The phase 2/3 trial uses an adaptive-design in which the phase 2 portion enrolled 180 patients with acute cellulitis or wound infections into one of the three arms: a conventional twice daily Taksta regimen, a novel loading-dose Taksta regimen, or linezolid twice-daily.
Treatment in all three arms was administered for 10 to 14 days. The phase 2 portion of the trial will provide predictive probabilities of non-inferiority of Taksta to linezolid in the phase 3 portion of the trial. The adaptive trial design enables Cempra to transition seamlessly to the phase 3 portion of the trial, after completion of the phase 2 portion.
Sodium fusidate is an antibiotic with an established record of treating staphylococcal infections, including methicillin-resistant S aureus (MRSA), outside the US. Its unique mechanism of action makes cross resistance with other antibiotics unlikely. Taksta is being investigated with a proprietary PK-PD-based dosing regimen that is expected to optimize efficacy.
Gordon Still, chief medical officer of Cempra, said: “Enrollment in our clinical trial was significantly faster than expected, which underscores the need for orally-administered agents that are effective against drug-resistant S aureus, including MRSA, and are safe and well-tolerated by patients.
“Because of the adaptive design incorporated into our clinical program we anticipate the start of the Phase 3 portion of this clinical trial shortly and we expect to complete enrollment by the end of 2010. We also look forward to presenting the results of the Phase 2 portion at an upcoming medical conference.”