Authors’ Response to ‘False equivalence of four month and six‐month ATT regimen: a case of comparing apples and oranges’

Malegaonkar et al. have raised concerns on two issues with reference to our paper entitled ‘4-month moxifloxacin containing regimens in the treatment of patients with sputum-positive pulmonary tuberculosis in South India – a randomised clinical trial’ in the letter ‘False equivalence of four month and six-month ATT regimen: A case of comparing apples and oranges’. They have flagged the use of an intermittent 6-month regimen as the control arm and questioned the rationality of using moxifloxacin in the treatment of drug-susceptible tuberculosis (TB). With reference to the first issue, the 6-month intermittent regimen was the standard of care in the Revised National TB Control Programme (RNTCP) throughout the recruitment phase of our clinical trial (May 2007 to October 2016). The change to the daily 6-month regimen was implemented in the RNTCP after study enrolment was completed. We have clearly and explicitly acknowledged this issue in our manuscript and have identified it as one of the limitations of the trial [1]. Also, having said that, a shorter 4-month regimen with all its inherent advantages with a high cure rate at end of treatment and a TB recurrence rate of less than 5% after 24 months of follow-up is a benchmark that most TB programme managers would accept, we believe. The concern about the need to preserve moxifloxacin for the treatment of drug-resistant TB is well taken. But we followed the philosophy that the best way to manage drug-resistant TB is to prevent it. And towards this goal, the search for a shorter treatment regimen has been a crucial research priority. Globally, there has been an interest in shorter regimens for drug-susceptible TB using the fluroquinolones for the last decade [2-4]. And recently a 4-month regimen of moxifloxacin and rifapentine was successful against drug-susceptible TB [5]. Moreover, we now have newer drugs in the TB treatment armamentarium and so need not be constrained with judicious use of the fluroquinolones in treating drug-susceptible TB. According to the National drug resistance survey, the majority (77%) of newly diagnosed TB patients are drug-sensitive and 2–3% of them are resistant to quinolones [6]. Hence, newly diagnosed TB patients would benefit from a regimen with quinolone. We reiterate that in spite of the limitations in our study the conclusions drawn within the scope of these limitations are valid and an important contribution to the quest for improving TB treatment and management.