# EDGAR Filing Document

**Accession Number:** 0001786205
**File Stem:** 0001104659-26-050371
**Filing Date:** 2026-4
**Character Count:** 8922
**Document Hash:** 25c7ff4d380f18b2756cc2e92d615347
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-26-050371.hdr.sgml**: 20260428

**ACCESSION NUMBER**: 0001104659-26-050371

**CONFORMED SUBMISSION TYPE**: S-8 POS

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20260428

**DATE AS OF CHANGE**: 20260428

**EFFECTIVENESS DATE**: 20260428

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Arcellx, Inc.
- **CENTRAL INDEX KEY:** 0001786205
- **STANDARD INDUSTRIAL CLASSIFICATION:** BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 472855917
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** S-8 POS
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 333-262571
- **FILM NUMBER:** 26908129

**BUSINESS ADDRESS:**
- **STREET 1:** 800 BRIDGE PARKWAY
- **CITY:** REDWOOD CITY
- **STATE:** CA
- **ZIP:** 94065
- **BUSINESS PHONE:** 240-327-0603

**MAIL ADDRESS:**
- **STREET 1:** 800 BRIDGE PARKWAY
- **CITY:** REDWOOD CITY
- **STATE:** CA
- **ZIP:** 94065

**As filed with the Securities and Exchange Commission on April 28, 2026**

**Registration No. 333-262571**

**Registration No. 333-269105**

**Registration No. 333-276346**

**Registration No. 333-284136**

**Registration No. 333-292559**

**UNITED STATES**

**SECURITIES AND EXCHANGE COMMISSION**

**Washington, D.C. 20549**

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**POST-EFFECTIVE AMENDMENT NO. 1 TO FORM S-8 REGISTRATION STATEMENT NO. 333-262571**

**POST-EFFECTIVE AMENDMENT NO. 1 TO FORM S-8 REGISTRATION STATEMENT NO. 333-269105**

**POST-EFFECTIVE AMENDMENT NO. 1 TO FORM S-8 REGISTRATION STATEMENT NO. 333-276346**

**POST-EFFECTIVE AMENDMENT NO. 1 TO FORM S-8 REGISTRATION STATEMENT NO. 333-284136**

**POST-EFFECTIVE AMENDMENT NO. 1 TO FORM S-8 REGISTRATION STATEMENT NO. 333-292559**

**FORM S-8**

**REGISTRATION STATEMENT**

***UNDER***

***THE SECURITIES ACT OF 1933***

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**Arcellx, Inc.**

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

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| | |
|:---|:---|
| **Delaware** | **47-2855917** |
| **(State or other jurisdiction of<br> incorporation or organization)** | **(IRS employer**<br> **identification number)** |

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**800 Bridge Parkway**

**Redwood City, CA 94065**

**(Address of Principal Executive Offices)**

**2022 Equity Incentive Plan**

**2017 Equity Incentive Plan**

**2022 Employee Stock Purchase Plan**

**(Full title of the Plans)**

**Andrew D. Dickinson**

**President and Treasurer**

**Arcellx, Inc.**

**333 Lakeside Drive**

**Foster City, CA 94404**

**(Name and address of agent for service)**

**(240) 327-0630**

**(Telephone number, including area code, of agent for service)**

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**Copy to:**

**Emily Oldshue**

 **Nicholas Roper**

 **Ropes & Gray LLP**

**Prudential Tower, 800 Boylston Street** 

**Boston, Massachusetts 02199** 

**(617) 951-7000**

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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 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 x 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. ◻

**DEREGISTRATION OF SECURITIES**

These Post-Effective Amendments (these "<u>Post-Effective Amendments</u>") are being filed by Arcellx, Inc. (the "<u>Registrant</u>") to deregister all shares of the Registrant's common stock, par value $0.001 per share ("<u>Shares</u>"), that remain unissued under the following Registration Statements on Form S-8 (each, a "<u>Registration Statement</u>", and collectively, the "<u>Registration Statements</u>") previously filed by the Registrant with the U.S. Securities and Exchange Commission (the "<u>SEC</u>"):

