Nasdaq warns Mersana (NASDAQ: MRSN) on $50M value rule breach

Rhea-AI Filing Summary

Mersana Therapeutics, Inc. reported that Nasdaq has notified the company it is not in compliance with Nasdaq Listing Rule 5450(b)(2)(A), which requires a minimum Market Value of Listed Securities of $50.0 million. This is a deficiency notice only and does not immediately affect the listing of Mersana’s common stock, which continues to trade on the Nasdaq Global Select Market under the symbol MRSN.

The company has 180 calendar days, until March 4, 2026, to regain compliance by having its market value close at or above $50.0 million for at least ten consecutive business days before that date. If Mersana does not regain compliance by the deadline, its securities would be subject to delisting, though it would have the right to appeal to a Nasdaq hearings panel. Mersana plans to monitor its market value and consider available options to address the issue, while noting there is no assurance it will regain or maintain compliance with Nasdaq rules.

Positive

• None.

Negative

• Nasdaq MVLS deficiency and delisting risk: Mersana fell below Nasdaq’s $50.0 million market value of listed securities requirement and must regain compliance by March 4, 2026 to avoid potential delisting proceedings.

Insights

Equity Markets Analyst

Nasdaq has flagged Mersana for a market value shortfall, creating potential delisting risk if not remedied by March 4, 2026.

Mersana Therapeutics has received a deficiency notice from Nasdaq for failing to meet the minimum Market Value of Listed Securities requirement of $50.0 million under Listing Rule 5450(b)(2)(A). The company’s stock remains on the Nasdaq Global Select Market, so there is no immediate trading disruption, but the notice highlights that its equity valuation has fallen below Nasdaq’s threshold.

The company has 180 calendar days, until March 4, 2026, to regain compliance by maintaining an MVLS of at least $50.0 million for ten consecutive business days. If it cannot achieve this, Nasdaq may move toward delisting, although Mersana would be able to appeal to a hearings panel. Management states it will monitor MVLS and consider available options, while cautioning there is no assurance of regaining or sustaining compliance.

This situation introduces listing-status uncertainty, which can matter for investor access and liquidity. The key milestone is whether the company’s MVLS closes at or above the required level for the ten-day window before the March 4, 2026 compliance deadline; failure to do so could trigger the formal delisting process and an appeal scenario.

8-K Event Classification

Item 3.01 — Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing

1 item

Item 3.01 Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing Securities

The company received a delisting notice or transferred its listing to a different exchange.

Understanding 8-K Material Events →

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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): September 5, 2025

MERSANA THERAPEUTICS, INC.

(Exact name of registrant as specified in its charter)

Delaware		001-38129		04-3562403
(State or other jurisdiction of incorporation)		(Commission File Number)		(IRS Employer Identification No.)

840 Memorial Drive Cambridge, Massachusetts		02139
(Address of Principal Executive Offices)		(Zip Code)

Registrant’s telephone number, including area code: (617) 498-0020

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 Instruction 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, $0.0001 par value	MRSN	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 3.01 Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing.

On September 5, 2025, Mersana Therapeutics, Inc. (the “Company”) received written notice (the “Notice”) from the Listing Qualifications Department of The Nasdaq Stock Market LLC (“Nasdaq”) notifying the Company that the Company is not in compliance with Nasdaq Listing Rule 5450(b)(2)(A) (the “MVLS Rule”), which requires the Company to maintain a minimum Market Value of Listed Securities (“MVLS”) of $50.0 million. The Notice is only a notification of deficiency, not of imminent delisting, and has no current effect on the listing of the Company’s common stock, which continues to trade on The Nasdaq Global Select Market under the symbol “MRSN.”

In accordance with the MVLS Rule, the Company has a period of 180 calendar days, or until March 4, 2026 (the “Compliance Date”), to regain compliance with the MVLS Rule. To regain compliance, the Company’s MVLS must close at $50.0 million or more for a minimum of ten consecutive business days prior to the Compliance Date. In the event the Company does not regain compliance with the MVLS Rule prior to the Compliance Date, Nasdaq will notify the Company that its securities are subject to delisting. At that time, the Company will have the opportunity to appeal the delisting determination to a Nasdaq hearings panel. The Company intends to monitor its MVLS and consider its available options to regain compliance with the MVLS Rule. However, there can be no assurance that the Company will be able to regain compliance with the MVLS Rule or maintain compliance with other Nasdaq listing rules.

SIGNATURES

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

	MERSANA THERAPEUTICS, INC.
Date: September 5, 2025	By:	/s/ Brian DeSchuytner
		Brian DeSchuytner
		Senior Vice President, Chief Operating Officer and Chief Financial Officer

FAQ

What did Mersana Therapeutics (MRSN) disclose about its Nasdaq listing status?

Mersana Therapeutics disclosed that Nasdaq notified the company it is not in compliance with Listing Rule 5450(b)(2)(A), which requires a minimum Market Value of Listed Securities of $50.0 million.

Is Mersana Therapeutics (MRSN) being delisted from Nasdaq now?

No. The notice is a notification of deficiency only and has no current effect on the listing. Mersana’s common stock continues to trade on the Nasdaq Global Select Market under the symbol MRSN.

How long does Mersana (MRSN) have to regain compliance with Nasdaq’s MVLS rule?

Mersana has 180 calendar days, until March 4, 2026, to regain compliance with Nasdaq’s MVLS rule.

What must Mersana (MRSN) do to regain compliance with the Nasdaq MVLS requirement?

To regain compliance, Mersana’s Market Value of Listed Securities must close at $50.0 million or more for at least ten consecutive business days before the March 4, 2026 compliance date.

What happens if Mersana (MRSN) cannot meet the Nasdaq MVLS requirement by March 4, 2026?

If Mersana does not regain compliance by March 4, 2026, Nasdaq will notify the company that its securities are subject to delisting, and Mersana would then have the opportunity to appeal to a Nasdaq hearings panel.

How does Mersana (MRSN) plan to address the Nasdaq compliance issue?

Mersana states it intends to monitor its Market Value of Listed Securities and consider available options to regain compliance, but it notes that there is no assurance it will succeed.