Harpoon Therapeutics Reports Fourth Quarter and Full Year 2018 Financial Results and Provides Corporate Update

March 14, 2019 Off By BusinessWire

Lead Tri-specific T cell Activating Construct (TriTAC) candidate,
HPN424, continues to advance in a Phase 1 clinical trial for the
treatment of prostate cancer
Initial public offering, successfully completed in February, raised
approximately $70.7 million in net cash proceeds
Advanced HPN328, a DLL3 (Delta-like 3) -targeting TriTAC, for the
treatment of small cell lung cancer, into IND-enabling studies
Webcast and conference call today at 1:30 p.m. PT

SOUTH SAN FRANCISCO, Calif.–(BUSINESS WIRE)–Harpoon Therapeutics, Inc. (NASDAQ: HARP), a clinical-stage
immunotherapy company developing a novel class of T cell engagers, today
reported financial results for the fourth quarter and full year ended
December 31, 2018 and provided a corporate update.

“The past year included achievement of significant clinical, scientific
and operational milestones for Harpoon Therapeutics,” said Gerald
McMahon Ph.D., President and Chief Executive Officer of Harpoon
Therapeutics. “T cell engagers are gaining momentum as exciting
immuno-oncology therapies and Harpoon has built a proprietary TriTAC
platform to take this approach to a new level. HPN424 has entered a
Phase 1 clinical trial in prostate cancer and HPN536 is poised to enter
clinical development for ovarian and other mesothelin (MSLN) expressing
tumors in the near future, followed by HPN217 targeting B cell
maturation antigen (BCMA) for the potential treatment of multiple
myeloma. In addition, we successfully completed our initial public
offering in February, an important milestone in the company’s history
which further strengthened our balance sheet.”

“Our scientific expertise has led to the discovery and development of
three TriTACs on paths for clinical development. We are pleased to
announce today that we have selected an additional drug candidate,
targeting DLL3, for potential clinical development in small cell lung
cancer,” said Holger Wesche, Chief Scientific Officer of Harpoon. “This
candidate, HPN328, has entered IND-enabling studies and we expect a
Phase 1 trial to begin in 2020.”

2018 Business Highlights

Advanced our lead TriTAC product candidate, HPN424 into a Phase 1
clinical trial in prostate cancer. Utilizing its proprietary TriTAC
platform, Harpoon has developed HPN424, a half-life extending T cell
engager specifically designed to target prostate specific membrane
antigen, or PSMA, for the treatment of prostate cancer. PSMA is
present in 80-95% of patients with advanced prostate cancer. In July,
Harpoon filed an IND for HPN424 and in August, commenced a Phase 1
trial. The Phase 1 trial is designed to enroll patients with
progressive metastatic castration-resistant prostate cancer (mCRPC) in
two parts, dose escalation and dose expansion. The company is
currently enrolling patients in the dose escalation part of the trial.
Advanced two additional TriTAC product candidates, creating a robust
development pipeline. The company’s proprietary TriTAC platform was
designed to advance the therapeutic potential of T cell engagers, with
a proprietary half-life extended format. Harpoon achieved multiple
development milestones with its TriTAC pipeline in 2018 and intends to
have four TriTACs in on-going clinical trials by the end of 2020.
- HPN536 is a mesothelin-targeting TriTAC, designed as a potential
  therapy for ovarian cancer and other solid tumors. Mesothelin, a
  clinically validated target, is expressed on malignant cells of
  ovarian cancer, mesothelioma, pancreatic carcinoma, non-small cell
  lung cancer and triple-negative breast cancer, among others.
  Harpoon submitted the IND for HPN536 in December and received FDA
  clearance in January 2019. Harpoon anticipates a Phase 1/2a trial
  will commence in the first half 2019.
- HPN217 is a TriTAC that targets BCMA and is in preclinical
  development for the potential treatment of multiple myeloma. At
  the 2018 American Society of Hematology Annual Meeting, the
  company released new preclinical data for HPN217 which
  demonstrated BCMA- and T cell-dependent antitumor activity in
  tissue culture and in xenografts modeling multiple myeloma and
  lymphoma. Harpoon expects to file an IND for HPN217 later this
  year.
Harpoon raised approximately $89.7 million in two financings in 2018.
In November, the company closed a Series C equity financing, receiving
$69.7 million in net proceeds. In July, in connection with the
successful filing of the IND for HPN424, Harpoon received $20.0
million in net proceeds for closing the second tranche of its Series B
equity financing.
Harpoon broadened its leadership team, adding expertise to support
clinical development and public company readiness. Additions in 2018
included the appointments of Georgia Erbez as Chief Financial Officer
and Natalie Sacks, M.D., as Chief Medical Officer. Holger Wesche,
Ph.D., was promoted to Chief Scientific Officer. The leadership team
at Harpoon has proven expertise in drug development, spanning
early-stage development of oncology therapies through
commercialization.
Expanded the board with the appointment of three independent
directors: Jonathan Drachman, M.D., former Chief Medical Officer,
Seattle Genetics; Scott Myers, Chairman and Chief Executive Officer,
Rainier Therapeutics; and Julie Eastland, Chief Business and Financial
Officer, Rainier Therapeutics. These board members, along with the
existing directors, provide a wealth of experience in drug
development, financial strategy and business development.

Recent Developments

In January 2019, Harpoon announced preliminary data for HPN424 that
suggested HPN424 activated T cells in a manner that is consistent with
target engagement. In addition, early evidence suggested that there
was sufficient drug exposure during the treatment course to support
once-weekly dosing. Side effects were consistent with T cell
activation and were managed clinically.
In February 2019, Harpoon successfully completed its initial public
offering, raising net proceeds of approximately $70.7 million.
Harpoon today announced the designation of its fourth TriTAC in
development, HPN328, for the potential treatment of small cell lung
cancer (SCLC). HPN328 targets DLL3, a protein highly expressed in a
majority of SCLC tumors but not in normal tissue. This selective
expression makes DLL3 an attractive drug target for T cell engagers.
Harpoon is currently conducting IND-enabling studies and expects to
initiate a Phase 1 clinical trial of HPN328 in 2020.

