Sutro Biopharma Inc. filed SEC Form 8-K: Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing

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): June 20, 2025

SUTRO BIOPHARMA, INC.

(Exact name of Registrant as Specified in Its Charter)

Registrant’s Telephone Number, Including Area Code: (650) 881-6500

N/A

(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 Instruction A.2. below):

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

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. ☐

On June 20, 2025, Sutro Biopharma, Inc. (the “Company”) received written notice from The NASDAQ Stock Market, LLC (“NASDAQ”) indicating that the Company is not in compliance with the $1.00 minimum bid price requirement for continued listing on The NASDAQ Global Market, as set forth in Listing Rule 5450(a)(1). In accordance with Listing Rule 5810(c)(3)(A), the Company has a period of 180 calendar days, or until December 17, 2025, to regain compliance with the minimum bid price requirement. To regain compliance, the closing bid price of the Company’s common stock must meet or exceed $1.00 per share for a minimum of ten consecutive business days during this 180-day period.

If the Company is not in compliance by December 17, 2025, the Company may be afforded a second 180 calendar day period to regain compliance, if it elects to transfer to The Nasdaq Capital Market to take advantage of the additional compliance period offered on that market. To qualify, the Company would be required to meet the continued listing requirement for market value of publicly held shares and all other initial listing standards for The NASDAQ Capital Market, except for the minimum bid price requirement. In addition, the Company would be required to notify NASDAQ of its intent to cure the minimum bid price deficiency, which may include, if necessary, implementing a reverse stock split.

If the Company does not regain compliance within the allotted compliance periods, including any extensions that may be granted by NASDAQ, NASDAQ will provide notice that the Company’s common stock will be subject to delisting. The Company would then be entitled to appeal the NASDAQ Staff’s determination to a NASDAQ Listing Qualifications Panel and request a hearing.

The Company intends to monitor the closing bid price of its common stock and, if necessary, plans to implement a reverse stock split prior to December 17, 2025.

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.