SCHEDULE 13D/A 0001214659-25-001762 0001232621 XXXXXXXX LIVE 3 Common Stock, par value $0.001 per share 05/15/2025 false 0001564824 01671P100 Allakos Inc.

825 Industrial Road Suite 500 San Carlos CA 94070

Kevin Tang 858-200-3830 4747 Executive Drive Suite 210 San Diego CA 92121 0001232621 N TANG CAPITAL MANAGEMENT, LLC WC N DE 0.00 10000.00 0.00 10000.00 10000.00 N 100 OO 0001178579 N KEVIN TANG WC N X1 0.00 10000.00 0.00 10000.00 10000.00 N 100 IN 0001191935 N TANG CAPITAL PARTNERS, LP WC N DE 0.00 10000.00 0.00 10000.00 10000.00 N 100 PN Y TANG CAPITAL PARTNERS INTERNATIONAL, LP WC N DE 0.00 0.00 0.00 0.00 0.00 N 0 PN Y TANG CAPITAL PARTNERS III, INC WC N NV 0.00 0.00 0.00 0.00 0.00 N 0 CO Y TANG CAPITAL PARTNERS IV, INC WC N NV 0.00 0.00 0.00 0.00 0.00 N 0 CO 0001970065 N CONCENTRA BIOSCIENCES, LLC AF N DE 0.00 10000.00 0.00 10000.00 10000.00 N 100 OO 0002064010 N CONCENTRA MERGER SUB III, INC AF N DE 0.00 0.00 0.00 0.00 0.00 N 0 CO Common Stock, par value $0.001 per share Allakos Inc. 825 Industrial Road Suite 500 San Carlos CA 94070 This Schedule 13D/A (this "Statement") amends the Schedule 13D (the "Original Schedule 13D") filed on February 3, 2025, as amended on April 3, 2025 and April 17, 2025. Items 4 and 5 of the Statement are hereby amended and supplemented to the extent hereinafter expressly set forth. Except as amended hereby, the original disclosure set forth in the Statement shall remain unchanged. All capitalized terms used and not expressly defined herein have the respective meanings ascribed to such terms in the Original Schedule 13D. Item 4 of the Schedule 13D is amended by adding the following: Closing of the Merger: As previously disclosed, each of Concentra, the Issuer and Merger Sub III entered into the Merger Agreement, which provides for an Offer by Merger Sub III for all of the Issuer's Common Stock. The Offer commenced on April 15, 2025. On May 15, 2025, the Offer expired and Merger Sub III accepted for purchase a total of 73,398,243 shares tendered and not withdrawn, representing approximately 81.21% of the total shares of the Issuer issued and outstanding. Following the expiration of the Offer, Merger Sub III merged with and into the Issuer on May 15, 2025, pursuant to Section 251(h) of the Delaware General Corporation Law, and, among other things, each share of common stock of Merger Sub III issued and outstanding immediately before the Effective Time automatically converted into the right to receive the Offer Price, with the Issuer surviving as a wholly owned subsidiary of Concentra. The information previously provided in response to Item 5 is hereby amended and restated by replacing the text thereof in its entirety with the following: The information set forth in the cover pages of this Schedule 13D is hereby incorporated by reference into this Item 5. As of the date hereof the Reporting Persons beneficially own an aggregate of 10,000 shares of the Issuer's Common Stock, representing 100% of the outstanding shares. See item 5(a) above. Except as described in this Amendment No. 3, there have been no transactions in the Issuer's Common Stock during the past 60 days by the Reporting Persons. No person other than a Reporting Person has the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, Common Stock beneficially owned by the Reporting Persons. Not applicable. TANG CAPITAL MANAGEMENT, LLC /s/ Kevin Tang 05/19/2025 KEVIN TANG /s/ Kevin Tang 05/19/2025 TANG CAPITAL PARTNERS, LP /s Kevin Tang 05/19/2025 TANG CAPITAL PARTNERS INTERNATIONAL, LP /s/ Kevin Tang 05/19/2025 TANG CAPITAL PARTNERS III, INC /s/ Kevin Tang 05/19/2025 TANG CAPITAL PARTNERS IV, INC /s/ Kevin Tang 05/19/2025 CONCENTRA BIOSCIENCES, LLC /s/ Kevin Tang 05/19/2025 CONCENTRA MERGER SUB III, INC /s/ Kevin Tang 05/19/2025