In yet another setback for the drugmaker, Pfizer has withdrawn marketing applications before the FDA and European regulators for its Dalbavancin anti-infective, which it hoped to sell for treating complicated skin infections, including MRSA, a highly resistant bacteria.

Three years ago, Pfizer paid $1.9 billion for Vicuron Pharmaceuticals just as it Diflucan anti-fungal was about to lose patent protection. “By acquiring Vicuron, we can help bring two very important new medicines to patients around the world,” former Pfizer ceo Hank McKinnell crowed at the time, referring to Dalbavancin.

At the time, the drugmaker paid a premium price and noted the antibiotic was due for FDA approval in late 2005. (Back story). However, Pfizer received an approvable letter, indicating further data was needed before approval could be justified (read more).

Now, though, Pfizer will conduct an additional Phase 3 clinical study, along with a pediatric trial. “After careful consideration of feedback and ongoing dialogue with regulatory authorities, Pfizer has decided to study dalbavancin further in patients with complicated skin and skin structure infections,” Mark Kunkel, Pfizer’s global medical therapeutic area leader for anti-infectives and HIV in a statement.