In 2009, evidence of resistance to artemisinin (ACT) was reported. Initially in the Thai-Cambodia border region, and now increasingly in Southeast Asia, ACTs are taking longer and longer to clear the parasite from patients. One of our phase III studies showed that while the prescribed ACT still has the same efficacy (a 98% cure rate in this study), it took 72 hours to clear the parasite from the patient, when a few years ago, it took only 30 hours. This longer parasite clearance time is a clear warning that we urgently need new classes of antimalarials beyond ACT.
MMV's first step is to determine whether resistance is only to artemisinin, or whether all artemisinin-like molecules (i.e. endoperoxides) in our pipeline are compromised. We are currently working in collaboration with Oxford University to test OZ439, a non-artemisinin-based endoperoxide, in clinical trial sites involved in the TRAC (Tracking Resistance to Artemisinin Collaboration) initiative. If these studies are successful and demonstrate OZ439's efficacy in resistant zones, we could have a new combination therapy in place of ACTs available for patients in 5 years' time. MMV also has a number of other new compounds in its pipeline that hold promise of becoming next-generation non-endoperoxide-based antimalarials.