Bharat Biotech's plans to advance its tuberculosis vaccine candidate MTBVAC (BBV169) into Phase III clinical trials have been put on hold after the Subject Expert Committee (SEC) on Vaccines sought additional data and protocol revisions before granting further approval.
The proposal was reviewed during the meeting of the SEC - Vaccine held on May 28, 2026. The company presented its Phase III clinical trial protocol along with an interim report from the ongoing Phase II clinical study.
The proposed study is a randomized, double-blind, placebo-controlled, multicentre Phase III clinical trial designed to evaluate the efficacy, safety, and immunogenicity of MTBVAC (BBV169), a live attenuated Mycobacterium tuberculosis vaccine, for preventing tuberculosis disease in Indian adolescents and adults.
During the review, the committee noted that Bharat Biotech had submitted the interim Phase II clinical study report containing 90-day safety data and 56-day immunogenicity data as per the approved protocol. The interim analysis demonstrated that MTBVAC generated immunogenicity responses comparable to the currently used BCG vaccine in both QuantiFERON-TB (QFT) negative and QFT positive participants.
However, the SEC observed several gaps in the submitted data. The committee pointed out that detailed immunogenicity data for MTBVAC at Days 0, 28, and 56 had not been provided and would be required to reconfirm the primary objectives of the Phase II study.
The experts also noted that age-stratified analyses for adolescent and adult participants, as mandated under the approved protocol, were missing from the submission. In addition, the graphical presentation of cell-mediated immune responses and responder-rate analyses from the Phase I immunogenicity assessment needs to be reverified and supported with raw subject-level data.
Another key concern raised by the committee related to a reported serious adverse event (SAE). The SEC recommended that genomic analysis be conducted to determine whether the event was associated with a naturally occurring tuberculosis strain or a vaccine-derived strain.
Following detailed deliberations, the committee advised Bharat Biotech to submit the missing information along with a revised Phase III clinical trial protocol. The revised protocol should incorporate the committee’s recommendations regarding primary efficacy endpoints, double-blind administration procedures, immunogenicity cohort selection, and statistical methods for evaluating efficacy outcomes.
The proposal will be reconsidered after the company submits the requested data and revised study design for further evaluation by the committee.
MTBVAC is among the few tuberculosis vaccine candidates globally being developed from a live attenuated Mycobacterium tuberculosis strain and is being closely watched as a potential next-generation alternative to the century-old BCG vaccine.
