Atezolizumab Plus Bevacizumab and Chemotherapy Falls Short of PFS Improvement in Phase 3 Ovarian Cancer Trial

The phase 3 IMagyn500 clinical trial failed to meet its primary end point of progression-free survival with the addition of atezolizumab to bevacizumab plus paclitaxel and carboplatin chemotherapy in patients with newly diagnosed advanced ovarian cancer.

The addition of atezolizumab (Tecentriq) to bevacizumab (Avastin) plus paclitaxel and carboplatin chemotherapy failed to lead to an improvement in progression-free survival (PFS) in the treatment of patients with newly diagnosed advanced ovarian cancer, thus the coprimary end point of the phase 3 IMagyn500 clinical trial (NCT03038100) was not met, according to topline results of the study released by Roche.

Data for the coprimary end point of overall survival are still immature and will continue to be followed in the next planned analysis. Overall, the safety profile for the regimen appeared consistent with the known safety profile of the combination. Further follow-up will evaluate this combination as treatment of patients with newly diagnosed advanced ovarian cancer.

“Ovarian cancer remains one of the most aggressive cancers and is difficult to treat in its advanced stages,” said Levi Garraway, MD, PhD, chief medical officer and head, Global Product Development, Roche, in a statement. “While we are disappointed by these results, we remain committed to improving outcomes for women living with this disease and are pleased that Avastin remains a key component in the treatment of front-line ovarian cancer.”

This trial is under evaluation in the atezolizumab gynecologic development program, which builds on the addition of this combination to other regimens for the treatment of patients with ovarian and cervical cancers. The program has been able to help women with newly diagnosed, advanced or relapsed ovarian cancer and cervical cancers remain alive without worsening of disease in 7 pivotal phase 3 studies involving more than 5000 women.

This multicenter, randomized, double-blind study is evaluating both the efficacy and safety of atezolizumab in addition to bevacizumab and chemotherapy in patients with stage III or IV ovarian cancer who are receiving neoadjuvant or adjuvant therapy. Patients were randomized 1:1 to receive either atezolizumab or placebo in addition to bevacizumab, paclitaxel, and carboplatin either before or after tumor reductive surgery.

The secondary end points of the study include objective response rate, safety, tolerability, and patient-reported improvements in abdominal pain and bloating.

The IMagyn050 clinical trial is under evaluation in collaboration with the GOG Foundation, Inc. and the European Network of Gynecological Oncological Trial groups (ENGOT and ENGOT OV-39).

Patients had to have an ECOG performance status of 0, 1, or 2 to be included in the trial, as well as a life expectancy greater than 12 weeks. For patients who receive therapeutic anticoagulation, they must be on a stable anticoagulant regimen. Patients with a diagnosis of borderline epithelial ovarian cancer, recurrent invasive epithelial ovarian, fallopian tube, or primary peritoneal cancer that were treated with only surgery, and those with non- epithelial ovarian cancer were unable to enroll in the study.

Atezolizumab is a monoclonal antibody immunotherapy that binds with PD-L1, which is expressed on tumor cells and tumor-infiltrating immune cells, blocking its interactions with both PD-1 and B7.1 receptors. Atezolizumab may be able to enable the activation of T cells by inhibiting the PD-L1 protein.

The antibody has potential in combination with other immunotherapies, targeted therapies, and chemotherapies across a broad spectrum of cancers. The development of atezolizumab is based on greater understanding of the immune system interactions with tumors and how harnessing the immune system combats cancer more effectively.

Atezolizumab has received approval in the United States, European Union, and other countries around the world, either alone or in combination with targeted therapies and chemotherapies in select subtypes of lung cancer, urothelial cancer, and triple-negative breast cancer. It is also approved in the United States in combination with bevacizumab for the treatment of patients with unresectable or metastatic hepatocellular carcinoma.

Atezolizumab is under investigation in an extensive program, which includes ongoing and planned phase 3 studies in lung cancer, genitourinary cancer, skin cancer, breast cancer, gastrointestinal cancer, gynecological cancers, and head and neck cancers. The agent is being evaluating either alone or in combination with other therapies.

Reference

Roche provides update on phase III study of Tecentriq in women with advanced stage ovarian cancer. News Release. July 13, 2020. Accessed July 13, 2020. https://bit.ly/2ARVC2u