SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

SCHEDULE 13D/A

Under the Securities Exchange Act of 1934

(Amendment No. 1)^*

(Name of Issuer)

(Title of Class of Securities)

(CUSIP Number)

Cambridge Equities, LP

Attn: Charles Kenworthy

9922 Jefferson Boulevard

Culver City, California 90232

(310) 836-6400

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

(Date of Event Which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of Rule 13d-1(e), 13d-1(f) or 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 for other parties to whom copies are to be sent.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

* See Instructions

* See Instructions

* See Instructions

* See Instructions

This Amendment No. 1 amends and supplements the Schedule 13D (as so amended, this “Schedule 13D”) filed with the Securities and Exchange Commission (the “SEC”) on December 24, 2014, by certain of the Reporting Persons (as defined below) with respect to the common stock, par value $0.0001 per share (“Common Stock”), of Sorrento Therapeutics, Inc., a Delaware corporation (“Sorrento”). In addition, the Chan Soon-Shiong Family Foundation is being added as a joint filer to this Schedule 13D. The filing of any amendment to this Schedule 13D (including the filing of this Amendment No. 1) shall not be construed to be an admission by any person that a material change has occurred in the facts set forth in this Schedule 13D or that such amendment is required under Rule 13d-2 of the Securities Exchange Act of 1934, as amended.

Item 2 of this Schedule 13D is hereby amended and restated as follows:

Item 3 of this Schedule 13D is hereby amended to include the following information:

On December 7, 2015, Dr. Soon-Shiong purchased 100,000 shares of Common Stock on the open market, at a weighted average per share price of $7.8909, for an aggregate purchase price of $789,090. On December 8, 2015, Dr. Soon-Shiong purchased 14,000 shares of Common Stock on the open market, at a weighted average per share price of $8.011, for an aggregate purchase price of $112,154. On December 9, 2015, Dr. Soon-Shiong purchased 39,764 shares of Common Stock on the open market, at a weighted average per share price of $7.9291, for an aggregate purchase price of $315,292.73. Dr. Soon-Shiong used personal funds to purchase such shares (collectively, the “December 2015 Shares”).

On July 24, 2015, Cambridge Equities donated 7,188,061 shares of Common Stock to the Foundation.

Item 4 of this Schedule 13D is hereby amended to include the following information:

The Reporting Persons and the Company have entered into a Certification and Agreement, dated as of December 17, 2015 (the “Standstill Agreement”). The Standstill Agreement contains certifications by Dr. Soon-Shiong that the Reporting Persons do not have the intention to control or influence the management or policies of the Company or engage in any of the actions specified in Item 4 of Schedule 13D under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), other than the disposition of Common Stock. As part of the Standstill Agreement, the Company agreed to amend, prior to December 21, 2015, that certain Amended and Restated Rights Agreement, dated December 22, 2014, with Philadelphia Stock Transfer, Inc., as rights agent (the “Rights Agreement”), such that none of the purchases of the December 2015 Shares would constitute a “Triggering Event” within the meaning of the Rights Agreement.

Under the Standstill Agreement, the Reporting Persons agreed that, during the period of December 17, 2015 through June 17, 2016, none of the Reporting Persons or any its affiliates or representatives will (a) acquire or offer to acquire, seek, propose or agree to acquire, or make a proposal to acquire, by means of a purchase, tender or exchange offer, merger, business combination or in any other manner, beneficial ownership of Sorrento, or any of its securities, or any assets or property thereof; (b) make or in any way participate in any solicitation of proxies to vote, or seek to advise or influence any person or entity with respect to the voting of, or grant of consents with respect to, any voting securities of Sorrento; (c) make any public announcement with respect to, or solicit or submit a proposal for, or offer of (with or without conditions), any merger, business combination, recapitalization, reorganization, purchase of a material portion of the assets and properties of or other similar extraordinary transaction involving Sorrento or any of its securities; (d) form, join or in any way participate in a “group” (as defined in Section 13(d)(3) of the Exchange Act) with respect to any securities of Sorrento or otherwise in connection with any of the foregoing; (e) otherwise act, alone or in concert with others, to seek to control or influence the management, board of directors or policies of Sorrento; (f) disclose any intention, plan or arrangement inconsistent with any of the foregoing; (g) advise, assist or encourage, or join with, any other persons in connection with any of the actions or matters referred to in the foregoing clauses (a) through (f); or (h) agree to take any of the actions or matters referred to in the foregoing clauses (a) through (g). Under the Standstill Agreement, the Reporting Persons also agreed to restrictions on their ability to request an amendment, waiver or termination of any of the prohibitions described in the foregoing clauses (a) through (h).

