Exhibit 5.2

	ROPES & GRAY LLP
	PRUDENTIAL TOWER
	800 BOYLSTON STREET
	BOSTON, MA 02199-3600
	WWW.ROPESGRAY.COM

October 8, 2025

Zenas BioPharma, Inc.

852 Winter Street, Suite 250

Waltham, MA 02451

Re: Registration Statement on Form S-3ASR

Ladies and Gentlemen:

We have acted as counsel to Zenas BioPharma, Inc., a Delaware corporation (the “Company”), in connection with the Registration Statement on Form S-3ASR (the “Registration Statement”) filed on the date hereof by the Company with the Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933, as amended (the “Securities Act”), relating to the issuance and sale of up to $200,000,000 of shares (the “Shares”) of the common stock of the Company, $0.0001 par value (the “Common Stock”). The Shares will be sold pursuant to an Open Market Sale Agreement^SM, dated October 8, 2025, by and between the Company and Jefferies LLC (the “Agreement”).

In connection with this opinion letter, we have examined such certificates, documents and records and have made such investigation of fact and such examination of law as we have deemed appropriate in order to enable us to render the opinions set forth herein. In conducting such investigation, we have relied, without independent verification, upon certificates of officers of the Company, public officials and other appropriate persons.

The opinion expressed below is limited to the Delaware General Corporation Law.

Based upon and subject to the foregoing, we are of the opinion that when the Shares are issued out of the Company’s duly authorized Common Stock and issued and delivered in accordance with the terms of the Agreement against payment of the consideration set forth therein, the Shares will be duly authorized, validly issued, fully paid and non-assessable.

We hereby consent to your filing this opinion as an exhibit to the Registration Statement and to the use of our name therein and in the related prospectus under the caption “Legal Matters.” In giving such consent, we do not thereby admit that we are in the category of persons whose consent is required under Section 7 of the Securities Act or the rules and regulations of the Commission thereunder.

Very truly yours,

/s/ Ropes & Gray LLP

Ropes & Gray LLP