Stockholders' equity - Schedule of warrants or rights (Detail) - $ / shares			3 Months Ended	12 Months Ended
	Apr. 22, 2024	Aug. 11, 2023	Jun. 30, 2025	Jun. 30, 2024
Outstanding, beginning of period				2,348,039
Pre-funded warrants issued	5,749,152
Purchase warrants expired			(6,300)
Outstanding, ending of period			20,443,496	34,271,146
Weighted Average Exercise Price, beginning of period				$ 8.86
Weighted average exercise price, Purchase warrants expired			178.5
Weighted Average Exercise Price, ending of period			$ 0.9672	$ 1.8453
Series 2 Warrants [Member]
Common warrants exercised			(1,553,927)	(98,039)
Pre-funded warrants exercised			$ 1.9299	$ 1.9299
Common warrants [Member]
Common warrants issued		16,002,175
Common warrants exercised			(10,192,840)	(738,187)
Common warrants issued		$ 3.86
Pre-funded warrants exercised			$ 3.86	$ 3.86
Pre-funded warrants [Member]
Pre-funded warrants issued		15,126,226
Common warrants issued			300,000
Pre-funded warrants issued	2,584,239
Common warrants exercised			(2,374,583)	(953,307)
Pre-funded warrants issued	$ 0.0001	$ 0.0001	$ 0.0001
Pre-funded warrants exercised			$ 0.0001	$ 0.0001