GSK’s rosiglitazone under fire again

There’s more trouble for pharma major GlaxoSmithKline’s (GSK) anti-diabetes drug rosiglitazone.

The drug, which has been under attack over side effects, has now been downgraded based on research carried out by the British Medical Journal (BMJ).

The journal concludes that rosiglitazone (brand name Avandia) lacks a distinct clinical advantage over another diabetes drug, pioglitazone (brand name Actos, manufactured by Japanese major Takeda Pharmaceuticals), but is more likely to trigger heart failure than its rival.

Rosiglitazone has been in the eye of a storm since the US Food and Drug Administration issued a ‘black box’ warning in 2007 about heart risks associated with the medicine. A black box warning is the strongest type of warning the regulator issues about side effects of drugs.

This was followed by the American Diabetes Association and the European Association for the Study of Diabetes advising against use of rosiglitazone.

Then, in November last year, the Drugs Controller General of India asked rosiglitazone manufacturers in the country to print a warning on the drug’s label, cautioning about its risks, if used by patients with heart problems.

All this has led to GSK’s worldwide sales from rosiglitazone, marketed as Windia in India, dwindling from a whopping £1.4 billion in 2006 to £877 million in 2007, and further to £512 million in 2008, as per industry estimates.

In an effort to salvage the situation, GSK in June brought out its own study on rosiglitazone, conducted over five and a half years on over 4,400 patients in 25 countries, showing the drug did not increase heart risks, or lead to hospitalisation or death, as compared with other common diabetes treatments such as metformin or sulfonylurea.

GSK’s chief medical officer, Ellen Strahlman, argued that rosiglitazone remained an important diabetes medicine for the appropriate patients.
Industry experts believe the new study by BMJ could further cloud the sales of the drug, especially in the developed markets.

“In India, it really would not have much of an impact as issues concerning side effects are not exactly blown out of proportion, like in the US or EU,” said an analyst with a broking firm in Mumbai.

According to market intelligence provider ORG IMS, the market for rosiglitazone in India, which has over 42 million diabetics, is Rs 28 crore. GSK has a 20% share of the market, with local companies such as Dr Reddy’s Laboratories, Sun Pharma, Glenmark Pharma, Cipla making up the rest.

Healthcare experts say rosiglitazone should not be given to diabetics with heart problems.

This is a huge number as about 25-30% of type II diabetics have some form of heart ailment, said A Ramachandran, president, India Diabetes Research Foundation. “So in diabetics with heart problems, and also those who are overweight, metformin is used.”
“However, in diabetics with no heart problems, rosiglitazone is effective,” says V Sarma, diabetologist, Fortis Hiranandani Hospital in New Bombay.