Nantahala Capital Management, LLC (“Nantahala”)

Wilmot B. Harkey

Daniel Mack (together the “Reporting Persons”)

19 Old Kings Highway S, Suite 200

Darien, CT 06820

Nantahala is a Massachusetts limited liability company.

Each of Messrs. Harkey and Mack is a citizen of the United States of America.

Title of Class of Securities:

80874P109

If this statement is filed pursuant to Rule 13d-1(b), or 13d-2(b) or (c), check whether the person filing is a:

(a) ¨ Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o).

(b) ¨ Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c).

(c) ¨ Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c).

(d) ¨ Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C 80a-8).

(e) x An investment adviser in accordance with §240.13d-1(b)(1)(ii)(E).

(f) ¨ An employee benefit plan or endowment fund in accordance with §240.13d-1(b)(1)(ii)(F).

(g) x A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G).

(h) ¨ A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813).

(i) ¨ A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3).

(j) ¨ Group, in accordance with §240.13d-1(b)(1)(ii)(J).

Amount Beneficially Owned:

As of December 31, 2018, Nantahala may be deemed to be the beneficial owner of 8,090,485 Shares held by funds and separately managed accounts under its control and as the managing members of Nantahala, each of Messrs. Harkey and Mack may be deemed to be a beneficial owner of those Shares. The 8,090,485 Shares includes 69,683 options held by the Reporting Persons that may be exercised for 6,968,300 Shares within sixty days.

Percent of Class:

As of the date hereof, each of the Reporting Persons may be deemed to be the beneficial owner of 8.8% of the total number of Shares outstanding (based upon information provided by the Issuer on Form 10-Q filed November 8, 2018, there were 91,706,419 Shares outstanding as of November 5, 2018).

Nantahala Capital Management, LLC

Each of Messrs. Harkey and Mack:

Nantahala Capital Partners SI, LP, a fund advised by Nantahala, has the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, approximately 5.1% of the outstanding shares of common stock beneficially owned by Nantahala reported herein. This includes options held by Nantahala Capital Partners SI, LP that may be exercised for 3,946,500 Shares within sixty days.

By signing below each Reporting Person certifies that, to the best of such person's knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having such purpose or effect.