Good and bad news on tuberculosis (TB) treatments this week, with Otsuka filing a desperately-needed treatment for resistant strains of the disease but reports of further shortages with one of the current mainstay therapies.
On the positive side, Otsuka says it has now filed delamanid as a treatment for multi-drug resistant (MDR) pulmonary TB in patients who are also being treated with a background regimen of anti-TB drugs.
If it reaches the market, delamanid will be the first medicine in Japan specifically approved to treat MDR-TB, which generally means strains of the bacterium that are resistant to at least isoniazid and rifampicin/rifampin. It is classed as an orphan drug in this last-line setting, and if approved would be the first new drug available in Japan to treat TB in four decades.
“It is estimated that 440,000 new cases of MDR-TB emerge each year, leading to 150,000 annual deaths,” said Otsuka in a statement. Around a third of the world’s population is thought to be infected with the bacterium, and there were an estimated 1.4 million TB-related deaths in 2011, according to the World Health Organization (WHO).
The filing is being made on the back of a trial in 481 MDR-TB patients – published in the New England Journal of Medicine last year – which found that 45 per cent of patients treated with delamanid achieved a TB cure rate – defined as negative sputum culture – compared to 29.6 per cent of the placebo group.
Delamanid has already been filed for approval in Europe and is undergoing regulatory review, and the Japanese pharma company says it is also preparing a marketing application in the US.
Other drugs for MDR-TB coming through the pipeline include Johnson & Johnson/Tibotec’s bedaquiline (approved in the US as Sirturo, filed in Europe), the TB Alliance’s PA-824 (phase II) and Sequella/PanACEA’s SQ 109 (phase I).
Rifampin shortage
On the downside, Pfizer and Bedford Laboratories have said manufacturing problems are affecting supplies of rifampin, which remains a cornerstone of TB therapy despite being launched several decades ago
In Bedford’s case, the shortage happened because of ongoing quality problems at contract manufacturer Ben Venue, which is currently operating under an FDA consent decree which allows it to manufacture around 100 critical medicines to help alleviate serious drug shortages.
Meanwhile, Pfizer said vials of the rifampin product may not be sufficiently potent thanks to degradation of the drug, noting that affected lots will be discoloured, appearing as brown/black powder rather than red. The company has rifampin on back order as a result of the problem.
New of the rifampin shortage comes on the heels of supply problems with Sanofi’s Rifamate (rifampin plus isoniazid), which was added to the FDA’s shortage list last week.
