This past Friday, 1/30/2009, the FDA approved Takeda Pharmaceuticals North America Kapidex (dexlansoprazole) for the treatment of gastroesophageal reflux disease (GERD). Kapidex is an enantiomer of lansoprazole (Prevacid). In addition to the change in enantiomer, Kapidex is formulated with two type of enteric-coated granules to provide two separate releases of medication. According to the Takeda press release ” the first peak occurs one to two hours after administration, followed by a second peak within four to five hours. In addition, Kapidex can be taken regardless of when food is consumed.”
At first reading, it appears from the results of the Phase 3 clinical studies that the formulation doesn’t make much difference. Per the press release, in two identically designed, double-blind, eight-week, randomized, active-controlled trials compared treatment with Kapidex to treatment with Prevacid in patients with erosive esophagitis (EE),Kapidex(60 mg) produced high overall healing rates at week eight when compared to lansoprazole 30 mg (87%, and 85%, respectively, in the first study; and 85%, and 79%, respectively, in the second study).
However, Kapidex appears to have a couple of potential advantages over current therapies – no food effect and the possibility of control of symptoms at night. Takeda performed a traditional food effect study, showing no clinically meaningful differences in intragastric pH:
From this short review, it appears that nocturnal symptoms are not well controlled by current therapies. I could not find a study on dexlansoprazole that addresses this need directly, though the pharmacokinetics suggest the potential.
Further, Takeda’s retrospective analyses of the Phase 3 trial data suggests that Kapidex had better healing rates than Prevacid for patients with more severe grades of symptoms.
From a development point of view, this drug would appear to be a 505(b)(2) candidate. Certainly the safety could be said to be well established. The challenge is the clinical development since the action of this class of drugs is not systemic. By changing the pharmacokinetic profile, Takeda was faced with demonstrating both dose and efficacy. In the phase 3 trials, doses of 60- and 90 mg of dexlansoprazole were compared to the standard 30 mg Prevacid dose; the 60 mg was shown to have healing rates similar to the 30 mg Prevacid.
See this site for very nice overview of the clinical development studies. A number pf Phase 3 trials were conducted internationally to meet country-specific registration requirements.