ArQule’s data confirm miransertib’s potential for treating PS and PROS patients

Encouraging preliminary safety and clinical activity data confirm
miransertib’s potential for treating PS and PROS patients

Registrational study, MOSAIC (Miransertib in Overgrowth Syndromes in
Adults and Children), expected to begin enrollment in Q3 2019

BURLINGTON, Mass.–(BUSINESS WIRE)–$ARQL #arql–ArQule, Inc. (Nasdaq:ARQL) today announced preliminary results from the
company’s phase 1/2 study of its pan-AKT inhibitor, miransertib (ARQ
092), in patients with PIK3CA-related Overgrowth Spectrum (PROS) and
Proteus syndrome (PS) in an oral presentation at the European Society of
Human Genetics Conference in Gothenburg, Sweden.

“The results presented from our ongoing phase 1/2 study highlight the
potential for miransertib to provide a molecularly targeted treatment
for patients with rare PI3K/AKT driven overgrowth diseases,” said Dr.
Brian Schwartz, Chief Medical Officer of ArQule. “We have been committed
to rapidly advancing miransertib for patients with these devastating
diseases since collaborating with The National Human Genome Research
Institute in 2015 and are now poised to start the registrational study,
MOSAIC, in the third quarter of this year. We are thrilled with the
preliminary safety and clinical activity data and look forward to
continued clinical progress for the program.”

Dr. Chiara Leoni, an Investigator on the study from the Fondazione
Policlinico Universitario Agostino Gemelli, said, “The precision
medicine approach of the study has led to very encouraging preliminary
results with the observed safety and tolerability profile, along with
clinically meaningful improvement in disease related symptoms in
patients. In addition, the majority of patients have had stable disease
while on treatment, demonstrating the potential of miransertib to halt
disease progression. The ability to attain durable treatment responses
with a manageable safety profile is an important step forward for this
patient population that currently has no medicinal treatment options,
and I look forward to advancing the registrational MOSAIC study in the
coming months.”

The reported interim data are from the phase 1/2 study, an
international, multi-center, open-label 2-part study evaluating
miransertib in patients with PS and PROS. The first part of the study is
evaluating the safety, tolerability, PK profile and preliminary evidence
of clinical activity of miransertib at different dose levels. MOSAIC,
the registrational part of the study, is expected to begin patient
enrollment in Q3 2019.

Key findings presented include:

• Recommended initial dose for the registrational study was defined as
  15mg/m² QD with subsequent maximum dose increase to 25mg/m²
• A manageable safety profile was observed in patients as young as 2
  years old, with mostly Grade 1 or 2 AEs
• Improvement in disease related symptoms and performance status as
  measured by Karnofsky/Lansky scale was reported in the majority of
  patients
• The majority of patients demonstrated improvement or no disease
  progression extending beyond 1 year on treatment

The presentation, Preliminary results from the company’s phase 1/2
study of its pan-AKT inhibitor, miransertib (ARQ 092), in patients with
PIK3CA-related Overgrowth Spectrum (PROS) and Proteus syndrome (PS),
is available on the company’s website at www.arqule.com/publications-presentations/.