Dalbavancin is expected to have FDA approval soon
Drug used for treating MRSA
Hospital pharmacies might expect a new antibiotic, dalbavancin, to be available soon, since the FDA sent Pfizer Inc. an approvable letter in late December 2007.
Dalbavancin is a potent antibiotic that is designed for treating methicillin-resistant Staphylococcus aureus (MRSA). It's a member of the glycopeptide class of antibiotics and works similarly to vancomycin.
The new agent has a long half-life, which makes it a potential treatment for osteomyelitis, an acute or chronic bone infection usually caused by bacteria, says Cindy A. Loffler, PharmD, a critical care pharmacist in the department of clinical pharmacy at the University of California, San Francisco. Loffler also is a researcher who studies S. aureus infections and treatments.
"Dalbavancin can be given once a week, unlike vancomycin," Loffler says.
It won't take vancomycin's place because of its long-term potency, which makes it unsuitable for patients with renal problems, she notes.
"Also, if we dose it incorrectly, and if the patient doesn't have a gram-positive infection, then using dalbavancin could lead to resistance," Loffler explains.
Hospital pharmacies will want to stock the drug when its approved, but it might find its niche in the outpatient area, Loffler says.
"It'd be nice for home use, so the patient could come in and get one dose for infusion purposes," she adds.
It's other potential use would be for hospital patients who are admitted for months at a time, including those in step-down units, Loffler says.
Researchers and pharmaceutical companies have been looking for alternatives to vancomycin because of poor cure rates found among some MRSA patients treated with the vancomycin.1
So if physicians find that vancomycin fails to cure a patient's MRSA, then prescribing dalbavancin might become a second step.
Since the two drugs are similar there could be class resistance, but the alternatives are limited, Loffler notes.
"I think this is the only agent in the drug pipeline that is this long-acting for treating MRSA," Loffler says.
Also, it looks like dalbavancin could be used for treating methicillin-resistant S. epidermidis (MRSE), she says.
One factor driving the market for new agents like dalbavancin is that hospitals are seeing high rates of MRSA, Loffler says.
"In our institution, we're seeing MRSA rates of 50% [among patients infected with Staphylococcus aureus], versus methicillin-susceptible," she says. "That's high, and that's why when we start patients on antibiotics now, the majority of them will get vancomycin for coverage of MRSA."
Also, clinicians are seeing a trend of a higher break-point, a higher minimum inhibitory concentration (MIC) of what amount of antibiotic is needed to kill the organism, Loffler says.
"So we're seeing a drift of MIC to be higher, and we know that patients do have higher MICs on vancomycin," she explains. "So if we have a MIC of 2 on vancomycin, we would consider switching the patient because vancomycin will not be effective to kill the organism."
Dalbavancin's antibacterial potency makes it a viable alternative. Phase II and III clinical trials demonstrated that dalbavancin was effective and well-tolerated for treatment of catheter-related bloodstream infections, skin-structure infections, and soft-tissue infections.2
Among clinical trial participants receiving dalbavancin, the most common adverse events were pyrexia, headache, and diarrhea.2
References
- Loffler CA, Macdougall C. Update on prevalence and treatment of methicillin-resistant Staphylococcus aureus infections. Expert Rev Anti Infect Ther 2007;5:961-981.
- Das B, Sarkar C, Biswas R, et al. Review: Dalbavancin--a novel lipoglycopeptide antimicrobial for gram positive pathogens. Pak J Pharm Sci 2008;21:78-88.
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