til-20260401

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): April 1, 2026

Instil Bio, Inc.

(Exact name of registrant as specified in its Charter)


Delaware	001-40215	83-2072195
(State or Other Jurisdiction of Incorporation)	(Commission File Number)	(IRS Employer Identification No.)



3963 Maple Avenue, Suite 350 Dallas, Texas						75219
(Address of Principal Executive Offices)						(Zip Code)

(972) 499-3350

(Registrant’s Telephone Number, Including Area Code)

Not Applicable

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instructions A.2. below):


☐			Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)


☐			Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)


☐			Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))


☐			Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class

Trading

Symbol(s)

Name of each exchange on which registered

Common Stock, $0.000001 par value

TIL

The Nasdaq Stock Market LLC

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 4.01 Changes in Registrant’s Certifying Accountant.

On April 1, 2026, the Audit Committee of the Board of Directors of Instil Bio, Inc. (the “Company”) approved the appointment of RSM US LLP (“RSM”) as the Company’s independent registered public accounting firm for the fiscal year ending December 31, 2026. This action resulted in the replacement of Deloitte & Touche LLP (“Deloitte”) as the Company’s independent registered public accounting firm, which the Audit Committee dismissed effective April 1, 2026.

The reports of Deloitte on the Company’s consolidated financial statements for the fiscal years ended December 31, 2025 and 2024 did not contain an adverse opinion or disclaimer of opinion and were not qualified or modified as to uncertainty, audit scope or accounting principles. In connection with the audits of the Company's consolidated financial statements for the fiscal years ended December 31, 2025 and 2024, and in the subsequent period through April 1, 2026, there were no disagreements with Deloitte on any matters of accounting principles or practices, financial statement disclosure or auditing scope and procedures which, if not resolved to the satisfaction of Deloitte, would have caused Deloitte to make reference to the matter in their report. There were no reportable events (as that term is described in Item 304(a)(1)(v) of Regulation S-K) during the fiscal years ended December 31, 2025 and 2024, or in the subsequent period through April 1, 2026.

The Company has provided a copy of the foregoing disclosures to Deloitte and requested that Deloitte furnish it with a letter addressed to the Securities and Exchange Commission stating whether Deloitte agrees with the above statements. A copy of Deloitte’s letter, dated April 3, 2026, is filed as Exhibit 16.1 to this Form 8-K.

During the two most recent fiscal years and in the subsequent interim period through April 1, 2026, neither the Company nor anyone on its behalf has consulted with RSM with respect to the application of accounting principles to a specified transaction, either completed or proposed, or the type of audit opinion that would have been rendered on the Company’s consolidated financial statements, or any other matters set forth in Item 304(a)(2)(i) or (ii) of Regulation S-K.

Item 9.01 Financial Statements and Exhibits.


(d) Exhibits

Exhibit No.						Description
16.1						Letter from Deloitte & Touche LLP to the Securities and Exchange Commission dated April 3, 2026
104						Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Instil Bio, Inc.

Date:

April 3, 2026

By:

/s/ Sandeep Laumas, M.D.

Sandeep Laumas, M.D.

Chief Financial Officer and Chief Business Officer

(Principal Financial Officer and Principal Accounting Officer)

Instil Bio Inc. filed SEC Form 8-K: Changes in Registrant's Certifying Accountant, Financial Statements and Exhibits