# EDGAR Filing Document

**Accession Number:** 0001442836
**File Stem:** 0001104659-23-026764
**Filing Date:** 2023-2
**Character Count:** 19616
**Document Hash:** 3f628ed759c2131d9a984e828882eb98
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-23-026764.hdr.sgml**: 20230228

**ACCESSION NUMBER**: 0001104659-23-026764

**CONFORMED SUBMISSION TYPE**: S-8

**PUBLIC DOCUMENT COUNT**: 6

**FILED AS OF DATE**: 20230228

**DATE AS OF CHANGE**: 20230228

**EFFECTIVENESS DATE**: 20230228

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Mersana Therapeutics, Inc.
- **CENTRAL INDEX KEY:** 0001442836
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **IRS NUMBER:** 000000000
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** S-8
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 333-270110
- **FILM NUMBER:** 23686172

**BUSINESS ADDRESS:**
- **STREET 1:** 840 MEMORIAL DRIVE
- **CITY:** CAMBRIDGE
- **STATE:** MA
- **ZIP:** 02139
- **BUSINESS PHONE:** 617-498-0020

**MAIL ADDRESS:**
- **STREET 1:** 840 MEMORIAL DRIVE
- **CITY:** CAMBRIDGE
- **STATE:** MA
- **ZIP:** 02139

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MERSANA THERAPEUTICS INC
- **DATE OF NAME CHANGE:** 20080813

As filed with the Securities and Exchange Commission on February 28, 2023

Registration No. 333-<u> </u>

**UNITED STATES**

**SECURITIES AND EXCHANGE COMMISSION**

**Washington, D.C. 20549**

**FORM S-8**

**REGISTRATION STATEMENT UNDER**

**THE SECURITIES ACT OF 1933**

**MERSANA THERAPEUTICS, INC.**

(Exact name of registrant as specified in its charter)

---

| | |
|:---|:---|
| **Delaware** | **04-3562403** |
| (State or Other Jurisdiction of Incorporation<br> or Organization) | (I.R.S. Employer<br> Identification No.) |
| **840 Memorial Drive**<br> **Cambridge, MA** | **02139** |
| (Address of Principal Executive Offices) | (Zip Code) |

---

**Mersana Therapeutics, Inc. 2017 Stock Incentive Plan**

**Mersana Therapeutics, Inc. 2017 Employee Stock Purchase Plan**

(Full Title of the Plans)

**Anna Protopapas**

**President and Chief Executive Officer**

**Mersana Therapeutics, Inc.**

**840 Memorial Drive**

**Cambridge, MA 02139**

(Name and Address of Agent For Service)

**(617) 498-0020**

(Telephone Number, Including Area Code, of Agent For Service)

***Copies to*** **:**

**Alejandra Carvajal, Esq.**

**Chief Legal Officer, Secretary**

**Mersana Therapeutics, Inc.**

**840 Memorial Drive**

**Cambridge, MA 02139**

**(617) 498-0020**

**Rosemary G. Reilly, Esq.**

**Craig Hilts, Esq.<br> Wilmer Cutler Pickering Hale and Dorr LLP<br> 60 State Street<br> Boston, Massachusetts 02109<br> (617) 526-6000**

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of "large accelerated filer," "accelerated filer," "smaller reporting company," and "emerging growth company" in Rule 12b-2 of the Exchange Act.

Large accelerated filer ◻ Accelerated filer ◻ <br> Non-accelerated filer ⌧ Smaller reporting company ⌧ <br> 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 7(a)(2)(B) of the Securities Act. ◻

**EXPLANATORY NOTE**

This Registration Statement has been filed by Mersana Therapeutics, Inc. (the "Registrant") to register (i) 4,205,794 additional shares of common stock, $0.0001 par value per share, of the Registrant (the "Common Stock") under the Mersana Therapeutics, Inc. 2017 Stock Incentive Plan (the "2017 Plan"), pursuant to the provisions of the 2017 Plan providing for an automatic increase in the number of shares reserved and available for issuance under the 2017 Plan on January 1, 2023 and (ii) 450,000 additional shares of Common Stock under the Mersana Therapeutics, Inc. 2017 Employee Stock Purchase Plan, as amended (the "2017 ESPP" and, together with the 2017 Plan, the "Plans"), pursuant to the provisions of the 2017 ESPP providing for an automatic increase in the number of shares reserved and available for issuance under the 2017 ESPP on January 1, 2023.

