Excitement has greeted mid-stage data on Otsuka Pharmaceutical Co's delamanid which could be the first new tuberculosis treatment to be approved in half a century.

Data from a Phase IIb study has been published in the New England Journal of Medicine which shows that delamanid is effective as a treatment for multidrug-resistant TB. Results from the trial showed a 53% increase in sputum culture conversion (SCC) after two months between subjects receiving delamanid 100 mg twice-daily plus a background regimen (BR) compared to placebo plus BR alone.

Some 481 patients ages 18 to 64 with suspected MDR-TB were enrolled in the study and took at least one dose of delamanid. The findings revealed that 45.4% in the delamanid 100 mg BID group and 41.9% of study subjects in the delamanid 200 mg BID group achieved SCC after two months of treatment, compared with 29.6% in the placebo group.

Otsuka quoted Manfred Danilovits of Tartu University Hospital in Estonia and lead investigator as saying that "existing TB treatment regimens are long and cumbersome, which can lead to incomplete treatment, resulting in an increased risk of relapse and developing drug resistance". He added that this study shows delamanid "may help achieve earlier sputum conversion thereby reducing infectiousness and enhancing overall treatment options for MDR-TB".

Masuhiro Yoshitake, Otsuka's operating officer, said that TB treatment has been a priority for the firm "for more than 30 years, and over time we have become the largest private funder of TB R&D". He noted that the findings "are a major step forward for the TB community and offer compelling support for bringing delamanid to market as one of the first new drugs to treat TB in more than 40 years".

Delamanid belongs to a class of compounds, known as nitro-dihydro-imidazooxazoles, which work by inhibiting synthesis of mycolic acid. The latest class of anti-TB drugs was discovered in 1963.

According to the latest World Health Organisation Global Tuberculosis Control report, in 2010 8.8 million people became sick, and nearly 1.4 million people died from TB or TB-related causes. It is estimated that 440,000 new cases of MDR-TB emerge each year, leading to 150,000 annual deaths.