BPaLM regimen–promise, peril, and policy gaps in India’s 2024 drug-resistant tuberculosis guidelines

Drug-resistant tuberculosis (DR-TB) continues to threaten global TB elimination goals, with significant burdens both worldwide and in India. Globally, an estimated 3.2% of new TB cases and 16% of previously treated cases have multidrug-resistant or rifampicin-resistant TB (MDR/RR-TB), accounting for nearly 400,000 incident cases annually.[1] India contributes almost one-third of this burden, with MDR-TB detected in approximately 3.5% of new cases and 27% of previously treated patients.[2] Managing DR-TB has historically required long, toxic, and operationally demanding regimens–often extending beyond 18 months and associated with treatment fatigue, high default rates, and severe adverse effects. Against this background, the World Health Organization recommended the all-oral, 6-month BPaLM regimen–bedaquiline, pretomanid, linezolid, and moxifloxacin. In November 2024, India’s National TB Elimination Programme incorporated BPaLM into its National Guidelines for Management of Drug-Resistant TB, positioning it prominently as the first-line regimen for eligible MDR/RR-TB patients aged 14 years and older.[2] The guidelines outline indications, drug doses, monitoring requirements, and extension criteria, marking a major policy transition toward shorter, modern DR-TB therapy. The guidelines’ decision to make BPaLM widely accessible is praiseworthy. It aligns with global recommendations and reflects confidence in evidence from clinical trials demonstrating high cure rates with significantly reduced treatment duration.[3] The eligibility criteria outlined in the guidelines–covering drug susceptibility, comorbidities, prior drug exposure, and baseline Electrocardiography (ECG) thresholds–are appropriately comprehensive and help ensure safe implementation. Inclusion of pyridoxine prophylaxis and clear descriptions of drug doses demonstrate attention to toxicity mitigation. However, closer appraisal reveals several limitations and unaddressed concerns. All four components of the regimen carry significant toxicities. Bedaquiline is linked to QT interval prolongation and emerging resistance;[4] pretomanid may cause hepatotoxicity and myelosuppression; moxifloxacin carries additional risk of QT prolongation and musculoskeltal symptoms; and linezolid, the most toxic component, is associated with neuropathy, optic neuritis, anemia, and bone marrow suppression. These risks underscore the need for intensive and repeated monitoring, which guidelines rightly emphasize–but the feasibility at scale is difficult and questionable. The guidelines require baseline ECGs, complete blood counts, liver and renal function tests, electrolytes, and neuropathy and vision screening before initiation. In real-world programmatic settings, patients often lose 7–14 days completing these investigations, delaying initiation of therapy. The guidelines are silent on how these delays may impact disease progression, transmission, or patient adherence. Furthermore, periodic and extensive monitoring–including repeated ECGs and toxicity assessments–demands infrastructure and trained personnel that remain unevenly distributed across India. Without parallel investments in capacity-building, these requirements risk widening inequities between well-resourced and peripheral DR-TB centers. Linezolid dose modification aims to preserve efficacy while managing toxicity. However, the allowance to extend the regimen from 26 weeks to 39 weeks when linezolid dose is reduced materially weakens the promise of a “6-month regimen.” Many patients may end up undergoing a significantly longer course, undermining one of BPaLM’s key advantages and increasing overall toxicity exposure. The guidelines also inadequately address the risk of subtle Grade I–II neuropathy going unnoticed in busy clinics; by the time more severe symptoms emerge, neurological damage may be irreversible. Resistance concerns also warrant closer attention. The guidelines permit initiation of BPaLM while baseline drug susceptibility testing (DST) to bedaquiline and linezolid is pending, citing low resistance levels nationally. It risks the inadvertent emergence of resistance if patients harbor unrecognized baseline resistance. Furthermore, amplification of resistance can occur with bedaquiline during its large-scale rollout, considering its long half-life and wide tissue distribution. DST capacity for newer agents remains limited in India, and without rapid expansion, undetected resistance may compromise both individual and programmatic outcomes. The guidelines provide clear criteria for regimen modification or discontinuation but do not address the system-level barriers that may hinder timely implementation–transport costs, workforce shortages, limited neurological assessment, and ECG interpretation expertise. Looking ahead, the limitations of the BPaLM regimen highlight the need for safer next-generation agents. Promising newer oxazolidinones–including sutezolid, delpazolid, and tedizolid–may offer similar efficacy with substantially lower neurotoxicity, and next-generation diarylquinolones aim to improve on bedaquiline’s cardiac safety. Continued investment in research and accelerated regulatory pathways will be critical. In conclusion, the latest national guidelines bring India closer to global best practices in DR-TB care. Yet the regimen’s toxicity, monitoring demands, and real-world barriers require careful attention. With stronger infrastructure, pharmacovigilance, and patient-centered implementation, BPaLM can be transformative–but only if its risks are acknowledged and proactively managed.