Pfizer Announces Top-Line Efficacy Results From A Phase 4 Study Of PRISTIQ® (desvenlafaxine) For The Treatment Of Major Depressive Disorder (MDD) In Adults

Thu Jan 24, 2013 8:01am EST

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New Data Add to Evidence Supporting PRISTIQ as a Treatment Option for MDD
NEW YORK--(Business Wire)--
Pfizer Inc. (NYSE: PFE) announced today that a Phase 4 study evaluating the
efficacy of PRISTIQ® (desvenlafaxine) Extended Release Tablets met its primary
endpoint. The study supports the efficacy of 50 mg/day and 100 mg/day doses of
PRISTIQ compared with placebo over eight weeks of treatment in adult patients
with major depressive disorder (MDD) as measured by the 17-item Hamilton Rating
Scale for Depression (HAM-D17) total score.1

In this study, the most common treatment-emergent adverse events observed were
consistent with the known safety and tolerability profile of PRISTIQ.1

"These positive top-line results add to the growing body of evidence that
supports PRISTIQ as a treatment option for adults with major depressive
disorder," said Steven J. Romano, M.D., senior vice president, head of Medicines
Development Group, Global Primary Care Business Unit, Pfizer Inc. "We know how
challenging it can be to treat and manage major depressive disorder. We continue
to study PRISTIQ in order to provide clinicians with more information that can
better guide their treatment decisions for MDD patients." 

The Phase 4 study was designed as a multi-center, randomized, double-blind,
placebo-controlled, eight-week, parallel group study in adult patients with
MDD.1 The primary efficacy endpoint was the change from baseline in HAM-D17
total score at week eight.1 The HAM-D17 is a validated assessment tool used to
rate the severity of a patient's major depressive symptoms.2 The study enrolled
924 patients who were randomized in a 1:1:1 ratio to one of the following
treatment arms: PRISTIQ 50 mg/day, PRISTIQ 100 mg/day or placebo.1

Results from this PRISTIQ Phase 4 study will be submitted for presentation at
upcoming scientific congresses and for publication in a peer-reviewed medical

About Major Depressive Disorder (MDD)

An estimated 33 to 35 million U.S. adults are likely to experience major
depression at some point during their lifetime.3 The criteria for MDD include
having five or more of the symptoms of depression listed below during the same
two-week period and representing a change from previous functioning. Depressed
mood or diminished interest or pleasure must be among the depression symptoms
reported from the following list: depressed mood; diminished interest or
pleasure; significant weight loss or change in appetite; insomnia/hypersomnia;
psychomotor agitation; fatigue or loss of energy; feelings of worthlessness or
excessive/inappropriate guilt; difficulty concentrating; and recurrent thoughts
of death.4

About PRISTIQ® (desvenlafaxine)

PRISTIQ, a selective serotonin and norepinephrine reuptake inhibitor (SNRI), is
a prescription medication that was approved by the U.S. Food and Drug
Administration (FDA) in 2008 for the treatment of MDD in adults.5 The
recommended dose for PRISTIQ is 50 mg once daily, with or without food. In
clinical studies, doses of 50-400 mg/day were shown to be effective, although no
additional benefit was demonstrated at doses greater than 50 mg/day and adverse
events and discontinuations were more frequent at higher doses.5

Important Safety Information About PRISTIQ


Antidepressants increased the risk compared to placebo of suicidal thinking and
behavior (suicidality) in children, adolescents and young adults in short-term
studies of Major Depressive Disorder (MDD) and other psychiatric disorders.
Anyone considering the use of PRISTIQ or any other antidepressant in a child,
adolescent or young adult must balance this risk with the clinical need.
Short-term studies did not show an increase in the risk of suicidality with
antidepressants compared to placebo in adults beyond age 24; there was a
reduction in risk with antidepressants compared to placebo in adults aged 65 and
older. Depression and certain other psychiatric disorders are themselves
associated with increases in the risk of suicide. Patients of all ages who are
started on antidepressant therapy should be monitored appropriately and observed
closely for clinical worsening, suicidality or unusual changes in behavior.
Families and caregivers should be advised of the need for close observation and
communication with the prescriber. PRISTIQ is not approved for use in pediatric


* PRISTIQ is contraindicated in patients with a known hypersensitivity to
PRISTIQ or venlafaxine. 
* Serotonin syndrome and MAOIs: Do not use monoamine oxidase inhibitors (MAOIs)
intended to treat psychiatric disorders with PRISTIQ or within seven days of
stopping treatment with PRISTIQ. Do not use PRISTIQ within 14 days of stopping
an MAOI intended to treat psychiatric disorders. In addition, do not start
PRISTIQ in a patient who is being treated with an MAOI such as linezolid or
intravenous methylene blue.

