As previously reported, on December 2, 2016, Selecta Biosciences, Inc. (the “Company”) entered into a License and Option Agreement (the “License Agreement”) and Stock Purchase Agreement (the “Stock Purchase Agreement”) with Spark Therapeutics, Inc. (“Spark”). Under the License Agreement, Spark paid the Company an upfront payment of $10 million and agreed to make two additional payments in the amount of $2.5 million each. The first of these additional payments was scheduled to be made on or before May 31, 2017 (the “May 2017 License Payment”). Under the Stock Purchase Agreement, Spark purchased shares of the Company’s Common Stock (the “Common Stock”) for an aggregate purchase price of $5.0 million and has the right to purchase two additional tranches of Common Stock for an aggregate purchase price of $5.0 million each. Payment for the first additional tranche of Common Stock (the “May Acquisition Right Shares”) was to be made between May 1, 2017 and June 1, 2017.

On June 5, 2017, the Company notified Spark that the License Agreement would automatically terminate in accordance with Section 9.2(e) because Spark had not made the May 2017 License Payment by May 31, 2017, unless the May 2017 License Payment was made within five days. On June 6, 2017, the Company and Spark entered into a letter agreement (the “Letter Agreement”), to which the parties agreed that Spark would make the May 2017 License Payment by June 6, 2017. The parties also agreed that Spark would be deemed to have delivered notice on May 31, 2017 exercising its right to purchase the May Acquisition Right Shares, and that if the payment for such shares is made by June 8, 2017, the License Agreement would not terminate for Spark’s failure to purchase such shares. On June 6, 2017, the Company received the May 2017 License Payment and on June 8, 2017, Spark purchased 324,362 shares of Common Stock to the Stock Purchase Agreement, as amended by the Letter Agreement, for an aggregate purchase price of $5.0 million. The Company is relying on the exemption from the registration requirements of the Securities Act of 1933, as amended, set forth in Section 4(a)(2) thereof and Rule 506 of Regulation D promulgated thereunder.

Item 3.02. Unregistered Sales of Equity Securities.

The information contained in Item 1.01 of this Current Report on Form 8-K is incorporated by reference into this Item 3.02.

About SELECTA BIOSCIENCES, INC. (NASDAQ:SELB)

Selecta Biosciences, Inc. is a clinical-stage biopharmaceutical company. The Company using its synthetic vaccine particle (SVP) technology to discover and develop targeted therapies that are designed to modulate the immune system to treat rare and serious diseases. The Company is engaged in the research and development of nanoparticle immunomodulatory drugs for the treatment and prevention of human diseases. The Company’s product candidates are in development. The Company’s SVP technology encapsulates an immunomodulator in biodegradable nanoparticles to induce antigen-specific immune tolerance to mitigate the formation of anti-drug antibodies (ADAs) in response to life-sustaining biologic drugs. The Company’s technology allows for the design of SVP therapies that can stimulate immune responses against a range of relevant antigens. Its initial immune-stimulating product candidate is a synthetic vaccine against nicotine for the market of smoking cessation and relapse prevention.