LONDON (Reuters) - The safety of GlaxoSmithKline Plc’s controversial diabetes drug Avandia was attacked in a new analysis by German researchers on Wednesday, dealing a fresh blow to the group’s second-biggest product.
They found little evidence that Avandia improved the quality or length of diabetics’ lives and concluded it could actually worsen complications of the disease, after studying pooled data from 18 past trials involving 8,000 patients.
Dr Bernd Richter of Duesseldorf’s Heinrich-Heine University, who led the research, questioned whether it was ethical to conduct any further clinical tests with Avandia, since “less dangerous” alternative treatments were available.
Glaxo dismissed his review as misleading and said it strongly disagreed with the conclusions, which were published in the Cochrane Library journal.
Avandia, known generically as rosiglitazone, has been under a cloud since May, when top U.S. cardiologist Dr Steven Nissen published a pooled, or meta, analysis of 42 previous trials that showed it increased the risk of heart attack by 43 percent.
Prescriptions for Avandia tumbled after that, and analysts slashed future earnings forecast for the medicine, which sold 1.6 billion pounds ($3.3 billion) worldwide in 2006.
Richter said his research had been conducted independently of Nissen’s, and the timing was a coincidence, though the two teams reached similar conclusions.
The German analysis found Avandia produced about the same reductions in blood sugar levels as other oral antidiabetic drugs, but patients taking Glaxo’s pill gained up to 11 pounds in body weight, and their chance of developing edema, or swelling, doubled.
Avandia was also linked to heart failure and bone fractures.
“I see a bundle of adverse effects, and I don’t see really good positive effects,” Richter told Reuters.
He noted that even very small risks could be significant for such a widely used medicine. “On a global scale, tiny risks can translate into big effects, because millions of people are taking this drug,” he said.
Avandia’s share of the U.S. new prescription market for oral antidiabetics crashed to 6.3 percent at the end of June from 11.5 percent in early May, although weekly figures show it picked up by 0.2 percentage points in the first week of July.
Dresdner Kleinwort analysts said the data suggested Avandia demand was stabilizing, and the German analysis was unlikely to significantly alter doctors’ perceptions.
Glaxo shares were down 0.5 percent in a weaker market for European drug stocks by late morning.
Glaxo said Richter’s analysis provided no new evidence about the use of Avandia in clinical practice.
“It’s looking at a very thin slice of the total available evidence for rosiglitazone and really ignoring a huge amount of research,” Ronald Krall, chief medical officer of the world’s second-largest drugmaker, said in a telephone interview.
Krall said Glaxo had studied Avandia in more than 52,000 patients, and this much larger dataset showed Avandia had a similar safety profile to other oral antidiabetic drugs.
The issue will come to a head on July 30, when U.S. Food and Drug Administration advisers meet to discuss the drug’s safety. Krall said he was confident Glaxo had a compelling body of evidence to present at the meeting.