Presentation Plan. Abbreviations. Before A Lao technician said in 2000: 9/02/10

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1 Clinical and Laboratory Assessment of Antimalarial Drug Efficacy in the Lao P.D.R 1. Introduction Presentation Plan 2. Studies conducted before 2 (in-vivo) 3. Studies after 2: - In-vitro study - Molecular study - Clinical trials Abbreviations CQ = Chloroquine SP = Fansidar QN = Quinine A = Artesunate M = Mefloquine AL = Artemether-lumefantrine (Coartem) DP = Dihydroartemisinin-piperaquine (Artekin) Before 25 Malaria: important cause of morbidity & mortality in Laos (Prevalence ~ 14%) Chloroquine (CQ) & sulfadoxine-pyrimethamine (SP): did not work anymore in neighboring countries A Lao child with severe malaria But CQ & SP: Lao nationally recommended antimalarials for treatment of uncomplicated malaria! A Lao technician said in 2:..in Laos, chloroquine still works OK and there is no resistance of malaria parasites. If you don t believe me, let s see in your study. Efficacy of Antimalarial Drugs in Laos before 2 1. Ebisawa et al., 197 (Japan J Exp Med 4: ) - Antimalarial drugs: CQ, SP, QN + SP - Nam-Ngum dam, Vientiane (1968); N = 18 Results CQ SP QN+SP (n=64) (n=26) (n=18) Sensitive 59 (92%) 25 (96%) 18 (1%) RI 5 (8%) 1 (4%) 1

2 2. AL Tawil, 1977 (Bull WHO: ) - Antimalarial drug: CQ - Nam-Ngum dam, Vientiane ( ) - N = 48 (follow up: 7 days) Results Sensible = 28 (58%) RI = 8 (17%) RII = 1 (21%) RIII = 2 (4%) 42% 3. Giboda et al., 1992 (Southeast Asian J Trop Med Pub Hlth 23: ) - Antimalarial drug: CQ - Nam-Ngum dam, Vientiane (1989) - N = 15 (1 days of follow up?) Results Sensitive = 9 (6%) RI = 2 (13%) RII = 2 (13%) RIII = 2 (13%) 4% 4. Pillai et al., 21 (JID 183: ) - Antimalarial drug: CQ (28 days DOT) - Vangvieng District, Vientiane ( ) - N = 39 Results Sensitive = 21 (54%) RI = 5 (13%) RII - RIII = 13 (33%) 46% 5. Guthmann et al., 22 (Ann Trop Med Parasitol 96: 553-7) - Antimalarial drug: CQ (28 days DOT) - Sekong Province (1999-2) - N = 88 Results ARC = 53 (6%) ETF = 6 (7%) LTF = 29 (33%) 4% Centre of Malariology, Parasitology & Entomology (CMPE), Ministry of Health, Laos CMPE - LAOS Station of Malariology, Parasitology & Entomology, Savannakhet Provincial Health, Laos FEUANG PHALANXAY XEPON 2

3 Effects (parasite killing) E max EC ng/ml Log drug concentrations In vitro antimalarial susceptibility patterns of P. falciparum malaria in Laos (Phanlanxay District, Savannakhet 23-24) P. falciparum isolates defined as resistant (N = 18): Chloroquine 65 % Quinine 4 % Mefloquine 8 % (Mayxay et al., 27: Am J Trop Med Hyg 76:245-5) - Blood spots collected on filter papers - DNA extraction - PCR to study gene mutation Target of drug Normal gene (DHFR) 18 Serine Enzyme structure Mutation of gene (DHFR) 18 Asparagines Target of drug Change of enzyme structure 3

4 Distribution of P. falciparum molecular markers associated with SP & CQ in Laos Collaboration with Dr. Tim Anderson, Texas, USA Countrywide survey ~884 blood spot samples on Namtha n = 23 Bokeo n = 12 Xayabuly n = 6 Udomxai n = 12 Phongsaly n = 2 Vientiane n = 27 Phabang n = 36 Special zone n = 1 Xiengkhuang n = 4 Huaphan n = Dhfr gene mutation in parasites (resistant to P) from 17 provinces of Laos Borikhamxai n = 11 No resistance mutations 1 mutation 2 mutations 3 mutations 4 mutations filter paper from 17 provinces Molecular markers: PfDHFR & DHPS, PfCRT Vientiane Capital (no malaria transmission) (Mayxay et al., 27: Am J Trop Med Hyg 77: 36-43) Khammuan n = 16 Savannakhet n = 392 Saravan n = 33 Xekong n = 28 Champasack Attapeu n = 33 n = 24 Namtha n = 23 Bokeo n = 12 Xayabuly n = 7 Udomxai n = 15 Phongsaly n = 2 Vientiane n = 29 Phabang n = 35 Special zone n = 1 Xiengkhuang n = 4 Huaphan n = Borikhamxai n = 1 Dhps gene mutation in parasites (resistant to S) from 17 provinces of Laos No resistance mutations 1 mutation 2 mutations 3 mutations 4 mutations Namtha n = 53 Bokeo n = 14 Xayabuly n = 7 Udomxai n = 23 Phongsaly n = 2 Vientiane n = 47 Phabang n = 39 Special zone n = 1 Xiengkhuang n = 7 Huaphan n = 3 Borikhamxai n = 12 pfcrt 76-allele frequency in parasites (resistant to CQ) from 17 provinces of Laos 76-K (Wild type) 76-T (Mutant type) Vientiane Capital (no malaria transmission) Khammuan n = 21 Vientiane Capital (no malaria transmission) Khammuan n = 25 (Mayxay et al., 27: Am J Trop Med Hyg 77: 36-43) Savannakhet n = 416 Saravan n = 34 Xekong n = 27 Champasack Attapeu n = 31 n = 18 (Mayxay et al., 27: Am J Trop Med Hyg 77: 36-43) Savannakhet n = 452 Saravan n = 49 Xekong n = 36 Champasack Attapeu n = 41 n = 25 Distribution of P. falciparum molecular markers associated with SP & CQ resistance in Laos Countrywide (884 blood spot samples on from 17 provinces) Molecular markers: pfdhfr & pfdhps; pfcrt Proportion of mutation: Pf-dhfr (resistant to pyrimethamine): 77% with >1 mutations (164 frequency = 6%) Pf-dhps (resistant to sulphadoxine): 21% with >1 mutations Pf-crt (resistant to chloroquine): 85% with 76T mutations - Patients take antimalarial drugs - Follow up (7, 14, 28, 42, 63 days) - Assessment: Cure rate Fever clearance time Parasite clearance time (Mayxay et al., 27. Am J Trop Med Hyg 77: 36 43) 4