Any reference herein to the Rights Agreement is qualified in its entirety to the full text of the Rights Agreement, which was filed as Exhibit 4.1 to the Current Report on Form 8-K filed by the Company with the SEC on December 23, 2014, and is incorporated herein by reference.

The foregoing description of the Standstill Agreement is a summary only and is qualified in its entirety by reference to the full text of the Standstill Agreement, which is filed as Exhibit 6 to this Schedule 13D and is hereby incorporated herein by reference in response to this Item 4.

Items 5(a), 5(b) and 5(c) of this Schedule 13D is hereby amended to include the following information:

As previously disclosed, Cambridge Equities beneficially owns, that certain warrant (the “Warrant”), dated December 22, 2014, exercisable for 1,724,138 shares of Common Stock (the “Warrant Shares”) at an exercise price of $5.80 per share, representing approximately, 4.4% of the outstanding Common Stock of the Company. As previously disclosed, the terms and conditions of the Warrant prohibit Cambridge Equities from exercising any portion of the Warrant to the extent that, after giving effect to the issuance of the requested number of Warrant Shares, Cambridge Equities and its affiliates or group members would beneficially own in excess of 19.9% of the number of shares of Common Stock outstanding immediately upon giving effect to such issuance.

MP 13 Ventures does not directly own any Common Stock. As the general partner of Cambridge Equities, however, MP 13 Ventures may be deemed to beneficially own all Common Stock beneficially owned by Cambridge Equities.

Dr. Soon-Shiong beneficially owns 873,938 shares of Common Stock. In addition, Dr. Soon-Shiong may be deemed to control each of Cambridge Equities, MP 13 Ventures and the Foundation and thus may be deemed to beneficially own all Common Stock beneficially owned by each of Cambridge Equities, MP 13 Ventures and the Foundation. As a result, Dr. Soon-Shiong may be deemed to beneficially own, in the aggregate, 9,786,137 shares of Common Stock, representing approximately 22.3% of the outstanding Common Stock of the Company.

The Foundation has the sole power to vote and direct the disposition of all Common Stock directly owned by the Foundation, except to the extent it may be deemed to share such power with Dr. Soon-Shiong by virtue of Dr. Soon-Shiong’s control over the Foundation. Cambridge Equities has the sole power to vote and direct the disposition of the Warrant and any Warrant Shares issued upon the exercise of the Warrant, except to the extent Cambridge Equities may be deemed to share such power with MP 13 Ventures and Dr. Soon-Shiong by virtue of their respective control over Cambridge Equities. Dr. Soon-Shiong has the sole power to vote and direct the disposition of all Common Stock directly owned by him.

The filing of this Schedule 13D shall not be construed as an admission that any Reporting Person is the beneficial owner of any of the shares of Common Stock that such Reporting Person may be deemed to beneficially own. The joint filing of this Schedule 13D shall not be construed as an admission that any Reporting Person is part of a “group” (as defined in Section 13(d)(3) of the Exchange Act) with each other.

The number of shares of Common Stock reported here as being beneficially owned by the Reporting Persons or as may be deemed to be beneficially owned by the Reporting Persons include all of the Warrant Shares notwithstanding terms and conditions of the Warrant that prohibit its exercise to the extent that, after giving effect to the issuance of the requested number of Warrant Shares, Cambridge Equities and its affiliates or group members would beneficially own in excess of 19.9% of the number of shares of Common Stock outstanding immediately upon giving effect to such issuance. Similarly, the percentage ownership of Cambridge Equities and MP 13 Ventures that is reported herein was calculated as if such Warrant were fully exercisable and not subject to such prohibition. The percentage ownership of Dr. Soon-Shiong that is reported herein, however, was calculated to reflect such prohibition in order to avoid overstating his beneficial ownership of Common Stock.

Item 6 of this Schedule 13D is hereby amended to include the following information:

The information set forth in Item 4 above is hereby incorporated by reference in response to Item 6.

Item 7 of this Schedule 13D is hereby amended to include the following information:

SIGNATURE

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

Dated: December 21, 2015

EXHIBIT INDEX

Exhibit 5

JOINT FILING AGREEMENT

In accordance with Rule 13d-1(k)(1) promulgated under the Securities Exchange Act of 1934, as amended, the undersigned agree to the joint filing on behalf of each of them of a Schedule 13D (including any and all amendments thereto) with respect to the common stock, par value $0.0001 per share, of Sorrento Therapeutics, Inc., and further agree that this Joint Filing Agreement shall be included as an exhibit to such joint filings.

