AstraZeneca has suffered a setback after advisors to the US Food and Drug Administration rejected the infant lung drug motavizumab.

MedImmune, the Anglo-Swedish drugmaker’s biologics unit, has revealed that the FDA’s Antiviral Drugs Advisory Committee has voted 14 to 3 to recommend that motavizumab should not be approved the prevention of serious respiratory syncytial virus (RSV) disease in high-risk infants. The monoclonal antibody is the follow-up to Synagis (palivizumab), which had sales of $545 million in the first quarter, up 5%.

The panellists believe that the data provided merely shows that motavizumab is only as effective in reducing RSV hospitalisations as Synagis. They have suggested that more clinical trials may be needed to be conducted in children, while staff documents released before the meeting stated that “we clearly have a safety signal suggesting motavizumab has more significant hypersensitivity reactions” than the older drug.

AstraZeneca is still backing the treatment and Genevieve Losonsky, head of clinical development for infectious disease at MedImmune, said “we continue to believe motavizumab offers a meaningful clinical benefit to patients at high risk for a very common and serious illness”. She added that “we will work to address the issues raised by the committee and look forward to continuing to work with the FDA as it completes its review of our application”.

It is the second time this week that AstraZeneca has received some bad news from the FDA. The company was earlier presented with a complete response letter asking for more information on Axanum, which combines aspirin and Nexium (esomeprazole) tablets, for the risk reduction of low dose aspirin-associated gastric and/or duodenal ulcers. The company also received a CRL for the supplemental new drug application for Nexium for the risk reduction of low-dose aspirin-associated peptic ulcers.

FDA orders change to Symbicort label
Meantime, the FDA has ordered AstraZeneca to change the label on its asthma combo Symbicort (budesonide/formoterol), following up from a warning issued in February where the agency stated that long-acting beta agonists (LABAs), such as formoterol, should never be used alone in the treatment of the disease.

The FDA said that it also had to order GlaxoSmithKline to change the label on Advair (fluticasone/salmeterol) and Serevent (salmeterol), while the warnings also cover Novartis and Merck & Co's Foradil (formoterol), Dainippon Sumitomo’s Brovana (arformoterol) and Mylan’s Perforomist (formoterol).

Most of the companies accepted the changes but AstraZeneca (and GSK) were not convinced, hence the FDA’s order. Cathy Bonuccelli, head of the clinical respiratory and inflammation unit at AstraZeneca, said the firm is still confident about the positive benefit-risk profile of Symbicort, saying such combination therapies “continue to play a critical role in helping appropriate patients control asthma symptoms”.

The updated label only impacts the asthma indication for Symbicort, not its other approved use for chronic obstructive pulmonary disease.