The Registrant previously filed with the Securities and Exchange Commission (the "SEC") (i) registration statements on Form S-8 (File Nos. [333-236775](https://www.sec.gov/Archives/edgar/data/1442836/000110465920027172/tm2011260d1_s8.htm), [333-230159](https://www.sec.gov/Archives/edgar/data/1442836/000110465919013638/a19-6106_1s8.htm) and [333-219388)](https://www.sec.gov/Archives/edgar/data/1442836/000110465917046155/a17-18222_1s8.htm) on February 28, 2020, March 8, 2019 and July 21, 2017, respectively, with respect to the Plans (the "Prior Combined Registration Statements") and (ii) registration statements on Form S-8 (File Nos. [333-263085](https://www.sec.gov/Archives/edgar/data/1442836/000110465922028125/tm227614d1_s8.htm), [333-255975](https://www.sec.gov/Archives/edgar/data/1442836/000110465921064019/tm2115779d2_s8.htm) and [333-222845)](https://www.sec.gov/Archives/edgar/data/1442836/000110465918006237/a18-5194_1s8.htm) on February 28, 2022, May 10, 2021 and February 2, 2018, respectively, with respect to the 2017 Plan (collectively, the "Prior 2017 Plan Registration Statements" and together with the Prior Combined Registration Statements, the "Prior Registration Statements"). This Registration Statement relates to securities of the same class as that to which the Prior Registration Statements relate and is submitted in accordance with General Instruction E to Form S-8 regarding registration of additional securities. In accordance with such instruction, except as otherwise set forth below, the contents of the Prior Registration Statements relating to the Plans are incorporated herein by reference.

