UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): February 28, 2020

SUTRO BIOPHARMA, INC.

(Exact name of registrant as specified in its charter)

(650) 392-8412

(Registrant’s telephone number, including area code)

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 1.01.   Entry into a Material Definitive Agreement.

On February 28, 2020, (the “Effective Date”), Sutro Biopharma, Inc. (the “Company”) entered into a loan and security agreement (the “Agreement”) with Oxford Finance LLC (“Oxford”), as the collateral agent and a lender, and Silicon Valley Bank, as a lender (together with Oxford, the “Lenders”), pursuant to which the Lenders have agreed to lend the Company up to an aggregate of $25.0 million in a series of term loans (the “Term A Loan”). Upon entering into the Agreement, the Company borrowed $25.0 million from the Lenders, with approximately $9.6 million of such amount applied to the repayment of the outstanding principal, interest and final payment fees owed pursuant to the prior loan and security agreement dated August 4, 2017.

Under the terms of the Agreement, the Company may, at its sole discretion, borrow from the Lenders up to an additional $5.0 million (the “Term B Loan” and together with the Term A Loan, the “Term Loans”) upon the achievement by the Company of the closing of a new collaboration agreement that includes an upfront payment of at least $50.0 million to the Company, as determined by Oxford in its sole and absolute discretion (the “Term B Milestone Event”).  The Company may draw the Term B Loan during the period commencing on the date of the occurrence of the Term B Milestone Event and ending on the earliest of (i) December 31, 2020, (ii) the thirtieth (30th) day following the occurrence of the Term B Milestone Event, and (iii) the occurrence of an event of default.

The proceeds from the Term Loans under the Agreement may be used to satisfy the Company’s future working capital needs and to fund its general business requirements. The Company’s obligations under the Agreement are secured by all assets of the Company, other than its intellectual property. The Company has also agreed not to encumber its intellectual property assets, except as permitted by the Agreement.

All of the Term Loans mature on March 1, 2024 (the “Maturity Date”) and will be interest-only through March 1, 2022, followed by 24 equal monthly payments of principal and interest. The Term Loans will bear interest at a floating per annum rate equal to the greater of (i) 8.07% or (ii) the sum of (a) the greater of (1) the thirty (30) day U.S. LIBOR rate reported in the Wall Street Journal on the last business day of the month that immediately precedes the month in which the interest will accrue or (2) 1.67%, plus (b) 6.40%.  

The Company will be required to make a final payment of 3.83% of the original principal amount of the Term Loans drawn, payable on the earlier of (i) the Maturity Date, (ii) the acceleration of any Term Loans, or (iii) the prepayment of the Term Loans (the “Final Payment”). The Company may prepay all, but not less than all, of the Term Loans upon 30 days’ advance written notice to Oxford, provided that the Company will be obligated to pay a prepayment fee equal to (i) 3.00% of the principal amount of the applicable Term Loan prepaid on or before the first anniversary of the applicable funding date, (ii) 2.00% of the principal amount of the applicable Term Loan prepaid between the first and second anniversary of the applicable funding date, and (iii) 1.00% of the principal amount of the applicable Term Loan prepaid thereafter, and prior to the Maturity Date (each, a “Prepayment Fee”).

The Agreement contains customary affirmative and restrictive covenants, including covenants regarding incurrence of additional indebtedness or liens, investments, transactions with affiliates, delivery of financial statements, maintenance of inventory, payment of taxes, maintenance of insurance, protection of intellectual property rights, dispositions of property, business combinations or acquisitions, among other customary covenants. The Company is also restricted from paying dividends or making other distributions or payments on its capital stock, subject to limited exceptions. The Agreement provides that an event of default will occur if, among other triggers, there occurs any circumstances that could reasonably be expected to result in a material adverse change in the business, or operations or condition (financial or otherwise) of the Company or a material impairment of the prospect of the Company to repay any portion of its obligations under the Agreement. The Agreement also includes customary representations and warranties, other events of default and termination provisions.

In connection with entering into the Agreement, the Company issued to the Lenders warrants exercisable for 81,257 shares of the Company’s common stock (the “Warrants”). The Warrants are exercisable in whole or in part, immediately, and have a per share exercise price of $9.23, which is the closing price of the Company’s common stock reported on the Nasdaq Global Market on the day prior to the Effective Date. The Warrants will terminate on the earlier of February 28, 2030 or the closing of certain merger or consolidation transactions.

The foregoing is only a summary of the material terms of the Agreement and the Warrants, and does not purport to be complete and is qualified in its entirety by reference to the full text of the Agreement and the Warrants, which will be filed as exhibits to the Company’s Annual Report on Form 10-K for the year ended December 31, 2019.

Item 2.03.  Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant.

The information set forth under Item 1.01 above is hereby incorporated by reference into Item 2.03.

Item 3.02.  Unregistered Sales of Equity Securities.

The information set forth under Item 1.01 above that relates to the issuance of the Warrants is hereby incorporated by reference into Item 3.02.

The Warrants described in Item 1.01 above were offered and sold in reliance upon the exemption from registration provided by Section 4(a)(2) under the Securities Act of 1933, as amended (the “Securities Act”), in that the issuance of the Warrants did not involve a public offering.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.