Contingent consideration - Additional Information (Detail)	12 Months Ended
	Jun. 30, 2023 AUD ($) Milestone	Jun. 30, 2023 EUR (€) Milestone	Jun. 30, 2022 AUD ($)	Jun. 30, 2022 EUR (€)
Disclosure of contingent liabilities [line items]
Milestone payments not booked	$ 492,703,722	€ 300,500,000	$ 456,063,136	€ 300,500,000
Milestone payment discount rate	20.00%	20.00%	15.00%	15.00%
Glioblast Pty Ltd [member]
Disclosure of contingent liabilities [line items]
Number of contingent milestone payments \| Milestone	4	4
Milestone Two [member]
Disclosure of contingent liabilities [line items]
Contingent consideration \| $	$ 1,250,000
Contingent consideration – EVT801 [Member]
Disclosure of contingent liabilities [line items]
Percentage of discount rate on milestone payments	7.00%	7.00%	6.00%	6.00%
Contingent consideration – EVT801 [Member] \| Milestone Three [Member]
Disclosure of contingent liabilities [line items]
Probability of milestone payments	100.00%	100.00%	100.00%	100.00%
Contingent consideration – EVT801 [Member] \| Milestone Four [member]
Disclosure of contingent liabilities [line items]
Probability of milestone payments	80.00%	80.00%	100.00%	100.00%
Contingent consideration – EVT801 [Member] \| Milestone Five [member]
Disclosure of contingent liabilities [line items]
Probability of milestone payments	63.00%	63.00%	100.00%	100.00%