ORI is a lipoglycopeptide with rapid bactericidal activity against Gram‐positive bacteria including MRSA. Its concentration‐dependent activity and long half‐life allow for single dose administration.
SOLO I and SOLO II were Phase 3, multicenter, double‐blind, randomized studies of identical design. Adults with ABSSSI requiring IV therapy received either a single 1200 mg IV dose of ORI, or IV VAN for 7 to 10 days (1 g or 15 mg/kg twice daily); from the second day the VAN dose could be adjusted based on patient’s clinical status, renal function or vancomycin plasma concentrations. Three efficacy endpoints were tested: 1) primary composite endpoint at 48 to 72 h (cessation of spreading or reduction in size of the baseline lesion, absence of fever, and no rescue antibiotic); 2) investigator‐assessed clinical cure 7 to 14 days after end of treatment; and 3) ≥20% reduction in lesion area at 48 to 72 h. Identity and antimicrobial susceptibility of baseline pathogens were determined centrally (Eurofins Medinet, Chantilly, VA); MRSA was confirmed via mecA testing.
In the combined studies 1959 patients were enrolled. All pre‐specified endpoints met the 10% non‐inferiority margin in each SOLO study. In the combined studies, MRSA infection at baseline was confirmed in 204 ORI patients and 201 VAN patients. In patients with confirmed MRSA infection, efficacy outcomes were similar for ORI and VAN for the primary composite endpoint and investigator‐assessed clinical cure (Table). A greater proportion of MRSA patients treated with ORI attained >20% reduction in lesion size at 48 to 72 h compared to VAN (difference 6.1%; p = 0.032) (Table). Overall safety profiles were similar between treatment groups in the mITT population and in the MRSA subgroup: 68.1% of ORI patients and 67.7% of VAN patients reported at least one adverse event in the MRSA subgroup. The most frequently reported AEs for ORI in these patients were nausea (14.7%), headache (9.3%) and vomiting (8.3%).
A single 1200 mg dose of ORI was non‐inferior to 7 to 10 days of VAN in treating ABSSSI caused by MRSA, with a similar safety profile. ORI was more effective than VAN in reducing lesion size by >20% at 48 to 72 h in patients with MRSA. In summary ORI provides a single‐dose alternative to multi‐dose therapies for ABSSSI.
To cite this abstract:Holland T, Wikler M, Moeck G, Arhin F, Jiang H, Good S, Corey G. A Single Dose of Oritavancin (Ori) Compared to 7‐10 Days of Vancomycin (Van) in the Treatment of Acute Bacterial Skin and Skin Structure Infections (Absssi): An Analysis of the MRSA Subpopulation in the Solo Non‐Inferiority Studies. Abstract published at Hospital Medicine 2014, March 24-27, Las Vegas, Nev. Abstract 170. Journal of Hospital Medicine. 2014; 9 (suppl 2). https://www.shmabstracts.com/abstract/a-single-dose-of-oritavancin-ori-compared-to-710-days-of-vancomycin-van-in-the-treatment-of-acute-bacterial-skin-and-skin-structure-infections-absssi-an-analysis-of-the-mrsa-subpopulat/. Accessed July 21, 2019.