Sage Therapeutics Reports Positive Top-line Results from Phase 2 Placebo-Controlled Trial of SAGE-217 in Major Depressive Disorder

– SAGE-217 met primary endpoint and provided rapid, profound and
durable effects through 2-week treatment period and additional 4-week
follow-up –

– Well-tolerated and demonstrated highly statistically significant
mean reduction in the HAM-D score compared to placebo at 15 days
(p<0.0001) beginning after one dose and maintained through Week 4 with numerical superiority though Week 6 –

– All secondary endpoints were consistent with primary endpoints at
Day 15, including remission in 64% of SAGE-217 patients versus 23% of
placebo patients (p=0.0005) –

– Data support further development of SAGE-217 for MDD and related
disorders –

– Conference call scheduled today at 8:00 A.M. ET –

CAMBRIDGE, Mass.–(BUSINESS WIRE)–Sage Therapeutics (NASDAQ: SAGE), a clinical-stage biopharmaceutical
company developing novel medicines to treat life-altering central
nervous system (CNS) disorders, today announced positive top-line
results from the Phase 2, double-blind, placebo-controlled clinical
trial of SAGE-217 in the treatment of 89 adult patients with moderate to
severe major depressive disorder (MDD). In the trial, treatment for 14
days with SAGE-217 was associated with a statistically significant mean
reduction in the Hamilton Rating Scale for Depression (HAM-D) 17-Item
total score from baseline to Day 15 (the time of the primary endpoint)
of 17.6 points for SAGE-217, compared to 10.7 for placebo (p<0.0001). Statistically significant improvements were observed in the HAM-D compared to placebo by the morning following the first dose through Week 4 and the effects of SAGE-217 remained numerically greater than placebo through the end of follow-up at Week 6. At Day 15, 64 percent of patients who received SAGE-217 achieved remission, defined as a score of 7 or less on the HAM-D scale, compared with 23 percent of patients who received placebo (p=0.0005). Other secondary endpoints were all similarly highly significant at Day 15 (p≤0.002).

SAGE-217 was generally well-tolerated with no serious or severe adverse
events; the most common adverse events (AEs) in the SAGE-217 group were
headache, dizziness, nausea, and somnolence. A low rate of
discontinuations due to AEs was reported; overall reports of AEs were
similar between drug (53%) and placebo (46%), with a safety profile
consistent with that seen in earlier trials. SAGE-217 was granted Fast
Track Designation by the U.S. Food and Drug Administration (FDA) in May
2017.

“These very encouraging data suggest the potential of SAGE-217 in the
treatment of MDD as well as other mood-related disorders that we may
pursue,” said Jeff Jonas M.D., chief executive officer of Sage
Therapeutics. “There has been little innovation in the discovery and
development of treatments for depression in the last two decades.
Coupled with our recent positive Phase 3 data read-out evaluating
brexanolone for the treatment of postpartum depression, the findings in
this study suggest our pipeline of proprietary GABAA
modulators may impact novel and fundamental brain mechanisms, offering
potential development opportunities in a variety of indications. The
positive activity and safety findings of SAGE-217 in MDD support
advancing the program into later stage clinical development and we will
work with the FDA to determine next steps in the further development of
SAGE-217.”

The GABA system is the major inhibitory signaling pathway of the central
nervous system (CNS), and contributes significantly to regulating CNS
function. SAGE-217 is a novel, highly potent and selective, next
generation GABAA receptor positive allosteric modulator that
is being developed as a once-daily, oral therapy for the treatment of
various CNS disorders. SAGE-217 was discovered by Sage, and the Company
maintains worldwide rights to the compound.

“There are currently significant gaps in the disease management of
depression and our development goal at Sage is to change patients’
expectations by transforming the treatment landscape for MDD,” said
Steve Kanes, M.D., Ph.D., chief medical officer of Sage Therapeutics.
“If successfully developed, SAGE-217 has the potential to offer the
first truly new mechanism of action in the pharmacologic treatment of
depression in more than 20 years. If the results from this trial are
replicated in Phase 3 trials, SAGE-217 may meet the needs of patients
with MDD for a once-daily oral treatment that potentially provides a
rapid, well-tolerated and durable response with a high rate of
remission.”

