CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2026	Dec. 31, 2025
Current assets:
Cash and cash equivalents	$ 47,451	$ 63,032
Short-term investments	47,620	114,648
Prepaid expenses	1,357	2,939
Other current assets	376	674
Total current assets	96,804	181,293
Property and equipment, net	17,077	20,572
Operating lease right-of-use assets	120,468	126,177
Restricted cash	13,691	13,691
Other assets	1,000	1,000
Total assets	249,040	342,733
Current liabilities:
Accounts payable	5,808	8,887
Accrued expenses and other current liabilities	8,978	12,600
Deferred revenue — related party	7,934	7,824
Operating lease liability	8,972	8,137
Total current liabilities	31,692	37,448
Deferred revenue, net of current — related party	56,033	58,127
Operating lease liability, net of current	103,506	108,290
Research and development funding liability	18,000	18,000
Total liabilities	209,231	221,865
Commitments and contingencies
Stockholders’ equity
Common stock, par value of $0.00001 per share; 775,000,000 shares authorized; 180,737,548 and 180,514,014 shares issued and outstanding as of June 30, 2026 and December 31, 2025, respectively	2	2
Additional paid-in capital	1,019,401	1,009,138
Accumulated other comprehensive (loss) income	(9)	82
Accumulated deficit	(979,585)	(888,354)
Total stockholders’ equity	39,809	120,868
Total liabilities and stockholders’ equity	$ 249,040	$ 342,733

Research And Development Funding Liability, Noncurrent

No definition available.

Name:	prme_ResearchAndDevelopmentFundingLiabilityNoncurrent
Namespace Prefix:	prme_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).