Cefozoplan, Meropenem, or Imipenem-Cilastatin Versus Cefepime As an Empirical Therapy in High Risk Febrile Neutropenic Adult Patients: A Multicenter Prospective Randomized Trial

In the IDSA guideline published in 2010 on the use of antimicrobial agents in neutropenic cancer patients, monotherapy with an anti-pseudomonal beta-lactam agent, such as cefepime (CFPM), carbapenem [meropenem (MEPM) or imipenem-cilastatin (IPM)], or piperacillin-tazobactam, is recommended as an empiric therapy for high risk febrile neutropenia (FN) patients. There have been few reports on the efficacy of cefozopran (CZOP), one of the 4^thgeneration beta-lactams, in the treatment of such patients. We conducted an open-label randomized controlled study to evaluate the clinical efficacy of CZOP, MEPM, or IPM in high-risk FN adult patients with hematologic malignancies and solid tumors, using CFPM as a control.

In this trial, 386 patients registered from 23 centers were randomized to receive either 4^thgeneration beta-lactam (CFPM 2g, q12h IV or CZOP 2g, q12h IV) or carbapenem (MEPM 1g, q12h IV or IPM 1g, q12h IV). The primary endpoint was response to treatment defined as complete defervescence by day 7 with improvement in infection-related symptoms and laboratory findings. The clinical data were analyzed both by intention to treat and per protocol. We also evaluated the efficacy of each of the initial four drugs at days 3 to 5as a secondary endpoint.

386 patients received the assigned antibiotic (CFPM: n=95, CZOP: n=98, MEPM: n=96, IPM: n=97) and 377 were evaluated for efficacy (CFPM: n=94, CZOP: n=95, MEPM: n=94, IPM: n=94). The 4 groups were comparable in terms of the baseline characteristics, including as age (median: 59 years (range: 17–87)), sex (male: n=215, female: n=171), body weight (median: 55 kg (range: 32–100)), underlying malignancy (leukemia: n=212 (54.9%), lymphoma: n=122 (31.6%), multiple myeloma: n=37 (9.6%), myelodysplastic syndrome: n=6 (1.6%), and other malignancy: n=9 (2.3%)), duration of initial antibiotic therapy (median: 7 days (range: 1–29)), median duration of severe neutropenia (neutrophil count < 100×10⁶/L) (median: 6 days (range: 0–56)) and MASCC score (median: 21 (range:3–26)). Only neutrophil count at onset of IPM was significantly lower compared to the other treatments (CFPM: 38×10⁶/L, CZOP: 35 x10⁶/L, MEPM: 18×10⁶/L, and IPM: 3×10⁶/L, p=0.003). In intention-to-treat analysis, the response rates at day 7 were not significantly different among the four arms (CFPM: 63%, CZOP: 59%, MEPM: 61%, IPM: 69% (P=0.52)). The three antibiotics investigated in this trial were as effective as the reference agent, CFPM, in both the intention-to-treat and per-protocol populations. In both the intention-to-treat and per protocol analyses, success rates of the initial therapy at days 3 to 5 were not significantly different among four drugs [CFPM: 52 and 54%, CZOP: 46 and 47%, MEPM: 54 and 55%, IPM: 49 and 53% (P=0.70 and 0.68, respectively)].

CZOP, MEPM, and IPM were as effective as CFPM for adult FN patients with hematological malignancies and solid tumors as an empiric therapy.

Tamura:Kyowa Hakko Kirin Co., Ltd,: Consultancy.