Summary of Top-line Results from the
Placebo-Controlled Phase 2 Trial

Effect on Depressive
Symptoms through end of Treatment (Day 15):

  • Treatment with SAGE-217 was associated with a statistically
    significant mean reduction from baseline in the Hamilton Rating Scale
    for Depression (HAM-D) total score at Day 15 of 17.6 points compared
    with a 10.7 point mean reduction associated with placebo (p<0.0001).
  • The majority of patients (64%) who received SAGE-217 achieved
    remission at Day 15 as determined by a HAM-D total score less than or
    equal to 7 (compared with 23% of patients who received placebo,
    p=0.0005).
  • Other secondary endpoints (e.g., MADRS, CGI-I) were similarly highly
    significant at Day 15 (p≤0.002).

Effect on Depressive Symptoms over Time:

  • Statistically significant mean reductions from baseline in the
    Hamilton Rating Scale for Depression (HAM-D) total score were observed
    following the first dose (Day 2) and maintained through Week 4, two
    weeks after end of treatment (p<0.0318).
  • At Week 4, the mean reduction from baseline in HAM-D total score was
    15.6 for the SAGE-217 group and 11.9 for the placebo group (p=0.0243).
  • At Week 6, the mean reduction in HAM-D total score for the SAGE-217
    group was 15.0 and numerically, but not statistically improved
    compared to the placebo group reduction of 13.0.
  • Rates of remission at Week 4 and Week 6 for patients treated with
    SAGE-217 were 52 percent and 45 percent compared to 28 percent and 33
    percent for placebo, with statistical significance maintained at Week
    4 (p=0.0221) but not Week 6.

Safety and Tolerability:

  • SAGE-217 was generally well tolerated in the trial. The overall
    incidence of patients who experienced adverse events was 53 percent
    for the SAGE-217 treatment group and 46 percent for the placebo group.
  • There were no deaths, serious or severe adverse events.
  • Rates of discontinuation from dosing of study drug due to adverse
    events were low; two patients (4.4%) treated with SAGE-217 and none
    treated with placebo.
  • The most common adverse events in the SAGE-217 group were headache,
    dizziness, nausea and somnolence.
  • There was no signal for increased risk for patients treated with
    SAGE-217 as measured by structured assessments of suicidality and
    sedation.

Conference Call Information
Sage will host a conference call
and webcast today at 8:00 A.M. ET to discuss the top-line results from
the Phase 2 SAGE-217 trial in MDD. The live webcast can be accessed on
the investor page of Sage’s website at investor.sagerx.com. The
conference call can be accessed by dialing 866-450-8683 (toll-free
domestic) or 281-542-4847 (international) and using the conference ID
2675527. A replay of the webcast will be available on Sage’s website
approximately two hours after the completion of the event and will be
archived for up to 30 days.

About the Placebo-controlled Phase 2 trial of SAGE-217 in MDD:
In
the randomized, double-blind, parallel-group, placebo-controlled trial,
89 eligible patients (with a minimum total score of 22 on the Hamilton
Rating Scale for Depression) were stratified based on use of
antidepressant treatment (current/stable or not treated/withdrawn ≥30
days) and randomized in a 1:1 ratio to receive SAGE-217 Capsules (30mg)
(n=45) or matching placebo (n=44). All doses of study drug were
administered at night with food. The study consisted of a 14-day
treatment period, and a 4-week follow-up period. The mean HAM-D total
scores at baseline were 25.2 for the SAGE-217 group and 25.7 for the
placebo group (overall range 22-33), representing patients with moderate
to severe MDD. Approximately 90 percent of patients in each group
completed the study.

About Major Depressive Disorder
Major depressive disorder
(MDD) is a common but serious mood disorder in which patients exhibit
depressive symptoms, such as a depressed mood or a loss of interest or
pleasure in daily activities consistently for at least a two-week
period, and demonstrate impaired social, occupational, educational or
other important functioning. It is estimated that approximately 16
million people in the U.S. suffer from MDD each year. While
antidepressants are widely used for treatment, large scale studies have
demonstrated the need for additional therapies.

