OVERVIEW, BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Concentration of Revenue (Details) - Sales - Customer Concentration Risk	3 Months Ended		9 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Concentration Risk [Line Items]
Concentration risk, percentage	33.20%	84.80%	57.30%	80.30%
Loxo Oncology
Concentration Risk [Line Items]
Concentration risk, percentage	0.00%	3.60%	22.70%	5.90%
Pierre Fabre
Concentration Risk [Line Items]
Concentration risk, percentage	19.00%	9.20%	19.90%	10.60%
Novartis Pharmaceutical
Concentration Risk [Line Items]
Concentration risk, percentage	14.20%	37.30%	14.70%	47.20%
ASLAN
Concentration Risk [Line Items]
Concentration risk, percentage	0.00%	34.70%	0.00%	16.60%