Daptomycin (DAP) Use in Patients with Hematologic (HEM) Cancer History; Post-Marketing Experience in a Registry.

Background: DAP is a novel lipopeptide antibiotic, approved for complicated skin and skin structure infections, with potent in vitro activity against many resistant Gram-positive organisms. Registration studies often limit or exclude patients with severe illness. Antibiotic resistant Gram-positive pathogens are frequently encountered in compromised patient populations; however, minimal information is available pre-approval in these patients.

Methods: Cubicin® Outcomes Registry and Experience (CORE) is a Phase IV retrospective observational chart review (45 institutions) to quantitate characteristics and clinical outcomes of patients (pts) receiving DAP. A standard case report form including demographic, disease state, clinical, and microbiologic data was completed by each investigator. Cure, failure, and improvement were assessed using standard definitions. Nonevaluable pts had insufficient data available to determine clinical outcome. Of the 1160 pts in CORE, 56 were reported with a history of HEM cancer. Eighteen (32%) were nonevaluable; 6 of those expired. This report describes the 38 pts with an assigned outcome.

Results: Fifty-five percent of pts were female, 63% were 31 to 65 years of age, and 76% of infections developed in a hospital setting. Common comorbidities included cardiovascular disease (24%), immunosuppression (18%), and transplant (11%). The most common infections were; bacteremia catheter-related (53%), skin and skin structure (34%), and bacteremia noncatheter-related (18%). Seventy-one percent (27/38) of pts were culture positive before DAP with the most common pathogens being Enterococcus sp. (52%, of which 71% were VRE), coagulase-negative staphylococci (41%), and S. aureus (19%, of which 80% were MRSA). A high percentage of pts (92%) received antibiotics (abx) prior to DAP. The most frequent initial dosing regimens were 4mg/kg QD (50%), and 6mg/kg QD (29%). The mean duration of DAP therapy was 13.6 days (range 2–44). Dose (P=0.3) and duration (P=0.58) did not vary by primary pathogen. Twenty-nine (76%) pts received concomitant abx therapy, most commonly with fluoroquinolones (31%), metronidazole (28%) or cephalosporins (24%). The mean time to clinical response was 2.4 days (n=28) and unaffected by primary pathogen (P=0.43) or the influence of concomitant abx therapy (P=0.55). All pts were reported as cured (66%) or improved (34%).

Conclusion: The data from the CORE registry demonstrates that DAP shows early clinical response and clinical cure for HEM patients where catheter associated infections and VRE are prevalent. These data provide preliminary data on the use of DAP in this compromised patient population. This information should lead to further prospective studies in cancer patients with DAP.