Oritavancin in the treatment of immunocompromised patients with complicated skin and skin-structure infections

Abstract number: P1850

Hartman C.S., Wasilewski M.M., Moriarty S.R., Bates B.M.

Objectives: Oritavancin, a novel semisynthetic lipoglycopeptide with activity against a wide range of Gram-positive bacteria, including vancomycin-resistant staphylococci and enterococci, is presently under regulatory review for the treatment of complicated skin and skin structure infections (cSSSI). Immunocompromised patients are a vulnerable population who run the risk of increased morbidity and lower cure rates compared to immunocompetent patients.

Methods: Two randomised, double-blind, multicentre, phase 3 trials were designed to test whether 3 to 7 days of oritavancin (ORI) was noninferior to 10 to 14 days of vancomycin/cephalexin (VAN) in the treatment of cSSSI. Test-of-cure (TOC) occurred between Days 21 to 35. Described here are results from the group of patients considered to be immunocompromised at study entry. The immunocompromised group includes patients with baseline HIV/AIDS, AIDS, neutropenia, adverse events of neutropenia or those taking immunosuppressive concomitant medications.

Results: 1763 patients received study medication, of which 85 were immunocompromised. Clinical cure rates in non-immunocompromised patients in the clinically evaluable (CE) population at TOC were 76.9% (688/895) in ORI compared to 76.1% (337/443) for VAN. Similar response rates were observed in the immunocompromised group of patients and clinical cure rates in the CE population at TOC were 77.3% (34/44) in ORI compared to 66.7% (10/15) for VAN. Overall, more immunocompromised patients had at least one AE (78.0% for ORI and 76.9% for VAN) than patients who were immunocompetent (52.2% for ORI and 61.7% for VAN). Laboratory changes were similar between ORI and VAN treatment groups in patients with and without immunocompromise.

Conclusions: Oritavancin is a novel lipoglycopeptide with demonstrated efficacy and a favourable safety profile with short course therapy (3–7 days) in immunocompromised patients in two phase 3 studies of cSSSI.