Positive Phase III Results for Skin-Infection Drug Oritavancin
Single dose non-inferior to twice-daily vancomycin (Dec. 20)
Results have been announced from a phase III trial of oritavancin (Medicines Company), which is under investigation for the treatment of acute bacterial skin and skin-structure infections (ABSSSI) caused by susceptible gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA).
All protocol-specified primary and secondary efficacy endpoints of the SOLO-1 trial were met. Oritavancin was shown to be non-inferior to vancomycin in the efficacy analyses for the early clinical evaluation (48- to 72-hour) endpoints required by the FDA. The efficacy of the two drugs was similar in the overall population and in a subgroup of patients with microbiologically confirmed MRSA infections.
In the SOLO-1 trial, patients with ABSSSI were randomly assigned to receive treatment with a single intravenous (IV) dose of oritavancin (n = 475) or with 7 to 10 days of twice-daily IV doses of vancomycin (n = 479). The FDA primary efficacy endpoint was a composite of the cessation of lesion spread, the absence of fever, and no rescue antibiotics. The co-primary endpoint was a reduction in the lesion area of 20% or greater.
In the overall study population, 82% of patients treated with oritavancin achieved the FDA primary endpoint compared with 79% of vancomycin-treated patients. A reduction of 20% or greater in lesion area was observed in 87% and 83% of the oritavancin and vancomycin groups, respectively.
In patients with confirmed MRSA infection (104 in the oritavancin group and 100 in the vancomycin group), the FDA primary endpoint was achieved in 81% of oritavancin-treated patients and in 80% of vancomycin-treated patients. Ninety percent of the oritavancin group had a 20% or greater reduction in lesion area, compared with 84% of the vancomycin group.
Overall, the drugs’ safety profiles were similar: 60% of patients treated with oritavancin and 64% of patients treated with vancomycin experienced at least one adverse event (AE). Fewer treatment-emergent AEs considered by investigators as related to study drug were reported among patients treated with oritavancin than among those treated with vancomycin (23% vs. 31%, respectively; P = 0.003). The safety results also included fewer skin and subcutaneous-tissue AEs in the oritavancin group versus the vancomycin group (12% vs. 19%, respectively; P = 0.001). Apart from these events, the AE rates were similar in both treatment arms, including rates of phlebitis.
Source: The Medicines Company; December 20, 2012.