150 years Chlorfenapyr: An important new tool for combatting insecticide resistance James W. Austin, PhD, BCE ASTMH: Combatting Resistance: New Approaches to Vector Control October 26, 2015

150 years Chlorfenapyr: Background 2 N-substituted halogenated pyrrole (CL303630) Commercialized as Pirate®, Stalker®, Phantom®, Mythic® and will be Sylando® for Public Health IRAC Group 13 (uncouplers)  MoA affects Respiratory Capability  Pro-insecticide Mixed-Function-Oxidases activate molecule…possibly manipulated? Non-Repellent!

150 years Pyrroles posit some unique attributes:  CFP is pro-uncoupler - ethoxyethyl protecting group is removed by N-dealkylation  No Cross Resistance with other insecticides  Sometimes negative cross resistance observed  Nonspecific MoA and pro-insecticide nature posit low resistance potentials  Not repellent to most targets; Mosquitoes not repelled after 24 h drying 3 Chlorfenapyr: Background

150 years + Outer membrane Inner membrane Matrix Intermembrane space Electron Transport Chain uses food energy to drive protons out of matrix Food + O 2 H2OH2O ADP ATP CO matrix Coupled – Protons drive ATP Synthase Uncoupler transports protons – No ATP made chlorfenapyr Protons – couple food oxidation to ATP production Removal of protecting group allows proton binding mitochondrion Protecting group ATP Synthase Proton flow drives ATP synthesis - Chlorfenapyr: Uncoupling of Mitochondrial Respiration

150 years Results: Chlorfenapyr molecule has shown least irritant effect against susceptible and resistant strains among all the insecticides tested allowing more landing time to the vector species on the impregnated surfaces to pick-up lethal dose. Conclusion: Chlorfenapyr could be an ideal insecticide for management of multiple-insecticide-resistance including pyrethroids. Chlorfenapyr: Non-Repellent Activity Source: Verma et al. (2015)J Vector Borne Dis 52, March 2015, pp. 99–103

150 years Confidential 6 Successful Trials Can be difficult to interpret:  Remember, Chlorfenapyr is a physiological toxin…. Physiological state of cohorts influences outcomes (e.g., lab vs wild strains) Testing modality is THE KEY here –What lab method best captures and supports field/hut studies (e.g., cone vs cylinders, vs tunnel assays) Reliance on conventional known paradigms (for testing) is problematic –Diagnostic doses may only be relevant to specific strains and conditions –Following WHOPES guidelines for neurotoxins is inconsistent for MoA –Cone assays, durations of exposure, post exposure recording, higher control mortality owed to longer post exposure intervals, understanding testing parameters of dual a.i.s in public health, etc. Chlorfenapyr: Testing considerations

150 years Source: Yuan (2015) Acta Tropica 143 pp. 13–17 Black et al. (1994) Pest. Biochem. Phys., 50, Chlorfenapyr: Testing considerations antagonistic synergistic

150 years % Mortality of Aedes aegypti susceptible 72h after exposure in cone bioassays to 250 mg/m 2 chlorfenapyr.at three different temperatures during exposure and holding time. Mortality influenced by holding time and temperature in lab bioassays; Field conditions less so Increased metabolic rates and enhanced monooxygenase activity at higher temperature generally posit greater mortality Temp effects reduced during scotophase due to elevated circadian rhythm (especially in field) Chlorfenapyr: Testing considerations Dose acquisition and uptake  Partitions between living and dead  Quantifying conversion (CL303268) in vitro metabolism studies  Induction by P450s  LSTM and BASF collaboration Additional studies were needed:

150 years Source: Oxborough et al. (2015) Malaria Journal 14:124 Chlorfenapyr: Testing considerations WHOPES methodology will not capture the real potential of non-neurotoxins well

150 years 10 Source: Oxborough et al. (2015) Malaria Journal 14:124 Chlorfenapyr: Testing considerations Physiological state is absolutely influential for observing the rate of intoxication

150 years 11 Interceptor G2 Mortality rates of An. gambiae sl collected in experimental huts with treatments Blood feeding rates of An. gambiae sl collected in experimental huts with treatments Chlorfenapyr*: Phase II LLIN Trials Burkina Faso Trials for Interceptor G2 Trials show: 1) Interceptor G2 outperformed positive control nets at this location, 2) Chlorfenapyr killed more wild resistant mosquitoes than standards, and 3) Blood feeding rates were similar for all nets (*mixture nets)

150 years Chlorfenapyr: conclusions Chlorfenapyr is a great repurposed tool which can complement existing malaria control programs Hut trials continue for chlorfenapyr used in LLINs and IRSs Collaboration with IVCC and other partners continue for optimization of chlorfenapyr’s utility in public health programs Future studies continue to identify opportunities and clarify limits to chlorfenapyr

150 years By The Numbers In 2013: 3.3 billion people in nearly 100 countries were at risk of being infected with malaria 198 million people contracted malaria globally 584,000 people died of malaria 90% of deaths caused by malaria were in Africa 78% of deaths were among children under the age of five Sources: malaria/publications/ world_malaria_report_2 014/en/ Image: BASF chlorfenapyr field trials, IRSS VK7 test site, Bobo-Dioulasso, Burkina Faso Malaria Thank You

150 years