Now that Valeant ($VRX) has officially nabbed Dendreon's ($DNDN) cancer vaccine Provenge, the Canadian drugmaker will have to nurse the treatment to health. Turning sales around won't be easy--the infused product comes with a sky-high price tag and manufacturing challenges. Not to mention two hot oral competitors: Johnson & Johnson's ($JNJ) Zytiga, along with Xtandi from Astellas and Medivation ($MDVN), have entrenched themselves in the prostate cancer market while Dendreon floundered. Plus, Valeant will have to build up an oncology marketing team and salesforce. Report