Cabozantinib/Atezolizumab Significantly Improves PFS in Metastatic CRPC

"Cabozantinib in combination with atezolizumab represents a potential new treatment modality for patients with metastatic [CRPC], and we look forward to sharing the full data at a future medical meeting," according to Neeraj Agarwal, MD, FASCO.

Cabozantinib (Cabometyx) in combination with atezolizumab (Tecentriq) elicited a statistically significant improvement in progression-free survival (PFS) compared with abiraterone (Zytiga) plus prednisone or enzalutamide (Xtandi) in patients with previously treated metastatic castration-resistant prostate cancer (CRPC) and measurable soft tissue disease, according to a press release from Exelixis, Inc on the phase 3 CONTACT-02 study (NCT04446117).

Investigators also observed a trend towards improved overall survival (OS) for patients receiving cabozantinib plus atezolizumab, although these data were immature and lacked statistical significance at the time of the prespecified analysis. The trial will advance to the next OS analysis per the investigators’ plans.

Cabozantinib plus atezolizumab produced a safety profile that was comparable with prior reports for each individual agent. Additionally, investigators observed no new safety signals in the trial.

“These positive findings from [the] CONTACT-02 [trial] are highly encouraging given the need for additional, non-cytotoxic or non-chemotherapeutic treatment options for this patient population,” lead investigator Neeraj Agarwal, MD, FASCO, professor and president endowed chair of Cancer Research at Huntsman Cancer Institute, University of Utah, said in the press release. “Cabozantinib in combination with atezolizumab represents a potential new treatment modality for patients with metastatic [CRPC], and we look forward to sharing the full data at a future medical meeting.”

Investigators of the international, multi-center, randomized phase 3 CONTACT-02 trial assessed 575 patients with metastatic CRPC, measurable visceral disease or measurable extrapelvic adenopathy, and receipt of 1 prior novel hormonal therapy. In the experimental arm, patients received 40 mg of cabozantinib orally once a day plus 1200 mg of atezolizumab intravenously once every 3 weeks. In the comparator arm, patients received either 1000 mg of abiraterone orally once a day plus 5 mg of prednisone orally once a day or 160 mg of enzalutamide orally once a day.

The trial’s primary end points were PFS per RECIST v1.1 criteria and OS. Objective response rate per RECIST v1.1 criteria served as a secondary end point.

Patients 18 years and older with histologically or cytologically confirmed adenocarcinoma of the prostate and surgical or medical castration with serum testosterone no higher than 50 ng/dL at screening were able to enroll on the trial. Additional eligibility criteria included having measurable metastatic disease, progressive disease at study entry, an ECOG performance status of 0 or 1, recovery from any toxicity related to any previous treatments, and adequate organ and marrow function.

Those who received any prior nonhormonal therapy for metastatic CRPC or radiotherapy within 4 weeks prior to randomization were unable to enroll on the trial. Patients were also unable to enroll on the trial if they had known brain metastases or cranial epidural disease, symptomatic or impending spinal cord compression, received an attenuated vaccine within 30 days before randomization, or had uncontrolled, significant intercurrent or recent illness.

“We are pleased to report positive findings from the CONTACT-02 trial, in which cabozantinib in combination with an immune checkpoint inhibitor has demonstrated an efficacy benefit in another tumor type with significant unmet need. We look forward to discussing these findings with the [FDA] and to presenting further details at an upcoming medical meeting,” Vicki L. Goodman, MD, executive vice president of Product Development & Medical Affairs and chief executive officer at Exelixis, concluded.

Reference

Exelixis and Ipsen announce positive results from phase 3 CONTACT-02 pivotal trial evaluating cabozantinib in combination with atezolizumab in metastatic castration-resistant prostate cancer. News release. Exelixis, Inc. August 21, 2023. Accessed August 21, 2023. https://shorturl.at/hlpq1