Note 3 — Agreements with Royalty Pharma

On January 7, 2022, we entered into the 2022 RPI Transactions with affiliates of Royalty Pharma International plc. Pursuant to the 2022 RPI Transactions, the RP Multi Tranche Loan Agreement and the RP Aficamten RPA described below, are determined to be debt instruments subsequently measured at amortized cost and were entered into with parties that were at the time of our entry into the 2022 RPI Transactions affiliated and in contemplation of one another. We used the relative fair value method and made separate estimates of the fair value of each freestanding financial instrument and then allocated the proceeds in proportion to those fair value amounts. Arrangement consideration for the RP Multi Tranche Loan Agreement and the RP Aficamten RPA totaled $150 million, consisting of the two $50 million up front payments for the signing of the RP Multi Tranche Loan Agreement and the RP Aficamten RPA and milestone of $50 million for the initiation of the first pivotal trial in oHCM for aficamten that was deemed probable at the signing of the agreements.

On May 22, 2024, we entered into the 2024 RPI Transactions with affiliates of Royalty Pharma International plc, which included an amendment to the RP Aficamten RPA, a component of the 2022 RPI Transactions. The 2024 RPI Transactions include the 2024 RP OM Loan Agreement, the RP Ulacamten RPA, the RP Stock Purchase Agreement, the RP Multi Tranche Loan Agreement Amendment and the RP Aficamten RPA Amendment, as described below, are accounted for as a debt modification of the 2022 RPI Transactions.

Liabilities Related to RPI Transactions Measured at Fair Value

As permitted under ASC 825, we elected the fair value option for recognizing the liabilities related to the 2024 RP OM Loan Agreement and the RP Ulacamten RPA. The fair value option was elected because these liabilities included embedded derivatives which would have otherwise required separate recognition and measurement. The Company elected the fair value option as it is believed to be more practical for each liability as a single unit of account at fair value. Under the fair value option, debt issuance costs are expensed as incurred and the Company is required to record the fair value option elected arrangements at their fair value on the date of issuance and at each balance sheet thereafter. Changes in the estimated fair value of the arrangements are recognized as changes in fair value of liabilities related to RPI Transactions in the condensed consolidated statement of operations and comprehensive loss.

Accounting for RPI Transactions Measured at Fair Value

The fair values of the liabilities for the RP OM Loan Agreement and RP Ulacamten RPA are based on significant unobservable inputs, including the probability of clinical success and regulatory approval based on historical industry success rates for product development specific to cardiovascular products, the estimated date of a product launch, estimates of pricing, sales ramp, variables for the timing of the related events, probability of change of control, and discount rates (which range from 12% to 17% and 12% to 18% as of March 31, 2026 and 2025, respectively), which are deemed to be Level 3 inputs in the fair value hierarchy. As products containing omecamtiv mecarbil and ulacamten have not yet been commercialized, the estimates are highly subjective. For example, assumed increases in the probability of the clinical success for the omecamtiv mecarbil or ulacamten programs could increase the value of the liabilities. Similarly, assumed decreases in the discount rates used in the fair value measurements could also increase the value of the liabilities at period end.

The Company recorded a loss of $1.6 million for the three months ended March 31, 2026, and a gain of $3.9 million for the three months ended March 31, 2025, associated with the change in fair value of the liabilities related to 2024 RP OM Loan Agreement and the RP Ulacamten RPA. The change in the fair value has been recognized in the condensed consolidated statement of operations and comprehensive loss.

Liabilities Related to Revenue Participation Right Purchase Agreements

RP Aficamten Royalty Purchase Agreement

The carrying amount of the RP Aficamten Liability is based on our estimate of the future royalties to be paid to RPI ICAV over the life of the arrangement as discounted using an imputed rate of interest. In the second quarter of 2024, we recorded an additional $33.3 million to the carrying value related to the 2024 RPI Transactions entered into May 22, 2024. The imputed rate of interest on the carrying value of the RP Aficamten Liability was approximately 26.0% as of March 31, 2026 and 23.5% as of March 31, 2025.

2017 RP Omecamtiv Mecarbil Royalty Purchase Agreement

The carrying amount of the RP OM Liability is based on our estimate of the future royalties to be paid to RPFT over the life of the arrangement as discounted using an imputed rate of interest. The excess of future estimated royalty payments over the $92.3 million of allocated proceeds, less issuance costs, is recognized as non-cash interest expense using the effective interest method. The imputed rate of interest on the RP OM Liability is reassessed periodically and is not reduced below 0%. The imputed rate of interest on the carrying value of the RP OM Liability was 0.0% and approximately 0.1% as of March 31, 2026 and March 31, 2025.

Accounting for Revenue Participation Right Purchase Agreements

We periodically assess the amount and timing of expected royalty payments using a combination of internal projections and forecasts from external sources. The RP OM Liability and the RP Aficamten Liability are measured using the effective interest method based on estimates of future royalty payments over the life of the arrangements. To the extent such payments are greater or less than our initial estimates or the timing of such payments is materially different than its original estimates, we will prospectively adjust the amortization of the RP OM Liability and the RP Aficamten Liability and the effective interest rate. A significant change to unobservable inputs could also result in a material increase or decrease to the effective interest rate of the liabilities. Note, for the RP OM Liability, the effective interest rate is reassessed periodically and will not be reduced below 0%.

There are a number of factors that could materially affect the amount and timing of royalty payments, a number of which are not within our control. The RP OM Liability and the RP Aficamten Liability are recognized using significant unobservable inputs. The estimates of future royalties require the use of several assumptions such as: the probability of clinical success, the probability of regulatory approval, the estimated date of a product launch, estimates of eligible patient populations, estimates of prescribing behavior and patient compliance behavior, estimates of pricing, payor reimbursement and coverage, and sales ramp. A significant change in unobservable inputs could result in a material increase or decrease to the effective interest rate of the RP OM Liability and the RP Aficamten Liability.

We review our assumptions on a regular basis and our estimates may change in the future as we refine and reassess our assumptions. Changes to the RP Aficamten Liability and the RP OM Liability are as follows (in thousands):

RP Multi Tranche Term Loan

Tranche 7 under the RP Multi Tranche Loan Agreement Amendment for $175.0 million is drawable at Cytokinetics’ discretion within one year of FDA approval of aficamten in oHCM.

As of March 31, 2026, the estimated fair value of the Tranche 1, Tranche 4, Tranche 5, and Tranche 6 term loans was $277.3 million. The fair value was estimated based on Level 3 inputs.

Derivative Liabilities Measured at Fair Value

We have bifurcated and recognized the embedded derivatives in the RP Multi Tranche Loan Agreement. These embedded derivatives include repayment features based upon a change in control.

The fair values of the derivative liabilities is determined using the probability-weighted expected return method and the “with and without” method. The fair values are based on significant unobservable inputs, including the probability of change of control, the probability of default (less than 10%), discount rates (ranging from 12% to 13% for the three months ended March 31, 2026 and 12% to 14% for the three months ended March 31, 2025) and other factors.