Pfizer and Astellas are underlining the benefits of Xtandi as part of a combination therapy for certain patients with non-metastatic hormone-sensitive prostate cancer (nmHSPC) with an overall survival win.
The new data come from the companies’ phase 3 Embark study, which in 2023 led to the FDA approval of Xtandi in patients with nmHSPC with biochemical recurrence (BCR) at high risk of metastasis.
In the trial, Xtandi was studied as a single agent and in combination with leuprolide against placebo and leuprolide. For the trial's primary endpoint, the Xtandi combo delivered a statistically significant improvement in metastasis-free survival compared with placebo and leuprolide.
At the time, the trial's overall survival data were mature.
Now, Xtandi plus leuprolide has proved it can, in fact, extend the lives of these patients, demonstrating a “statistically significant and clinically meaningful improvement” in overall survival, Pfizer announced in a July 10 press release.
Xtandi as a monotherapy, however, did not reach statistical significance on the overall survival measure.
The results solidify the Xtandi regimen as the first and only androgen receptor inhibitor-based treatment to yield an overall survival benefit in the patient group, according to the release.
“These positive results add to the robust clinical support for the use of Xtandi and broaden clinical confidence, offering men with high-risk BCR evidence that they might live longer when they start Xtandi early,” Pfizer's oncology chief development officer, Johanna Bendell, M.D., said in a press release.
Xtandi was first approved in 2012 for late-stage castration-resistant prostate cancer and has since picked up several expansions, with the latest in 2023 marking its move into earlier prostate cancer treatment settings.
An estimated 20% to 40% of men who have been treated for prostate cancer will experience a BCR within 10 years, with about 9 out of 10 men with high-risk BCR developing metastatic disease.
Xtandi, a flagship product for Astellas, delivered a significant 21.6% growth spurt during the company's 2024 fiscal year, generating 912 billion yen ($6.2 billion). Sales expanded “in all regions” over the year, the company noted.