tuberculosis (TB), a contagious bacterial lung infection, is caused by bacteria
tuberculosis). TB can be transmitted from one person to another by breathing in
air droplets from a cough or sneeze of an infected person.
last 20 years have witnessed a rising incidence of multidrug-resistant TB
(MDR-TB), that is, TB caused by strains of Mycobacterium tuberculosis
that is unresponsive to traditional TB medications such as isoniazid and
rifampin. Every year, globally nearly 440,000 MDR-TB cases are recorded and
such patients are treated with 4-6 drug combination.
Delamanid (OPC-67683) is a drug from the
nitro-dihydro-imidazooxazole family of mycolic acid synthesis inhibitors, which
are pre-clinically proven to be effective against drug-responsive TB and
MDR-TB. A 2-week study revealed that 200 to 300 mg of daily delamanid was as
efficacious as rifampin in terms of antibacterial action.
The current clinical trial, across multiple
countries, involved 481 patients aged 18 to 64 years and with sputum
culture-positive MDR-TB and chest radiography consistent with TB. For 2 months,
the patients received 100mg two-times-a-day delamanid (161 patients), 200 mg
two-times-a-day (160 patients), or placebo (160 patients). Patients were also
treated with a 4 to 5 drug combination therapy as per WHO recommendation for
MDR-TB treatment. Sputum cultures
were evaluated every week and sputum-culture conversion was said to occur when
five or more sequential cultures were negative for M. tuberculosis.
The cultures were considered positive
based on the presence of colonies with specific morphological features.
Sputum-culture conversion was observed in 45.4% and 41.9% of 100mg
and 200mg delamanid treated patients respectively as well as in 29.6% of placebo
group patients. Adverse events were
mild to moderate and evenly distributed
among the groups.
treatment with delamanid promoted sputum-culture conversion in MDR-TB patients.
Thus, delamanid may be the answer to the growing problem of multi-drug
Reference: Delamanid for
Multidrug-Resistant Pulmonary Tuberculosis; Maria Tarcela et al; N Engl J Med 2012; 366:2151-2160 June 7, 2012