15. Commitments and Contingencies

Operating Leases

On April 18, 2022, the Company entered into an operating lease agreement for office space located in Lexington, Massachusetts (the "Office Lease"). On August 8, 2022, the Company commenced occupancy of the leased space. The lease ran through September 30, 2025 and the Company did not renew or continue occupancy of these premises upon lease expiration.

The Company accounts for the Office Lease under the provisions of ASC 842. The Company recorded a right-of-use asset and a corresponding operating lease liability on the Company's consolidated balance sheets upon the accounting commencement date in August 2022. The lease liability was measured at the accounting commencement date utilizing a 12% discount rate. The lease expired in September 2025 and therefore both the right-of-use asset and the operating lease liability had a balance of $0 at December 31, 2025. The Company recorded lease expense related to the Office Lease of $118,277 and other short-term payments of $19,958 for the year ended December 31, 2025 in selling, general and administrative expenses. The Company recorded lease expense of $141,182 and other short-term payments of $21,959 for the year ended December 31, 2024 in selling, general and administrative expenses.

The Office Lease contained escalating payments during the lease period. Upon execution of the Office Lease, the Company prepaid one month of rent, which applied to the first month's rent, and a security deposit, which is held in escrow and will be credited after the termination of the lease with a refund expected in the first half of 2026.

As of December 31, 2025, a security deposit of approximately $25,000 was included in prepaid expenses and other current assets on the Company’s consolidated balance sheet related to the Office Lease.

No future minimum lease payments remained under this lease as of December 31, 2025.

Guarantees

As permitted under Delaware law, the Company indemnifies its officers and directors for certain events or occurrences while the officer or director is, or was, serving at the Company’s request in such capacity. The term of the indemnification is for the officer’s or director’s lifetime. The maximum potential amount of future payments the Company could be required to make is unlimited; however, the Company has directors’ and officers’ insurance coverage that limits its exposure and enables it to recover a portion of any future amounts paid.

In the ordinary course of business, the Company enters into indemnification agreements with certain suppliers and business partners where the Company has certain indemnification obligations limited to the costs, expenses, fines, suits, claims, demands, liabilities and actions directly resulting from the Company’s gross negligence or willful misconduct, and in certain instances, breaches, violations or nonperformance of covenants or conditions under the agreements.

As of December 31, 2025, and 2024, the Company had not experienced any material losses related to these indemnification obligations, and no material claims with respect thereto were outstanding. The Company does not expect significant claims related to these indemnification obligations and, consequently, concluded that the fair value of these obligations is negligible, and no related reserves were established.

Third-party clinical trial supply organization

In July 2025, the Company entered into a clinical trial supply agreement in the amount of approximately $6.5 million with a clinical trial supply organization whereby the clinical trial supply organization will provide services for the Company's Phase 2b clinical study in PAH, known as IMPROVE-PAH. In November 2025, the Company transitioned the PAH Phase 2b study to a Phase 3 study. The estimated total remaining contract costs as of December 31, 2025 is approximately $6.3 million. The estimated period of performance for the committed work with the clinical trial supply organization is through the first quarter of 2028.

Third-party clinical research organization

In August 2025, the Company entered into an arrangement with a contract research organization (“CRO”) to support the Company's Phase 2b clinical study in PAH, known as IMPROVE-PAH. As of December 31, 2025, the total contracted amount under this arrangement is $25.5 million, of which $2.6 million is subject to achievement of certain performance milestones by the CRO. In November 2025, the Company transitioned the PAH Phase 2b study to a Phase 3 study and began evaluating the arrangement together with the CRO. The estimated total remaining contract costs as of December 31, 2025 is approximately $18.4 million, excluding potential milestone payments. The estimated period of performance for the committed work with the CRO is through 2028. The Company made an upfront payment of $1.9 million to the CRO, of which $1.0 million will be held as a retainer until the end of the study and applied against final invoicing and $0.9 million will be applied to passthrough costs as incurred.

The amount and timing of any such payments related to the $2.6 million performance milestones are contingent upon the vendor meeting specific criteria. As of December 31, 2025, the achievement of these milestones is not considered probable, and the potential payments cannot be reasonably estimated. Accordingly, no liability has been recorded in the accompanying consolidated financial statements. The Company will continue to evaluate this arrangement each reporting period and will recognize a liability when achievement of the milestones become probable, and the amount can be reasonably estimated.

In March 2026, the Company signed a change order with the CRO related to our transition to a Phase 3 study in the amount of $48.2 million, increasing the total contracted amount under the arrangement to $73.7 million, of which $7.5 million is subject to achievement of certain performance milestones by the CRO.

License Agreements

Sphaera Pharma Pte. Ltd.

On March 2, 2012, we entered into a collaborative research and development agreement, (“Sphaera Agreement”), with Sphaera Pharma Pte. Ltd. (“Sphaera”), to collaborate on the development of prodrug technology to be applied to protein kinase inhibitors for oncology and non-oncology indications. Under the terms of the Sphaera Agreement, each party would retain its preexisting intellectual property, but any intellectual property conceived or reduced to practice under and certain results arising from the Sphaera Agreement would be assigned to us. On October 5, 2012, we and Sphaera amended the Sphaera Agreement to reflect joint patent applications (the “Joint Applications”) in the U.S. and India by us and Sphaera for a series of novel compounds. Under the terms of the Sphaera Agreement, as amended, certain imatinib variants (“Company Compounds”) comprising thirteen prodrug moieties detailed in the Joint Applications are owned by us. We have an exclusive license from Sphaera (even as to Sphaera) under the Joint Applications to the Company Compounds, and Sphaera is expressly prohibited from developing any Company Compound for which we have filed an investigational new drug application (“IND”) (unless we abandon development of the Company Compound). IKT-001 is a Company Compound, and we have informed Sphaera that an IND has been filed for IKT-001.

In 2023, Sphaera liquidated and transferred its interests to Pivot Holding LLC, a U.S. entity (“Pivot”). On September 30, 2024, the Company and Pivot agreed to amend the agreement and for the Company to pay $500,000 upon signing as well as payment of the following milestones by the Company. A one-time payment of $4.4 million is due upon FDA Approval (as described in the Sphaera

Agreement) and a low single digit royalty is due on net sales of an FDA approved drug. The parties agreed that no further FDA Approval milestone payment(s) shall be due to Pivot in the event that the Company receives additional FDA Approval(s).

The prosecution of patents related to the Company Compounds, which includes the prodrug technology, is the responsibility of the Company.

Litigation

From time to time, the Company may become involved in various lawsuits and legal proceedings which arise in the ordinary course of business. When the Company is aware of a claim or potential claim, it assesses the likelihood of any loss or exposure. If it is probable that a loss will result and the amount of the loss can be reasonably estimated, the Company will record a liability for the loss. In addition to the estimated loss, the recorded liability would include probable and estimable legal costs associated with the claim or potential claim. Litigation is subject to inherent uncertainties, and an adverse result in these or other matters may arise from time to time that may harm the Company’s business. The Company is not currently a party to any material litigation or legal proceedings.