The US Food and Drug Administration's Vaccines and Related Biological Products Advisory Committee agreed that the extensive data from clinical trials in more than 40,000 people support the efficacy and safety of Zostavax (zoster vaccine live (Oka/Merck), Merck's investigational vaccine, to prevent shingles in adults aged 60 and over.

The advisory committee did not agree that the data presented were sufficient to support the efficacy and safety of Zostavax in adults aged 50 - 59 as the company had proposed. The advisory committee also suggested areas for additional analysis. Merck plans to work with the FDA on these analyses as well as the design of Merck's already planned post-licensure studies, informs the release.

The FDA is not bound by the committee's recommendation but takes its advice into consideration when reviewing investigational vaccines.

"Shingles can be a very painful disease that can lead to serious and long-lasting complications. We are pleased with today's outcome and look forward to working with the FDA as it continues its review of our application for this vaccine," said Peter S. Kim, president, Merck Research Laboratories.

The company filed a biologics license application (BLA) with the FDA on April 25 for Zostavax to reduce the risk of shingles; to reduce the risk of postherpetic neuralgia, the persistent, often debilitating long-term nerve pain that is the most common complication of shingles; and to reduce the total burden of pain and discomfort caused by shingles.

In addition to the US regulatory application, Merck has filed regulatory applications for Zostavax in several other world markets including the European Union, Canada and Australia.

Merck presented data from several studies conducted in more than 40,000 people, including data from the phase III Shingles Prevention Study (SPS) of 38,500 adults age 60 and over. The SPS was a department of veteran's affairs (VA) study conducted in collaboration with the National Institute of Allergy and Infectious Diseases (NIAID) at the National Institutes of Health (NIH) and Merck at 22 US research sites over a period of five years.

Shingles is caused by the reactivation of latent varicella zoster virus, the same virus that causes chickenpox. Shingles may first appear as abnormal skin sensations ranging from itching or tingling to severe pain on a single area of the body or face. It then usually progresses to a rash and fluid-filled blisters accompanied by pain in almost every case.

Zostavax is one of three late-stage investigational vaccines at Merck.