# EDGAR Filing Document

**Accession Number:** 0001968254
**File Stem:** 0001437749-26-018628
**Filing Date:** 2026-5
**Character Count:** 8417
**Document Hash:** ce56acc08f6cdba266b4c87b4f79c943
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001437749-26-018628.hdr.sgml**: 20260527

**ACCESSION NUMBER**: 0001437749-26-018628

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20260522

**FILED AS OF DATE**: 20260527

**DATE AS OF CHANGE**: 20260527

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Krempa David
- **CENTRAL INDEX KEY:** 0001968254

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-38738
- **FILM NUMBER:** 261027902

**MAIL ADDRESS:**
- **STREET 1:** 29125 W FIELD PARKWAY
- **STREET 2:** SUITE 235
- **CITY:** DEER PARK
- **STATE:** IL
- **ZIP:** 60010
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Eton Pharmaceuticals, Inc.
- **CENTRAL INDEX KEY:** 0001710340
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 371858472
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 21925 W. FIELD PARKWAY
- **STREET 2:** SUITE 235
- **CITY:** DEER PARK
- **STATE:** IL
- **ZIP:** 60010-7278
- **BUSINESS PHONE:** (847) 787-7361

**MAIL ADDRESS:**
- **STREET 1:** 21925 W. FIELD PARKWAY
- **STREET 2:** SUITE 235
- **CITY:** DEER PARK
- **STATE:** IL
- **ZIP:** 60010-7278

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## FORM 4

### STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

[ ] Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Krempa David<br><sub>(Last) (First) (Middle)</sub><br>C/O ETON PHARMACEUTICALS, INC.<br>21925 W. FIELD PARKWAY, SUITE 235<br><sub>(Street)</sub><br>DEERPARK, IL 60010-7208<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2026-05-22 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[ ] Director [ ] 10% Owner<br>[X] Officer (give title below) [ ] Other (specify below)<br>_Chief Business Officer_ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Eton Pharmaceuticals, Inc. [ ETON ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[X] Form filed by One Reporting Person<br>[ ] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | 3. Transaction Code (V) | 3. Transaction Code (V) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | Code | V | Amount | (A) or (D) | Price | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| Common Stock | 2026-05-22 |  | M |  | 30591 | A | $3.58 | 68046 | D |  |
| Common Stock | 2026-05-22 |  | S |  | 32963 | D | 33.2208<sup>(1)(7)</sup> | 35083 | D |  |
| Common Stock | 2026-05-22 |  | S |  | 9315 | D | 33.8802<sup>(1)(2)</sup> | 25768 | D |  |
| Common Stock | 2026-05-22 |  | S |  | 519 | D | $35 | 25249 | D |  |
| Common Stock | 2026-05-26 |  | M |  | 25000 | A | $1.38 | 50249 | D |  |
| Common Stock | 2026-05-26 |  | M |  | 12524 | A | $1.37 | 62773 | D |  |
| Common Stock | 2026-05-26 |  | S |  | 37524 | D | 31.4927<sup>(1)(3)</sup> | 25249 | D |  |
| Common Stock | 2026-05-27 |  | M |  | 12476 | A | $1.37 | 37725 | D |  |
| Common Stock | 2026-05-27 |  | M |  | 7203 | A | $3.58 | 44928 | D |  |
| Common Stock | 2026-05-27 |  | S |  | 19679 | D | 31.4739<sup>(1)(5)</sup> | 25249 | D |  |

---

## Table II - Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | 4. Transaction Code (V) | 4. Transaction Code (V) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 6. Date Exercisable and Expiration Date | 6. Date Exercisable and Expiration Date | 7. Title and Amount of Underlying Securities | 7. Title and Amount of Underlying Securities | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | Code | V | (A) | (D) | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| Employee Stock Option | $3.58 | 2026-05-22 |  | M |  |  | 30591 | 2020-03-12<sup>(4)</sup> | 2030-03-11 | Common Stock | 30591 | $0 | 125609 | D |  |
| Employee Stock Option | $1.38 | 2026-05-26 |  | M |  |  | 25000 | 2017-08-07<sup>(8)</sup> | 2027-08-06 | Common Stock | 25000 | $0 | 0 | D |  |
| Employee Stock Option | $1.37 | 2026-05-26 |  | M |  |  | 12524 | 2017-11-10<sup>(6)</sup> | 2027-11-09 | Common Stock | 12524 | $0 | 12476 | D |  |
| Employee Stock Option | $1.37 | 2026-05-27 |  | M |  |  | 12476 | 2017-11-10<sup>(6)</sup> | 2027-11-09 | Common Stock | 12476 | $0 | 0 | D |  |
| Employee Stock Option | $3.58 | 2026-05-27 |  | M |  |  | 7203 | 2020-03-12<sup>(4)</sup> | 2030-03-11 | Common Stock | 7203 | $0 | 118406 | D |  |

---

### Footnotes:

(1) The Reporting Person will provide upon request by the Securities and Exchange Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.

(2) The shares were sold in multiple trades at prices ranging from $33.68 to $34.66. The price reported above reflects the weighted average sales price.

(3) The shares were sold in multiple trades at prices ranging from $31.27 to $32.16.  The price reported above reflects the weighted average sales price.

(4) The shares subject to the option vested in 48 equal monthly installments from the date of grant (3-12-2020) until fully vested.

(5) The shares were sold in multiple trades at prices ranging from $31.25 to $31.825. The price reported above reflects the weighted average sales price.

(6) The shares subject to the option vested annually from the date of grant (11-10-2017) in four equal installments.

(7) The shares were sold in multiple trades at prices ranging from $32.67 to $33.65. The price reported above reflects the weighted average sales price.

(8) The shares subject to option vested annually from the date of grant (8-7-2017) in four equal installments.

**Remarks:**
The reporting person has authorized and designated the named person to file this Form 4 on the reporting person's behalf for indefinite duration.

**Signature:** /s/ Judith Matthews  
**Date:** 2026-05-27

### Remarks:

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

**Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.**