3SBio Inc. — Capital/Financing Update 2016

Jun 7, 2016

Hong Kong Exchanges and Clearing Limited and The Stock Exchange of Hong Kong Limited take no responsibility for the contents of this announcement, make no representation as to its accuracy or completeness and expressly disclaim any liability whatsoever for any loss howsoever arising from or in reliance upon the whole or any part of the contents of this announcement.

3SBIO INC.

(incorporated in the Cayman Islands with limited liability) (Stock Code: 1530)

VOLUNTARY ANNOUNCEMENT

ESTABLISHMENT OF A JOINT VENTURE AND PURCHASE OF SECURITIES

This announcement is made by the board (the “ Board ”) of directors (the “ Directors ”) of 3SBio Inc. (the “ Company ” and together with its subsidiaries, the “ Group ”) on a voluntary basis.

On June 6, 2016, Shenyang Sunshine Pharmaceutical Company Limited (“ Shenyang Sunshine ”), a wholly-owned subsidiary of the Company, entered into a legally binding term sheet with TNK Therapeutics (“ TNK ”), an independent third party and a subsidiary of Sorrento Therapeutics, Inc., a company whose shares are listed on the Nasdaq Stock Market (NASDAQ: SRNE) (“ Sorrento ”), to establish a joint venture company which will be owned by Shenyang Sunshine as to 51% and by TNK as to 49%.

The joint venture is expected to develop and commercialize (i) proprietary immunotherapies, including those developed from, or using TNK’s chimeric antigen receptor T cell (“ CAR-T ”) technology targeting carcinoembryonic antigen (“ CEA ”) positive cancers and (ii) two more CAR-T candidates for cellular therapy.

Shenyang Sunshine is expected to make an initial contribution of US$10 million to the joint venture and TNK is expected to grant the joint venture an exclusive license to the anti-CEA CAR-T technology for the Greater China market, including Mainland China, Hong Kong and Macau.

The anti-CEA CAR-T therapy was originally developed by Sorrento to treat several solid tumors, including liver cancer, colorectal cancer and pancreatic cancer. The preliminary clinical data were encouraging. It has been tested in a murine model with no toxicity, and is found to be very efficient to slow tumor growth. Phase II trials are underway in the United States to treat CEA-positive metastatic breast cancer, colorectal cancer, gastric cancer, liver cancer and adenocarcinomas.

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Separately, on June 6, 2016, the Group entered into a securities purchase agreement to purchase for an aggregate price of US$10 million: (i) 1,801,801 shares of common stock (with an average purchase price of approximately US$5.55 per share); and (ii) a warrant to purchase 261,438 shares of common stock (the “ Purchase ”). The exercise of the warrant is not subject to any vesting or exercise conditions and the exercise price of the warrant is US$8.5 per share.

According to the latest publicly available information, as of May 12, 2016, Sorrento had 40,213,733 shares of common stock outstanding.

The establishment of the joint venture with TNK and/or the Purchase (whether each on a standalone basis or together on an aggregated basis) do not constitute notifiable transaction(s) or connected transaction(s) for the Company under Chapters 14 and 14A of the Rules Governing the Listing of Securities on The Stock Exchange of Hong Kong Limited.

Information about Sorrento

Sorrento is an antibody-centric, clinical stage biopharmaceutical company that develops new treatments for cancer, inflammation and autoimmune diseases. Sorrento’s lead products are multiple late-stage biosimilar and biobetter antibodies, as well as clinical CAR-T therapies targeting solid tumors.

Information about anti-CEA CAR-T therapy

CEA is a tumor-associated antigen commonly expressed on a wide variety of tumors. Levels of CEA in the bloodstream are relatively low unless certain diseases, including distinct forms of cancer, are present. The most common cancers, which cause increased CEA levels, are carcinomas of the colon and rectum. Others include cancers of the pancreas, stomach, breast and lung, medullary carcinoma of the thyroid and ovarian cancer. Anti-CEA CAR-T therapy is effective in slowing growth of the CEA-positive MIPCEA tumor in a murine model, with no toxicity found on any of the animals. Anti-CEA CAR-T therapies have been tested in a series of phase I and phase II clinical studies in the United States. Several patients receiving the anti-CEA CAR-T therapy showed evidence of tumor response, while the side effects were manageable.

By order of the Board 3SBio Inc. Mr. LOU Jing Chairman

Hong Kong, June 7, 2016

As at the date of this announcement, the Board comprises Mr. LOU Jing, Mr. TAN Bo, Ms. SU Dongmei and Mr. HUANG Bin as executive Directors; Mr. LIU Dong and Mr. LV Dong as non-executive Directors; and Mr. PU Tianruo, Mr. David Ross PARKINSON and Mr. MA Jun as independent non-executive Directors.

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