Exhibit 4.7

Form of Convertible Promissory Note

THIS INSTRUMENT AND THE SECURITIES ISSUABLE UPON THE CONVERSION HEREOF HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “ACT”). THEY MAY NOT BE SOLD, OFFERED FOR SALE, PLEDGED, HYPOTHECATED, OR OTHERWISE TRANSFERRED EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE ACT OR UPON RECEIPT BY THE COMPANY OF AN OPINION OF COUNSEL SATISFACTORY TO THE COMPANY THAT REGISTRATION IS NOT REQUIRED UNDER THE ACT.

CONVERTIBLE PROMISSORY NOTE

FOR VALUE RECEIVED, Eos SENOLYTIX, Inc., a Delaware corporation (the “Company”), hereby promises to pay to the order of [PURCHASER NAME] (the “Holder”), the principal sum of US$[PRINCIPAL AMOUNT], together with interest thereon from the date of this Note. Interest will accrue at a simple rate of eight percent (8%) per annum, payable at maturity. Unless earlier converted into Conversion Shares pursuant to Section 4 of that certain Securities Purchase Agreement dated [DATE], by and among the Company, the Holder and the other parties thereto (as may be amended and/or modified from time to time in accordance therewith, the “Purchase Agreement”), the principal and accrued interest of this Note will be due and payable by the Company on the Maturity Date.

This Convertible Promissory Note (this “Note”) is one of a series of Notes issued pursuant to the Purchase Agreement, and capitalized terms not defined herein will have the meanings set forth in the Purchase Agreement.

1. Payment. All payments will be made in lawful money of the United States of America at the principal office of the Company, or at such other place as the Holder may from time to time designate in writing to the Company. Payment will be credited first to accrued interest due and payable, with any remainder applied to principal. The Company may prepay the principal and accrued interest on this Note at any time in accordance with Section 4.4 of the Purchase Agreement.

2. Security. This Note is a general unsecured obligation of the Company.

3. Conversion of the Notes. This Note and any amounts due hereunder will be convertible into Conversion Shares in accordance with the terms of Section 4 of the Purchase Agreement.

4. Amendments and Waivers; Resolutions of Dispute; Notice. The amendment or waiver of any term of this Note, the resolution of any controversy or claim arising out of or relating to this Note and the provision of notice among the Company and the Holder will be governed by the terms of the Purchase Agreement.

5. Successors and Assigns. This Note applies to, inures to the benefit of, and binds the respective successors and assigns of the parties hereto; provided, however, that the Company may not assign its obligations under this Note without the written consent of the Requisite Noteholders. Any transfer of this Note may be effected only pursuant to the Purchase Agreement and by surrender of this Note to the Company and reissuance of a new note to the transferee. The Holder and any subsequent holder of this Note receives this Note subject to the foregoing terms and conditions, and agrees to comply with the foregoing terms and conditions for the benefit of the Company and any other Purchasers (or their respective successors or assigns).

6. Officers and Directors not Liable. In no event will any officer or director of the Company be liable for any amounts due and payable pursuant to this Note.

7. Limitation on Interest. In no event will any interest charged, collected or reserved under this Note exceed the maximum rate then permitted by applicable law, and if any payment made by the Company under this Note exceeds such maximum rate, then such excess sum will be credited by the Holder as a payment of principal.

8. Transfer of Notes. This Note may not be transferred without the prior written consent of the Company.

9. Events of Default. If there shall be any Event of Default (as defined below) hereunder, at the option and upon the declaration of the Requisite Noteholders and upon written notice to the Company (which election and notice shall not be required in the case of an Event of Default under subsection (ii) or (iii) below), this Note shall accelerate, and all principal and unpaid accrued interest shall become due and payable. In addition, upon the occurrence and during the continuance of any Event of Default, the outstanding principal balance of this Note shall bear interest at a rate equal to fifteen percent (15%) per annum (the “Default Rate”), in lieu of the interest rate otherwise applicable to this Note, from the date of such Event of Default until such Event of Default is cured or waived or this Note is paid in full, whichever occurs first. The occurrence of any one or more of the following shall constitute an “Event of Default”:

(i) the Company fails to pay timely any of the principal amount due under this Note on the date the same becomes due and payable or any unpaid accrued interest or other amounts due under this Note on the date the same becomes due and payable;

(ii) the Company files any petition or action for relief under any bankruptcy, reorganization, insolvency or moratorium law or any other law for the relief of, or relating to, debtors, now or hereafter in effect, or makes any assignment for the benefit of creditors or takes any corporate action in furtherance of any of the foregoing; or

(iii) an involuntary petition is filed against the Company (unless such petition is dismissed or discharged within 60 days under any bankruptcy statute now or hereafter in effect, or a custodian, receiver, trustee or assignee for the benefit of creditors (or other similar official) is appointed to take possession, custody or control of any property of the Company).

10. Company Waiver; Delays and Omissions. The Company hereby waives demand, notice, presentment, protest and notice of dishonor. It is agreed that no delay or omission to exercise any right, power or remedy accruing to the Holder, upon any breach or default of the Company under this Note shall impair any such right, power or remedy, nor shall it be construed to be a waiver of any such breach or default, or any acquiescence therein, or of or in any similar breach or default thereafter occurring; nor shall any waiver of any single breach or default be deemed a waiver of any other breach or default theretofore or thereafter occurring.

11. [California Corporate Securities Law. THE SALE OF THE SECURITIES WHICH ARE THE SUBJECT OF THIS NOTE HAS NOT BEEN QUALIFIED WITH THE COMMISSIONER OF CORPORATIONS OF THE STATE OF CALIFORNIA AND THE ISSUANCE OF SUCH SECURITIES OR THE PAYMENT OR RECEIPT OF ANY PART OF THE CONSIDERATION THEREFOR PRIOR TO SUCH QUALIFICATION OR IN THE ABSENCE OF AN EXEMPTION FROM SUCH QUALIFICATION IS UNLAWFUL. PRIOR TO ACCEPTANCE OF SUCH CONSIDERATION BY THE COMPANY, THE RIGHTS OF ALL PARTIES TO THIS NOTE ARE EXPRESSLY CONDITIONED UPON SUCH QUALIFICATION BEING OBTAINED OR AN EXEMPTION FROM SUCH QUALIFICATION BEING AVAILABLE.]¹

12. Choice of Law. This Note, and all matters arising out of or relating to this Note, whether sounding in contract, tort, or statute, will be governed by and construed in accordance with the internal laws of the State of Delaware, without giving effect to the conflict of laws provisions thereof to the extent such principles or rules would require or permit the application of the laws of any jurisdiction other than those of the State of Delaware.

13. Approval. The Company hereby represents that its board of directors, in the exercise of its fiduciary duty, has approved the Company’s execution of this Note based upon a reasonable belief that the principal provided hereunder is appropriate for the Company after reasonable inquiry concerning the Company’s financing objectives and financial situation. In addition, the Company hereby represents that it intends to use the principal of this Note primarily for the operations of its business, and not for any personal, family or household purpose.

¹ NTD: REMOVE IF NOT SOLD TO PURCHASER DOMICILED IN CA.