GlaxoSmithKline Receives FDA Approval For Augmentin XR(TM) Extended Release Tablets

GlaxoSmithKline today announced that Augmentin XR(TM) (amoxicillin/clavulanate potassium) Extended Release Tablets has received United States Food and Drug Administration (FDA) approval for the treatment of adults with acute bacterial sinusitis (ABS) or community-acquired pneumonia (CAP). Specifically, Augmentin XR is indicated for the treatment of patients with ABS or CAP confirmed or suspected to be caused by Beta-lactamase-producing bacteria such as Haemophilus influenzae, Moraxella catarrhalis and Streptococcus pneumoniae (S. pneumoniae) with reduced susceptibility to penicillin (i.e., penicillin MICs* = 2 mcg/mL). S. pneumoniae with penicillin MIC >/= 2 mcg/mL are considered resistant to penicillin.

Augmentin XR employs a unique extended release formulation -- bi-layer tablets that provide an immediate release of amoxicillin and clavulanate potassium and an extended release of amoxicillin. This enhanced formulation prolongs the time that the bacterium is exposed to the antibiotic and promotes coverage of tough-to-treat S. pneumoniae. Augmentin XR is the first antibiotic to be approved for the treatment of both ABS and CAP caused by strains of this bacterium with reduced penicillin susceptibility (MIC = 2 mcg/mL).

"Years ago, most antibiotics approved for respiratory tract infections were effective," said Michael Benninger, M.D., Chairman of the Department of Otolaryngology - Head and Neck Surgery at Henry Ford Hospital, Detroit, Mich. "But recently, S. pneumoniae resistance to penicillin has increased dramatically - to about 20 percent nationwide - making antibiotic selection very important. Augmentin XR will be important in physicians' efforts to continue to successfully fight infection, given today's environment of bacterial resistance."

Bacterial Respiratory Infections Becoming Harder to Treat

In recent years, common bacteria such as S. pneumoniae, Haemophilus influenzae and Moraxella catarrhalis that cause respiratory tract infections like ABS and CAP have become increasingly resistant to antibiotics. Antibiotic resistance occurs when bacteria change in different ways that reduce or eliminate the effectiveness of drugs, chemicals or other agents designed to cure or prevent infections. The surviving bacteria continue to multiply in the body, possibly causing more harm. Widespread use of antibiotics promotes the spread of antibiotic resistance. According to the U.S. Centers for Disease Control and Prevention, antibiotic resistance is a serious public health problem.

"With Augmentin XR, GlaxoSmithKline has responded to a medical need for antibiotics that continue to be effective in this era of evolving drug resistance," said Brian Lortie, Vice President, Anti-Infectives, GlaxoSmithKline. "We are proud to offer physicians a powerful new tool to help them with this emerging public health problem."

About Augmentin XR

Augmentin XR is a member of the Beta-lactam class of antimicrobials and is made up of amoxicillin and clavulanate potassium. Each Augmentin XR Extended Release Tablet contains 1000 mg of amoxicillin and 62.5 mg of clavulanate. The clavulanate component is critical because it inactivates Beta-lactamase, an enzyme produced by certain bacteria, including Haemophilus influenzae and Moraxella catarrhalis, that render many Beta-lactam antibiotics (e.g., amoxicillin and penicillin) inactive. Augmentin XR Extended Release Tablets and Augmentin ES-600(TM) (amoxicillin/clavulanate potassium) Powder for Oral Suspension are the only high-dose amoxicillin oral antibiotics that also inactivate Beta-lactamase.

Augmentin Tablets (250 mg or 500 mg) cannot be used to provide the same dosages as Augmentin XR Extended Release Tablets. This is because Augmentin XR contains 62.5 mg of clavulanate, while the Augmentin(R) 250 mg and 500 mg tablets each contain 125 mg of clavulanate. In addition, the Extended Release Tablets provide an extended time course of plasma amoxicillin concentrations compared to immediate release Tablets. Thus two Augmentin 500 mg tablets are not equivalent to one Augmentin XR tablet.

Clinical Trial Results

Augmentin XR has shown strong clinical success. Adults with ABS were evaluated in three clinical studies. In one comparative study, the rate of clinical success in patients with ABS was 87 percent (N=123) at test of cure. In two non-comparative, multicenter trials for ABS, clinical success with Augmentin XR was 93 percent (N= 677) and 94 percent (N=632) at test of cure.

In patients suffering from CAP, in three comparative studies (N=582), the clinical success rates at test of cure (day 16 to day 39 following start of therapy) ranged from 86 (N=204) to 95 percent (N=114).

Microbiologic eradication rates for key pathogens in these studies are as follows:

    - In ABS clinical trials, Augmentin XR eradicated S. pneumoniae 
      with penicillin MIC = 2  mcg/mL in 93 percent (N= 14) of 
      strains from clinically evaluable patients.  S. pneumoniae 
      strains with penicillin MIC >/= 2 mcg/mL are considered 
      penicillin resistant.
    - In CAP clinical trials, Augmentin XR eradicated S. pneumoniae 
      with penicillin MIC = 2 mcg/mL in 100 percent (N=10) of strains 
      from clinically evaluable patients.  
    - In combined ABS studies, Augmentin XR eradicated Beta-lactamase 
      producing Haemophilus influenzae and Moraxella catarrhalis in 
      97 percent (N=30) and 98 percent (N=57) of strains from 
      clinically evaluable patients.
    - In addition, Augmentin XR eradicated Beta-lactamase producing 
      Haemophilus influenzae and Moraxella catarrhalis in 94 percent 
      (N=16) and 87 percent (N=15) of strains from clinically 
      evaluable patients, respectively in combined CAP studies.