· [Registration Statement No. 333-262571](https://www.sec.gov/Archives/edgar/data/1786205/000119312522029800/d269275ds8.htm) pertaining to the registration of (i) 1,512,859 Shares issuable under the Registrant's
 2022 Equity Incentive Plan (the " <u>2022 Plan</u> "), (ii) 2,784,016 Shares issuable pursuant to options outstanding
 under the Registrant's 2022 Plan, (iii) 312,500 Shares issuable under the Registrant's 2022 Employee Stock Purchase
 Plan (the " <u>2022 ESPP</u> "), (iv) 5,316,437 Shares issuable pursuant to options outstanding under the Registrant's
 2017 Equity Incentive Plan (the " <u>2017 Plan</u> ") and (v) 952,804 Shares issuable pursuant to restricted stock
 units outstanding under the Registrant's 2017 Plan, which was filed with the SEC on February 7, 2022.

· [Registration Statement No. 333-269105](https://www.sec.gov/Archives/edgar/data/1786205/000119312523000861/d428807ds8.htm) pertaining to the registration of (i) 2,205,299 Shares issuable under the Registrant's
 2022 Plan and (ii) 312,500 Shares issuable under the Registrant's 2022 ESPP, as amended and restated, which was filed
 with the SEC on January 3, 2023.

· [Registration Statement No. 333-276346](https://www.sec.gov/Archives/edgar/data/1786205/000119312524000702/d54365ds8.htm) pertaining to the registration of (i) 2,613,888 Shares issuable under the Registrant's
 2022 Plan and (ii) 312,500 Shares issuable under the Registrant's 2022 ESPP, as amended and restated, which was filed
 with the SEC on January 2, 2024.

· [Registration Statement No. 333-284136](https://www.sec.gov/Archives/edgar/data/1786205/000119312525001660/d833036ds8.htm) pertaining to the registration of (i) 2,714,041 Shares issuable under the Registrant's
 2022 Plan and (ii) 312,500 Shares issuable under the Registrant's 2022 ESPP, as amended and restated, which was filed
 with the SEC on January 6, 2025.

· [Registration Statement No. 333-292559](https://www.sec.gov/Archives/edgar/data/1786205/000119312526000940/d75969ds8.htm) pertaining to the registration of (i) 2,895,867 Shares issuable under the Registrant's
 2022 Plan and (ii) 312,500 Shares issuable under the Registrant's 2022 ESPP, as amended and restated, which was filed
 with the SEC on January 2, 2026.

On April 28, 2026, pursuant to an Agreement and Plan of Merger (the "<u>Merger Agreement</u>"), dated as of February 22, 2026, by and among the Registrant, Gilead Sciences, Inc. ("<u>Parent</u>") and Ravens Sub, Inc. ("<u>Merger Sub</u>"), Merger Sub merged with and into the Registrant (the "<u>Merger</u>"), with the Registrant continuing as the surviving corporation and becoming a wholly owned subsidiary of Parent. As a result of the transactions contemplated by the Merger Agreement, the Registrant has terminated any and all offerings and sales of securities pursuant to the Registration Statements. In accordance with the undertakings made by the Registrant in each Registration Statement to remove from registration, by means of a post-effective amendment, any of the securities of the Registrant registered under such Registration Statement which remain unsold at the termination of the offering, the Registrant hereby terminates the effectiveness of each Registration Statement and removes from registration all of the securities that remain unsold under each Registration Statement as of the date hereof, if any. Each Registration Statement is hereby amended, as appropriate, to reflect the deregistration of such securities. After giving effect to these Post-Effective Amendments, there will be no remaining securities registered by the Registrant pursuant to the Registration Statements.

The foregoing description of the Merger, the Merger Agreement and the transactions contemplated thereby does not purport to be complete and is subject to, and qualified in its entirety by, the Merger Agreement, which is attached as [Exhibit 2.1](https://www.sec.gov/Archives/edgar/data/1786205/000119312526063955/d112937dex21.htm) to the Registrant's Current Report on Form 8-K filed with the SEC on February 23, 2026.

**SIGNATURE**

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 these Post-Effective Amendments to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Redwood City, State of California, on April 28, 2026.

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| | |
|:---|:---|
| **ARCELLX, INC.** | **ARCELLX, INC.** |
| By: | /s/ Andrew D. Dickinson |
|  | Name: Andrew D. Dickinson |
|  | Title: President and Treasurer |

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No other person is required to sign these Post-Effective Amendments in reliance upon Rule 478 under the Securities Act of 1933, as amended.