Extended Data Figure 3. In vivo blood-stage efficacy study of BRD7929.

a, BRD7929 shows single-dose in vivo efficacy in a P. berghei model of malaria. CD-1 mice were inoculated intravenously with approximately 2 × 10⁷ P. berghei (ANKA GFP-luc) blood-stage parasites intravenously 24 h before treatment and BRD7929 was administered as a single 50, 25, or 12.5 mg kg⁻¹ dose orally at 0 h (n = 4 for each group, this study was conducted once). Infections were monitored using IVIS. A single 100 mg kg⁻¹ dose of artesunate results in rapid suppression of parasites, but owing to its short half-life, the parasites re-emerge very quickly. A single 25 mg kg⁻¹ dose of BRD7929 resulted in 100% cure of the infected animals. One in four animals treated with a single oral dose of 12.5 mg kg⁻¹ showed recrudescence at 6 days after treatment, but all other animals administered with 12.5 mg kg⁻¹ were also completely parasite-free for 30 days. To ensure that no viable parasites remained, approximately 100 µl of combined blood samples from the four animals treated with 25 mg kg⁻¹ of BRD7929 was intravenously injected into two naive mice and parasitaemia was monitored for an additional 30 days. No parasites were detected, suggesting that BRD7929 achieved a sterile cure for P. berghei with a single oral dose of as low as 25 mg kg⁻¹. The same colour scale is used for the all images; not all time-point images are shown here. b, Bioluminescent intensity was quantified from each mouse and plotted against time. The dotted horizontal line represents the mean bioluminescence intensity level obtained from all the animals before the parasite inoculation. c, BRD7929 shows single-dose in vivo efficacy in a P. falciparum huRBC NSG mouse blood-stage model. huRBC NSG mice were inoculated intravenously with approximately 1 × 10⁷ P. falciparum 3D7^HLH/BRD blood-stage parasites 48 h before treatment and BRD7929 was administered as a single 50, 25, 12.5 or 6.12 mg kg⁻¹ dose orally at 0 h (n = 2 for each group, this study was conducted once). Infections were monitored using the IVIS. No recrudescence was observed at doses as low as a single 12.5 mg kg⁻¹ of BRD7929 in the infected animals. To ensure that no viable parasites remained, approximately 350 µl of combined blood samples from the two animals treated with 12.5 mg kg⁻¹ of BRD7929 was cultured in vitro and monitored for an additional 30 days. No parasites were detected, suggesting that BRD7929 achieved a sterile cure for P. falciparum 3D7^HLH/BRD with a single oral dose as low as 12.5 mg kg⁻¹ (see Fig. 4a). The same colour scale is used for the all images; not all time point images are shown. Images of mice treated with vehicle on days 11 and 20 are not shown, because the bioluminescent signal was too high to show in the same colour scale as other images.