Rifapentine- and moxifloxacin-containing short-course regimens for mild spinal tuberculosis: study protocol for a multicenter, randomized, non-inferiority phase II clinical trial.

BACKGROUND: Spinal tuberculosis is the most common form of osteoarticular infection, with recommended anti-tuberculosis treatment durations typically being long (9-18 months), even for mild cases, increasing the risks of drug resistance, toxicity, and poor patient adherence. This study aims to explore, in patients with mild spinal tuberculosis, whether a new combination of anti-tuberculosis drugs (containing rifapentine and moxifloxacin) could shorten the treatment duration.

METHODS AND ANALYSIS: This trial is an open-label, randomized, controlled, non-inferiority trial comparing the efficacy and safety of a short-course regimen [6-month anti-TB regimen] containing rifapentine and moxifloxacin with empirical long-course regimen [12-month anti-TB regimen] in the treatment of patients with mild spinal tuberculosis. Patients diagnosed with mild spinal tuberculosis who meet the inclusion and exclusion criteria will be recruited and randomized in a 1:1 ratio to either of the two arms. Empirical long-course regimen includes rifampin, isoniazid, pyrazinamide and ethambutol (2RHZE/10RH), while short-course regimen includes rifapentine, moxifloxacin, isoniazid and pyrazinamide (2HRtZM/4HRtM). The primary outcomes are TB-recurrence rate at 24 months after completion of treatment and proportion of participants with grade 3 or higher adverse events during treatment with study medications.

DISCUSSION: This trial will provide evidence whether a short-course regimen of anti-TB drugs (2HRtZM/4HRtM) is non-inferior to the empirical long-course regimen (2RHZE/10RH) in patients with mild spinal tuberculosis. If non-inferiority is established, it will contribute to a more optimized treatment for spinal tuberculosis.

CLINICAL TRIAL REGISTRATION: This study is registered with https://clinicaltrials.gov/ct2/show/NCT06917495 as NCT06917495.