If the filing person has previously filed a statement on Schedule 13G to report the acquisition which is the subject of this Schedule 13D, and is filing this schedule because of Rule 13d-1(e), Rule 13d-1(f) or Rule 13d-1(g), check the following box  ¨.

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Rule 13d-7(b) for other parties to whom copies are to be sent.

This statement on Schedule 13D relates to the common stock, par value $0.001 per share (the “Common Stock”), of Xenetic Biosciences, Inc., a Nevada corporation (the “Issuer”). The principal executive offices of the Issuer are located at: 40 Speen Street, Suite 102, Framingham, MA 01701.

Set forth in Schedule 1 to this Schedule 13D are the name, business address and present principal occupation or employment and citizenship of each executive officer and director of OPKO Health, Inc. (the “Reporting Person” or “OPKO”).

On September 7, 2018, the Securities and Exchange Commission filed a civil complaint in the Southern District of New York (the “Complaint”), against a number of individuals and entities, including OPKO and its CEO and Chairman, Dr. Phillip Frost and Frost Gamma Investments Trust (“FGIT”), an entity of which Dr. Frost is trustee. In December 2018, OPKO, Dr. Frost and FGIT entered into settlements with the SEC, which, upon approval by the court in January 2019, resolved the claims against OPKO, Dr. Frost and FGIT. Under the terms of the settlement between the SEC, Dr. Frost and FGIT, and without admitting or denying any of the allegations in the Complaint, Dr. Frost agreed to injunctions from violations of Sections 5(a) and (c) and 17(a)(2) of the Securities Act of 1933, claims which may be satisfied by strict liability and negligence, respectively, and Section 13(d) of the Exchange Act, also a strict liability claim; to pay a civil monetary penalty, disgorgement and pre-judgment interest, which have been paid; and to be prohibited, with certain exceptions, from trading in penny stocks. Pursuant to the settlement between OPKO and the SEC, and without admitting or denying any of the allegations of the Complaint, OPKO agreed to be enjoined from future violations of Section 13(d) of the Securities Exchange Act of 1934 (the “Exchange Act”), a claim that requires no showing of scienter, and to pay a civil monetary penalty, which has been paid. OPKO also agreed, within certain stipulated time periods, to: (i) establish a Management Investment Committee (“MIC”) that will make recommendations to an Independent Investment Committee (“IIC”) of OPKO’s board of directors in connection with existing and future strategic minority investments; and (ii) retain an Independent Compliance Consultant (“ICC”) on a time-limited basis to, among other things, advise OPKO on whether filings pursuant to Section 13(d) of the Exchange Act for previous strategic minority investments made at the suggestion of or in tandem with Dr. Frost and his related persons or entities should be made or amended to reflect group membership with Dr. Frost. The ICC has concluded his work. The ICC determined that certain prior investments by OPKO and Dr. Frost with respect to other issuers should have been grouped under Section 13(d) of the Exchange Act and that amended filings under Section 13(d) of the Exchange Act should be made. OPKO and Dr. Frost made the recommended filings on May 9, 2019.

On January 5, 2016, OPKO completed a stock exchange agreement (the “Exchange Agreement”) with Relative Core Cyprus Limited (“Relative Core”) pursuant to which Relative Core agreed to transfer and sell to OPKO that certain number shares of the Issuer having a fair market value of $5.0 million in exchange for that number of shares of OPKO’s common stock having a fair market value of $5.0 million. OPKO issued 494,462 shares of its common stock to Relative Core and received 10,204,082 shares of the Issuer’s Common Stock from Relative Core.

On March 1, 2019, OPKO Pharmaceuticals, LLC (“OPKO Pharmaceuticals”), a subsidiary of OPKO entered into an assignment agreement with the Issuer (the “Assignment Agreement”), pursuant to which the Issuer agreed to acquire all of OPKO Pharmaceuticals’ right, title and interest in and to that certain Intellectual Property License Agreement (the “IP License Agreement”), entered into between The Scripps Research Institute (“Institute”) and OPKO Pharmaceuticals, regarding certain patents related to novel CAR T platform technology and through which the Institute granted an exclusive royalty-bearing license to the patent rights owned by the Institute to OPKO Pharmaceuticals in exchange for royalties, subject to the terms of the IP License Agreement.

Under the Assignment Agreement and the IP License Agreement, on July 19, 2019, Xenetic issued to OPKO Pharmaceuticals 164,062 shares of the Issuer’s Common Stock (the “OPKO Transaction Shares”) and to the Institute 54,687 shares of Issuer’s Common Stock (the “Institute Transaction Shares”). In connection with the Assignment Agreement, OPKO Pharmaceuticals has entered into a voting agreement with the Issuer (the “Voting Agreement”) pursuant to which OPKO Pharmaceuticals agreed, among other things, to vote its shares in the Issuer in favor of the transactions contemplated by the Assignment Agreement, and a lock-up agreement (the “Lock-up Agreement”) with the Issuer which restricts OPKO Pharmaceuticals’ sale or transfer of any of the OPKO Transaction Shares for at least 180 days as provided therein and as otherwise required by law.

Exhibit 1    Assignment Agreement⁽¹⁾ 

Exhibit 2    Voting Agreement⁽¹⁾ 

Exhibit 3    Lock-up Agreement⁽¹⁾ 

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.