In 2017, Kvasina was given a four-year doping suspension after a positive drugs test at that year's Flèche du Sud.

[1] Born in Nova Gradiška, Kvasina was named by Synergy Baku as part of their squad for the 2016 season.

Molidustat represents a class of drugs that act on the same physiological pathways and enzyme cascades as those which are activated during altitude training.

Under normal oxygen environmental conditions, HIF is kept in check (its actions are inhibited) by an enzyme called prolyl hydroxylase (PH).

Moldustat stops PH from blocking HIF, thus, increasing both the concentrations of EPO and red blood cells in the body, imitating altitude training.