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This article discusses the progress and challenges in TB drug research and development (R&D), including the limited number of compounds in the pipeline, chronic under-funding, and bottlenecks in both research and clinical trial capacity. It also highlights the need for increased engagement from the private sector and improved access to tools and expertise for academic scientists. The article concludes with a proposal to address these challenges and boost TB drug R&D.
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PROGRESS & MAIN CHALLENGES IN TB DRUG R&D Expert consultation Geneva 11 Apr 2008 Martina Casenghi, PhD Biologist
An improved landscape for TB drug R&D Establishment of TB Alliance in 2000-Associated approximately with half of projects in the pipeline Few multinational Pharma companies (Novartis, GSK, AstraZeneca, Eli-Lilly, Sanofi Aventis, J&J, Pfizer) engaged in R&D for anti-TB drug on a “no-profit-no-loss” basis Several other small-middle size Pharma companies -i.e. Otsuka, Lupin, Chiron, FasGen, Sequella etc.- engaged in R&D for anti-TB drug TB Alliance strategy for identification of novel compounds -shortening of treatment -active against MDR-TB -no interactions with ARVs
DISCOVERY (STOP TB WG on new Drugs Annual Meeting, Cape Town Nov 2007)
HIV drug preclinical pipeline: ~ 100 compounds! (TAG report http://www.aidsinfonyc.org/tag/tx/pipeline2006a.html) Pre-clinical (STOP TB WG on new Drugs Annual Meeting, Cape Town Nov 2007)
HIV drug clinical pipeline: ~ 30 compounds! (TAG report http://www.aidsinfonyc.org/tag/tx/pipeline2006b.html) Clinical Development (STOP TB WG on new Drugs Annual Meeting, Cape Town Nov 2007)
Limitations of current pipeline • Approximately 40 compounds in the pipeline-That’s not enough • In average in a drug discovery program for anti-infectives only 1 compound in 20 makes it (Payne et al., 2007) • Glickman et al. (Glickman et al., Science 2006): • likelihood of introducing at least one successful anti-TB drug by 2010 is < 5% • likelihood to introduce a novel regimen with at least 2 new drugs by 2015 is < 1%
Chronic under-funding Problem of chronic under-funding - 2006 funding to TB R&D= $400 M - 5 fold increase funding necessary to meet targets of Global Plan C. Feur, Nov 2007, TB R&D: a critical analysis of funding trends 2005-2006. Treatment Action Group
Critical bottlenecks in TB drug R&D Gaps in the TB drug R&D pipeline: -MSF/Weill Cornell Medical college supported symposium to discuss roadblocks and possible solutions (Jan 2007) RESEARCH: • Drug Discovery DEVELOPMENT: • Clinical Trial Capacity • Accelerate TB drug development -Test new drugs in MDR-TB patients -need for reliable biomarkers that correlates with clinical cure
DRUG DISCOVERY Academia Basic science: identification molecular pathways essential for bacterial survival Lead to preclinical candidate Pre-clinical development Clinical Trials Early discovery Hit to lead Target identification Target validation Biotech and Pharma companies Preclinical and Clinical development Drug candidate Validated hits Leads Inhibitors drug Phenotypic screenings
Filling the TB drug pipeline THE PROBLEM: A) TB drug R&D too risky from a commercial perspective limited engagement from private sector Drugs Pharma companies DALYs (MSF TB drug pipeline report, Oct 2006) - Small number of compounds in the pipeline is reflected by low number of Pharma companies involved in TB R&D
Filling the TB drug pipeline THE PROBLEM: B) Academic scientists carry out drug discovery projects but in sub-optimal conditions because of: • ACCESS TO TOOLS & EXPERTISE BARRIER Lack of access to: -appropriate compound libraries -screening facilities -medicinal chemistry and pharmacology expertise 2) FUNDING BARRIER: limited access to funding streamlines to run applied research projects C) TB Alliance had limited capacity to impact early stage drug discovery
Academia Basic science: identification molecular pathways essential for bacterial survival TB Alliance Target identification ? Target validation Preclinical and Clinical development Drug candidate Validated hits Leads Inhibitors drug Biotech and Pharma companies
Filling the TB drug pipeline PROBLEM PERSIST DESPITE THE CONTRIBUTION OF RECENT INITIATIVES: - NIH/NIAID funded facilities for compound screenings (TACCF) and comprehensive target validation (TARGET) • Gates foundation funded projects a) Grand Challenges for Global Health # 11 “Drugs for treatment of latent TB infection” : grant awarded in 2005, $20M b) TB drug Accelerator: launched beginning of 2006, $40M over 2 years • EU funded New Medicines for TB (NM4TB) project (about 10 M euro over 5 years) • TB drug R&D facilities established by few multinational companies (often represent private partner of grant funded consortia)
Filling the TB drug pipeline MAJOR CHALLENGE THAT THESE RECENT INITIATIVES HAVE TO FACE: • Run drug discovery projects on a VIRTUAL basis • Big consortia, collaborators spread all over the world-coordination is a challenge Certainly helpful contributions but NOT able to trigger the substantial boost in TB drug R&D that is necessary
Filling the TB drug pipeline PROPOSAL EMERGED at the MSF TB drug symposium (Jan 2007): (Nathan, Nat. Med 2007)
Critical bottlenecks in TB drug R&D RESEARCH: • Drug Discovery DEVELOPMENT: • Clinical Trial Capacity
Clinical Trial capacity gap THE PROBLEM: -Clinical Trials need to be performed in high burden countries - High-burden countries have poor capacity to run clinical trials conforming to international guidelines (ICH/GCP and GLP) • CLINICAL TRIAL CAPACITY: • Infrastructures (lab and health facilities adequate to run research projects conforming to international standards) • Trained personnel • Functioning Institutional review boards/ethics committees • Regulatory guidance at national level
Clinical Trial capacity gap • BUILDING of CLINICAL TRIALS CAPACITY in HIGH BURDEN COUNTRIES: (Schluger et al., PLoS Med. 2007): • -Currently, specific funding for clinical trials capacity building is tied to individual drugs in the pipeline • Important to make direct investments in the infrastructure rather than taking a product-by-product approach • Big funding gap: • 2005 worldwide expenditures in clinical trials= US $20-30M • Experts estimation of needed funding= US$ 300-US$500M annually
CONCLUSIONS • TB DRUG R&D landscape significantly improved in the last 10 years • Current approaches and initiatives represent useful contribution to revitalize the field BUT they are NOT sufficient to: • ensure the creation of a sustainable pipeline • ensure the delivery of new products with timeframes that reflect the urgency of the situation • Alternative mechanisms and approaches to fund and organize R&D activities are required if we want to trigger a real change that can radically solve the problem
CONCLUSIONS (Nathan, Nat. Med 2007)