# EDGAR Filing Document

**Accession Number:** 0001069308
**File Stem:** 0001193125-23-026904
**Filing Date:** 2023-2
**Character Count:** 9213
**Document Hash:** d2428af4b0ee21658a693cb126a0e63e
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-23-026904.hdr.sgml**: 20230207

**ACCESSION NUMBER**: 0001193125-23-026904

**CONFORMED SUBMISSION TYPE**: 8-K

**PUBLIC DOCUMENT COUNT**: 13

**CONFORMED PERIOD OF REPORT**: 20230207

**ITEM INFORMATION**: Other Events

**ITEM INFORMATION**: Financial Statements and Exhibits

**FILED AS OF DATE**: 20230207

**DATE AS OF CHANGE**: 20230207

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Acer Therapeutics Inc.
- **CENTRAL INDEX KEY:** 0001069308
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **IRS NUMBER:** 320426967
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 8-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-33004
- **FILM NUMBER:** 23595005

**BUSINESS ADDRESS:**
- **STREET 1:** ONE GATEWAY CENTER (300 WASHINGTON ST.)
- **STREET 2:** SUITE 356
- **CITY:** NEWTON
- **STATE:** MA
- **ZIP:** 02458
- **BUSINESS PHONE:** (844) 902-6100

**MAIL ADDRESS:**
- **STREET 1:** ONE GATEWAY CENTER (300 WASHINGTON ST.)
- **STREET 2:** SUITE 356
- **CITY:** NEWTON
- **STATE:** MA
- **ZIP:** 02458

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Opexa Therapeutics, Inc.
- **DATE OF NAME CHANGE:** 20060616

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** PharmaFrontiers Corp.
- **DATE OF NAME CHANGE:** 20051011

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** PHARMAFRONTIERS CORP
- **DATE OF NAME CHANGE:** 20040816

?xml version="1.0" encoding="utf-8" ? 8-K

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### UNITED STATES

### SECURITIES AND EXCHANGE COMMISSION

#### WASHINGTON, D.C. 20549

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### FORM 8-K

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#### 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 7, 2023

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## ACER THERAPEUTICS INC.

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

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| | | |
|:---|:---|:---|
| **Delaware** | **001-33004** | **32-0426967** |
| **(State or other jurisdiction**<br> **of incorporation)** | **(Commission**<br> **File Number)** | **(IRS Employer**<br> **Identification No.)** |

---

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| | |
|:---|:---|
| **One Gateway Center, Suite 356<br>300 Washington Street**<br> **Newton, Massachusetts** | **02458** |
| **(Address of principal executive offices)** | **(Zip Code)** |

---

#### Registrant's telephone number, including area code: (844) 902-6100

#### N/A

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

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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:

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| | | |
|:---|:---|:---|
| **Title of Each Class** | **Trading**<br> **Symbol** | **Name of Each Exchange**<br> **on Which Registered** |
| Common Stock, $0.0001 par value per share | ACER | The Nasdaq Stock Market LLC |

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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. ☐

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| | |
|:---|:---|
| **Item 8.01.** | **Other Events.**  |

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On February 7, 2023, Acer Therapeutics Inc. (the "Company") filed a prospectus supplement relating to the offer and sale from time to time of shares (the "Shares") of its common stock, $0.0001 par value per share, with an aggregate offering price of up to $11,000,000 pursuant to the Company's existing at-the-market (ATM) facility and Amended and Restated Sales Agreement, dated March 18, 2020, among the Company, JonesTrading Institutional Services LLC and Roth Capital Partners, LLC. A copy of the opinion of Pillsbury Winthrop Shaw Pittman LLP relating to the legality of the issuance and sale of the Shares is attached as Exhibit 5.1 hereto.