The undersigned further agree that each party hereto is responsible for the timely filing of such Schedule 13D and any amendments thereto, and for the completeness and accuracy of the information concerning such party contained therein; provided that no party is responsible for the completeness or accuracy of the information concerning any other filing party, unless such party knows or has reason to believe that such information is inaccurate.

This Joint Filing Agreement may be executed in one or more counterparts, each of which shall be deemed to be an original instrument, but all of such counterparts together shall constitute but one agreement.

In evidence thereof the undersigned, being duly authorized, hereby execute this Joint Filing Agreement as of December 21, 2015.

Exhibit 6

CERTIFICATION AND AGREEMENT

THIS CERTIFICATION AND AGREEMENT (this “Agreement”) is dated this 17th day of December, 2015 (the “Effective Date”), by and among SORRENTO THERAPEUTICS, INC., a Delaware corporation (the “Company”), Patrick Soon-Shiong, M.D. (“Soon-Shiong”), CAMBRIDGE EQUITIES, LP (the “Cambridge”), MP 13 Ventures, LLC (“MP 13”), and CHAN SOON-SHIONG FAMILY FOUNDATION (the “Foundation”). Soon-Shiong, Cambridge, MP 13 and the Foundation are referred to herein collectively as the “Soon-Shiong Affiliates”.

RECITALS

WHEREAS, the Company is a party to that certain Amended and Restated Rights Agreement, dated December 22, 2014, with Philadelphia Stock Transfer, Inc., as Rights Agent (the “Rights Agreement”);

WHEREAS, on December 7, 8 and 9, 2015, certain of the Soon-Shiong Affiliates purchased an aggregate of 153,764 shares of common stock of the Company (collectively, the “Purchases”);

WHEREAS, Soon-Shiong has informed the Company that the Soon-Shiong Affiliates did not intend to become an Acquiring Person or for any of the Purchases to constitute a Triggering Event under the Rights Agreement, and that none of the Soon-Shiong Affiliates has the intention to control or influence the management or policies of the Company or engage in any of the actions specified in Item 4 of Schedule 13D under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), with respect to the Company, other than the disposition of the Company’s common stock (the “Common Stock”);

WHEREAS, the Company has agreed to amend the Rights Agreement such that none of the Purchases would, individually or collectively, constitute a Triggering Event under the Rights Agreement; and

WHEREAS, the Soon-Shiong Affiliates have agreed to be bound by a standstill agreement, the terms of which are as set forth herein.

AGREEMENT

NOW, THEREFORE, in consideration of the terms and conditions contained herein, and other good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged, the Company and each of the Soon-Shiong Affiliates hereby agree as follows:

Section 1. Certification. Soon-Shiong, on behalf of himself and each of the other Soon-Shiong Affiliates, hereby certifies to the Company that none of the Soon-Shiong Affiliates has the intention to control or influence the management or policies of the Company or engage in any of the actions specified in Item 4 of Schedule 13D under the Exchange Act with respect to the Company, other than the disposition of Common Stock.

Section 2. Rights Agreement. The Company agrees to, on or before December 21, 2015, amend the Rights Agreement such that none of the Purchases would, individually or collectively, constitute a Triggering Event under the Rights Agreement.

Section 3. Standstill. During the period commencing on the Effective Date and ending on June 17, 2016 (the “Restricted Period”), none of the Soon-Shiong Affiliates or any affiliate (as defined in Rule 144 promulgated under the Securities Act of 1933, as amended) or representative of any of the Soon-Shiong Affiliates (collectively, the “Soon-Shiong Group”) will:

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The Soon-Shiong Group also agrees that, during the Restricted Period, the Soon-Shiong Group will not (and the Soon-Shiong Group will cause its representatives who are acting on its behalf or on behalf of other persons acting in concert with the Soon-Shiong Group not to), directly or indirectly, request that the Company Group or any of its representatives, directly or indirectly, amend, waive or terminate any provision of this Section 3 (including this sentence).

