More than any other industry, drug development contains the most "what have you done for me lately" investors.

Witness Progenics Pharmaceuticals (Nasdaq: PGNX), which dropped more than 60% when its lead drug, Relistor, failed a phase 3 trial last month for postoperative ileus, a constipation-like condition that follows abdominal surgery.

Then the stock jumped more than 30% in the other direction yesterday after the drug was recommended for approval in the European Union for treating opioid-induced constipation (OIC), and is trading up another 26% today after the FDA approved it last night. In fact Progenics has roughly tripled since I said investors had overreacted to the failed drug study.

Yesterday, Progenics and marketing partner Wyeth (NYSE: WYE) received a positive recommendation from the Committee for Medicinal Products for Human Use, which advises the European Medicines Agency on which drugs to approve. Relistor should be approved in a few months and then Wyeth can begin working out pricing with insurance and health-care agencies in the various EU countries. Wyeth expects to begin selling the drug in the U.S. in June.

Wyeth and Progenics will likely have the OIC market all to themselves for a while. The nearest-term competitor, Entereg, from Adolor (Nasdaq: ADLR) and GlaxoSmithKline (NYSE: GSK), has enough long-term safety issues to keep it from being approved as a treatment for OIC.

Relistor will be used only after front-line treatments like Novartis' (NYSE: NVS) Ex-Lax have already been tried. The market may be relatively small, but for Progenics, which didn't have any approved drugs until now, any sales are better than none.