**Item 8.** **Exhibits.**

---

| | |
|:---|:---|
| <u>Number</u> | <u>Description</u> |
| [4.1](https://www.sec.gov/Archives/edgar/data/1442836/000110465922070125/tm2218123d1_ex3-1.htm) | [Fifth Amended and Restated Certificate of Incorporation of the Registrant, as amended, as of June 9, 2022 (incorporated by reference to Exhibit 3.1 to the Current Report on Form 8-K (File No. 001-38129) filed with the SEC on June 10, 2022).](https://www.sec.gov/Archives/edgar/data/1442836/000110465922070125/tm2218123d1_ex3-1.htm) |
| [4.2](https://www.sec.gov/Archives/edgar/data/1442836/000110465917044267/a17-17109_1ex3d2.htm) | [Amended and Restated Bylaws of the Registrant (incorporated by reference to Exhibit 3.2 to the Current Report on Form 8-K (File No. 001-38129) filed with the SEC on July 10, 2017).](https://www.sec.gov/Archives/edgar/data/1442836/000110465917044267/a17-17109_1ex3d2.htm) |
| [5.1\*](tm238018d1_ex5-1.htm) | [Opinion of Wilmer Cutler Pickering Hale and Dorr LLP, counsel to the Registrant](tm238018d1_ex5-1.htm) |
| [23.1\*](tm238018d1_ex5-1.htm) | [Consent of Wilmer Cutler Pickering Hale and Dorr LLP (included in Exhibit 5.1)](tm238018d1_ex5-1.htm) |
| [23.2\*](tm238018d1_ex23-2.htm) | [Consent of Ernst & Young LLP, independent registered public accounting firm](tm238018d1_ex23-2.htm) |
| [24.1\*](#S_001) | [Power of attorney (included on the signature pages of this registration statement)](#S_001) |
| [99.1](https://www.sec.gov/Archives/edgar/data/1442836/000104746917004050/a2232415zex-10_22.htm) | [Mersana Therapeutics, Inc. 2017 Stock Incentive Plan (incorporated by reference to Exhibit 10.22 to Amendment No. 1 to Registration Statement on Form S-1 (File No. 333-218412) filed with the SEC on June 16, 2017).](https://www.sec.gov/Archives/edgar/data/1442836/000104746917004050/a2232415zex-10_22.htm) |
| [99.2](https://www.sec.gov/Archives/edgar/data/1442836/000104746917004050/a2232415zex-10_23.htm) | [Form of Incentive Stock Option Agreement under the Mersana Therapeutics, Inc. 2017 Stock Incentive Plan (incorporated by reference to Exhibit 10.23 to Amendment No. 1 to Registration Statement on Form S-1 (File No. 333-218412) filed with the SEC on June 16, 2017).](https://www.sec.gov/Archives/edgar/data/1442836/000104746917004050/a2232415zex-10_23.htm) |
| [99.3](https://www.sec.gov/Archives/edgar/data/1442836/000104746917004050/a2232415zex-10_24.htm) | [Form of Nonqualified Stock Option Agreement under the Mersana Therapeutics, Inc. 2017 Stock Incentive Plan (incorporated by reference to Exhibit 10.24 to Amendment No. 1 to Registration Statement on Form S-1 (File No. 333-218412) filed with the SEC on June 16, 2017).](https://www.sec.gov/Archives/edgar/data/1442836/000104746917004050/a2232415zex-10_24.htm) |
| [99.4](https://www.sec.gov/Archives/edgar/data/1442836/000162828021016000/exhibit10110-q2021q2.htm) | [Form of Restricted Stock Unit Agreement under the Mersana Therapeutics, Inc. 2017 Stock Incentive Plan (incorporated by reference to Exhibit 10.1 to the Quarterly Report on Form 10-Q (File No. 001-38129) filed with the SEC on August 6, 2021).](https://www.sec.gov/Archives/edgar/data/1442836/000162828021016000/exhibit10110-q2021q2.htm) |
| [99.5](http://www.sec.gov/Archives/edgar/data/1442836/000162828023005376/exhibit1040mersana-espp201.htm) | [Mersana Therapeutics, Inc. 2017 Employee Stock Purchase Plan, as amended (incorporated by reference to Exhibit 10.40 to the Annual Report on Form 10-K (File No. 001-38129) filed with the SEC on February 28, 2023).](http://www.sec.gov/Archives/edgar/data/1442836/000162828023005376/exhibit1040mersana-espp201.htm) |
| [107\*](tm238018d1_ex-filingfees.htm) | [Filing Fee Table](tm238018d1_ex-filingfees.htm) |

---

\* Filed herewith.

**SIGNATURES**

Pursuant to the requirements of the Securities Act of 1933, as amended, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Cambridge, Commonwealth of Massachusetts, on February 28, 2023.

---

| | | |
|:---|:---|:---|
| **MERSANA THERAPEUTICS, INC.** | **MERSANA THERAPEUTICS, INC.** | **MERSANA THERAPEUTICS, INC.** |
| By: | /s/ Anna Protopapas | /s/ Anna Protopapas |
|  | Name: | Anna Protopapas |
|  | President and Chief Executive Officer | President and Chief Executive Officer |

---

**SIGNATURES AND POWER OF ATTORNEY**

We, the undersigned officers and directors of Mersana Therapeutics, Inc., hereby severally constitute and appoint Anna Protopapas and Brian DeSchuytner, and each of them singly (with full power to each of them to act alone), our true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution in each of them for him or her and in his or her name, place and stead, and in any and all capacities, to sign any and all amendments (including post-effective amendments) to this Registration Statement on Form S-8 of Mersana Therapeutics, Inc. and to file the same, with all exhibits thereto and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite or necessary to be done in and about the premises, as full to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents or any of them or their or his or her substitute or substitutes may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed by the following persons in the capacities indicated on February 28, 2023.

