News Release

Pfizer's ZYVOX(TM) more effective than vancomycin in treating complicated SSTIs caused by MRSA

Study results show better cure rates, shorter IV-therapy and reduced hospital stays among patients treated with ZYVOX

Peer-Reviewed Publication

Pfizer Inc.

San Diego, October 10, 2003 – Clinical cure rates were significantly better in patients treated with Pfizer's antibiotic ZYVOXTM (linezolid injection, tablets and for oral suspension) for complicated skin and soft tissue infections caused by known methicillin-resistant Staphylococcus aureus (MRSA) compared to patients treated with intravenous (IV) vancomycin. In the entire population studied, ZYVOXTM was as effective as all comparators. In addition, ZYVOX shortened the average duration of IV treatment by up to 10 days and reduced patients' hospital stays by more than two days according to results from a 1,200-patient study presented here at the annual meeting of the Infectious Diseases Society of America (IDSA).

"The rapid emergence of hospital- and community-acquired strains of resistant bacteria is an increasing global public health problem, particularly among hospitalized patients with MRSA skin and soft tissue infections," said Dr. John Weigelt, professor and vice chairman, department of surgery, chief, division of trauma & critical care, Medical College of Wisconsin, and the lead study investigator. "This study shows that ZYVOX was significantly more effective than vancomycin in patients infected with MRSA, in terms of both curing them and getting them out of the hospital sooner."

Better Efficacy and Shorter IV Treatment and Hospital Stays

In two data presentations from the same study presented at IDSA (abstracts 314 and 315), the study authors concluded that:

  • In the clinically evaluable population, ZYVOX had significantly better cure rates of 94.4 percent (n=436/462) versus 90.4 percent (n=394/436) for patients on vancomycin (P=0.0234). Cure rates in the MRSA population were 94.0 percent (n=126/134) for patients treated with ZYVOX compared to 83.6 percent (n=112/134) for vancomycin-treated patients (P=0.0108).
  • IV treatment duration was significantly shorter for ZYVOX-treated patients in the clinically evaluable population (mean 2.0 days in the ZYVOX group versus 9.1 days in the vancomycin group, P<0.0001) and in the population with proven MRSA (mean of 1.8 days in the ZYVOX group versus a mean of 12.6 days in the vancomycin group, P<0.0001).
  • ZYVOX significantly reduced patients' hospital length of stay in both the clinically evaluable population (mean 6.9 days; n=491, versus mean 9.3 days in the vancomycin group, n=472, P<0.0001) as well as the population with proven MRSA (mean 8.1 days in the ZYVOX group; n=143, versus mean 10.7 days in the vancomycin group; n=146, P=0.0026).
  • The incidence of drug-related adverse events was comparable between treatment arms. Most adverse events in both groups were classified as mild to moderate.

"These data show that ZYVOX is a major advance from traditional vancomycin therapy as it provides improved outcomes for patients with serious MRSA infections," said Dr. Weigelt. "In addition, ZYVOX offers significant advantages by decreasing the need for IV therapy and getting patients out of the hospital and home to their families sooner."

Resistant infections, such as MRSA, contribute to significant human and financial costs. Patients who acquire an infection caused by these resistant bacteria tend to have extended hospital stays and often have a poor prognosis . According to the U.S. Centers for Disease Control and Prevention, the financial burden of treating hospital-acquired infections caused by common forms of resistant bacteria, like MRSA, is estimated to be more than $1 billion annually.

Each year nearly two million patients in the United States acquire infections in hospitals. In addition, surgical site skin infections are reportedly the third most common type of hospital-acquired infections, accounting for as much as 14-25 percent of the total.

About the Study

This Phase IV, randomized, open label, comparator-controlled, multicenter study evaluated 1,200 patients' response to treatment with ZYVOX and vancomycin. Clinical efficacy outcomes (e.g., cured, improved, failed, or indeterminate) were measured by resolution of the signs and symptoms of infection compared with baseline. The clinical cure rate was defined as the number of cures divided by the number of cures plus failures. The study also compared the mean length of stay, defined as the total number of initial and readmission inpatient days during the study period, and the mean IV duration of each treatment.

Patients were randomly assigned in a 1:1 ratio to receive either IV or oral ZYVOX 600 mg every 12 hours (476 patients) or IV vancomycin 1 gram every 12 hours (454 patients) for seven to 21 days. Vancomycin patients with confirmed methicillin-susceptible Staphylococcus aureus (MSSA) infections could be switched to an oral or IV anti-staphylococcal penicillin. Test-of-cure assessment was seven days after the end of treatment. Hospital length of stay was determined as the total number of initial and readmission inpatient days during the 35-day study period.

###

About ZYVOX

ZYVOX was initially approved in the U.S. 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 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 500,000 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 osteomyelitis, caused by Staphylococcus aureus (both methicillin-resistant and -susceptible strains), Streptococcus pyogenes and Streptococcus agalactiae.

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.

Full prescribing information available upon request or at www.pfizer.com or www.zyvox.com


Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.