Three asthma drugs that have come under the scrutiny of drug regulators concerned about their safety will stay on the market, after a US Food and Drug Administration advisory panel voted unanimously in their favour.

Questions were raised about the three compounds – GlaxoSmithKline’s Serevent (salmeterol) and number one drug Advair (salmeterol/fluticasone), as well as Novartis’ Foradil (formoterol) – after reports of severe asthma attacks and fatalities in a small number of patients receiving GSK’s Serevent. Labelling for both Serevent and the combination product Advair, which contains the same active ingredient salmeterol, was revised in September last year to show a 1.7% increase in the relative risk of asthma death or a life-threatening experience versus placebo.

Meanwhile, Novartis also conducted a post-marketing study to investigate whether any severe adverse events could be tied to its product, Foradil, but – says the panel – it was not powered to assess asthma-related deaths. Deeming the data inconclusive, the committee members have pushed the onus onto Novartis and said it is up to the company to “demonstrate that formoterol has a different mechanistic or safety profile from salmeterol.”

Swiss giant Novartis must now add a black box warning that asthma-related deaths seen with Serevent may prove to be a class effect. However, Foradil is not a big product for Novartis, with sales for the second quarter up 8% to just $82 million. In the USA it is already feeling the impact of being linked to Serevent, slumping 25% to $3 million during the last three months.

However, thus far there seems to be little to worry GSK, which continued to reel in the revenues for Seretide and Advair during the first quarter of this year – up 22% to bring in a combined £690 million [[29/04/05a]]. For the full year 2004, sales rose 19% to £2.5 billion [[11/02/05a]]