A Trial to Evaluate OPC 67683 in Participants With Pulmonary Sputum Culture-positive, Multidrug-resistant Tuberculosis (TB)

Sputum culture conversion was defined to occur at the time of the collection of a sputum specimen with mycobacterial culture negative for growth of Mycobacterium tuberculosis (MTB) followed by at least one additional sputum specimen with mycobacterial culture negative for growth at least 27 days after the first negative specimen and not followed by any sputum specimens positive for growth in the MGIT system at any point during the remainder of the 84-day trial after the first negative culture.

Time to maximum (peak) plasma concentration following the first daily dose (Cmax1) was reported as tmax1 and time to maximum (peak) plasma concentration following the second daily dose (Cmax2) was reported as tmax2. Data for Tmax up to Day 56 was collected on Days 1, 14, 28 and 56.

Maximum (peak) plasma concentration following the first daily dose was reported as Cmax1 and maximum (peak) plasma concentration following the second daily dose was reported as Cmax2. Data for Cmax up to Day 56 was collected on Days 1, 14, 28 and 56.

Data for AUC0-24h up to Day 56 was collected on Days 1, 14, 28 and 56.

Data for Rac (Cmax) up to Day 56 was collected on Days 14, 28 and 56. Rac (Cmax) on Days 14, 28 or 56 compared to Cmax on Day 1 was computed.

Data for Rac (AUC) up to Day 56 was collected on Days 14, 28 and 56. Rac (AUC) on Days 14, 28 or 56 compared to AUC0-24h on Day 1 was computed.

Data for Tmax up to Day 56 was collected on Days 1, 14, 28 and 56.

Data for Cmax up to Day 56 was collected on Days 1, 14, 28 and 56.

Data for AUC0-24h up to Day 56 was collected on Days 1, 14, 28 and 56.

Data for Rac (Cmax) up to Day 56 was to be collected on Days 1, 14, 28 and 56. Rac (Cmax) on Days 14, 28 or 56 compared to Cmax on Day 1 was to be computed. Due to limited measurable data on Day 1 for delamanid metabolites, pharmacokinetic (PK) analysis was not conducted on Day 1 data for delamanid metabolites, and data for Rac (Cmax) was not available.

Data for Rac (AUC) up to Day 56 was to be collected on Days 1, 14, 28 and 56. Rac (AUC) on Days 14, 28 or 56 compared to AUC0-24h on Day 1 was to be computed. Due to limited measurable data on Day 1 for delamanid metabolites, PK analysis was not conducted on Day 1 data for delamanid metabolites, and data for Rac (AUC) was not available.

A participant achieving SCC using solid culture media was defined as one with sputum culture negative for growth of MTB on Day 57, and (a) not followed by a positive culture at any point thereafter, and (b) confirmed by at least one additional negative sputum culture at Day 84.

Mean change from baseline in time to culture positivity using the MGIT system was the value for "time to results" when a sputum culture result was positive (in days) using the MGIT system during the routine 42-day incubation period. A longer time to culture positivity represented a lower burden of MTB organisms present in the sputum. Baseline was defined as the average of Day -1 and Day 1 values, if the cultures on both days were positive; if only one culture was positive, the value for the positive culture was used as baseline.

AUC of change from baseline for time to culture positivity (i.e., TTD) (Days 0 to 57), summarizes overall participant response for treatment period. Larger AUC of change from baseline for time to culture positivity would strongly suggest a clinical response with reduction of burden of MTB organisms in sputum. For this analysis, ti=visit day of each visit; t0=Day 0, t1=Day 8, t2=Day 15, etc. and xi=change from baseline in time to culture positivity at each visit; AUC at each visit was determined as AUCi=(ti - ti-1)(xi+ xi-1)/2. Average AUC of change from baseline was the sum of all AUCi divided by a given participant's duration in the trial up to 57 days. Baseline (Day 0)=the average of Day -1 and Day 1 values, if cultures on both days were positive; if only one culture was positive, value for time to culture positivity for positive culture was used as baseline.

A participant achieving SCC using solid media is defined as one with sputum culture negative for growth of MTB on Day 57, and (a) not followed by a positive culture at any point thereafter, and (b) confirmed by at least one additional negative sputum culture at Day 84. A dose response in the percentage of participants achieving SCC using the MGIT system was tested by the Cochran-Armitage linear trend test with equally spaced dose scores (0, 1, and 2 for placebo, 100 mg BID, and 200 mg BID, respectively).

Initial SCC occurred at the time of the collection of the first sputum specimen with mycobacterial culture negative for growth of MTB using the MGIT system followed by at least one additional MGIT negative sputum specimen at least 27 days after the first negative specimen and no sputum specimens MGIT positive for growth at any point between the negative MGIT sputum specimens. Survival analysis methodology was performed to compare the Kaplan-Meier curves for time to SCC across 3 treatment groups. Comparisons between 100 mg BID and placebo and 200 mg BID and placebo were also performed with stratified log-rank tests. The benefit ratios (ratio of likelihoods that participants treated with delamanid BID + OBR would achieve SCC more rapidly than participants treated with placebo + OBR) for participants achieving SCC were computed.

