Thanks to the success of the Phase IIB trial, tafenoquine entered Phase III in April 2014, taking it closer to becoming the only new medicine approved for the treatment of relapsing malaria in over 60 years. Project Leader, Dr JP Kleim speaks about the partnership and what the future holds.
1. What was the biggest challenge you faced in the development of tafenoquine?
When GSK and MMV first began working together on tafenoquine, no one had successfully developed a drug for P. vivax since primaquine in the 1950s. So there really wasn’t any recent experience to guide us. Given the nature of relapsing malaria, one of the biggest challenges was the need for a long clinical follow-up. Patients in the Phase IIB trial were requested to come back for the last study assessment 6 months after the first study visit. For the trial to be successful, it was very important to ensure patients returned to the study centres, otherwise our primary efficacy analysis – the proportion of patients that were relapse free at 6 months – would have been jeopardized.
2. How did you ensure patients would return for follow-up in the Phase IIB trial?
By drawing on MMV’s network we were able to select appropriate clinical sites able to run the trial. GSK’s local presence ensured we had the operational support we needed. We placed a great deal of focus on the importance of patient retention and ensured everyone involved clearly understood this. Our efforts were certainly rewarded as 97% of patients returned for their 6 month visit. It was a remarkable MMV/GSK team achievement and really key to the successful completion of the Phase IIB trial.
3. MMV and GSK have been working together for a number of years on antimalarial research projects. What makes the partnership work so well?
Both GSK and MMV share the same view that malaria is one of the world’s deadliest diseases and that overcoming it requires a joint effort between the public and private sector. The partnership initially began in 2003 to work on a drug discovery “mini-portfolio”. At the time, it was a unique and ground-breaking agreement and it set the tone for collaboration on many other projects, including tafenoquine. There is a lot of synergy between the partners; both bring very different skills to the table. At GSK, we have the open lab in Tres Cantos, Spain, focused on drug discovery and a clinical development group in London, UK. But it’s really MMV that oversees the entire portfolio of investigational antimalarials. MMV has established governance and oversight committees of malaria and drug development experts that simply don’t exist anywhere else. Our senior review committees at GSK always take ESAC advice into consideration. Additionally, the expertise and network at MMV, spanning the public and private sectors as well as malaria-endemic regions, has been crucial to the progress of our efforts to tackle malaria. For tafenoquine, we look forward to continuing the successful partnership during the Phase III trial, which began in April 2014.