The evaluation of moxifloxacin for tuberculosis treatment shortening REMox Clinical Trial

st t Regimen: Streptomycin PAS Isoniazid 1957 Rifampin synthesized 1966 BMRC Trials - Addition of Rifampin 1980s Trials add Lower Dosage Pyrazinimide Trials Substitute Moxifloxacin into Regimen Pyrazinamide synthesized – liver toxicity Rx Lasts Up to 24 Months Rx Shortened to 9 Months Rx Shortened to 6 Months Rx Target: Months Current Treatment 2 Months: Rifampin, Isoniazid, Pyrazinamide, Ethambutol + 4 Months: Rifampin, Isoniazid Tuberculosis Treatment shortening

Moxifloxacin Drug Development in vitro Inhibits growth of mycobacteria - Gillespie, et al JAC 1999;44(3):393 Animal studies Bactericidal activity in mouse models - Miyazaki, et al AAC 1999;43(1):85, Nuermberger, et al AJRCCM 2003; 169:421 Human EBA studies Bactericidal activity in humans - Moshi, Tanzania - M alone for 5d vs H/R (Gosling, et al, AJRCCM 2003;168(11):1342) Phase 2 Clinical Trials M replacing E - ‘Study 27’ Burman WJ, et al AJRCCM 2006; 174(3):331-8; ‘JHU’ Conde MB, et al, Lancet 2009; 373 (9670):1183 M replacing H - ‘Study 28’ Dorman SE, et al AJRCCM 2009; 180(3):273 Phase 3 Clinical Trial REMox Clinical Trial (M replacing E/H (2 experimental arms) and shortened to 4 months versus standard 6 month treatment) Valerio J Chemo 2003 Use in clinical practise

Mexico Clinical site are sending sputum samples to Denver Cape Town and Stellenbosch Clinical sites are sending sputum samples to laboratory in Stellenbosch Westdene, Brits, Tembisa, Soweto 4 clinical sites are sending sputum samples to laboratory in Johannesburg India 28 clinical sites are sending sputum samples central laboratory in Delhi Thailand 2 clinical sites in Bangkok sending sputum samples central laboratory in Bangkok Kuala Lumpar Malaysia China 2 clinical sites in Beijing and Tianjin sending samples to laboratory in Tianjin Nairobi, Kenya Moshi, Tanzania Mbeya, Tanzania Lusaka, Zambia Durban 2 clinical sites (DICTU and CAPRISA) sending samples to central laboratory Nov 2005 EDCTP Grant Awarded Jun 2006 Collaboration with TB Alliance CRO Support Licensing Trial FDA Approval Sought Protocol Amendment, Second Phase III Arm Jan 2008 LUSAKA Cape Town, Stellenbosch Mbeya, Moshi Mexico, Johannesburg, Brits, Nairobi 2011 – Thailand, Malaysia, China and India ACTG sites – Durban, Johannesburg 1904 patients enrolled (target: 1900)

Study Evolution Ethics and regulatory approvals Drugs and packaging Protocol, working practice documents (SOPs), laboratory and quality manuals Database, CRFs and source proforma Local capacity development Site set-up, preparedness and local staff recruitment 5 Standardisation of practise – laboratory, clinical – across different sites, Different settings – standards of care Patient safety & Adverse Events Patient retention Study outcome definition

Trial Design & Primary Endpoints 1.Efficacy: Combined (by culture using solid media) failure of bacteriological cure AND relapse within one year of completion of therapy 2.Safety: Proportion of patients for whom adverse events of grade 3 or 4 are reported

Serious Adverse Events (n=144)

Serious Adverse Events Total (n=144) SAEs considered ‘possibly’, ‘probably’ or ‘definitely’ related to study drug (n=57) (30 – ‘unexpected’)

Abnormal liver function tests during TB treatment Asymptomatic increases in AST/ALT occur in nearly 20% of patients treated with ‘standard’ four-drug TB treatment - Most asymptomatic increases resolve spontaneously Severe hepatitis and fulminant liver failure can occur More likely with preexisting abnormalities Attributable to isoniazid, rifampicin, pyrazinamide, moxifloxacin - Combination therapy more complicated Study Protocol – Exclusion of patients with abnormalities at screening – Blood tests for liver function monitored Weeks 2, 4, 8, 12, 17 Any other visit the clinician suspects derangement of liver function – Clinical assessment at every study visit

ParameterReported hepatotoxicity events Total study (patients to w8) Total Female39%31% Age19-75 (median 35)17-81 (median 30) HIV positive12%9% - CD (median 34) (median 399) COUNTRY India South Africa Other African sites Malaysia/Thailand 28% (19) 51% (35) 4% (3) 16% (11) 15% (234) 52% (803) 21% (321) 11% (176) Onset timeScreening to week 45 (median week 6) NA

re·lapse (r-lps) n [rɪˈlæps ˈriːˌlæps]1. the act or an instance of relapsing 2. (Medicine) the return of ill health after an apparent or partial recovery[from Latin relabī to slip back, from RE - + labī to slip, slide] Patients with recurrence or persistence of symptoms and signs / culture of TB at or after treatment completion – laboratory error – duration of follow up – new infections – strain ‘evolution’

Relapse - What proportion are the same strain? Citation & Location MethodSAME STRAINSAME STRAIN – HIV negative Narayanan 2010 – Chennai, South India IS6110 RFLP Spoligotyping MIRU-VNTR 50% (24)21/23 (91%) Crampin Malawi IS6110 RFLP66% (26)15/16 (94%) Charalambous South Africa (miners) IS 6110 RFLP74% (31) Shamputa Bangladesh Spoligotyping, IS6110 RFLP, MIRU-VNTR 86% (30)

How is treatment failure/relapse defined in this study? Microbiology - Confirmed positive culture that is shown to be identical to the infecting strain at – End of treatment – During follow up UCL IS6110 RFLP MIRU-VNTR Sanger Centre genome sequencing DNA extracted from baseline/relapse samples

Defining study endpoints –success / failure Importance of ‘hard’ endpoints – bacteriological Clinical management in the context of a clinical trial – when to worry? Study treatment duration 4-6 months - blinded – When is the end of treatment sample? ‘Routine’ samples not usually taken Positive smear/culture Imperfect indication of clinical failure/ need for re-treatment – confirmatory sample – clinical findings - Repeat assessment

Relapse - What proportion are the same strain? Citation & LocationMethodSAME STRAINSAME STRAIN – HIV negative Narayanan 2010 – Chennai, South India IS6110 RFLP Spoligotyping MIRU-VNTR 50% (24)21/23 (91%) Crampin Malawi IS6110 RFLP66% (26)15/16 (94%) Charalambous South Africa (miners) IS 6110 RFLP74% (31) Shamputa 2007 – Bangladesh Spoligotyping, IS6110 RFLP, MIRU-VNTR 86% (30) REMox TB so far… MIRU-VNTR55% (22)52%

In this study… TOTALReinfectionRelapse HIV negative2948%52% HIV positive1136%64% TOTAL4045%55%

MIRU-VNTR method Mycobacterial interspersed repetitive units (MIRU) are mini-satellites which contain variable numbers of tandem repeats 41 MIRU loci have been identified in M.tb some of which vary in tandem repeat numbers between different strains PCR based method that uses length variation at the different loci to distinguish between different strains VNTR regions are amplified using primers specific for the flanking regions of the VNTRs Relative lengths of the VNTRs are determined by gel electrophoresis 12, 15, 24 loci have been used Confounding – strain evolution, contamination