As if Dendreon ($DNDN) didn't have enough to worry about, Johnson & Johnson's ($JNJ) prostate cancer pill Zytiga has now shown itself effective in patients who haven't yet received chemotherapy. That means it could gain broader use, in a population of patients that's larger than its current target.
On the advice of an independent committee, J&J's Janssen unit unblinded a clinical trial of Zytiga plus prednisone in 1,088 men who hadn't yet been treated with chemotherapy. Now, placebo patients in the study can get access to Zytiga, and J&J can prep for an FDA filing for a new indication. If approved, the new use would give Zytiga more ammunition in its competition with Dendreon's Provenge vaccine.
Indeed, Dendreon stock dropped on the news, as analysts called the J&J data a new threat to the vaccine. Robin Karnausakas of Deustche Bank said the study "could lead to some weakness in Provenge sales," in a note to investors today (as quoted by Bloomberg). Already Provenge has seen its prospects dented by Zytiga uptake, as reimbursement questions and a complicated treatment procedure put some doctors off the Dendreon product.