---

| | |
|:---|:---|
| **Signature** | **Title** |
| /s/ Anna Protopapas | President, Chief Executive Officer, and Director |
| Anna Protopapas | (*Principal Executive Officer*) |
| /s/ Brian DeSchuytner | Senior Vice President, Chief Financial Officer |
| Brian DeSchuytner | (*Principal Financial Officer*) |
| /s/Ashish Mandelia | Vice President, Controller |
| Ashish Mandelia | (*Principal Accounting Officer)* |
| /s/ David Mott | Director, Chairman of the Board |
| David Mott |  |
| /s/ Lawrence Alleva | Director |
| Lawrence Alleva |  |
| /s/ Willard H. Dere, M.D. | Director |
| Willard H. Dere, M.D. |  |
| /s/ Allene M. Diaz | Director |
| Allene M. Diaz |  |
| /s/ Andrew A. F. Hack, M.D., Ph.D. | Director |
| Andrew A. F. Hack, M.D., Ph.D. |  |
| /s/ Kristen Hege, M.D. | Director |
| Kristen Hege, M.D. |  |
| /s/ Martin H. Huber, M.D. | Director |
| Martin H. Huber, M.D. |  |

---

## Exhibit 5.1

**Exhibit 5.1**

![](tm238018d1_ex5-1img01.jpg)

+1 617 526 6000 (t)

+1 617 526 5000 (f)

February 28, 2023

Mersana Therapeutics, Inc.

840 Memorial Drive

Cambridge, Massachusetts 02139

Re: <u>Registration Statement on Form S-8; 2017 Stock Incentive Plan; 2017 Employee Stock Purchase Plan</u>

Ladies and Gentlemen:

We have assisted in the preparation of a Registration Statement on Form S-8 (the "Registration Statement") to be filed with the Securities and Exchange Commission (the "Commission") under the Securities Act of 1933, as amended (the "Securities Act"), relating to (i) an aggregate of 4,205,794 additional shares (the "Plan Shares") of common stock, $0.0001 par value per share (the "Common Stock"), of Mersana Therapeutics, Inc., a Delaware corporation (the "Company"), issuable under the Company's 2017 Stock Incentive Plan (the "2017 Plan"), and (ii) an aggregate of 450,000 additional shares (the "ESPP Shares" and together with the Plan Shares, the "Shares") of Common Stock issuable under the Company's 2017 Employee Stock Purchase Plan (the "2017 ESPP" and together with the 2017 Plan, the "Plans").

We have examined the Certificate of Incorporation and Bylaws of the Company, each as amended and restated to date, and originals, or copies certified to our satisfaction, of all pertinent records of the meetings of the board of directors and stockholders of the Company, the Registration Statement, the Plans and such other documents relating to the Company as we have deemed material for the purposes of this opinion.

In our examination of the foregoing documents, we have assumed the genuineness of all signatures, the authenticity of all documents submitted to us as originals, the conformity to original documents of all documents submitted to us as certified, photostatic or other copies, the authenticity of the originals of any such documents and the legal competence of all signatories to such documents.

We assume that the appropriate action will be taken, prior to the offer and sale of the Shares in accordance with the Plans, as applicable, to register and qualify the Shares for sale under all applicable state securities or "blue sky" laws.

We express no opinion herein as to the laws of any state or jurisdiction other than the General Corporation Law of the State of Delaware.

![](tm238018d1_ex5-1img002.jpg)

Mersana Therapeutics, Inc.

February 28, 2023

![](tm238018d1_ex5-1img01.jpg)

It is understood that this opinion is to be used only in connection with the offer and sale of the Shares while the Registration Statement is in effect.

Please note that we are opining only as to the matters expressly set forth herein, and no opinion should be inferred as to any other matters.

Based on the foregoing, we are of the opinion that the Shares have been duly authorized for issuance and, when the Shares are issued and paid for in accordance with the terms and conditions of the Plans, as applicable, the Shares will be validly issued, fully paid and nonassessable.

