Product Revenue, Net
The following table summarizes balances and activity for gross to net reserves (in thousands):
Chargebacks, Discounts for Prompt Pay and Other AllowancesRebates, Customer Fees/Credits, Co-Pay Assistance, and OtherTotals
Balance at December 31, 2023$— $— $— 
Provision related to sales in the current year8,045 35,115 43,160 
Adjustments related to prior year sales— — — 
Payments and customer credits issued(3,857)(13,412)(17,269)
Balance at December 31, 2024$4,188 $21,703 $25,891 
Provision related to sales in the current year36,640 208,462 245,102 
Adjustments related to prior year sales(1,573)(4,655)(6,228)
Payments and customer credits issued(30,417)(135,006)(165,423)
Balance at December 31, 2025$8,838 $90,504 $99,342 
Concentrations of Credit Risk and Significant Customers
The Company generates revenue from a small number of large, reputable customers. The following customers accounted for over 10% of total gross product revenue during the year ended December 31, 2025 and the year ended December 31, 2024. Rezdiffra was first made commercially available in April 2024, and therefore there were no sales and no corresponding customer concentrations in 2023.
Year ended December 31,
202520242023
Customer A
34 %39 %— %
Customer B
22 %21 %— %
Customer C
15 %14 %— %
Customer D
12 %12 %— %

About Revenue Disclosures

Revenue disclosures under ASC 606 explain how a company identifies performance obligations, allocates transaction prices, and determines when revenue is recognized. This section is essential for understanding whether reported revenue reflects genuine economic activity or aggressive accounting choices. Analysts examine the mix of point-in-time versus over-time recognition, which directly affects revenue timing and comparability.

Key signals: rising contract liabilities (deferred revenue) suggest strong future revenue visibility, while declining contract assets may indicate slowing project milestones. Watch for variable consideration estimates — rebates, returns, and performance bonuses that require management judgment. Significant changes in disaggregated revenue by geography or product line can reveal shifting business mix before it appears in headline numbers. Compare revenue growth against contract liability growth to assess sustainability, and scrutinize any changes in the timing of recognition that coincide with earnings pressure.