Abiraterone (Zytiga)This afternoon the FDA approved Ortho Biotech’s abiraterone acetate (Zytiga) in combination with prednisone for the treatment of castrate resistant prostate cancer in patients who have received prior chemotherapy with docetaxel.

Abiraterone was filed on December 20th, 2010 and received fast track designation, so the FDA approval comes 2 months ahead of the expected PDUFA date of June 20th.

It represents another exciting advance for this disease after what Dr Bernard Tombal described as a “Grand Cru” year for prostate cancer in 2010 following the successive launches of cabazitaxel (Jevtana), sipuleucel-T (Provenge) and denosumab (Xgeva), the first since docetaxel (Taxotere) was approved back in 2006 for chemotherapy naive metastatic disease.

I’ve written much about the clinical data from various oncology meetings over the last nine months such as ESMO last September and EAU in Vienna last month.  You can check out the data in the related posts below.

The big question on everyone’s mind, though, has been price.  Docetaxel is now generically available, Sanofi-Aventis’s cabazitaxel is around $6K per cycle (assumes ~$48K if 6 cycles are completed), Dendreon’s sipuleucel-T is $93K for three infusions.

Ruth Coxeter of CNBC Health Sciences was the first to tweet the confirmed abiraterone price of $5K per month, with a median of eight months of therapy.  This gives a treatment price of  ~$40K, which I think is very fair, although some patients will obviously take it for longer than that.

Ruth Coxeter, CNBC Pharma's Market

For those interested in the press release, you can read more here.

What does this approval mean?

abiraterone acetate (Zytiga)

For men with castrate resistant prostate cancer (CRPC) who have previously received chemotherapy, there is now a new treatment option for them to choose other than more chemotherapy with cabazitaxel in the form of easy to take pills (four per day).

The data from the 302 trial in the pre-chemo setting is expected later this year and is expected to be better than the 3.9 months overall survival benefit seen in the post chemotherapy setting reported at EAU last month.

In the analysis for the FDA approval, the overall survival benefit had increased further according to Ortho Biotech:

“In an updated analysis, results were consistent with those from the interim analysis with a 4.6 month difference between the two arms in median survival (15.8 months vs. 11.2 months [HR = 0.74]).”

At the European Association of Urology meeting earlier this year, Dr Johann De Bono (Royal Marsden) told a packed audience that the data for the circulating tumour cells (CTCs) would finally be available at the ASCO annual meeting in June.  It will be interesting to see whether this is a better surrogate measure of response than PSA. With the American Urology Association meeting coming up in a few weeks in DC, not doubt there will be more to discuss then.

All in all, it is good to see new treatment options emerge for the treatment of castrate resistant prostate cancer.