MRSA is the only major bacterial pathogen on the rise and has increased in hospitals around the country. MRSA can be extremely serious and lead to prolonged hospitalization, increased morbidity, risk of mortality and costs (driven by length of hospital stay).
"With the increase in MRSA and the economic burden associated with treating it, there clearly is a need for more cost-effective solutions," said Dr. Mark Kunkel, Senior Medical Director, Pfizer, Inc. "These data demonstrate that ZYVOX had better clinical cure rates and is associated with reduced healthcare cost when compared with vancomycin for complicated skin infections caused by MRSA. This is attributed to the fact that patients have an oral option with ZYVOX that can help them transition easily from the hospital to home and get them out of the hospital sooner."
Better Clinical Cure Rates and Lower Costs Results indicated that U.S. patients treated with ZYVOX had significantly better cure rates than vancomycin in both the intent-to-treat (ITT) group (92 percent versus 86 percent respectively) and the MRSA study sample (92 percent versus 82 percent respectively). In the overall worldwide study, clinical cure rates in the ITT population were not significantly different between ZYVOX and vancomycin (92 percent and 89 percent, respectively). In the same group, MRSA clinical cure rates were significantly better for ZYVOX than vancomycin (94 percent versus 83.6 percent, respectively).
Cost savings for all U.S. patients (the ITT population) treated with ZYVOX were $652 per patient, with an average total cost of $5,143 for ZYVOX versus $5,794 for vancomycin. For the MRSA confirmed patients, the savings were much higher compared with vancomycin ($1,030 per patient; $5,097 versus $6,128). The lower costs for patients treated with ZYVOX were attributed to the transition from IV to oral ZYVOX and an earlier discharge from the hospital.
About the Analysis
The clinical efficacy and cost-effectiveness of ZYVOX versus vancomycin were evaluated in a sub-analysis of 717 patients (366 linezolid 351 vancomycin) enrolled in the United States with cSSTIs due to suspected or proven MRSA (abstract 503). The patients were part of a randomized, open- label, comparator-controlled, multi-center phase IV study of greater than 1,100 patients, the largest study of cSSTIs caused by suspected or proven MRSA. Patients were randomized to receive either linezolid (oral or IV, 600 mg every 12 hours) or vancomycin (IV only, 1 g every 12 hours). Vancomycin patients with confirmed methicillin-susceptible Staphylococcus aureus (MSSA) infections could be switched to an oral or IV anti-staphylococcal penicillin. Clinical cure was defined as complete resolution of baseline clinical signs and symptoms.
Total cost included all costs incurred by the patients during hospitalization and following discharge. Infection-related costs were determined using nationally representative 2003 per diem average hospital costs for days in the medical/surgical, intensive care or step-down units. Costs of administrating IV therapy were applied to the duration of IV treatment and medications were valued at wholesale acquisition cost. The cost-effectiveness metric was incremental cost per additional patient cured. This study was funded by Pfizer Inc.
About MRSA
According to the U.S. Centers for Disease Control and Prevention, 100,000 persons are hospitalized each year with MRSA infections, with only a small portion of these persons acquiring the infection in a community setting. The National Nosocomial Infections Surveillance (NNIS) system reported a 40 percent increase in hospital-acquired MRSA infections in 1999 compared with the previous five years. A recent study showed that patients with MRSA infections may be in the hospital up to 10 days longer than patients with staph infections not resistant to methicillin.
About ZYVOX
ZYVOX was initially approved in the United States in April 2000 for the treatment of infections in adults with susceptible strains of designated organisms, including complicated skin and skin structure infections and nosocomial pneumonia including those caused by MRSA. In December 2002, ZYVOX was approved for use in pediatric patients and subsequently received approval for diabetic foot infections without concomitant osteomyelitis in July 2003. Since its introduction, ZYVOX has proven to be an important treatment option for designated infections known or suspected to be caused by MRSA. To date, an estimated 575,000 patients worldwide have been treated with ZYVOX for its approved indications.
ZYVOX is indicated for the treatment of infections caused by susceptible strains of designated organisms in adults and children, including patients with complicated skin and skin structure and diabetic foot infections, without concomitant osteomyelitis, caused by Staphylococcus aureus (both methicillin-resistant and -susceptible strains), Streptococcus pyogenes and Streptococcus agalactiae. ZYVOX also is indicated for the treatment of nosocomial pneumonia caused by Staphylococcus aureus (methicillin-susceptible and -resistant strains) or Streptococcus pneumoniae (including multidrug-resistant strains). Combination therapy may be clinically indicated if the documented or presumptive pathogens include Gram-negative organisms.
Patients receiving ZYVOX should have complete blood counts monitored weekly, since myelosuppression has been reported. This applies particularly to those who are given ZYVOX for longer than two weeks, have pre-existing myelosuppression, are receiving concomitant drugs that produce bone marrow suppression, or have a chronic infection and have received previous or concomitant antibiotic therapy. Lactic acidosis has been reported with the use of ZYVOX. In reported cases, patients experienced repeated episodes of nausea and vomiting. Patients who develop recurrent nausea or vomiting, unexplained acidosis, or a low bicarbonate level while receiving ZYVOX should receive immediate medical evaluation. The most commonly reported adverse events in clinical trials in adults were diarrhea, nausea and headache. ZYVOX formulations are contraindicated for use in patients who have known hypersensitivity to linezolid or any of the other product components.
Full prescribing information available upon request or at http://www.pfizer.com or http://www.zyvox.com.