Phase IIa cross-over study of propylene glycol-free melphalan (LGD-353) and alkeran in multiple myeloma autologous transplantation

Propylene Glycol-Free melphalan HCL for Injection (PGF-Mel) is a new formulation that incorporates Captisol, a specially modified cyclodextrin, to improve melphalan stability. In this phase IIa, open-label, randomized, cross-over design bioequivalence study, the pharmacokinetics of PGF-Mel were compared with the marketed formulation of melphalan, or Alkeran. Patients received half of the total dose of melphalan in the form of Alkeran and the other half in the form of PGF-Mel in an alternating manner. The pharmacokinetic measures were determined using WinNonlin 6.2 and bioequivalence was assessed using log-transformed systemic exposure parameters. Twenty-four patients, 11 females and 13 males, were enrolled between 4 February 2010 and 16 May 2011 at The University of Kansas Medical Center and The University of Kansas Cancer Center. The median age of enrolled subjects was 58 years (range: 48-65). All patients achieved myeloablation 3 days post autologous graft followed by successful neutrophil engraftment with a median of 11 days after transplant. Pharmacokinetic analysis showed that PGF-Mel was bioequivalent with Alkeran and also revealed that maximum plasma concentration (C max) and area under the plasma concentration-time curve (AUC) were higher (∼10%) after PGF-Mel administration. In conclusion, PGF-Mel is considered bioequivalent to Alkeran while also demonstrating a marginally higher systemic drug exposure.