously have received a maximum of 2 prior lines of systemic therapy after their diagnosis of platinum-resistance.

In the experimental arm of the study, patients received TTFields using the NovoTTF-100L(O) System together with weekly paclitaxel at a dose of 80 mg/m2 via intravenous infusion for 8 weeks, and then on days 1, 8, and 15 of each subsequent 28-day cycle. Those in the comparator arm received just the weekly paclitaxel given using the same dosing schedule.

Investigators sought to assess the safety and efficacy of TTFields together with paclitaxel in patients with platinum-resistant ovarian cancer through evaluating the primary end point of OS. Secondary end points of the study were progression-free survival, objective response rate, severity and frequency of adverse events, time to undisputable deterioration in health-related quality of life or death, and quality of life.

According to the press release, there is a potential survival benefit among the analysis of exploratory subgroups of patients who received only 1 previous line of therapy. These results suggest that further research is needed regarding the unmet need for the low percentage of ovarian cancer patients who have a limited response to frontline platinum-based treatment.

Full evaluation of the data from the phase 3 study, including subgroup analyses, is ongoing and the company is working with investigators to share the full results.

“Recurrent ovarian cancer is a particularly aggressive cancer and options for patients diagnosed with platinum-resistance remain extremely limited,” said Ignace Vergote, MD, PhD, principal investigator and chairman of the Belgium and Luxembourg Gynaecological Oncology Group and professor at the Catholic University of Leuven, Belgium, in the press release.¹ “We are committed to continuing research with TTFields and exploring innovative approaches to treat this area of immense unmet need, and we are extremely grateful to all the investigators and patients for their participation in these studies.”

REFERENCES:

1. Novocure provides update on phase 3 ENGOT-ov50 / GOG-3029 / INNOVATE-3 trial evaluating tumor treating fields therapy in platinum-resistant ovarian cancer. News release. Novocure. August 28, 2023. Accessed August 28, 2023. https://tinyurl.com/45deuwbh

2. Effect of tumor treating fields (TTFields, 200 kHz) concomitant with weekly paclitaxel for the treatment of recurrent ovarian cancer (ENGOT-ov50 / GOG-3029 / INNOVATE-3) ClinicalTrials.gov. Updated April 20, 2022. Accessed August 28, 2023. https://clinicaltrials.gov/ct2/show/NCT03940196