Injectable swine flu drug peramivir to treat complicated H1N1 round the corner

Paramivir is administered directly as intravenous (IV) injection, unlike oseltamivir pill and zanamivir inhaler

Updated: Intravenous (IV) H1N1 swine flu drug peramivir approved for emergency use in US: Biocryst (26 Oct, 2009)

Peramivir, a new antiviral injectable drug to treat complicated H1N1 swine flu from Shionogi Inc, may be launched next year.

Peramivir is neuraminidase inhibitor for intravenous infusion being developed by Shionogi in
Japan. Peramivir’s has shown high potent activity against influenza A and B viruses. Peramivir has also shown that it is active against highly pathogenic H5N1 (avian flu) viruses.

Permivir has strong binding to neuraminidase and it is not easily dissociated. Shionogi licensed peramivir from US-based BioCryst Pharmaceuticals, Inc in March 2007. Shionogi agreed to pay $35 million to Birmingham, Alabama-based BioCryst Pharmaceuticals Inc for rights to develop and sell peramivir in Japan.

Peramivir, Shionogi & Co believes, will earn annual sales of about 5 billion yen ($54 million) in Japan, if approved.

Shionogi plans to file data on peramivir to Japan’s health ministry in November for approval.

Peramvir is expected to reach markets as early as October next year, Shionogi sources said.

Currently, Roche Holding AG’s Tamiflu (oseltamivir) and GlaxoSmithKline Plc’s Relenza (zanamivir) are only available antivirals to  treat the pandemic H1N1 swine infection.

Paramivir also has an advantage over oseltamivir and zanamivir as it is administered directly as intravenous injection into the blood stream, allowing it to be effective more rapidly. Relenza is usually inhaled, while Tamiflu comes in pill form.

Two Phase3 clinical studies of peramivir conducted during the 2008-2009 influenza season have achieved the primary objectives Shionogi & Co announced in July.

Shionogi conducted a three-armed, multi-center,randomized, double-blind, multi-national Asian study that compared the efficacy and safety of a single dose treatment of i.v. peramivir (either 300 mg or 600 mg) and or al treatment with oseltamivir phosphate (Tamiflu) twice a day for 5 days.

A total of 1,099 uncomplicated patients infected with seasonal influenza virus were enrolled at 146 centers – Japan:100; Korea:25; Taiwan:21.

Both the 300 mg and 600 mg single dose peramivir groups positive outcomes compared to that the oseltamivir group.

In addition, Shionogi conducted a double-blind, multi-center Phase3 study of i.v. peramivir with dosing over multiple days. The study enrolled 42 influenza patients at high-risk of serious complications due to one or more qualifying conditions: diagnosis with poorly controlled diabetes mellitus, a chronic respiratory disease requiring pharmacotherapy, or current treatment with any immunosuppressive drug.

The results indicated that the symptoms of influenza of patients with high risk, which is
believed to be prolonged were also improved in shorter period.

Peramivir 300 mg or 600 mg i.v. single and multiple doses were generally safe and well tolerated in these trials.

Permavir is a good drug for severely ill flu patients as there is demand for intravenously administered drugs for such patients, experts said.

GSK’s Relenza administered in an unapproved intravenous form helped save a cancer patient with swine flu whose immune system was weakened by chemotherapy, the Lancet medical journal reported this month.

Shionogi, the maker of the Crestor cholesterol pill, is the first among three Japanese drugmakers to seek approval in Japan for flu treatments under development. Laninamivir from Daiichi Sankyo Co. and favipiravir from Fujifilm Holdings Corp.’s Toyama Chemical Co are the two ather antivirals currenly in development.

Shionogi is planning to make active ingredient in peramivir itself in future. Peramivir API will be imported  from a U.S. maker to produce courses for about 3 million people next year, company officials said.

11,636 cases have been confirmed In Japan, as of Sept. 1, according to the country’s Infectious Disease Surveillance Center. Seven people in the nation have died out of the 579 people hospitalized since the outbreak began in May, Japan’s health ministry said on its Web site.

Worldover, H1N1 epidemic, also known as swine flu, has killed at least 2,837 people globally since the outbreak in April, according to the World Health Organization.

Based in Osaka, Japan Shionogi’s core ethical drug business accounts for more than ninety percent of its total net sales. The Company specializes in three product areas related to cardiovascular and metabolic diseases; infectious diseases and immunological disorders; and cancer and related chronic pain.

Shionogi’s product lineup that includes the antihypertensives Landel ‚ a calcium antagonist; Longes ‚ an ACE inhibitor; and Crestor‚ a hyperchoresterolaemia treatment drug launched in 2005. Shionogi launched Irbetan, angiotensin II receptor antagonist, in July 2008. In the area of infectious diseases and immunological disorders‚ Flomox oral antibiotic‚ Flumarin injectable antibiotic and Vancomycin‚ an injectable antibiotic effective in treating methicillin-resistant Staphylococcus aureus (MRSA)‚ have each secured the top share of their respective markets.