# EDGAR Filing Document

**Accession Number:** 0001701108
**File Stem:** 0001193125-25-142807
**Filing Date:** 2025-6
**Character Count:** 7238
**Document Hash:** 508697dae01c95b896987f20d7ff9b00
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-25-142807.hdr.sgml**: 20250618

**ACCESSION NUMBER**: 0001193125-25-142807

**CONFORMED SUBMISSION TYPE**: 8-K

**PUBLIC DOCUMENT COUNT**: 12

**CONFORMED PERIOD OF REPORT**: 20250612

**ITEM INFORMATION**: Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers: Compensatory Arrangements of Certain Officers

**ITEM INFORMATION**: Submission of Matters to a Vote of Security Holders

**FILED AS OF DATE**: 20250618

**DATE AS OF CHANGE**: 20250618

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Spero Therapeutics, Inc.
- **CENTRAL INDEX KEY:** 0001701108
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 000000000
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 8-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-38266
- **FILM NUMBER:** 251057831

**BUSINESS ADDRESS:**
- **STREET 1:** 675 MASSACHUSETTS AVENUE
- **STREET 2:** 14TH FLOOR
- **CITY:** CAMBRIDGE
- **STATE:** MA
- **ZIP:** 02139
- **BUSINESS PHONE:** 857-242-1600

**MAIL ADDRESS:**
- **STREET 1:** 675 MASSACHUSETTS AVENUE
- **STREET 2:** 14TH FLOOR
- **CITY:** CAMBRIDGE
- **STATE:** MA
- **ZIP:** 02139

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Spero Therapeutics, LLC
- **DATE OF NAME CHANGE:** 20170316

?xml version='1.0' encoding='ASCII'? 8-K

### 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): June 12, 2025

## SPERO THERAPEUTICS, INC.

#### (Exact name of registrant as specified in its charter)

---

| | | |
|:---|:---|:---|
| **Delaware** | **001-38266** | **46-4590683** |
| **(State or other jurisdiction**<br> **of incorporation)** | **(Commission**<br> **File Number)** | **(I.R.S. Employer**<br> **Identification No.)** |

---

---

| | |
|:---|:---|
| **675 Massachusetts Avenue, 14<sup>th</sup> Floor** |  |
| **Cambridge, Massachusetts** | **02139** |
| **(Address of principal executive offices)** | **(Zip Code)** |

---

#### Registrant's telephone number, including area code (857) 242-1600
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:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

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

---

| | | |
|:---|:---|:---|
| **Title of each class** | **Trading**<br> **Symbol(s)** | **Name of each exchange**<br> **on which registered** |
| Common Stock, $0.001 par value | SPRO | The Nasdaq Global Select Market |

---

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 5.02** | **Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers**  |

---

At the 2025 Annual Meeting of Stockholders (the "Annual Meeting") of Spero Therapeutics, Inc. (the "Company") held on June 12, 2025, the Company's stockholders approved an amendment to the Company's 2017 Stock Incentive Plan, as amended (the "2017 Plan") to increase the total number of shares of the Company's common stock authorized for issuance under the 2017 Plan by 3,000,000 shares.

A detailed summary of the material features of the 2017 Plan, as amended, is set forth in the [Company's definitive proxy statement (the "Proxy Statement") for its Annual Meeting filed with the Securities and Exchange Commission on April 28, 2025](http://www.sec.gov/Archives/edgar/data/../../../ix?doc=/Archives/edgar/data/0001701108/000119312525100544/d797305ddef14a.htm#tx797305_12), which summary is incorporated herein by reference.

---

| | |
|:---|:---|
| **Item 5.07** | **Submission of Matters to a Vote of Stockholders**  |

---

On June 12, 2025, the Company held its Annual Meeting. Of the 55,910,641 shares of common stock issued and outstanding and eligible to vote as of the record date of April 21, 2025, a quorum of 40,015,633 shares, or approximately 71.57% of the outstanding shares, were present in person or by proxy.

The following actions were taken at the Annual Meeting:

1. The following nominees were reelected to serve on the Company's board of directors as Class II directors until the Company's 2028 annual meeting of stockholders, based on the following votes:

---

| | | | |
|:---|:---|:---|:---|
| **Name** | **Votes For** | **Votes Withheld** | **Broker Non-Votes** |
|  Frank E. Thomas | 25722977 | 449223 | 13843433 |
|  Patrick Vink, M.D. | 23247371 | 2924829 | 13843433 |
|  Esther Rajavelu | 25678198 | 494002 | 13843433 |

---

2. The selection of PricewaterhouseCoopers LLP as the Company's independent registered public accounting firm for the fiscal year ending December 31, 2025 was ratified, based on the following votes:

---

| | | | |
|:---|:---|:---|:---|
| **Votes For** | **Votes Against** | **Votes Abstained** | **Broker Non-Votes** |
| 39837359 | 174980 | 3294 | N/A |

---

3. The advisory vote of the compensation of the Company's named executive officers, as described in the Proxy Statement, was approved, based on the following votes:

---

| | | | |
|:---|:---|:---|:---|
| **Votes For** | **Votes Against** | **Votes Abstained** | **Broker Non-Votes** |
| 25178672 | 638744 | 354784 | 13843433 |

---

4. The amendment to the 2017 Plan to increase the total number of shares of common stock authorized for issuance thereunder by 3,000,000 shares, was approved, based on the following votes:

---

| | | | |
|:---|:---|:---|:---|
| **Votes For** | **Votes Against** | **Votes Abstained** | **Broker Non-Votes** |
| 22965487 | 3154609 | 52104 | 13843433 |

---

------

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

---

| | | |
|:---|:---|:---|
| Date: June 18, 2025 | **SPERO THERAPEUTICS, INC.** | **SPERO THERAPEUTICS, INC.** |
|  | By: | /s/ Esther Rajavelu |
|  |  | Esther Rajavelu |
|  |  | Chief Executive Officer, Chief Financial Officer and Chief Business Officer |

---