New drug to treat deadliest TB approved by US drug regulator

Pretamonid, a novel compound developed by the non-profit organization TB Alliance, was approved by the US Food & Drug Administration (FDA) on August 14.

The US drug regulator has approved a new tuberculosis (TB) drug for treating hard-to-treat drug-resistant TB that makes the treatment regimen shorter and simpler.

Pretomanid, a novel compound developed by the non-profit organization TB Alliance, was approved by the US Food & Drug Administration (FDA) on August 14.

TB is the leading infectious cause of death worldwide, killing at least 1.6 million people annually. There are more than half a million cases of multi drug-resistant TB (MDR-TB) annually, with about 6% of those cases being extensively drug-resistant TB (XDR-TB) cases. India accounts for nearly a quarter of the global TB cases.

The new drug was approved under the Limited Population Pathway for Antibacterial and Antifungal Drugs (LPAD pathway) as part of a three-drug, six-month, all-oral regimen for the treatment of people with XDR-TB or MDR-TB, who are treatment-intolerant or non-responsive.

The LPAD pathway was established by FDA as a tool to encourage further development of antibacterial and antifungal drugs to treat serious, life-threatening infections that affect a limited population of patients with unmet needs.

“FDA approval of this treatment represents a victory for the people suffering from these highly drug-resistant forms of the world’s deadliest infectious disease,” said Mel Spigelman, MD, president and CEO of TB Alliance. “The associated novel regimen will hopefully provide a shorter, more easily manageable and highly efficacious treatment for those in need.”

The three-drug regimen consisting of bedaquiline, pretomanid and linezolid – collectively referred to as the BPaL regimen – was studied in the pivotal Nix-TB trial across three sites in South Africa. The trial enrolled 109 people with XDR-TB and also MDR-TB.

Nix-TB data demonstrated a successful outcome in 95 of the first 107 patients after six months of treatment with BPaL and six months of post-treatment follow-up. For two patients, treatment was extended to nine months.

TB, in all forms, is treated with a combination of drugs; the most drug-sensitive forms of TB require six months of treatment using four anti-TB drugs.

Treatment of XDR-TB or MDR-TB takes longer and is more expensive, with patients currently taking a combination of as many as eight antibiotics, some involving daily injections, for 18 months or longer.

“Until very recently, people infected with highly drug-resistant TB had poor treatment options and a poor prognosis,” said Dr. Francesca Conradie, principal investigator of the Nix-TB trial.

“This new regimen provides hope with 9 out of 10 patients achieving culture negative status at 6 months post-treatment with this short, all-oral regimen.”

The drug is likely to be available in the US markets by the end of 2019.

TB activists want the drug to be made affordable so that poor patients could also access it.

“As the third new drug developed for TB in over half a century, and the first to be developed as part of a ready-to-use treatment regimen, pretomanid’s approval represents another potent tool for tackling difficult-to-treat drug-resistant forms of TB,” said Médecins Sans Frontières (MSF), in a statement.

“However, it must be made affordable to everyone who needs it, especially considering the substantial taxpayer and philanthropic contributions that went into its development,” it added.