The AR-12 orphan drug status was based on application packages that included relevant data from pre-clinical models for each condition.
In the application regarding cryptococcosis, results of an animal model evaluating AR-12 showed a reduction in brain fungal burden in combination with fluconazole, while for tularaemia, results of an animal model assessing AR-12 showed improved survival in combination with gentamicin.
Arno Therapeutics chief executive officer Alex Zukiwski said: "Following positive recommendation by the EMA’s Committee for Orphan Medicinal Products, we are very pleased with the European Commission’s designation of AR-12 as an orphan drug to treat two infectious diseases that continue to affect people across the globe and for which new therapeutic options are needed.
"This designation marks an important milestone that supports Arno’s global regulatory and development strategy.
"We believe AR-12 has potential as a promising approach to address unmet medical needs of patients infected with cryptococcosis and tularaemia and look forward to further investigating AR-12 in these two disease areas."
The company said that preliminary data shows that the mechanism of action of AR-12 may include induction of host cell autophagy and inhibition of fungal acetyl coenzyme A synthetase.