RATIONALE: A donor stem cell transplant can lower the body's immune system, making it difficult to fight off infection. Giving antibiotics, such as moxifloxacin, may help prevent bacterial infections in patients who have recently undergone donor stem cell transplant. It is not yet known whether moxifloxacin is more effective than a placebo in preventing bacterial infections in patients who have recently undergone donor stem cell transplant.

PURPOSE: This randomized phase III trial is studying moxifloxacin to see how well it works compared with a placebo in preventing bacterial infections in patients who have recently undergone donor stem cell transplant.

OBJECTIVES:

Primary

• Assess the safety and tolerability of giving prophylactic moxifloxacin hydrochloride during the post-engraftment phase in patients who have undergone allogeneic stem cell transplantation. (Pilot study)
• Compare the efficacy, in terms of reducing the incidence of clinically and microbiologically documented bacterial infections, in patients who have undergone allogeneic stem cell transplantation treated with prophylactic moxifloxacin hydrochloride vs placebo during the post-engraftment phase. (Phase III)

Secondary

• Determine the incidence of clinically and microbiologically documented bacterial infections in these patients. (Pilot study)
• Assess the impact of moxifloxacin hydrochloride on the incidence of bacteremia in these patients. (Phase III)
• Compare the percentage of time on systemic antibiotics and days hospitalized in patients treated with these regimens. (Phase III)
• Compare the incidence of veno-occlusive disease of the liver in patients treated with these regimens. (Phase III)
• Compare the incidence and severity of graft-versus-host disease in patients treated with these regimens. (Phase III)
• Compare the infection-related mortality and overall mortality of patients treated with these regimens.

OUTLINE: This is a pilot study followed by a randomized, double-blind, placebo-controlled, multicenter phase III study. Patients are stratified according to gender and race (white vs. non-white). The first 20 patients are assigned to the pilot study.

Patients assigned to the pilot study receive oral moxifloxacin hydrochloride once daily beginning after neutrophil recovery (ANC > 1,500/mm³) from allogeneic stem cell transplantation (ASCT) and continuing until day 100 post-transplantation in the absence of disease progression or unacceptable toxicity. Subsequent patients are randomized to 1 of 2 treatment arms.

• Arm I: Patients receive oral moxifloxacin hydrochloride once daily beginning after neutrophil recovery (ANC > 1,500/mm³) from ASCT and continuing until day 100 post-transplantation.
• Arm II: Patients receive oral placebo once daily beginning after neutrophil recovery (ANC > 1,500/mm³) from ASCT and continuing until day 100 post-transplantation.

In both arms, treatment continues in the absence of disease progression or unacceptable toxicity.

After completion of study treatment, patients are followed at day 120 post-transplantation.

PROJECTED ACCRUAL: A total of 240 patients will be accrued for this study.

DISEASE CHARACTERISTICS:

• Must be planning to undergo or have completed allogeneic stem cell transplantation (ASCT)

  • Must not be undergoing a nonmyeloablative ASCT

• Must not require antibiotic prophylaxis against bacterial pathogens during the post-engraftment phase as per ASCT protocol

• No known colonization with an antimicrobial-resistant organism normally sensitive to quinolones that is known to increase infection incidence (i.e., ciprofloxacin-resistant Pseudomonas not allowed; vancomycin-resistant Enterococcus and methicillin-resistant Staphylococcus aureus allowed)

PATIENT CHARACTERISTICS:

• Life expectancy ≥ 100 days
• Not pregnant or nursing
• Fertile patients must use effective contraception
• Negative pregnancy test
• No known hypersensitivity to fluoroquinolones
• No prolonged QTc interval on EKG (i.e., QTc > 440 milliseconds)
• No uncontrolled hypokalemia

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• No concurrent class IA (e.g., quinidine or procainamide) or class III (e.g., amiodarone or sotalol) antiarrhythmics
• No concurrent intravenous antibiotics for pre-enrollment infections except vancomycin, linezolid, dalfopristin, or quinupristin (Synercid®)