6. Investments and Fair Value Measurements

Available-for-Sale Securities

The estimated fair value of marketable securities is based on quoted market prices for these or similar investments obtained from a commercial pricing service. The fair market value of marketable securities classified within Level 1 is based on quoted prices for identical instruments in active markets. The fair value of marketable securities classified within Level 2 is based on quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; or model-driven valuations whose inputs are observable or whose significant value drivers are observable. Observable inputs may include benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers, and reference data including market research publications.

Available-for-sale securities are summarized below:

As of March 31, 2026, all of the Company’s available-for-sale securities had contractual maturities within one year, and the weighted-average maturity of marketable securities was approximately one month. There were no transfers between Level 1 and Level 2 during the periods presented, and there have been no material changes to the Company’s valuation techniques during the three months ended March 31, 2026.

Available-for-sale securities with unrealized losses as of March 31, 2026 are summarized below:

Available-for-sale securities with unrealized losses as of December 31, 2025 are summarized below:

The Company invests primarily in high credit quality and short-term maturity debt securities with the intent to hold such securities until maturity at par value. The Company does not intend to sell the investments that are currently in an unrealized loss position, and it is unlikely that it will be required to sell the investments before recovery of their amortized cost basis, which may be at maturity. The Company reviewed its available-for-sale debt securities and determined that there were no credit-related losses to be recognized as of March 31, 2026, and there were no individual securities that were in a significant unrealized loss position as of March 31, 2026.

For the three months ended March 31, 2026 and 2025, the Company did not sell any marketable securities.

Ampreloxetine Funding

The Company recognizes a contingent liability related to funding received from Royalty Pharma Investments (“Royalty Pharma”) in exchange for certain future royalty rights to ampreloxetine. The contingent liability consists of an upfront $25.0 million received in July 2022 and management’s estimate of (i) a risk-adjusted future contingent $15.0 million milestone; and (ii) the amount and timing of royalties to be paid to Royalty Pharma and then discounted over the life of the arrangement using an imputed rate of interest. The excess of future estimated royalty payments over the amount of cash funding received is recognized as interest expense using the effective interest method. The balance associated with the contingent liability was initially recorded as $25.0 million, net of allocated transaction costs, in July 2022 and is reported on the condensed consolidated balance sheets as “Future royalty payment contingency”.

There are a number of factors that could materially affect the amount and timing of the contingent $15.0 million milestone and royalty payments, some of which are not within the Company’s control. Such factors include, but are not limited to, changes in the projected market size, the introduction of competing products, patent protection matters, and regulatory product approval for ampreloxetine. The contingent liability was recognized using significant unobservable inputs. These inputs were derived using internal management estimates and reflect management’s judgements and forecasts. The significant unobservable inputs include the forecasted revenues, the probability and timing of the

regulatory milestone, and the expected term of the royalty stream, as well as the overall probability of ampreloxetine’s success. These estimates are considered Level 3 fair value inputs. A significant change in certain unobservable inputs, such as the probability of ampreloxetine’s success, could result in a material increase or decrease to the effective interest rate of the contingent liability. If ampreloxetine regulatory approval is not achieved or if ampreloxetine sales are never recognized, the Company would not be obligated to repay any of the funding amounts received from Royalty Pharma.

On March 3, 2026, the Company announced that its ampreloxetine Phase 3 clinical study top-line results did not meet its primary endpoint. As a result of this outcome, the Company decided to wind down the ampreloxetine program, and in accordance with accounting guidance under ASC 470, Debt, the Company ceased recognizing interest expense on the contingent liability balance beginning in the first quarter of 2026.

Contract Derivative

On December 27, 2024, the Company purchased a contract derivative to manage its exposure to financial risk and to mitigate potential tax liability. The Company determined that the contract derivative met the definition of a derivative under ASC Topic 815, Derivatives and Hedging.

The contract derivative is measured at fair value using the discounted cash flow method and includes unobservable inputs derived from management’s estimates and assumptions. Management’s estimates and assumptions are based in part on external data and internal data and involve a significant degree of judgment. The primary unobservable inputs, classified as Level 3 under the fair value hierarchy, include the remote possibility of a future payout of taxes. The discount rate utilized in the fair value model was 4.8%, as of December 31, 2025 and 5.1% as of March 31, 2026.

The contract derivative was recognized within non-current “Other assets” on the condensed consolidated balance sheets and changes to the contract derivative fair value were as follows for the three months ended March 31, 2026:

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For the three months ended March 31, 2026, the decrease in the contract derivative’s fair value was driven by an increase in the estimated discount rate, and the unrealized loss was recognized within “Interest and other income, net” on the condensed consolidated statements of operations.