*This Current Report on Form 8-K shall not constitute an offer to sell or the solicitation of an offer to buy any Shares, nor shall there be any sale of Shares in any state or other jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or other jurisdiction.* 

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| | |
|:---|:---|
| **Item 9.01.** | **Financial Statements and Exhibits.**  |

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(d) Exhibits

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| | |
|:---|:---|
| Exhibit<br>No. | Description |
| &nbsp;&nbsp;&nbsp;&nbsp;5.1 | [Opinion of Pillsbury Winthrop Shaw Pittman LLP.](d435757dex51.htm) |
| 23.1 | [Consent of Pillsbury Winthrop Shaw Pittman LLP (included in Exhibit 5.1).](d435757dex51.htm) |
| 104 | Cover Page Interactive Data File (embedded within the Inline XBRL document). |

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#### 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, thereunto duly authorized.

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| | | |
|:---|:---|:---|
| Dated: February 7, 2023 | ACER THERAPEUTICS INC. | ACER THERAPEUTICS INC. |
|  | By: | /s/ Harry S. Palmin |
|  |  | Harry S. Palmin |
|  |  | Chief Financial Officer |

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## Exhibit 5.1

**Exhibit 5.1** 

PILLSBURY WINTHROP SHAW PITTMAN LLP

11682 El Camino Real, Suite 200

San Diego, CA 92130

February 7, 2023

Acer Therapeutics Inc.

One Gateway Center, Suite 356

300 Washington Street

Newton, MA 02458

Re: Registration Statement on Form S-3

Ladies and Gentlemen:

We are acting as counsel for Acer Therapeutics Inc., a Delaware corporation (the "Company"), in connection with the offer and sale of shares of common stock, $0.0001 par value per share, of the Company having an aggregate offering price of up to $11,000,000 (the "Shares"), all of which are authorized but heretofore unissued shares, pursuant to (i) the Registration Statement on Form S-3 (File No. 333-261342) as amended by Amendment No. 1 (the "Registration Statement"), filed by the Company with the Securities and Exchange Commission (the "Commission") under the Securities Act of 1933 (the "Act") on November 24, 2021, (ii) the related prospectus dated December 7, 2021, as supplemented by the prospectus supplements dated May 17, 2022 and February 7, 2023 relating to the offer and sale of the Shares (as so supplemented, the "Prospectus"), and (iii) the Amended and Restated Sales Agreement, dated as of March 18, 2020, by and among the Company, Roth Capital Partners, LLC and JonesTrading Institutional Services LLC (the "Agreement").

We have reviewed the Agreement, Registration Statement, the Prospectus and such other documents, records, certificates and other materials, and have reviewed and are familiar with such corporate proceedings and satisfied ourselves as to such other matters, as we have considered relevant or necessary as a basis for our opinions set forth in this letter. In such review, we have assumed the accuracy and completeness of all agreements, documents, records, certificates and other materials submitted to us, the conformity with the originals of all such materials submitted to us as copies (whether or not certified and including facsimiles), the authenticity of the originals of such materials and all materials submitted to us as originals, the genuineness of all signatures and the legal capacity of all natural persons.

On the basis of the assumptions and subject to the qualifications and limitations set forth herein, we are of the opinion that the Shares have been duly authorized and, when issued and sold by the Company in the manner described in the Registration Statement and the Prospectus and in accordance with the terms of the Agreement and the resolutions adopted by the Board of Directors of the Company, will be validly issued, fully paid and nonassessable.

Our opinions set forth in this letter are limited to the General Corporation Law of the State of Delaware, as in effect on the date hereof.

We hereby consent to the filing of this letter as Exhibit 5.1 to the Company's Current Report on Form 8-K filed by the Company with the Commission on the date hereof and the incorporation thereof in the Registration Statement and to the use of our name under the caption "Legal Matters" in the Prospectus. In giving this consent, we do not thereby admit that we are within the category of persons whose consent is required under Section 7 of the Act or the rules and regulations of the Commission thereunder.

Very truly yours,

/s/ Pillsbury Winthrop Shaw Pittman LLP