Basilea's antibiotic left looking like strongest candidate

In a week that has seen an FDA advisory committee throw a number of knock out punches at the companies trying to win approval for new strong antibiotics, Basilea Pharmaceutica could emerge the one remaining company standing.

Although the Swiss group’s antibiotic Zevtera was not being reviewed, its potential competitors were. At the end of a week of twists and turns only one, Theravance’s telavancin, looks like having a chance of winning a marketing license in the US; albeit with strong safety warnings. With a green light in Switzerland and clearance from European regulators announced today, Basilea could be forgiven for feeling optimistic as the March 13 US PDUFA date approaches.

After years of neglect, research into new antibiotics to treat increasingly virulent and resistant bacteria strains, most famously MRSA, has moved to the top of the agenda. Unfortunately, as several products moved into the registration stage, the FDA realised that it needed to have another look at the methods it uses to establish efficacy; hence the advisory committee.

As well as examining the basis for using non-inferiority trials, a way of establishing whether a new antibiotic is as good as existing treatments, the panels reviewed Theravance’s telavancin, Targanta's oritavancin and Arpida’s iclaprim. The fact that Zevtera, generically known as ceftobiprole, was not included for review has been viewed as positive by analysts.

Oritavancin and iclaprim got clear negative votes due to problems with their data, while the panel was convinced with telavancin’s efficacy, to the extent that safety concerns were viewed as manageable. (Arpida pays for solo strategy as FDA voices serious iclaprim concerns, November 19, 2008 and Event - Targanta and Theravance face short wait for final FDA decisions, November 20, 2008).

Room for optimism

Zevtera itself has had its setbacks, and was handed an approvable letter back in March, with the FDA asking for more details on patients with diabetic foot ulcers and saying it needed more time to finish reviewing sites and the data. (Basilea plunges on ceftobiprole delay, but concerns go deeperMarch 18, 2008).

That has caused sales forecasts for the drug, which is to be co-promoted by Johnson & Johnson, to fall. Archived forecasts from EvaluatePharma show that consensus for 2012 peaked at $969m in November last year, and currently stands at $620m. Sales will be booked by J&J and Basilea will receive a co-promotion payment.

However, events over the last week means analysts might be getting ready to lift those numbers once again.

Competitive advantage

“You can’t really link approval in the EU to the US, but it is positive; the odds of US approval have increased marginally,” commented Karl Keegan, an analyst with Canaccord Adams. “The most exciting outcome of the panel in the US is that the competitive situation has improved.”

Mr Keegan said that when he initiated coverage of Basilea in last year, there were several competitors in the field, a situation that has now changed considerably. In September Pfizer withdrew its marketing application in the US and EU for dalbavancin, branded Zeven, so it could conduct an additional phase III trial in cSSSI, including MRSA infections. In the US approval of oritavancin and iclaprim looks unlikely, and while telavancin might win approval in the US, European approval will be sometime off.

Theravance and partner Astellas withdrew their marketing application in Europe last month, after the regulator said it was unable to establish a positive risk/benefit balance for the drug. They will re-file with more data next year. With decisions on both iclaprim and oritavancin not due until the end of 2009 in Europe, Zevtera looks like it has a strong commercial advantage in these markets.

Calling an FDA decision is always risky, and there is a possibility that the regulator will want to see further data in diabetic foot ulcers before Zevtera is approved to treat the most severe CSSSI cases. However, there is a strong chance that the drug will reach the US market next year.

With the pins toppling around it, Basilea looks like the strongest candidate.

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