Section 4. Governing Law; Jurisdiction; Waiver of Jury Trial. This Agreement shall be construed under the laws of the State of California, without regard to principles of conflicts of law or choice of law that would permit or require the application of the laws of another jurisdiction. The Company and each of the Soon-Shiong Affiliates each hereby agrees that all actions or proceedings arising directly or indirectly from or in connection with this Agreement shall be litigated only in the Superior Court of the State of California or the United States District Court for the Southern District of California, in either case located in San Diego County, California. The Company and each of the Soon-Shiong Affiliates each consents to the exclusive jurisdiction and venue of the foregoing courts and consents that any process or notice of motion or other application to either of said courts or a judge thereof may be served inside or outside the State of California or the Southern District of California by generally recognized overnight courier or certified or registered mail, return receipt requested, directed to such party at its or his address set forth below (and service so made shall be deemed “personal service”) or by personal service or in such other manner as may be permissible under the rules of said courts. THE COMPANY AND EACH OF THE SOON-SHIONG AFFILIATES EACH HEREBY WAIVES ANY RIGHT TO A JURY TRIAL IN CONNECTION WITH ANY LITIGATION PURSUANT TO THIS AGREEMENT.

Section 5. Counterparts. This Agreement may be executed in two or more identical counterparts, all of which shall be considered one and the same agreement and shall become effective when counterparts have been signed by each party and delivered to the other party; provided that a facsimile or electronic signature shall be considered due execution and shall be binding upon the signatory thereto with the same force and effect as if the signature were an original, not a facsimile or electronic, signature.

Section 6. Headings. The headings of this Agreement are for convenience of reference and shall not form part of, or affect the interpretation of, this Agreement.

Section 7. Severability. If any provision of this Agreement shall be invalid or unenforceable in any jurisdiction, such invalidity or unenforceability shall not affect the validity or enforceability of the remainder of this Agreement in that jurisdiction or the validity or enforceability of any provision of this Agreement in any other jurisdiction.

Section 8. Entire Agreement; Amendments. This Agreement supersedes all other prior oral or written agreements between the Company, the Soon-Shiong Affiliates and persons acting on their behalf with respect to the matters discussed herein, and this Agreement and the instruments referenced herein contain the entire understanding of the parties with respect to the matters covered herein and therein and, except as specifically set forth herein or therein, none of the Company or any of the Soon-Shiong Affiliates makes any representation, warranty, covenant or undertaking with respect to such matters. No provision of this Agreement may be amended other than by an instrument in writing signed by the Company and each of the Soon-Shiong Affiliates. No provision hereof may be waived other than by an instrument in writing signed by the party against whom enforcement is sought.

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Section 9. Notices. Any notices, consents, waivers or other communications required or permitted to be given under the terms of this Agreement must be in writing and will be deemed to have been delivered: (a) upon receipt, when delivered personally; (b) upon receipt, when sent by facsimile or electronic mail (provided confirmation of transmission is mechanically or electronically generated and kept on file by the sending party); or (c) one calendar day (excluding Saturdays, Sundays and national banking holidays) after deposit with an overnight courier service, in each case properly addressed to the party to receive the same.

The addresses and facsimile numbers for such communications shall be:

If to the Company:

Sorrento Therapeutics, Inc.

9380 Judicial Drive

San Diego, California 92121

Attn: Henry Ji, Ph.D.

Fax: 858 210 3759

Email: hji@sorrentotherapeutics.com

With a copy (which shall not constitute notice) to:

Paul Hastings LLP

1117 S. California Avenue

Palo Alto, California 94304

Attn: Jeff Hartlin

Fax: 650 320 1904

Email: jeffhartlin@paulhastings.com

If to any of the Soon-Shiong Affiliates:

Dr. Patrick Soon-Shiong

9922 Jefferson Boulevard

Culver City, California 90232

Email: pss@nantworks.com

With a copy (which shall not constitute notice) to:

Cambridge Equities, LP

9922 Jefferson Boulevard

Culver City, California 90232

Attn: General Counsel

Email: ckim@nantworks.com and ck@nantworks.com

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in each case or to such other address and/or facsimile number and/or to the attention of such other person as the recipient party has specified by written notice given to each other party five (5) days prior to the effectiveness of such change.

Section 10. Successors and Assigns. This Agreement shall be binding upon and inure to the benefit of the parties and their respective successors and assigns, including any purchasers of shares of capital stock of any entity in the Company Group.

Section 11. No Third Party Beneficiaries. This Agreement is intended for the benefit of the parties hereto and their respective permitted successors and assigns, and is not for the benefit of, nor may any provision hereof be enforced by, any other person or party.

[Signature Page Follows]

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IN WITNESS WHEREOF, the parties have executed this Certification and Agreement as of the date first written above.

SORRENTO THERAPEUTICS, INC.

[Signature page to the Certification and Agreement]