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): August 8, 2022

Harpoon Therapeutics, Inc.

(Exact name of Registrant as Specified in Its Charter)

(650) 443-7400

(Registrant’s Telephone Number, Including Area Code)

Not Applicable

(Former Name or Former Address, if Changed Since Last Report)

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 (see General Instructions A.2. below):

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

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 2.02 Results of Operations and Financial Condition.

On August 10, 2022, Harpoon Therapeutics, Inc. (“Harpoon”) issued a press release announcing its financial results for the three and six month periods ended June 30, 2022. A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated herein by reference.

The information in this Item 2.02 of this Form 8-K and the Exhibit 99.1 attached hereto shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that Section, or incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

On August 8, 2022, Georgia L. Erbez informed Harpoon of her intention to resign from her position as Harpoon’s Chief Financial Officer. Such resignation is expected to be effective as of August 31, 2022. Harpoon has initiated a replacement search, and Ms. Erbez has agreed to continue with Harpoon as a consultant to assist with the transition as needed until December 31, 2022. Harpoon and Ms. Erbez expect to enter into a consulting agreement, which will be described in a future Current Report on Form 8-K to be filed by Harpoon.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

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SIGNATURES

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.

Dated: August 10, 2022

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EX99.1

FOR IMMEDIATE RELEASE

Harpoon Therapeutics Reports Second Quarter 2022 Financial Results and Provides Corporate Update

Presented encouraging interim data for anti-DLL3 T cell engager HPN328 from ongoing dose escalation clinical trial at the 2022 ASCO Annual Meeting

Portfolio prioritization and resource alignment strengthens support for the advancement of HPN328, HPN217 and HPN601

SOUTH SAN FRANCISCO, Calif., August 10, 2022 - Harpoon Therapeutics, Inc. (Nasdaq: HARP), a clinical-stage immunotherapy company developing novel T cell engagers, today reported financial results for the second quarter ended June 30, 2022 and provided a corporate update.

“We continue to focus our resources and efforts on lead programs HPN328 and HPN217 from the TriTAC® platform and next generation ProTriTAC® T cell engager HPN601 to address unmet needs in both solid and liquid tumors,” said Julie Eastland, President and Chief Executive Officer of Harpoon Therapeutics. “We are making changes in resource allocation to ensure Harpoon is well positioned for future success in the current challenging biotech climate. The HPN536 program shows promise however, requires continued dose optimization. Based on our decision to prioritize other assets in our portfolio, we will seek a partnership for further development of this program in monotherapy and combination settings. As a result of our focus and cost saving initiatives, we expect our current cash balance to extend into the second half of 2023.”

Ms. Eastland continued, “Georgia Erbez, CFO, has decided to pursue a COO opportunity. We would like to thank Georgia for her leadership and financial stewardship since joining the company in 2018. Georgia built an organization that can provide the necessary support until we fill this role. We wish her continued success in her future endeavors.”

Recent Highlights and Upcoming Milestones

Tri-specific T cell Activating Construct (TriTAC®) Platform
 

HPN328 (DLL3) Phase 1/2 trial in small cell lung cancer (SCLC) and other neuroendocrine cancers

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HPN217 (BCMA) Phase 1/2 trial for relapsed, refractory multiple myeloma

HPN536 (MSLN) Phase 1/2a trial in ovarian cancer and other solid tumors

ProTriTAC™
 

ProTriTAC™ is a conditionally active T cell engager platform designed to be preferentially active in the tumor. This enables Harpoon’s T cell engagers to address more broadly expressed solid tumor targets across multiple tumor types.

HPN601 (EpCAM)

TriTAC-XR®
 

The proprietary TriTAC-XR extended-release T cell engager platform is designed to minimize on-target cytokine release syndrome (CRS), a characteristic of many T cell engagers that can lead to dose limiting toxicities and reduce the efficacy of these potent anti-tumor drugs.

Nomination of a second clinical candidate from one of our new platforms is expected by the end of 2022.

Corporate Update

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Second Quarter 2022 Financial Results

About Harpoon Therapeutics

Harpoon Therapeutics is a clinical-stage immunotherapy company developing a novel class of T cell engagers that harness the power of the body’s immune system to treat patients suffering from cancer and other diseases. T cell engagers are engineered proteins that direct a patient’s own T cells to kill target cells that express specific proteins, or antigens, carried by the target cells. Using its proprietary Tri-specific T cell Activating Construct (TriTAC®) platform, Harpoon is developing a pipeline of novel TriTACs initially focused on the treatment of solid tumors and hematologic malignancies. Harpoon has also developed a proprietary ProTriTAC™ platform, which applies a prodrug concept to its TriTAC platform to

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create a therapeutic T cell engager that remains inactive until it reaches the tumor. Harpoon’s third proprietary technology platform, extended release TriTAC-XR, is designed to mitigate cytokine release syndrome. For additional information about Harpoon Therapeutics, please visit www.harpoontx.com.

Cautionary Note on Forward-looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Words such as “anticipate,” “could,” “expect,” “look forward,” “plan,” “potential,” “target,” “goal”, “will,” “intend”, and similar expressions (as well as other words or expressions referencing future events, conditions or circumstances) are intended to identify forward-looking statements. These forward-looking statements are based on Harpoon Therapeutics’ expectations and assumptions as of the date of this press release. Each of these forward-looking statements involves risks and uncertainties that could cause Harpoon Therapeutics’ clinical development programs, future results or performance to differ significantly from those expressed or implied by the forward-looking statements. Forward-looking statements contained in this press release include, but are not limited to, statements about the development and advancement of Harpoon Therapeutics’ platforms and product candidates, including cash sufficiency forecast, progress, plans for partnerships, timing, scope, design and interim results of clinical trials, the safety and tolerability profile of product candidates, and other statements that are not historical fact. Many factors may cause differences between current expectations and actual results, including unexpected safety or efficacy data observed during clinical studies, preliminary data and trends may not be predictive of future data or results, may not demonstrate safety or efficacy or lead to regulatory approval by the FDA or other regulatory agencies, clinical trial site activation or enrollment rates that are lower than expected, unanticipated or greater than anticipated impacts or delays due to COVID-19, changes in expected or existing competition, changes in the regulatory environment, the uncertainties and timing of the regulatory approval process, the timing and results of unexpected litigation or other disputes, and the sufficiency of Harpoon Therapeutics’ cash resources. These and other factors that may cause Harpoon Therapeutics’ actual results to differ from those expressed or implied in the forward-looking statements in this press release are discussed in Harpoon Therapeutics’ filings with the U.S. Securities and Exchange Commission, including under “Risk Factors” in Harpoon Therapeutics’ quarterly report on Form 10-Q for the quarter ended March 31, 2022 and future filings by Harpoon Therapeutics, including the Form 10-Q that will be filed for the quarter ended June 30, 2022. Except as required by law, Harpoon Therapeutics assumes no obligation to update any forward-looking statements contained herein to reflect any change in expectations, even as new information becomes available.

Contacts:

ICR Westwicke

Robert H. Uhl

Managing Director

858-356-5932

robert.uhl@westwicke.com

Media:

uncapped communications

862-368-4464

media@harpoontx.com

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Harpoon Therapeutics, Inc.

Statement of Operations and Comprehensive Loss

(Unaudited)

(in thousands, except share and per share amounts)

Harpoon Therapeutics, Inc.

Selected Balance Sheet Data

(Unaudited)

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