SAN DIEGO and VANCOUVER, British Columbia, Dec. 17, 2018 /PRNewswire/ -- Sophiris Bio
Inc. (NASDAQ: SPHS) (the "Company" or "Sophiris"), a
biopharmaceutical company studying topsalysin (PRX302), a
first-in-class, pore-forming protein, in late-stage clinical trials
for the treatment of patients with urological diseases, today
provides an update from its Phase 2b
study of topsalysin for localized prostate cancer, including
top-line safety and biopsy results from the patients who received a
second administration of study drug, which appeared to be safe and
generally well-tolerated. Additional benefit was not observed on
targeted biopsy six months after re-treatment with a second
administration of topsalysin.
As previously stated, a total of 27% of patients (10/37)
demonstrated a clinical response six months following a single
administration of topsalysin. Six of the ten clinical responders
experienced a complete ablation of their tumor. Based on these
results, the Company is moving forward with its plans to propose a
single Phase 3 registration trial design using a single
administration of topsalysin, which it will discuss with regulatory
agencies in the coming months.
"We remain encouraged by both the safety and biopsy data from
the first administration of topsalysin and are working with
Sophiris to design a protocol for a potential Phase 3 registration
study using a single administration of topsalysin," stated
Professor Mark Emberton, principal
investigator in the Phase 2b trial
and Dean of the University College London Faculty of Medical
Sciences. "These data show that 27% of the patients who receive a
single administration of topsalysin may avoid or delay the need for
alternative treatment for their localized prostate cancer. Taking
into account the observed efficacy and safety profile to date
following a single administration, we believe urologists would
welcome a treatment like topsalysin for men with
clinically-significant localized prostate cancer."
Final Safety and Biopsy Results from a Single
Administration of Topsalysin:
The primary objectives of the Phase 2b clinical study were to evaluate the safety,
tolerability and efficacy, as assessed by targeted biopsy, of a
single administration of topsalysin, when used to focally ablate a
histologically-proven, clinically-significant lesion in patients
with low-to-intermediate localized prostate cancer. In the trial,
38 patients received a single administration of topsalysin. Six
months after administration, 37 of the 38 patients received a
follow-up targeted biopsy of the treated lesion, with one patient
having been lost to follow-up following re-location.
Based on the final results of the study, a single administration
of topsalysin continues to appear safe and well-tolerated by
patients. Adverse events considered related to topsalysin were
typically mild and typically occurred and were resolved on the day
of the administration. In addition, urine function was preserved,
no sexual dysfunction, no hypersensitivity reactions or other
serious systemic reactions to study medication were observed after
a single administration.
The final six-month follow-up biopsy results demonstrated that
27% of patients (10/37) achieved a clinical response, defined in
this study as no detectable tumor on targeted biopsy of the treated
lesion or a sufficient reduction to deem the lesion
clinically-insignificant (Gleason Score 6 (3+3) and a Maximum
Cancer Core Length (MCCL) of less than 6 millimeters). Of the ten
clinical responders in the Phase 2b
study, six men experienced a complete ablation with no histological
evidence of the tumor remaining.
Additionally, the final Phase 2b
single administration follow-up biopsy data show that:
- 41% of patients (15/37) experienced a partial response, defined
as a reduction in MCCL and/or Gleason pattern, but the targeted
lesion was still deemed clinically-significant; and
- 32% (12/37) of patients did not respond to treatment, defined
as no change in the targeted lesion or an increase in MCCL and/or
Gleason pattern.
"Now that we have completed this Phase 2b study, we are focused on moving topsalysin
into Phase 3 development," stated Randall
E. Woods, President and CEO of Sophiris. "We are in the
process of finalizing our proposed Phase 3 study design with our
thought leaders, which will be submitted for discussion first to
the European and then U.S. regulatory authorities to confirm the
design of the Phase 3 study. We are equally focused on determining
the best path forward for funding a potential Phase 3 study and
continue to engage in business development discussions as part of
this effort. We are also encouraged to see such strong
interest from the medical community in the development of a focal
treatment for clinically-significant localized prostate
cancer."
Top-line Results from the Second Administration of
Topsalysin
Another important objective for this Phase 2b study was to evaluate the safety of
re-administering topsalysin, and to determine if additional
clinical benefit could be observed following re-treatment of the
targeted lesion six months after initial treatment, as assessed by
targeted biopsy six months after re-administration. To be eligible
to receive a second dose, patients must not have experienced a
clinically-significant adverse event attributable to either
topsalysin or the dosing procedure. Additionally, patients must
have demonstrated evidence of a response to the first treatment
with topsalysin, either through a reduction in lesion size, Gleason
pattern, or MCCL. No patients who had a complete ablation following
the first dose received a second administration.
A top-line review of the safety data from a total of ten
patients who received a second administration indicates that a
second dose appears to be both safe and well-tolerated by patients.
There were no adverse events considered related to topsalysin that
were experienced by more than one patient following the second
administration. The adverse events that were considered related to
topsalysin were typically mild and resolved within two days.
Importantly, no hypersensitivity reaction or other serious systemic
reactions to topsalysin were observed. Urine function was preserved
and there were no reports of sexual dysfunction related to
topsalysin. As previously reported, an eleventh patient received a
second dose but unfortunately experienced a serious adverse event
of sudden cardiac death which, following a thorough review of
medical records, serology results and autopsy findings, was
considered unlikely related to topsalysin by both the investigator
and Company.
