The innovation gaps and challenges for the diagnostic and treatment of TB and MDR-TB Blessina Kumar TB/ HIV Activist Community Representative & Vice Chair STBP Coordinating Board
Diagnosis
Overview of tools for TB diagnosis Fraction of patients seen at given level In Surveillance house DST (MODS, NRA,CRI; Reference methods Reference special settings and Networks supervision 5% Labs conditions Resolution Testing (screening test negiative, drug resistance) Regional Labs DST LPA RIF/INH 2 d Screening Passive case finding Detect and treat District Level Subdistrict Level Integrated NAAT + 40% /2h 10% Microscopy Level 25% Clinical Screening Primary care Peripheral health clinic 60% * Adapted from: G. Roscigno presentation, Global consultation on GeneXpert MTB/RIF sytem, Geneva, Dec 2010 Diagnostics for tuberculosis-global demand and market potential. WHO/TDR and FIND.2006
Xpert MTB/RIF Endorsed by WHO in Dec 2010 for diagnosis of TB and RIF resistance Important advance- accelerates time to diagnosis and treatment initiation HOWEVER: Still not truly a POC technology for resource limited settings Implementation requires substantial logistical and financial investments Limited benefit for HIV infected patients and children (Lawn et al 2011; Nicol et al., 2011, rachow et al 2012 This shows the limitations of relying solely on adaptation to fulfil developing country needs.
TB Diagnostics: the test we need! Detection of active TB Test result allow decision on treatment initiation Patient can receive result on the same day Point-of-care: easy to perform in peripheral health centres DST (preferable but not minimum requirement) Drastic improvement in diagnosis of currently neglected populations: HIV co-infected patients and children Need to aim for a NON-Sputum based test
Strategic roadmap toward a lab free TB diagnosis A strategic roadmap toward the development of such a diagnostic tool will imply R&D efforts to focus on: further simplification of technological platforms for detection already identified biomarkers (e.g. nucleic acid); Identification of novel TB biomarkers (for adult as well as for paediatric TB), prioritizing those that can be suitable for development of point-of care format and that can be found in samples other than sputum. Improvement of specimen repositories that can serve the need of TB diagnostic R&D activities (i.e. identification and validation of diagnostic biomarkers; early evaluation of diagnostic test prototypes)
Treatment
Current TB therapy and unmet needs Forms of Disease Current therapy Unmet needs Drug susceptible TB (DS-TB) 4 drugs; >6 month therapy (2RHZE+4RH) Shorter, simpler therapy Drug resistant TB (MDR-TB) Long and complex regimen (including injectables) >18 month Poorly tolerated Totally oral, shorter and safer therapy TB/HIV coinfection Drug-drug interactions (DDI) No or low DDI, possible with ARVs co-administration with ARVs Paediatric TB Lack of adapted formulations Children friendly Poor knowledge on dosages formulations and length of therapy Paed therapy Latent TB infection 6-9 month Shorter, safer therapy
Clinical Development Phase I Phase II Phase III New chemical entities Bedaquiline (TMC207) PA-824 PNU 100480 AZD5847 SQ-109 Delaminid (OPC67683) Existing drugs Linezolid Rifapentin High dose RIF Moxifloxacin Gatifloxacin Rifapentin HIV drug clinical pipeline: 33 NCE in development Overall 48 clinical trials ongoing for antivirals for HIV (http://www.phrma.org/sites/default/files/1986/medicinesindevelopmenthivaids2011.pdf)
Development of new regimes TB requires a multi-drug regime so single drug development is not sufficient New drugs need to be combined with new regime development. TB Alliance, RESIST TB and the Tuberculosis Transformative Science Group (TB TSG- part of the ACTG) are involved in development and investigation of new regimes
Paediatric Drugs There are rising numbers of children who are infected with drug-resistant forms of TB There are no specific paediatric formulations of the drugs required to treat them. The paediatric DR-TB market is currently very small (potentially as small as 5000 patients per year) so offers no benefits for a manufacturer to enter. There is a lack of basic scientific research, PK data, for the doses required to treat DRTB in children which needs to be addressed d before paediatric i formulations can be made. Even for DSTB the current formulations do not match the guidelines
Conclusion What needs to change? We need more and sustainable funding for TB R&D, but also to spend funds differently: R&D should be needs driven and linked to developing country priorities Mdi Medical priorities iti should ldbe linked with binding financial i commitments More global coordination of R&D efforts is needed Incentive mechanisms that ensure that results of innovation are affordable to patients and governments in developing countries We need a different Global Innovation System for TB
Thank you blessi.k@gmail.com