Pfizer has suffered another development setback after the firm said it is withdrawing all of its marketing applications for dalbavancin, its investigational antibiotic for skin infections to conduct more clinical trials on the drug.

The New York-based giant said that following feedback from regulatory authorities in the USA and Europe, the company plans to conduct an additional Phase III trial with dalbavancin for the treatment of adults with complicated skin and skin structure infections caused by Gram-positive bacteria, including methicillin resistant Staphylococcus aureus. The global multi-centre study will generate additional data to support future submissions and a paediatric programme with dalbavancin is also planned.

Pfizer’s moves after the US Food and Drug Administration issued an approvable letter for dalbavancin in December and asked the firm to provide more data. The new trial is likely to take some 18 months to complete.

Mark Kunkel, medical leader for anti-infectives and HIV at Pfizer, noted that the firm has pulled the applications "after careful consideration of feedback and ongoing dialogue with regulatory authorities”. He added that dalbavancin “represents a potential important treatment advance and Pfizer is committed to ongoing research of its use in patients who suffer from serious skin infections, including those caused by MRSA”.

Pfizer got hold of the compound when it acquired Vicuron Pharmaceuticals in 2005 for $1.9 billion. Analysts had sales of around $250 million by 2012.

Meantime, Pfizer is at the centre of rumours linking the firm with a possible takeover bid for Bayer. Both companies declined to comment but analysts have spoken of the attractiveness of the German group which has a strong pipeline of drugs.

However Bayer is also the world's largest maker of crop chemicals and polyurethanes, businesses that Pfizer is not involved in and the diversified nature of the Leverkusen-headquartered group suggests that the rumour is just that.