2. Summary of Significant Accounting Policies (Tables)

9 Months Ended

Jan. 31, 2020

Accounting Policies [Abstract]

Disaggregation of revenue

	Three Months Ended January 31,				Nine Months Ended January 31,
	2020		2019		2020		2019
Manufacturing revenue	$	11,525	$	10,770	$	40,422	$	28,313
Process development revenue		2,060		3,011		6,730		8,235
Total revenues	$	13,585	$	13,781	$	47,152	$	36,548

Schedule of Restricted Cash

	January 31, 2020		April 30, 2019		January 31, 2019		April 30, 2018
Cash and cash equivalents	$	30,687	$	32,351	$	27,758	$	42,265
Restricted cash		350		1,150		1,150		1,150
Total cash, cash equivalents and restricted cash	$	31,037	$	33,501	$	28,908	$	43,415

Schedule of property and equipment

	January 31, 2020			April 30, 2019
Leasehold improvements	$	21,130		$	20,574
Laboratory and manufacturing equipment		14,968			12,858
Computer equipment and software		4,931			4,644
Furniture, fixtures and office equipment		685			528
Construction-in-progress		1,963			1,590
Total property and equipment, gross	$	43,677		$	40,194
Less: accumulated depreciation and amortization		(16,827	)		(14,569	)
Total property and equipment, net	$	26,850		$	25,625