Arix Bioscience
plc
Harpoon presents
interim Phase 1 data for HPN424
LONDON, 29 May 2020: Arix Bioscience plc (LSE:ARIX)
("Arix"), a global venture capital company focused on investing in
and building breakthrough biotech companies, notes that its
portfolio company Harpoon Therapeutics, Inc. (“Harpoon”) (Nasdaq:
HARP), today presented interim data from the ongoing
dose-escalation portion of a Phase 1 trial for HPN424 in patients
with metastatic castration-resistant prostate cancer (mCRPC) at the
American Society of Clinical Oncology (ASCO) 2020 Virtual
Scientific Program.
The announcement can be accessed on Harpoon’s investor website
at https://ir.harpoontx.com/news-releases and full text of
the announcement from Harpoon is contained below. Harpoon
management will host an investor conference call today, Friday 29
May, at 4pm EDT/ 9 pm BST to review the data presented at ASCO and
provide an update on other pipeline programmes. To listen to the
webcast and view the accompanying slide presentation, please go to:
https://ir.harpoontx.com/events-and-presentations
[ENDS]
Enquiries
For more information on Arix, please contact:
Arix Bioscience plc
Charlotte Parry, Head of Investor
Relations
+44 (0)20 7290 1072
charlotte@arixbioscience.com
Optimum Strategic Communications
Mary Clark, Supriya Mathur, Shabnam
Bashir
+44 (0)20 3714 1787
optimum.arix@optimumcomms.com
About Arix Bioscience plc
Arix Bioscience plc is a global venture capital company focused
on investing in and building breakthrough biotech companies around
cutting edge advances in life sciences. We collaborate with
exceptional entrepreneurs and provide the capital, expertise and
global networks to help accelerate their ideas into important new
treatments for patients. As a listed company, we are able to bring
this exciting growth phase of our industry to a broader range of
investors.
Arix Bioscience plc is listed on the Main Market of the London
Stock Exchange. For further information, please visit
www.arixbioscience.com
Harpoon Therapeutics Presents
Interim Phase 1 Data from an Ongoing Dose Escalation Trial for the
PSMA-targeting TriTAC® HPN424 at the ASCO20 Virtual Scientific
Program
- The on-going dose escalation Phase 1 study has enrolled 44
patients with progressive, metastatic castration-resistant prostate
cancer in 11 cohorts.
- Initial safety data showed that HPN424 is generally
well-tolerated, and cytokine-related adverse events have been
transient and manageable.
- Pharmacokinetic data supports weekly dosing and pharmacodynamic
data supports T cell activation and target engagement consistent
with the expected mechanism of action.
- Signals of clinical activity include multiple patients
remaining on study for more than 24 weeks, and serum PSA
declines.
- Management to host webcast and conference call to review the
interim Phase 1 data and provide a pipeline update today at
4 p.m. ET /1
p.m. PT
SOUTH SAN FRANCISCO, Calif.,
May 29, 2020 -- Harpoon Therapeutics,
Inc. (NASDAQ: HARP), a clinical-stage immunotherapy company
developing a novel class of T cell engagers, today presented
interim data from the ongoing dose-escalation portion of a Phase 1
trial for HPN424 in patients with metastatic castration-resistant
prostate cancer (mCRPC) at the American Society of Clinical
Oncology (ASCO) 2020 Virtual Scientific Program. HPN424 targets
prostate-specific membrane antigen (PSMA) and is based on Harpoon’s
proprietary Tri-specific T cell Activating Construct (TriTAC®)
platform designed to recruit a patient’s own immune cells to kill
tumor cells.
The presentation highlights interim results in 44 patients
across 11 dosing cohorts treated with HPN424 from the ongoing dose
escalation portion of a Phase 1 clinical trial. As of the
May 11, 2020 cut-off date, initial
data demonstrate:
- HPN424 is generally well-tolerated and support long-term
treatment, and cytokine-related adverse events have been transient
and manageable.
- Pharmacokinetic data support weekly dosing and pharmacodynamic
data support T cell activation as measured by reduction in
circulating tumor cells, increased serum cytokine levels and T cell
margination after HPN424 administration.
- Early signals of clinical activity include eight patients who
remained on study treatment for greater than 24 weeks. In addition,
eight patients exhibited decreases in PSA levels compared to
baseline, including two who showed PSA (prostate-specific antigen)
reductions of at least 50%.
“We are particularly encouraged by data supporting the predicted
mechanism of action of HPN424, and the early signs of clinical
activity in this heavily pretreated population,” stated
Gerald McMahon, Ph.D., President and
CEO, Harpoon Therapeutics. “These initial data from our lead
program represent the first of four product candidates in our
TriTAC clinical portfolio that can provide multiple opportunities
to accelerate our pipeline into more advanced clinical
studies.”
“We are excited to share the first clinical data from our HPN424
clinical program. Early data suggest that this novel, half-life
extended T cell engager can be administered safely. Several
patients remained on treatment for 24 weeks or more, which is
notable in this late-stage cancer population,” said Natalie Sacks, M.D., Chief Medical Officer of
Harpoon. “We will continue dose escalation, and plan to open an
expansion cohort later in 2020. Our goal is to develop an effective
immunotherapy treatment option for patients with prostate
cancer.”
