In March 2009, the Company entered into a license agreement, which was amended in April 2009 (as amended, the GSK License), with GlaxoSmithKline LLC (GSK) for exclusive, worldwide rights to certain patents underlying the Company’s NAV Technology Platform which are owned by The Trustees of the University of Pennsylvania (Penn) and exclusively licensed to GSK. Pursuant to the GSK License, the Company is obligated to pay GSK royalties on net sales of licensed products and sublicense fees.

Additionally, the Company is obligated to reimburse GSK for certain costs incurred related to the maintenance of the licensed patents. The Company was also obligated to pay $1.5 million to GSK upon the achievement of various milestones, all of which have been achieved and paid.

Expenses incurred by the Company related to the GSK License were recorded as follows (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2026		2025		2026		2025
Cost of license and royalty revenues:
Royalties on net sales of Zolgensma and Itvisma	$	760	$	5,204	$	1,809	$	7,786
Settlement payment		—		—		10,000		—
Other		136		5		140		243
Total cost of license and royalty revenues		896		5,209		11,949		8,029
General and administrative		48		53		79		107
	$	944	$	5,262	$	12,028	$	8,136

As of June 30, 2026 and December 31, 2025, the Company had recorded $0.9 million and $5.7 million, respectively, payable under the GSK License.

The Company was notified of a dispute with GSK over the amount of sublicense fees paid by the Company to GSK under the GSK License. GSK claimed there had been a significant underpayment by the Company with respect to sublicense fees. In February 2026, the Company and GSK engaged in non-binding mediation regarding the dispute. In March 2026, the Company and GSK entered into a settlement and release agreement (the GSK Settlement Agreement) to resolve the matter. The GSK Settlement Agreement provides for the mutual release of all past claims and certain future claims by the parties under the GSK License. Pursuant to the GSK Settlement Agreement, the Company paid $10.0 million to GSK in March 2026, which was recorded as cost of license and royalty revenues in the first quarter of 2026. Additionally, the Company will continue to pay sublicense fees to GSK on license fees earned under existing sublicense agreements, utilizing the Company's historical allocation methodologies for such sublicense payments.

In February 2026, a putative securities class action complaint was filed by Andre Kuik (Kuik) against the Company and certain of its current officers and directors in the United States District Court for the District of Maryland. The complaint asserted claims under Sections 10(b) and 20(a) of the Securities Exchange Act of 1934 and Rule 10b-5 promulgated thereunder, on behalf of a putative class of persons who purchased or otherwise acquired the Company's securities during the period from February 9, 2022 through January 27, 2026. The complaint alleged that the Company misled investors concerning the viability and safety of RGX-111, and that the Company's stock price declined following the announcement of the clinical hold imposed by the U.S. Food and Drug Administration (FDA) on the Company’s RGX-111 program on January 28, 2026. In August 2026, an amended complaint was filed focusing on interactions with FDA and Company statements prior to the Company’s receipt of a Complete Response Letter for RGX-121 in February 2026. The amended complaint asserts claims under Sections 10(b) and 20(a) of the Securities Exchange Act of 1934 and Rule 10b-5 promulgated thereunder, on behalf of a putative class of persons who purchased or otherwise acquired the Company's securities during the period from February 7, 2024 through March 3, 2026. The plaintiff seeks unspecified compensatory damages, attorneys' fees, expert fees and other costs, and other relief as the court may deem just and proper. The Company believes that it has meritorious defenses to the claims asserted and intends to vigorously defend against them. The Company does not believe that a loss is probable, and no reasonable range of loss is estimable, related to this matter. No liabilities related to this matter were recorded as of June 30, 2026.

In March 2026, a purported stockholder derivative complaint, as revised, was filed by plaintiff Roberto Medina (Medina) against the Company as nominal defendant and certain of its current officers and directors in the United States District Court for the District of Maryland. The complaint alleges breach of fiduciary duty and claims of unjust enrichment, abuse of control, gross mismanagement, waste of corporate assets, and alleged violations of Sections 10(b), 14(a) and 21D of the Securities Exchange Act of 1934 during the period from February 9, 2022 through January 27, 2026. The complaint alleges that the Company misled investors concerning the viability and safety of RGX-111 and that the Company's stock price declined following the announcement of the clinical hold imposed by the FDA on the Company’s RGX-111 program on January 28, 2026. The complaint seeks, among other relief, damages in favor of the Company, disgorgement of alleged profits, restitution, attorneys' fees, expert fees, corporate governance reforms, and other relief as the court may deem just and proper. In May 2026 a substantially similar suit was filed by plaintiff

Matthew Hay (Hay) in the United States District Court for the District of Maryland, containing largely similar factual and legal contentions and requested relief. In June 2026 the Medina and Hay derivative suits were consolidated and stayed through the resolution of the planned motion to dismiss in the Kuik securities suit. The Company believes the claims are procedurally defective. The Company does not believe that a loss is probable, and no reasonable range of loss is estimable, related to this matter. No liabilities related to this matter were recorded as of June 30, 2026.