Back by popular demand, I've compiled a calendar of expected U.S. Food and Drug Administration approval decisions. These can be make-or-break events for drug and biotech companies, so naturally, FDA decisions often move stocks significantly. The following calendar covers most of the expected drug approval decisions by the FDA through the end of the year. To be included in this FDA calendar, a drug must already be submitted and under review by the agency. For reasons of space, I left out pending FDA approvals for the large pharmaceutical companies. I put the calendar together using company reports and the BioMedTracker service from Sagient Research -- a handy, subscription-based tool for keeping track of biotech and drug catalysts. Hemispherx Biopharma ( HEB) Drug/indication: Ampligen for chronic fatigue syndrome FDA decision date: May 25 Hemispherx announced May 26 that the FDA requested a "brief delay" of one to two weeks to take actionf on the Ampligen application. Savient Pharmaceuticals ( SVNT) Drug/indication: Krystexxa for gout FDA advisory panel date: June 16 FDA decision date: Aug. 1 FDA advisory panel meetings in which outside experts offer recommendations on the approval of drugs are another important stock-moving event. Investors will be keying on the June 16 panel for Krystexxa for indications on how the FDA will ultimately rule on the drug's approval later in the year. BioDelivery Sciences ( BDSI) Drug/indication: Onsolis for breakthrough cancer pain FDA decision date: June 15 Onsolis is a fast-dissolving film applied to the lining of the mouth that delivers the potent painkiller fentanyl. The FDA sent a complete response letter on Onsolis last August requesting a risk-management plan for the drug. BioDelivery resubmitted Onsolis to the FDA in December. Commercial rights to the drug in North America and Europe were licensed to Meda AB, a specialty pharmaceutical firm.