In January 2022, the Company entered into a License and Collaboration Agreement (the “Acadia Agreement”) with Acadia Pharmaceuticals Inc. (“Acadia”) for the discovery, development and commercialization of novel RNA-based medicines for the treatment of severe and rare genetic neurodevelopmental diseases of the central nervous system. The Acadia Agreement focuses on the targets SYNGAP1, MECP2 (Rett syndrome), and an undisclosed neurodevelopmental target of mutual interest. In connection with each target, the Company will collaborate with Acadia to identify potential treatments for further development and commercialization as licensed products. With respect to SYNGAP1, the Company has agreed with Acadia to co-develop and co-commercialize licensed products for such target globally, and in connection therewith the Company granted to Acadia worldwide, co-exclusive (with the Company) licenses for such licensed products. With respect to MECP2 and the neurodevelopmental target, the Company granted to Acadia worldwide, exclusive licenses to develop and commercialize licensed products for such targets.

Pursuant to the terms of the Acadia Agreement, the Company received an upfront payment of $60.0 million from Acadia. Acadia agreed to fund the research to identify potential licensed products for MECP2 and the neurodevelopmental target, and the Company will equally fund with Acadia the research to identify potential licensed products for SYNGAP1. The Company is eligible to receive up to $907.5 million in potential total milestone payments based upon the achievement of certain development, regulatory, first commercial sales and sales milestone events across the programs for the three targets, assuming each milestone were achieved at least once. With respect to licensed products for MECP2 and the neurodevelopmental target, the Company is also eligible to receive tiered royalties at percentages ranging from the mid-single digits to the mid-teens on future net sales by Acadia of licensed products worldwide. Royalties payable under the Acadia Agreement are subject to standard royalty reductions. For SYNGAP1 licensed products that the Company is co-developing and co-commercializing, the Company will be responsible for 50% of the development and commercialization costs and will receive 50% of the profits from global commercialization. The Company is provided with a co-development and co-commercialization opt out option relating to the SYNGAP1 target indication at the Company’s discretion. Such opt-out would reduce development and commercialization milestones but would provide the Company with royalties on an escalating basis attributable to net sales milestones.

At the commencement of the Acadia Agreement, the Company identified three performance obligations consisting of pre-clinical research activities for each of the three targets, SYNGAP1, MECP2, and the undisclosed neurodevelopmental target. The exclusive or co-exclusive licenses granted to Acadia to conduct pre-clinical research activities on each of the three targets, and participation on each of the respective joint research committees were identified as promised services. However, the licenses granted to Acadia and the research activities were determined to be not distinct from each other, and therefore are considered a combined performance obligation for each of the three targets. Participation on each of the joint research committees was determined to be quantitatively and qualitatively immaterial in the context of the arrangement with Acadia.

The Company is recognizing the transaction price for the pre-clinical research activities for each of the three targets over time as the research services are provided. The transfer of control to Acadia occurs over this time period, and in management’s judgment, is the best measure of progress towards satisfying the performance obligation. An input method is used that measures the cost incurred to date in satisfying each of the three research activities in relation to the estimated total projected cost of each of the research activities to fulfill the respective obligations. The cumulative effect of revisions to estimated costs and/or the transaction price to complete the

research performance obligations will be recorded in the period in which changes are identified and amounts can be reasonably estimated.

Milestone payments that are not within the control of the Company, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. For other milestones, the Company evaluated factors such as the scientific, clinical, regulatory, commercial, and other risks that must be overcome to achieve the particular milestone in making this assessment. Milestones that are outside of the Company’s or Acadia’s control will not be recognized until such milestones are achieved. As to the other milestones, to date, no milestone payments have been included in the transaction price due to the uncertainty as to whether these milestones will be achieved. The Company will at the end of each reporting period reevaluate the probability of achievement of all milestones subject to constraint and, if necessary, adjust its estimate of the overall transaction price for each of the research activities on the three targets. Any such adjustments will be recorded on a cumulative catch-up basis.

As of March 31, 2025, the Company had $14.4 million in upfront consideration associated with the Acadia Agreement relating to performance obligations that are unsatisfied or partially unsatisfied.

On February 14, 2025 (the “Effective Date”), the Company entered into a License and Collaboration Agreement (the “Biogen Agreement”) with Biogen International GmbH (“Biogen”) for the joint development and commercialization of zorevunersen and other compounds targeting the SCN1A gene (the “Licensed Product”). Under the terms of the Biogen Agreement, the Company granted Biogen an exclusive, royalty-bearing license to develop, manufacture, and export licensed products in all territories outside the U.S., Canada, and Mexico (the “Biogen Territory”). In addition, Biogen has the option to exercise an exclusive, royalty-bearing, sublicensable and transferable license for certain future follow-on ASOs directed to SCN1A controlled by the Company.