Based on the top-line review of the six-month biopsy results
following the second administration of topsalysin, the Company has
concluded that there appears to be no additional clinical benefit
gained with a second administration. The decision to include a
second administration of topsalysin in any future clinical studies
is under review by the Company.
"While we are disappointed that no additional ablation occurred
following a second administration of topsalysin, we had already
planned the Phase 3 study around a single administration and will
continue to move forward accordingly, while we continue to evaluate
the potential benefit of a second dose separately," noted
Professor Emberton. "The results from the second
administration in no way impacts our excitement about topsalysin as
a potential targeted focal therapy in localized prostate
cancer.
Webcast scheduled for today at 9:00 a.m. Eastern
Time
The Sophiris management team will host a conference call and
webcast today, December 17, at 9:00 a.m. Eastern
Time to review the topsalysin prostate cancer data, along with
Professor Mark Emberton, Dean of University College London
Faculty of Medical Sciences and Principal investigator for the
Phase 2b clinical trial.
A live audio webcast will be accessible on the "Investor
Relations" page of the Sophiris corporate website
at www.sophirisbio.com. A replay will be available at the same
location.
About Localized Prostate Cancer
Prostate cancer is the second most common form of cancer in men
in the US with an estimated 161,000 new cases in 2017.
Approximately 80 percent of patients in the US are diagnosed with
localized disease. Research has shown that patients with early,
localized disease have a low likelihood of the cancer spreading
beyond the confines of the prostate; however, many men with
clinically-significant localized disease choose to undergo radical
treatment. Radical therapies include surgery to remove the entire
prostate and/or radiation. Potential toxicities from radical
treatments can be significant and permanent and include erectile
dysfunction, urinary incontinence and rectal toxicity.
About Topsalysin
Topsalysin (PRX302), an innovative, "First-in-Class"
transmembrane pore-forming protein, was genetically modified to be
activated only by enzymatically-active PSA, which is produced in
large quantities within the prostate of men with prostate cancer.
The targeted focal treatment of prostate cancer is in line with
current treatment trends for solid tumors such as breast and liver,
where the goal is to remove the tumor and preserve as much of the
organ and organ function as possible.
Topsalysin has the potential to provide a targeted focal therapy
for the ablation of localized prostate cancer lesions while
potentially avoiding many of the complications and side effects
associated with whole gland radical treatments. The increasing use
of multiparametric magnetic resonance imaging (mpMRI) and advances
in software to co-register previously obtained mpMRI images with
real-time three-dimensional ultrasound images enables urologists to
more accurately locate tumors within the prostate when taking
biopsies. This increases the accuracy with which men with
clinically significant lesions are identified. It also enables the
injection of an ablative agent, such as topsalysin, directly into
previously identified clinically significant tumors located within
the prostate.
About Sophiris
Sophiris Bio Inc. is a late-stage clinical biopharmaceutical
company developing topsalysin (PRX302) for the treatment of
patients with urological diseases. Topsalysin is in Phase 2
clinical development for the focal treatment of localized prostate
cancer as well as Phase 3 clinical development for the treatment of
the lower urinary tract symptoms of benign prostatic hyperplasia
(BPH). Topsalysin is a highly potent ablative agent that is
selective and targeted in that it is only activated by
enzymatically active PSA which is found in high concentrations in
the transition zone of the prostate and in and around prostate
tumor cells. More than 450 patients have received treatment with
topsalysin, which continues to appear to be safe and well
tolerated. For more information, please visit
www.sophirisbio.com.
Certain statements included in this press release may be
considered forward-looking, including the quotes of Sophiris'
President and CEO, and the quote of the principal investigator and
expectations about further development of topsalysin (PRX302),
including the expected advancement of topsalysin to a single Phase
3 clinical trial for the treatment of localized prostate cancer and
the expectations that the company will be able to fund a Phase 3
clinical trial. Such statements involve known and unknown risks,
uncertainties and other factors that may cause actual results,
performance or achievements to be materially different from those
implied by such statements, and therefore these statements should
not be read as guarantees of future performance or results. Some of
the risks and uncertainties that could cause actual results,
performance or achievements to differ include without limitation,
risks associated with clinical development, including the risks
relating to the design of a possible Phase 3 clinical trial in
localized prostate cancer, risks that the manufacturing of clinical
drug supply for Phase 3 clinical trials will not be completed when
expected or at the expected costs, risks that the Company will be
able to fund future clinical trials, and risks relating to the
timing and conduct of any future Phase 3 clinical trials and other
risks and uncertainties identified by Sophiris in its public
securities filings with the SEC. All forward-looking statements are
based on Sophiris' current beliefs as well as assumptions made by
and information currently available to Sophiris and relate to,
among other things, anticipated financial performance, business
prospects, strategies, regulatory developments, clinical trial
results, market acceptance, ability to raise capital and future
commitments. Readers are cautioned not to place undue reliance on
these forward-looking statements, which speak only as of the date
of this press release. Due to risks and uncertainties, including
the risks and uncertainties identified by Sophiris in its public
securities filings; actual events may differ materially from
current expectations. Sophiris disclaims any intention or
obligation to update or revise any forward-looking statements,
whether as a result of new information, future events or
otherwise.
Company Contact:
Peter
Slover
Chief Financial Officer
(858) 777-1760
Corporate Communications and Media Contact:
Jason
Spark
Canale
Communications
(619) 849-6005
jason@canalecomm.com
Investor Contact:
Bill
Slattery, Jr.
Burns McClellan
(212) 213-0006
bslattery@burnsmc.com
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SOURCE Sophiris Bio Inc.