We hereby consent to the filing of this opinion with the Commission in connection with the Registration Statement in accordance with the requirements of Item 601(b)(5) of Regulation S-K under the Securities Act. In giving such consent, we do not hereby admit that we are in the category of persons whose consent is required under Section 7 of the Securities Act or the rules and regulations of the Commission.

---

| |
|:---|
| Very truly yours, |
| /s/ WILMER CUTLER PICKERING HALE AND DORR LLP |
| Wilmer Cutler Pickering Hale and Dorr LLP |

---

## Exhibit 23.2

**Exhibit 23.2**

**Consent of Independent Registered Public Accounting Firm**

We consent to the incorporation by reference in the Registration Statement (Form S-8) pertaining to the 2017 Stock Incentive Plan and 2017 Employee Stock Purchase Plan of Mersana Therapeutics, Inc. of our report dated February 28, 2023, with respect to the consolidated financial statements of Mersana Therapeutics, Inc. included in its Annual Report (Form 10-K) for the year ended December 31, 2022, filed with the Securities and Exchange Commission.

*/s/ Ernst & Young LLP*

Boston, Massachusetts

February 28, 2023

## Ex-Filing

**Exhibit 107**

**Calculation of Filing Fee Tables**

**Form S-8**

(Form Type)

**Mersana Therapeutics, Inc.**

(Exact Name of Registrant as Specified in its Charter)

**Table 1—Newly Registered Securities**

---

| | | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| **Security <br> Type** | **Security Class <br> Title** | **Fee<br> Calculation<br> Rule** | **Amount<br> Registered <br> (1)** |  | **Proposed <br> Maximum<br> Offering Price<br> Per Unit** |  | **Maximum <br> Aggregate <br> Offering Price** | **Fee Rate** | **Amount of <br> Registration <br> Fee** |
| Equity | Common Stock, $0.0001 par value per share | Other | 4655794 | (2) | $5.52 | (3) | $25699983 | $110.20 per $1,000,000 | $2832.14 |
| **Total Offering Amounts** | **Total Offering Amounts** | **Total Offering Amounts** | **Total Offering Amounts** |  |  |  | $25699983 |  | $2832.14 |
| **Total Fee Offsets** | **Total Fee Offsets** | **Total Fee Offsets** | **Total Fee Offsets** |  |  |  |  |  |  |
| **Net Fee Due** | **Net Fee Due** | **Net Fee Due** | **Net Fee Due** |  |  |  |  |  | $2832.14 |

---

(1) In accordance with Rule 416 under the Securities Act of 1933, as amended (the "Securities Act"), this Registration Statement shall be deemed to cover any additional securities that may from time to time become issuable by reason of any stock dividend, stock split, recapitalization or any other similar transaction effected without the receipt of consideration which results in an increase in the number of outstanding shares of the Registrant's common stock.

(2) Consists of (a) 4,205,794 additional shares issuable under the Mersana Therapeutics, Inc. 2017 Stock Incentive Plan (the "2017 Plan") and (b) 450,000 additional shares issuable under the Mersana Therapeutics, Inc. 2017 Employee Stock Purchase Plan, as amended (the "2017 ESPP").

(3) Estimated solely for the purpose of calculating the registration fee pursuant to Rules 457(c) and 457(h) under the Securities Act. The proposed maximum offering price per share and maximum aggregate offering price are calculated based on (a) $5.76, the weighted average per share exercise price of 2,852,312 shares subject to outstanding stock option grants under the 2017 Plan, at exercise prices ranging from $3.62 to $7.76 per share and (b) $5.33, the average of the high and low sale prices of the Registrant's common stock as reported on the Nasdaq Global Select Market on February 24, 2023, for 1,353,482 shares issuable under the 2017 Plan and the 450,000 shares issuable under the 2017 ESPP. Pursuant to the 2017 ESPP, the purchase price of the shares of common stock reserved for issuance thereunder will be 85% of the lower of the fair market value of the common stock on (i) the first trading day of the applicable offering period and (ii) the exercise date.