Pfizer, Astellas' Xtandi Combo Therapy Cuts Risk Of Metastasis, Death In Prostate Cancer By 58%

Astellas Pharma Inc ALPMY and Pfizer Inc PFE announced detailed Phase 3 EMBARK trial data.

The companies tested Xtandi plus leuprolide and Xtandi as a monotherapy against placebo plus leuprolide in men with non-metastatic hormone-sensitive prostate cancer with high-risk biochemical recurrence (BCR). 

The 1,068-patient trial hit the primary endpoint, metastasis-free survival (MFS).

The companies released topline data from the study in March this year.

Xtandi (enzalutamide) plus leuprolide significantly reduced the risk of metastasis or death by 58% versus placebo plus leuprolide in non-metastatic hormone-sensitive prostate cancer. 

Secondary endpoints also saw improvements.

Xtandi monotherapy reduced the risk of metastasis or death by 37% versus leuprolide plus placebo. The combo arm of the study reduced the risk of PSA progression by 93%, while the monotherapy reduced it by 67%.

There’s also a “positive trend” in data on overall survival, a key secondary endpoint, but the companies said the data aren’t mature yet and still need a final analysis.

The most common adverse events in the combo arm were fatigue, hot flush, and arthralgia. In the patients on the Xtandi monotherapy, the most common adverse events were fatigue, gynecomastia, and arthralgia.

Price Action: PFE shares are up 1.31% at $39.40 on the last check Monday.