5 Therapeutic Efficacy of Chloroquine plus Sulphadoxine/Pyrimethamine Compared with Monotherapy with Either Chloroquine or Sulphadoxine/ Pyrimethamine in Uncomplicated Falciparum Malaria in Laos (Schwobel et al., 21. Trop Med Intl Health 8: 19-24) Attapeu Province (14 day-follow up) N = 17 Results CQ SP CQ+SP MQ (n=29) (n=28) (n=24) (n=26) ACR 16 (55%) 23 (82%) 2 (83%) 26 (1%) ETF 3 (1%) 1(4%) 1(4%) 45% 18% 17% LTF 1 (35%) 4 (14%) 3 (13%) Follow up of patient at home COMPARISON OF PARASITE CLEARANCE TIMES 3 Days PCT - Mean (SD) 2 1 CQ + SP AM AL Significant difference compared to other two groups P <.1 5

6 FCT - Mean (SD) COMPARISON OF FEVER CLEARANCE TIMES 5 Hours GAMETOCYTAEMIA AFTER TREATMENT % /11 (25.5%) 4/11 (3.6%) 5/11 (4.5%) CQ + SP AM AL Significant difference compared to other two groups P <.1 CQ + SP AM AL Significant difference compared to the other two groups (P <.1) PROBABLE SIDE EFFECTS AFTER TREATMENT Neuro-psychiatric AM Significant difference from CQ+SP other groups AL % (Mayxay et al., 26: Trop Med Intl Health 11: ) 6

7 COMPARISON OF PARASITE CLEARANCE TIMES 3 Days COMPARISON OF FEVER CLEARANCE TIMES Hours PCT - Mean (SD) 2 1 FCT - Mean (SD) Checking body temperature AM DP P =.14 AM DP P =.85 PROBABLE SIDE EFFECTS AFTER TREATMENT AM Significant difference AK between groups (P <.5) But the problem is Chinese GMP vs ICH GMP % A Phase III, randomized, non-inferiority trial, to assess the efficacy and safety of Dihydroartemisinin+Piperaquine (DHA +PPQ, Artekin) in comparison with Artesunate+Mefloquine (AS+MQ) in patients affected by acute, uncomplicated Plasmodium falciparum malaria in Asia 7

8 Treatment outcome (63 days follow up) (Mayxay et al., in preparation) Side Effects After Treatment % patients with at least one recorded potential side effect was significantly higher in AM [43/98 (44%)] compared to DP [64/22 (32%)] groups (P =.39). Incidence of post treatment dizziness, nausea, insomnia, and anorexia were all significantly higher in AM compared to DP recipients (P <.1). CONCLUSION: DP is not inferior to AM in the treatment of uncomplicated falciparum malaria in southern Laos and was associated with fewer adverse effects. Median (range) Conclusions 1. Chloroquine & sulphadoxine-pyrimethamine are not longer efficacious for the treatment of uncomplicated falciparum malaria in Laos 2. Artemisinin combination therapy (artesunate + mefloquine, artemether lumefantrine or coartem, dihydroartemisinin-piperaquine or artekin): work very well in Laos STUDY TEAM Mayfong Mayxay Samlane Phompida Siamphai Keola Paul N Newton Rattanaxay Phetsouvanh Ratsuda Yapom Nicholas J White Maniphone Khanthavong Anna Annerberg Alan Brockman Tiengkham Pongvongsa Kasia Stepniewska Niklas Lindegardh Vonthalome Thongpaseuth Shalini Nair Marion Barends Bouakham Vannachone Tim Anderson ACKNOWLEDGEMENTS Vanphanom Sychareun Souksavanh Bouachanh Syvoraphanh Stephane Proux Francois Nosten Kai-Amphon Keopasert Pitta Odai Xaisithideth Chanthala Vilaihong Phomma Manisack Phommasansack Bounpon Bangthon Thonglien Singnort Vilayphone Minit Bounmy. Wellcome Trust of Great Britain Lao children after malaria treatment 8