Pfizer receives prostate cancer drug boost with trial results

Pfizer, and its partner Astellas Pharma, received a major boost to its plans for prostate cancer treatment, Xtandi, by announcing it has received positive data for treating the condition at an early stage.

The data displayed that Xtandi, in combination with an anti-hormone therapy, was able to improve survival in men with non-metastatic castration-resistant prostate cancer without it spreading to other parts of the body. The good news comes at a faster clip than expected, after changes to the trial design allowed the companies to complete with fewer patients than had previously been anticipated.

Pfizer had acquired the drug through its $14 billion dear for Medivation, completed this time last year. The drug was the main driver behind the purchase but suffered from a drop in the sales at the beginning of the year that had analysts doubting the wisdom of the purchase.

However, the likelihood of now being able to extend the indication into a new patient population, with some suggesting it could double those eligible for the treatment, means sales look likely to be pushed beyond the $1 billion mark, annually. With an additional two further clinical trials running into further indications, and positive noises coming from the companies involved, any fears of the purchase look set to be forgotten.

"We are delighted with the significant results seen in the PROSPER study, showing that Xtandi plus ADT delayed clinically detectable metastases compared to ADT alone in patients with non-metastatic CRPC whose only sign of underlying disease was a rapidly rising prostate-specific antigen level. We look forward to discussing the data with regulatory authorities," said Mace Rothenberg, Chief Development Officer, Oncology, Pfizer Global Product Development.

Astellas also looks set to benefit from this data windfall, as it develops and markets the drug outside of the US – after it had jointly developed the drug alongside Medivation.

Xtandi’s main rival in the area is Johnson & Johnson’s Zytiga, which revealed strong data at this year’s ASCO revealing reduced risk of death in low-risk and high-risk cancer patients. The data released by Pfizer now looks to steady fears that the competition would erode its own sales.