8-K

Date: March 19, 2026

CYTOMX THERAPEUTICS, INC.

/s/ Christopher W. Ogden

Christopher W. Ogden

SVP, Chief Financial Officer

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): March 17, 2026

CYTOMX THERAPEUTICS, INC.

(Exact name of Registrant as Specified in Its Charter)

Delaware

001-37587

27-3521219

(State or Other Jurisdiction

of Incorporation)

(Commission

File Number)

(IRS Employer

Identification No.)


151 Oyster Point Blvd
Suite 400
South San Francisco, California		94080
(Address of Principal Executive Offices)		(Zip Code)

Registrant’s telephone number, including area code: (650) 515-3185

Former Name or Former Address, if Changed Since Last Report: N/A

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, $0.00001 par value per share

CTMX

Nasdaq Global Select Market

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 8.01 Other Events.

On March 17, 2026, CytomX Therapeutics, Inc. (the “Company”) entered into an underwriting agreement (the “Underwriting Agreement”) with Jefferies LLC, Piper Sandler & Co. and Cantor Fitzgerald & Co., as representatives of the several underwriters named therein (collectively, the “Underwriters”), in connection with the offering, issuance and sale by the Company of 45,990,567 shares of the Company’s common stock, $0.00001 par value per share (the “Common Stock”), at an offering price of $5.30 per share, and pre-funded warrants to purchase 1,179,245 shares of Common Stock (the “Pre-Funded Warrants”) at a price of $5.29999 per Pre-Funded Warrant.

In addition, under the terms of the Underwriting Agreement, the Company granted the Underwriters the option, for 30 days, to purchase up to 7,075,471 additional shares of Common Stock at the public offering price.

The offering was made pursuant to a registration statement on Form S-3 (Registration No. 333-294342) filed on March 16, 2026, including a base prospectus contained therein, and a prospectus supplement dated March 17, 2026. On March 19, 2026, the offering closed and the Company completed the sale and issuance of an aggregate of 45,990,567 shares of Common Stock and Pre-Funded Warrants to purchase 1,179,245 shares of Common Stock.

The Company estimates the net proceeds from the offering will be approximately $234.4 million, after deducting underwriting discounts and commissions and estimated offering expenses payable by the Company. The Company intends to use the net proceeds of the offering for the continued development of Varseta-M and other pipeline programs, as well as general corporate purposes and working capital needs.

The Underwriting Agreement contains customary representations, warranties and agreements by the Company, customary conditions to closing, indemnification obligations of the Company and the Underwriters, including for liabilities under the Securities Act of 1933, as amended, other obligations of the parties and termination provisions.

The foregoing descriptions of the Underwriting Agreement and the Pre-Funded Warrants are not complete and are qualified in their entirety by reference to the full text of the Underwriting Agreement and form of Pre-Funded Warrant, copies of which are filed as Exhibits 1.1 and 4.1 to this Current Report on Form 8-K, respectively, and are incorporated by reference herein.

Latham & Watkins LLP, counsel to the Company, has issued an opinion regarding the validity of the foregoing securities offered and sold in the offering, a copy of which is filed a Exhibit 5.1 hereto.

Item 9.01

Financial Statements and Exhibits.

(d) Exhibits.


Exhibit No.		Description

1.1		Underwriting Agreement, dated as of March 17, 2026, among CytomX Therapeutics, Inc. and Jefferies LLC, Piper Sandler & Co. and Cantor Fitzgerald & Co., as representatives of the several underwriters named therein.

4.1		Form of Pre-Funded Warrant.

5.1		Opinion of Latham & Watkins LLP.

23.1		Consent of Latham & Watkins LLP (included in Exhibit 5.1).

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.

SEC Form 8-K filed by CytomX Therapeutics Inc.