PRODUCT REVENUES, NET, ACCOUNTS RECEIVABLE,NET AND RESERVES FOR PRODUCT REVENUES (Tables)

12 Months Ended

Dec. 31, 2023

Receivables, Net, Current [Abstract]

Summary of Product Revenues

Net product revenues, which includes revenues associated with EXONDYS 51, AMONDYS 45 and VYONDYS 53 (collectively, the “PMO Products”) and ELEVIDYS consisted of the following:

	For the Year Ended December 31,
	2023		2022
	(in thousands)
PMO Products
United States	$	797,944	$	747,101
Rest of World		146,576		96,668
Total PMO product revenues, net	$	944,520	$	843,769
ELEVIDYS
United States		200,356		—
Total ELEVIDYS product revenues, net	$	200,356	$	—
Total product revenues, net	$	1,144,876	$	843,769

Schedule of Product revenue Concentration risks

The following table summarizes the Company's net product revenues, by customer, for those customers that exceeded 10% for the periods indicated:

	For the Year Ended December 31,
	2023			2022			2021
Product revenues, net
Customer 1		41	%		48	%		48	%
Customer 2		26	%		33	%		39	%
Customer 3	*			*				10	%

* Customer did not exceed 10% of the Company's net product revenues within the applicable year.

Summary of Change in Reserves for Discounts and Allowances

The following table summarizes an analysis of the change in reserves for discounts and allowances for the periods indicated:

	Chargebacks			Rebates			Prompt Pay			Other Accruals			Total
	(in thousands)
Balance, as of December 31, 2021	$	799		$	60,506		$	2,798		$	6,363		$	70,466
Provision		12,446			108,514			12,904			47,654			181,518
Adjustments relating to prior year		—			(5,679	)		—			30			(5,649	)
Payments/credits		(12,828	)		(95,848	)		(12,359	)		(30,602	)		(151,637	)
Balance, as of December 31, 2022	$	417		$	67,493		$	3,343		$	23,445		$	94,698
Provision		44,191			129,724			15,067			69,664			258,646
Adjustments relating to prior year		536			(5,103	)		—			—			(4,567	)
Payments/credits		(17,658	)		(93,920	)		(14,579	)		(57,848	)		(184,005	)
Balance, as of December 31, 2023	$	27,486		$	98,194		$	3,831		$	35,261		$	164,772

Summary of Total Reserves Included in Consolidated Balance Sheets

The following table summarizes the total reserves above included in the Company’s consolidated balance sheets for the periods indicated:

	As of December 31,
	2023		2022
	(in thousands)
Reduction to accounts receivable, net	$	64,697	$	25,914
Component of accrued expenses		100,075		68,784
Total reserves	$	164,772	$	94,698