Primaquine has an indispensable role in malaria elimination as vivax radical cure and the transmission blocking of Plasmodium falciparum. Children are a key risk group for both malaria species and should be a priority group but there are currently no child-friendly primaquine formulations that comply with international standards. The latter is a Global Fund precondition for bulk purchase and global distribution to malaria control programmes.
To overcome this challenge, the DPP consortium (http://www.dpp-project.org) was formed from partners in France, Africa, the UK and IPCA, the drug manufacturer, to pool their multidisciplinary expertise and respond to the WHO call for prequalifying multiple strengths of child-friendly primaquine for field use. Accordingly, we are developing tablets strengths of 2.5, 3.75, 5 & 7.5 mg for maximum dosing flexibility.
Sensory studies have been performed in France and the UK to select optimal taste-masking excipients that mask primaquine`s bitterness, a key reason for poor treatment adherence. With this information, IPCA will improve the basic formulation and produce palatable tablets. In parallel, preliminary work is on-going to develop stable primaquine granules, another child-friendly option offering greater dosing flexibility over dispersible tablets.
Primaquine prequalification requires first the demonstration of bioequivalence of IPCA`s primaquine compared to the Sanofi reference primaquine (planned for 2022). Field trials to assess the safety, efficacy and acceptability of primaquine as radical cure and transmission blocking will follow.
We expect our paediatric primaquine tablets to be prequalified within the life of the project (by 2025) and this will be followed by registration in malaria endemic countries. Child-friendly primaquine is essential for malaria elimination and deployed quality-assured primaquine that children will take will be a substantial step forward.