Interest Expense. Interest expense increased by $10.5 million, from $0.4 million for the three months ended June 30, 2024 to $11.0 million for the three months ended June 30, 2025. The increase was primarily attributable to interest expense under our royalty monetization liabilities, driven largely by an increase in forecasted Zolgensma royalties expected to be paid to HCR under the 2020 Royalty Purchase Agreement and interest expense incurred to date under the 2025 Royalty Bond issued in May 2025.
Comparison of the Six Months Ended June 30, 2025 and 2024
License and Royalty Revenue. License and royalty revenue increased by $68.3 million, from $37.2 million for the six months ended June 30, 2024 to $105.5 million for the six months ended June 30, 2025. The increase was primarily attributable to $70.0 million of upfront license revenue recognized under our collaboration with Nippon Shinyaku in the first quarter of 2025.
Service Revenue. Service revenue increased by $4.1 million, from $0.7 million for the six months ended June 30, 2024 to $4.9 million for the six months ended June 30, 2025. The increase was primarily attributable to $4.5 million of development service revenue recognized under our collaboration with Nippon Shinyaku in the first half of 2025.
Research and Development Expense. Research and development expenses increased by $8.9 million, from $103.7 million for the six months ended June 30, 2024 to $112.6 million for the six months ended June 30, 2025. The increase was primarily attributable to the following:
•an increase of $8.9 million in manufacturing-related expenses and other clinical supply costs for our lead product candidates, largely driven by ABBV-RGX-314 clinical supply and purchases of raw materials; and
•an increase of $2.0 million in personnel-related costs as a result of increased headcount of development personnel, net of a $1.7 million decrease in stock-based compensation expense.
The increase in research and development expenses was partially offset by a decrease of $2.7 million in overall costs for clinical trials, preclinical activities and other early-stage development.
General and Administrative Expense. General and administrative expenses increased by $3.1 million, from $37.1 million for the six months ended June 30, 2024 to $40.2 million for the six months ended June 30, 2025. The increase was primarily attributable to personnel-related costs for general and administrative personnel and professional services and consulting fees, including legal and other corporate advisory services.
Interest Expense. Interest expense increased by $17.1 million, from $2.4 million for the six months ended June 30, 2024 to $19.6 million for the six months ended June 30, 2025. The increase was primarily attributable to interest expense under our royalty monetization liabilities, driven largely by an increase in forecasted Zolgensma royalties expected to be paid to HCR under the 2020 Royalty Purchase Agreement and interest expense incurred to date under the 2025 Royalty Bond issued in May 2025.
Liquidity and Capital Resources
Sources of Liquidity
As of June 30, 2025, we had cash, cash equivalents and marketable securities of $363.6 million, which were primarily derived from the royalty monetization in May 2025 and the up-front payment received under the Nippon Shinyaku Collaboration Agreement in March 2025, each as described below, and the sale of our common stock and pre-funded warrants in March 2024. We expect that our cash, cash equivalents and marketable securities as of June 30, 2025 will enable us to fund our operating expenses and capital expenditure requirements, and are sufficient to meet our financial commitments and obligations, for at least the next 12 months from the date of this report based on our current business plan.
In May 2025, we entered into a loan agreement with HCR pursuant to which HCR will provide us with an aggregate limited recourse loan of up to $250.0 million (the 2025 Royalty Bond). The 2025 Royalty Bond is disbursable to us in three tranches, with $150.0 million funded on the closing date in May 2025, $50.0 million available to be funded if sales of a specified product exceed a specified sales threshold prior to December 31, 2026, and $50.0 million available to be funded if both parties exercise an option in 2027. Proceeds received from the initial funding tranche of the 2025 Royalty Bond in May 2025, net of discounts and transaction costs, were $144.5 million. The 2025 Royalty Bond matures in 2035, subject to potential extension, and bears interest at a rate of 9.75% plus the 3-month secured overnight financing rate as administered by the Federal Reserve Bank of New York (SOFR), with a minimum interest rate of 14.0%. Prior to the maturity date, interest and principal under the 2025 Royalty Bond shall be paid quarterly to HCR solely from proceeds received, net of upstream obligations to licensors, from certain specified royalties, milestone payments, license fees and other consideration payable to us under the Zolgensma license with Novartis Gene Therapies, the Nippon Shinyaku Collaboration Agreement and certain other NAV Technology Platform license agreements.