Anticipated Milestones

Harpoon plans to have three TriTAC product candidates in the clinic by
the end of 2019, with a fourth expected in 2020, as follows:

HPN424 – present additional Phase 1 data in the second half of
2019 at a medical conference
HPN536 – initiate Phase 1/2a trial in the first half of 2019
HPN217 – initiate Phase 1 trial in the second half of 2019
HPN328 – initiate Phase 1 trial in 2020

Fourth Quarter and Full Year 2018 Financial Results

Harpoon Therapeutics ended 2018 with $89.5 million in cash and cash
equivalents compared to $29.4 million as of December 31, 2017. Net
cash provided by financing activities for the year ended December 31,
2018 was $88.3 million, primarily comprised of $69.7 million in net
cash proceeds received from the November 2018 issuance of Series C
convertible preferred stock and $20.0 million in net cash proceeds
received from the July 2018 issuance of Series B convertible preferred
stock as a result of the IND filing for HPN424. Net cash used in
operations for the year ended December 31, 2018 was $27.1 million.
Net loss for the fourth quarter ended December 31, 2018 was $9.7
million compared to $4.9 million for the fourth quarter ended December
31, 2017. Net loss for the year ended December 31, 2018 was $27.4
million, compared to $16.8 million for the prior year.
Revenue for the fourth quarter ended December 31, 2018 was $1.1
million compared to $0.7 million for the fourth quarter ended December
31, 2017. Revenue for the year ended December 31, 2018 was $4.8
million, compared to $0.7 million for the prior year. During both
periods, the revenue primarily consisted of the amortized portion of
the deferred $17.0 million upfront payment received in October 2017
under a collaboration agreement with AbbVie.
Research and development expense for the fourth quarter ended December
31, 2018 was $8.7 million compared to $4.8 million for the fourth
quarter ended December 31, 2017. R&D expense for the year ended
December 31, 2018 was $26.4 million, compared to $13.6 million for the
prior year. The increases in both comparative periods were primarily
due to clinical development expenses and an increase in
personnel-related expenses, including conducting preclinical studies,
initiating the first clinical trial for lead product candidate,
HPN424, and manufacturing activities for four TriTAC product
candidates in various stages of development.
General and administrative expense for the quarter ended December 31,
2018 was $2.2 million compared to $0.9 million for the quarter ended
December 31, 2017. General and administrative expenses for the year
ended December 31, 2018 were $6.1 million, compared to $3.6 million
for the prior year. The increases over both comparative periods were
primarily due to an increase in consulting and accounting services
related to quarterly reviews and year-end audits and an increase in
headcount.

Conference Call Information

Harpoon will host a conference call and live audio webcast this
afternoon at 1:30 p.m. PT / 4:30 p.m. ET to discuss the fourth quarter
and full year 2018 financial results and provide a corporate update.

The live call may be accessed by dialing 866-951-6894 for domestic
callers and 409-261-0624 for international callers and using conference
ID: 2497976. A live webcast of the call will be available online from
the investor relations section of the Harpoon Therapeutics website at https://ir.harpoontx.com/events-and-presentations.

An archived replay of the webcast will be available on Harpoon
Therapeutics’ website shortly after the conference call.

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 T cell engagers, or TriTACs,
initially focused on the treatment of solid tumors and hematologic
malignancies. 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 “may,” “will,” “expect,” “plan,” “anticipate,” “target,”
“estimate,” “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 progress, timing, scope and results of clinical
trials, the association of data with treatment outcomes and the timing
and likelihood of development milestones for product candidates. Many
factors may cause differences between current expectations and actual
results, including unexpected safety or efficacy data observed during
preclinical or clinical studies, clinical trial site activation or
enrollment rates that are lower than expected, changes in expected or
existing competition, changes in the regulatory environment, the
uncertainties and timing of the regulatory approval process, and
unexpected litigation or other disputes. 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 the “Risk Factors” sections contained
therein. 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.


Harpoon Therapeutics, Inc.
Statements of Operations
(in thousands, except share and per share amounts)

	Three Months Ended December 31,						Twelve Months Ended December 31,
	2018			2017			2018			2017
	(Unaudited)						(Audited)
Revenue
Collaboration and license revenue	$	1,063		$	708		$	4,750		$	708
Total revenue		1,063			708			4,750			708
Operating expenses
Research and development		8,717			4,791			26,368			13,622
General and administrative		2,215			912			6,106			3,614
Total operating expenses		10,932			5,703			32,474			17,236
Loss from operations		(9,869	)		(4,995	)		(27,724	)		(16,528	)
Interest income		148			57			395			78
Interest expense		—			—			—			(285	)
Other expense		(8	)		(4	)		(37	)		(95	)
Net loss	$	(9,729	)	$	(4,942	)	$	(27,366	)	$	(16,830	)
Net loss per share, basic and diluted		(8.15	)		(5.27	)		(25.65	)		(18.81	)
Weighted-average shares used in computing net loss per share, basic and diluted		1,193,797			938,372			1,066,877			894,901


Harpoon Therapeutics, Inc.
Selected Balance Sheet Data
(Audited)

	As of December 31,
	2018			2017
	(in thousands)
Assets:
Cash and cash equivalents	$	89,493		$	29,423
Total assets		102,580			31,872
Total liabilities		26,482			18,974
Total convertible preferred stock		129,577			39,841
Total stockholders’ deficit		(53,479	)		(26,943	)