India’s second largest pharmaceutical company, Cipla, has said it plans to start manufacturing a generic version of Roche’s influenza drug Tamiflu (oseltamivir) in order to help governments around the world prepare for a possible flu pandemic.

Cipla, which made a name for itself a few years back by selling cut-price versions of antiretroviral drugs to countries affected by HIV/AIDS in defiance of the patents held by the originator companies, said it was responding to a shortage of the drug as avian flu spreads around the globe and the world gears up for a pandemic.

The announcement comes just after Roche has insisted it will not outsource Tamiflu production in its entirety to another company because the process is so complex, taking two to three years to set up and 12 months to complete each production run. Last week the company said it planned to double its own manufacturing of the drug by the end of the year, and again by mid-2006, in order to meet burgeoning demand [[13/10/05b]].

Cipla, however, claims to have overcome the difficulties in manufacturing oseltamivir. On Friday, chief executive YK Hameid said the company has already completed reverse engineering of the drug and is able to start manufacturing right away.

The move is likely to spark a strong response from Roche, which is enjoying something of a bonanza for Tamiflu as governments around the world race to stockpile the drug as part of flu pandemic response plans. Sales of Tamiflu are set to more than double in 2005 to 800 million Swiss francs, up from 330 million francs last year, while Roche is also rumoured to be poised for a massive order from US and European governments that could be worth up to £1 billion pounds.

But, faced with a growing conviction around the world that a pandemic is just around the corner, Roche is already under pressure from calls to concede to the kind of compulsory licensing for Tamiflu that has already been applied across the spectrum of HIV medications. Last week, United Nations Secretary-General Kofi Annan led calls for other companies to be allowed to make the drug, while consumer groups in the USA have also joined in by saying that the country should import generic versions of the drug to make sure there is sufficient supply.

Cipla only plans to sell it in regions where patents are absent or difficult to enforce, such as Africa, the Middle East, Latin America and Asia, and said it would steer clear of marketing it in markets such as the USA and Europe. The Indian company said it would sell its version of oseltamivir at a discount to Roche’s Tamiflu, but would not go into details.

Roche has donated 20,000 packs of its Tamiflu drug to Turkey to protect workers who may come into contact with poultry infected with avian flu, after an outbreak of the virus was reported there last week. It has also agreed to donate two million doses of the drug to the World Health Organisation as part of an emergency stockpile of drugs and vaccines held at the agency.

Meanwhile, there was worrying news on Friday after it was discovered that the H5N1 strain of influenza - odds on to be the strain that causes the next pandemic - has already developed resistance to Tamiflu.

A report on the website of the journal Nature (October 14) describes a patient in Vietnam in whom the virus has developed partial resistance to Tamiflu, raising fears that national strategies to combat a pandemic - in most cases based on stockpiles of Roche’s drug - may not be adequate, and emphasising the need for new drug treatments.