New TB drug ready for clinical trial

A new candidate drug against tuberculosis is all set to be tried on drug-resistant TB patients in India with the hope that it would end a 50 year search for a new medicine against the disease that kills 1000 Indians daily.

Almost all TB drugs currently in use were developed in the 1950s and 1960s. The last one was rifampicin in 1966. Isoniazid and pyrazinamide came in 1952 and ethambutol in 1961.

“In the last half a century, there were combinations but no new molecule. Recently one molecule (from a large pharmaceutical company) received US Food and Drug Administration's approval for critical patients. But it is yet to complete the phase-III trial,” said Geeta Vani Rayasam, a senior researcher in the Council of Scientific and Industrial Research.

Scientists are firming up their plans to start a Phase-II B clinical trial of the molecule – Pa824 – following encouraging Phase-I trials that assessed the drug's safety.

The clinical trial is being spearheaded by the Open Source Drug Discovery team of Council of Scientific and Industrial Research that has taken up the challenge of de-risking the high-cost drug development process in the absence of pharmaceutical industry's lack of interest on TB drugs. “We will seek the Drugs Controller General of India approval by March. The trial will be held in LRS Institute of Tuberculosis and Respiratory Diseases in Delhi involving 250-300 multi drug resistant TB patients,” Zakir Thomas, who heads the OSDD programme told Deccan Herald.

This will be the first clinical trial of a TB drug in India by a public-funded organisation. In the past National Institute for Research on Tuberculosis in Chennai carried out India leg of a clinical trial for a molecule developed by a multinational firm. On the contrary Pa824 was synthesised in India decades ago. After a series of ownership changes, the molecule was licensed to CSIR for further development and clinical trial by an international non-governmental organisation known as TB Alliance.

As many as 8 phase-I trials were conducted in the USA and South Africa in the last 5 years. The drug candidate was found to be safe expect in higher dose.

Two phase-II trials were conducted in Brazil and South Africa with promising results.
The Indian trial will have three arms, each involving 60-100 patients.