Initial SCC occurred at the time of the collection of the first sputum specimen with mycobacterial culture negative for growth of MTB using solid culture media that was followed by at least one additional negative sputum specimen at least 27 days after the first negative specimen and no sputum specimens positive for growth on solid culture media at any point between the negative sputum specimens using solid culture media. Survival analysis methodology was performed to compare the Kaplan-Meier curves for time to SCC across 3 treatment groups. Comparisons between 100 mg BID and placebo and 200 mg BID and placebo were also performed with stratified log-rank tests. The benefit ratios (ratio of likelihoods that participants treated with delamanid BID + OBR would achieve SCC more rapidly than participants treated with placebo + OBR) for participants achieving SCC were computed.

Final SCC was defined as SCC at Day 57 or the latest time point of the first negative sputum culture establishing SCC for a given participant after the last positive sputum culture observed during the 56-day treatment period, whichever comes first. Survival analysis methodology was performed to compare the Kaplan-Meier curves for time to SCC across 3 treatment groups. Comparisons between 100 mg BID and placebo and 200 mg BID and placebo were also performed with stratified log-rank tests. The benefit ratios (ratio of likelihoods that participants treated with delamanid BID + OBR would achieve SCC more rapidly than participants treated with placebo + OBR) for participants achieving SCC were computed.

Final SCC is defined as SCC at Day 57 or the latest time point of the first negative sputum culture establishing SCC for a given participant after the last positive sputum culture observed during the 56-day treatment period, whichever comes first. Survival analysis methodology was performed to compare the Kaplan-Meier curves for time to SCC across 3 treatment groups. Comparisons between 100 mg BID and placebo and 200 mg BID and placebo were also performed with stratified log-rank tests. The benefit ratios (ratio of likelihoods that participants treated with delamanid BID + OBR would achieve SCC more rapidly than participants treated with placebo + OBR) for participants achieving SCC were computed.

Criteria for potentially clinically significant vital sign abnormalities: Heart rate [beats per minute (BPM)]: >=120, increase >=15, <=60, decrease >=15; systolic blood pressure [millimeter of mercury (mmHg)]: >=160, increase >=20, <=90, decrease >=20; diastolic blood pressure (mmHg): >=105, increase >=15, <=50, decrease >=15; weight (kg) gain: increase >=5%; or weight loss: decrease >=5%; temperature [degrees Celsius (C)]: >=38.5, increase of >=1.1. Only categories with at least 1 participant with event are reported.

Criteria for categorical changes in 6 12-lead Electrocardiogram results: Vent Rate Outliers Notable Decreases- >= 25% decrease from Baseline and ventricular rate < 50 beats per minute (beats/min), notable increases- >= 25% decrease from Baseline and ventricular rate > 100 beats/min; PR outliers notable changes- >= 25% change from Baseline when PR > 200 milliseconds (msec); QRS outliers notable changes- >= 25% change from Baseline when QRS > 100 msec; QT new onset (> 500 msec); QT correction with Bazett formula (QTcB) and QT interval with Fridericia's correction (QTcF) new onset > 500 msec, > 480 msec, > 450 msec, where new onset (> 450, 480, 500 msec) means a participant who attains a value > 450, 480, 500 msec during Treatment Period but not at each Baseline Visit; change >= 30, <= 60 msec; change > 60 msec; and new abnormal U waves, ST segment changes, T wave changes, abnormal rhythm, RBBB, LBBB, myocardial infarction(MI). Only categories with at least 1 participant with event are r

The laboratory values were one of the parameters to measure the safety and tolerability of individual participants. Participants with potentially clinically significant laboratory values in clinical chemistry, hematology, coagulation, adrenal function tests, urinalysis and thyroid function tests that were identified based on pre-defined criteria were reported. Any value outside the normal range was flagged for the attention of the investigator who assessed whether or not a flagged value is of clinical significance. The categories with at least one participant with abnormal lab value as assessed by the investigator are reported.

The concomitant anti-TB medication were classified as per WHO 2008 guidelines and included: Category 1- first-line oral anti-tuberculosis drugs; Category 2- injectable anti-tuberculosis drugs; Category 3- fluoroquinolones; Category 4- oral bacteriostatic second-line anti-tuberculosis drugs; Category 5- anti-tuberculosis drugs with unclear efficacy or unclear role in MDR-TB treatment (not recommended by WHO for routine use in MDR-TB participants).

An adverse event (AE) was defined as any untoward medical occurrence in a clinical trial participant and which does not necessarily have a causal relationship with the treatment. An AE can therefore be any unfavorable and unintended sign (including e.g., an abnormal laboratory assessment result), symptom or disease temporally associated with participation in the clinical trial, whether or not it is considered causally related to the medicinal product or procedures of the clinical trial. A clinically significant worsening in the health of the participant compared with the participant's health status documented at baseline constituted a TEAE.

Any changes in the ECG waves or segments as assessed by the investigator were reported.