Trial Design and Interim Results from
the HPN424 Phase 1 Clinical Trial
This Phase 1 trial is a multicenter, open-label study designed
to evaluate the safety, tolerability, pharmacokinetics and activity
of HPN424 in patients with mCRPC who are progressing at the time of
enrollment and have had at least two prior systemic treatments for
metastatic disease. The initial ongoing phase of the trial is dose
escalation, with the goal of determining a recommended dose for the
expansion phase. The escalation phase began with single patient
cohorts and transitioned to a 3x3 design when Grade 2 toxicity was
observed. HPN424 is being administered to patients once weekly by
intravenous infusion. The primary outcome measures are an
assessment of safety and tolerability, pharmacokinetics, and
pharmacodynamics. Secondary endpoints include duration of response,
progression free and overall survival. Tumor assessments include
PSA, CT and bone scans performed every 9 weeks.
As of the May 11, 2020 cut-off
date, 44 patients have been treated in 11 cohorts with doses
ranging from 1.3 to 120 ng/kg. Enrolled patients had a median of 7
prior therapies, including 73% with prior chemotherapy, and a
median of two prior novel hormonal agents. Median PSA level was
244, with a range of 0.1-5000 ng/ml. The most frequent adverse
events were chills ((all grade n= 32 (73%), grade >3 n=0
(0%)), pyrexia (all grade n=21 (48%), grade > 3 n=0 (0%)), and
cytokine release syndrome (CRS) (all grade n=14 (32%),
grade >3 n=3 (7%)). Cytokine-related adverse events were
transient, and all patients with these adverse events were
retreated successfully with HPN424. Dexamethasone premedication was
instituted in cohort 4 (24 ng/kg) and has been successfully
administered to mitigate cytokine-related symptoms in patients
treated with higher doses in subsequent cohorts. One DLT of
asymptomatic Grade 3 serum lipase elevation was observed which
resolved and the patient was retreated successfully as scheduled.
The most common reasons for study discontinuation were due to
progressive disease (72%) and unrelated adverse events (9%).
HPN424 demonstrated dose proportional increase in
Cmax and AUC with a current estimate of median
T1/2 of 24.9 hours (range: 9.0 – 312 hours).
Dose-dependent, transient increases in peripheral cytokine and
chemokine levels were observed, including increases in interleukin
6, peaking at 5 hours post infusion and returning to baseline 24
hours post-administration. Maximal cytokine/chemokine levels
attenuated with each successive dose within six weeks. Baseline
circulating tumor cells (CTC) ranged from 0-160 cells/ml of whole
blood. Reduction in CTC was seen in 12 of 27 patients with
evaluable CTC compared to baseline.
Eight of 26 patients (31%) with at least 24 weeks in follow-up
remained on study beyond 24 weeks. Eight patients showed a PSA
decline from baseline ranging from -4 to -76%, including patients
with initial rises in PSA after study entry. Two patients had
confirmed PSA partial responses with declines of 50% or
greater.
Patients continue to be enrolled in the escalation phase of the
trial, with a goal to identify a dose for an expansion phase
planned for the second half of 2020. The expansion phase of the
trial will further evaluate the safety and activity of HPN424 in
patients with mCRPC. The trial is titled, “A Phase 1 Open-label,
Multicenter, Dose Escalation and Dose Expansion Study of the
Safety, Tolerability, and Pharmacokinetics of HPN424 in Patients
with Advanced Prostate Cancer Refractory to Androgen Therapy”. For
additional information about the trial, please
visit www.clinicaltrials.gov using the identifier
NCT03577028.
Conference Call and Webcast Today
Harpoon’s management team will host a webcast and conference
call today at 4 p.m. ET /
1 p.m. PT to review the ASCO data and
provide an update on other pipeline programs. The live call may be
accessed by dialing:
877-407-9716 for domestic callers
201-493-6779 for international callers
A live webcast of the call will be available from the Events and
Presentations section of the company’s website
at https://ir.harpoontx.com/events-and-presentations and
will be archived there shortly after the live event.
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. HPN424 targets PSMA and is in a Phase
1 trial for metastatic castration-resistant prostate cancer. HPN536
targets mesothelin and is in a Phase 1/2a trial for cancers
expressing mesothelin, initially focused on ovarian and pancreatic
cancers. HPN217 targets BCMA and is in a Phase 1/2 trial for
relapsed, refractory multiple myeloma. HPN328 targets DLL3 and
Harpoon plans to initiate a Phase 1/2a trial in the second half of
2020. 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 anticipated results of
clinical trials, the timing of the presentation of data, the
association of data with potential treatment outcomes, the
development and advancement of product candidates, and the timing
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
clinical studies, 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, 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.
Contacts:
Harpoon Therapeutics, Inc.
Georgia Erbez
Chief Financial Officer
650-443-7400
media@harpoontx.com
Westwicke ICR
Robert H. Uhl
Managing Director
858-356-5932
robert.uhl@westwicke.com