Biota Holdings Limited (ASX: BTA) today announced that a recently completed Japanese Phase III prevention study of lnavir® (laninamivir octanoate, CS-8958) met its primary endpoint, significantly reducing the transmission of influenza within a household. The trial was conducted by Daiichi Sankyo who co-own the product and hold the marketing rights to the drug in Japan. The study also assessed safety. Daiichi Sankyo intends to apply for approval to market Inavir for the prevention of influenza before the end of 2012.

“We are thrilled by the positive outcomes reported by Daiichi Sankyo of Inavir as a preventative agent,” said Biota CEO, Peter Cook. “Approval in this new indication will significantly expand the market applicability for Inavir and further solidify its role in pandemic control. We continue to believe that Inavir’s demonstrated efficacy, combined with its ease of use, have the opportunity to significantly improve clinical outcomes for the treatment and now prevention, of influenza.”

The World Health Organization (WHO) estimates that annual influenza epidemics around the world cause between 3 and 5 million cases of severe illness and between 250,000 and 500,000 deaths every year. Inavir is the first product in a range of second generation influenza anti-virals, co-owned by Biota and Daiichi Sankyo. As the first drug of a new class of long acting neuraminidase inhibitors (LANIs), Inavir provides a full course of treatment via a single inhaled dose. The drug was approved in Japan in September 2010 for the treatment of influenza in adults and children. In April 2011, Biota was awarded a fully-appropriated contract from the Office of Biomedical Advanced Research (BARDA) within the U.S. Department of Health and Human Services (HHS) for up to $231 million toward the advanced development of Inavir in the U.S.

Study DesignThe study was a multi-centred, placebo controlled, double blinded study designed to evaluate Inavir’s ability to prevent the transmission of influenza A and B within families with a confirmed sufferer. Over 1,500 subjects were enrolled into the study.

The prophylactic effect of the two dosage regimes against influenza infection was measured against placebo and the protective efficacy calculated. A protective efficacy equal to or greater than 70% was required to meet the primary endpoint.

The primary endpoint measure was the proportion of household members that contracted influenza, as defined by an elevated body temperature, a positive measure of influenza virus in a PCR diagnostic assay and the display of at least two (2) of the following symptoms: headache; muscle or joint pain; fatigue; chill or perspiration; nasal discharge; sore throat; or cough.

Efficacy – Primary EndpointCompared to placebo, lnavir® in both dose regimes significantly reduced the proportion of patients contracting influenza (p < 0.0001) and produced protective efficacies in excess of 70%.

Safetylnavir® was generally well tolerated and the safety profile of Inavir remained consistent with that seen previously in the clinical development program.

OtherThe above is provided as a high level summary of the study’s commercially relevant findings. Further information is expected to be provided through peer reviewed scientific publications and presentations that are intended to follow in the ensuing months, including demographics of subjects and index patients, dosage, treatment of index patients, virology, and analysis of secondary endpoints.

About BiotaBiota is a leading anti-infective drug development company based in Melbourne, Australia, with key expertise in respiratory diseases, particularly influenza. Biota developed the first-in-class neuraminidase inhibitor, zanamivir, subsequently marketed by GlaxoSmithKline as Relenza. Biota research breakthroughs include a series of candidate drugs aimed at treatment of respiratory syncytial virus (RSV) disease and Hepatitis C (HCV) virus infections. Biota has a well advanced program for human rhinovirus (HRV) infection with a completed Phase IIb study in asthmatic subjects.

In addition, Biota and Daiichi Sankyo co-own a range of second generation influenza antivirals, of which the lead product lnavir®, is marketed in Japan. Biota holds a contract from the US Office of Biomedical Advanced Research and Development Authority (BARDA) for the advanced development of laninamivir in the USA.

Relenza? is a registered trademark of the GlaxoSmithKline group of companies.
Inavir® is registered to Daiichi Sankyo.