About the Hamilton Rating Scale for Depression (HAM-D)
HAM-D
is a validated rating scale used to provide an assessment of depression,
and as a guide to evaluate recovery. This scale is an accepted
regulatory endpoint for depression. The scale is used in clinical
research to rate the severity of a patient’s depression by probing mood,
feelings of guilt, suicide ideation, insomnia, agitation, anxiety,
weight loss, and somatic symptoms.

About SAGE-217
SAGE-217 is a next generation positive
allosteric modulator that has been optimized for selectivity to synaptic
and extrasynaptic GABA receptors and a pharmacokinetic profile intended
for daily oral dosing. The GABA system is the major inhibitory signaling
pathway of the brain and CNS, and contributes significantly to
regulating CNS function. SAGE-217 is currently being developed for MDD
and certain other mood and movement disorders.

About Sage Therapeutics
Sage Therapeutics is a
clinical-stage biopharmaceutical company committed to developing novel
medicines to transform the lives of patients with life-altering central
nervous system (CNS) disorders. Sage has a portfolio of novel product
candidates targeting critical CNS receptor systems, GABA and NMDA.
Sage’s lead program, a proprietary IV formulation of brexanolone
(SAGE-547), is in Phase 3 clinical development for postpartum
depression. Sage is developing its next generation modulators, including
SAGE-217 and SAGE-718, in various CNS disorders. For more information,
please visit www.sagerx.com.

Forward-Looking Statements
Various statements in this
release concern Sage’s future expectations, plans and prospects,
including without limitation: our expectations regarding the potential
for SAGE-217 in the treatment of MDD and related disorders; our
statements regarding plans for further development of SAGE-217 and
related regulatory activities and the potential for successful
development; our view of the potential of the GABA mechanism and our
product candidates, including SAGE-217, in the treatment of CNS diseases
and disorders; our views as to the unmet need for additional treatment
options in MDD and the potential of SAGE-217 to meet the unmet need, and
our estimates as to the number of patients with MDD. These
forward-looking statements are neither promises nor guarantees of future
performance, and are subject to a variety of risks and uncertainties,
many of which are beyond our control, which could cause actual results
to differ materially from those contemplated in these forward-looking
statements, including the risks that: we may not be able to successfully
demonstrate the efficacy and safety of SAGE-217 or any of our other
product candidates at each stage of development; success in early stage
clinical trials may not be repeated or observed in ongoing or future
studies of SAGE-217 or any of our other product candidates; ongoing and
future clinical results may not support further development or be
sufficient to gain regulatory approval to market SAGE-217 or any of our
other product candidates; we may decide that a development pathway for
one of our product candidates in one or more indications is no longer
feasible or advisable or that the unmet need no longer exists; decisions
or actions of the FDA or other regulatory agencies may affect the
initiation, timing, design, size, progress and cost of clinical trials
and our ability to proceed with further development; we may encounter
unexpected safety or tolerability issues with SAGE-217 or any of our
other product candidates in ongoing or future development; the actual
size of the MDD patient population may be significantly lower than our
estimates and, even if SAGE-217 is successfully developed and approved
for MDD, it may only be approved or used to treat a subset of the MDD
population; and we may encounter technical and other unexpected hurdles
in the development and manufacture of SAGE-217 or any of our other
product candidates; as well as those risks more fully discussed in the
section entitled “Risk Factors” in our most recent Quarterly Report on
Form 10-Q, and discussions of potential risks, uncertainties, and other
important factors in our subsequent filings with the Securities and
Exchange Commission. In addition, any forward-looking statements
represent our views only as of today, and should not be relied upon as
representing our views as of any subsequent date. We explicitly disclaim
any obligation to update any forward-looking statements.

Contacts

Investor Contact:
Sage Therapeutics
Paul Cox,
617-299-8377
paul.cox@sagerx.com
or
Media
Contact:

Suda Communications LLC
Maureen L. Suda,
585-355-1134
maureen.suda@sagerx.com