Type these words into Google. "Filariasis + DEC + World Health Organisation"
The pages full of hits that will show up relate to treatment of native tribes in remote areas of third world countries.
Therefore these studies show the dosing to only be done once and then again one week later at the most.
There are a myriad of studies online that follow these individuals up a year later.
None of them are therefore relevant to providing information on possible cure rates when the patient and the medication are available
daily and consistently.