Data Show Zyvox is More Effective Compared to Vancomycin for the Treatment of Presumed MRSA Skin Infections

BOSTON -- Treatment with ZYVOX® (linezolid injection, tablets and for oral suspension) for complicated skin and soft tissue infections (cSSTIs) caused by suspected or proven methicillin-resistant Staphylococcus aureus (MRSA) resulted in higher cure rates and decreased healthcare costs compared with intravenous (IV) vancomycin, according to a U.S. sub-analysis of data presented Oct. 1, 2004 at the annual meeting of the Infectious Diseases Society of America (IDSA). 

These data, analyzed from the largest MRSA cSSTI study to date, demonstrated significantly better cure rates and costs savings of approximately $1,000 per patient when compared with vancomycin in the MRSA population.  ZYVOX is the only oral therapy approved by the Food and Drug Administration (FDA) for complicated skin and soft tissue infections (cSSTIs) caused by MRSA and is available in interchangeable IV and oral formulations.

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 of 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 vs. 86 percent respectively) and the MRSA study sample (92 percent vs. 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 vs. 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 vs. $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.   

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.

According to the 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.