Under the Biogen Agreement, the parties are jointly developing zorevunersen, with the Company leading global development. The Company and Biogen share global development costs based on an agreed budget. The Company is responsible for 70.0% of these development costs and Biogen is responsible for the remaining 30.0% of these development costs.

In connection with the closing of this transaction in February 2025, the Company received an upfront payment of $165.0 million and is eligible to receive development and commercial milestone payments that could total up to approximately $50.0 million and $335.0 million, respectively, if all the specified milestones set forth in this collaboration are achieved. In addition, the Company is eligible to receive tiered, double-digit royalties ranging from the low double-digit to high teen percentages of future net sales on the licensed products. Royalties payable under the Agreement are subject to standard royalty reductions.

At the commencement of the Agreement, the Company evaluated the Biogen Agreement and determined that it was reflective of a vendor-customer relationship and comprised of the following performance obligations within the scope of ASC 606.

As of the Effective Date, the Company identified the following performance obligations in the Biogen Agreement that were evaluated under the scope of ASC 606: (i) an exclusive royalty-bearing sublicensable, transferable license under the licensed intellectual property to exploit Licensed Products in the Biogen Territory, and non-exclusive, royalty-free, sublicensable, transferable license under the licensed intellectual property to develop, manufacture and export any Licensed Products in the Biogen Territory (collectively “IP License” and considered as one performance obligation), and (ii) development services, that are expected to generate data necessary for regulatory approval in the Biogen Territory for the licensed products (“Global Development Activities”).

The IP License is considered functional intellectual property and distinct from the Global Development Activities, as Biogen can benefit from the license on its own or together with other readily available resources. Global Development Activities are considered distinct as they are not expected to significantly modify or customize the initial intellectual property as the Licensed Product is in Phase 3 of clinical development at contract inception.

The Company determined that the initial transaction price under ASC 606 was $243.4 million and is comprised of the non-refundable upfront payment of $165 million and $78.4 million of estimated variable consideration attributed to cost reimbursement in reimbursement for Global Development Activities. The Company utilized the expected value method to estimate the variable consideration for the future reimbursement of the Global Development Activities, and any subsequent adjustments arising from changes in estimates will be recorded on a cumulative catch-up basis in the period of such adjustment.

The Company determined that royalties and sales milestones relate solely to the licenses of intellectual property and are therefore excluded from the transaction price under the sales- or usage-based royalty exception of ASC 606. In addition, the Company estimated the probability, likelihood, and magnitude of a reversal of revenue for the commercial milestone payments and determined that any variable consideration related to commercial milestones was deemed to be fully constrained at inception and therefore excluded from

the initial transaction price due to high degree of uncertainty and risks associated with these potential payments as the Company can not assert that it is probable that a significant reversal in the amount of cumulative revenue recognized would not occur.

The Company developed the estimated standalone selling price, at inception, for each of the performance obligations with the objective of determining the price at which we would sell each item if it were to be sold regularly on a standalone basis. The Company developed the estimated standalone selling price for the IP License primarily based on the probability-weighted present value of expected future cash flows associated with the underlying license or activity. In developing such estimates, the Company applied judgment in determining the forecasted revenues, taking into consideration the applicable market conditions and relevant entity-specific factors, the probability of success and the discount rate. The estimated standalone selling price for the Global Development Activities is primarily based on the costs necessary to perform the service plus a reasonable margin. In management’s judgment the above inputs provide a faithful estimate and reflects a consideration that would be received to transfer the promised goods or services in an orderly transaction between unrelated market participants. As such, the estimated standalone selling price reflects the best estimate of the fair value that market participants would pay for each performance obligation on a standalone basis.

The Company allocated the transaction price to the performance obligations on a relative stand-alone selling price basis consistent with the allocation objective of ASC 606.

The IP License performance obligation was satisfied at a point in time upon transfer of the IP License to Biogen. Control of the IP License was transferred on the Effective Date as Biogen could begin to use and benefit from the IP License immediately. For the Global Development Activities performance obligation, the Company measures proportional performance over time using an input method based on costs incurred relative to the total estimated costs of the obligation by determining the proportion of costs incurred as a percentage of total costs the Company expects to expend. This ratio is applied to the transaction price allocated to this performance obligation to arrive at the cumulative revenue that should be recognized at each reporting date. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition.

The following table provides a summary of the transaction price allocated to each performance obligation, in addition to revenue activity during the period:


	As of March 31, 2025
	Transaction Price Allocated		Revenue Recognized
Performance obligations
IP License	$	150,779	$	150,779
Global Development Activity		92,644		1,642
	$	243,423	$	152,421

As of March 31, 2025 the Company had $14.0 million in upfront consideration associated with the Biogen Agreement relating to performance obligations that are unsatisfied or partially unsatisfied.