Selected Warnings and Precautions

* All patients treated with antidepressants should be monitored appropriately
and observed closely for clinical worsening, suicidality and unusual changes in
behavior, especially during the first few months of treatment and when changing
the dose. Consider changing the therapeutic regimen, including possibly
discontinuing the medication, in patients whose depression is persistently worse
or includes symptoms of anxiety, agitation, panic attacks, insomnia,
irritability, hostility, aggressiveness, impulsivity, akathisia, hypomania,
mania or suicidality that are severe, abrupt in onset or were not part of the
patient's presenting symptoms. Families and caregivers of patients being treated
with antidepressants should be alerted about the need to monitor patients.
* The development of a potentially life-threatening serotonin syndrome has been
reported with selective serotonin reuptake inhibitors (SSRIs) and serotonin and
norepinephrine reuptake inhibitors (SNRIs), including with PRISTIQ, both when
taken alone, but especially when co-administered with other serotonergic agents
(including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol,
tryptophan, buspirone and St. John's Wort) and with drugs that impair metabolism
of serotonin (in particular, MAOIs, both those intended to treat psychiatric
disorders and also others, such as linezolid and intravenous methylene blue). If
such events occur, immediately discontinue PRISTIQ and any concomitant
serotonergic agents, and initiate supportive treatment. If concomitant use of
PRISTIQ with other serotonergic drugs is clinically warranted, patients should
be made aware of a potential increased risk for serotonin syndrome, particularly
during treatment initiation and dose increase. 
* Patients receiving PRISTIQ should have regular monitoring of blood pressure
since increases in blood pressure were observed in clinical studies.
Pre-existing hypertension should be controlled before starting PRISTIQ. Caution
should be exercised in treating patients with pre-existing hypertension or other
underlying conditions that might be compromised by increases in blood pressure.
Cases of elevated blood pressure requiring immediate treatment have been
reported. For patients who experience a sustained increase in blood pressure,
either dose reduction or discontinuation should be considered. 
* SSRIs and SNRIs, including PRISTIQ, may increase the risk of bleeding events.
Concomitant use of aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs),
warfarin and other anticoagulants may add to this risk. 
* Mydriasis has been reported in association with PRISTIQ; therefore, patients
with raised intraocular pressure or those at risk of acute narrow-angle glaucoma
(angle-closure glaucoma) should be monitored. 
* PRISTIQ is not approved for use in bipolar depression. Prior to initiating
treatment with an antidepressant, patients should be adequately screened to
determine the risk of bipolar disorder. 
* PRISTIQ should be used cautiously in patients with a history or family history
of mania or hypomania or with a history of seizure disorder. 
* Caution is advised in administering PRISTIQ to patients with cardiovascular,
cerebrovascular or lipid metabolism disorders. Increases in blood pressure and
small increases in heart rate were observed in clinical studies with PRISTIQ.
PRISTIQ has not been evaluated systematically in patients with a recent history
of myocardial infarction, unstable heart disease, uncontrolled hypertension or
cerebrovascular disease. 
* Dose-related elevations in fasting serum total cholesterol, low-density
lipoprotein (LDL) cholesterol and triglycerides were observed in clinical
studies. Measurement of serum lipids should be considered during PRISTIQ
* On discontinuation, adverse events, some of which may be serious, have been
reported with PRISTIQ and other SSRIs and SNRIs. Abrupt discontinuation of
PRISTIQ has been associated with the appearance of new symptoms. Patients should
be monitored for symptoms when discontinuing treatment. A gradual reduction in
dose rather than abrupt cessation is recommended whenever possible. 
* The recommended dose in patients with severe renal impairment or end-stage
renal disease (ESRD) is 50-mg every other day. The dose should not be escalated
in patients with moderate or severe renal impairment or ESRD. 
* Products containing desvenlafaxine and products containing venlafaxine should
not be used concomitantly with PRISTIQ. 
* Hyponatremia may occur as a result of treatment with SSRIs and SNRIs,
including PRISTIQ. Discontinuation of PRISTIQ should be considered in patients
with symptomatic hyponatremia. 
* Interstitial lung disease and eosinophilic pneumonia associated with
venlafaxine (the parent drug of PRISTIQ) therapy have been rarely reported.

Adverse Reactions

* Adverse reactions in patients in short-term, fixed-dose studies (incidence ≥5%
and twice the rate of placebo in the 50 mg or 100 mg dose groups) were: nausea,
dizziness, insomnia, hyperhidrosis, constipation, somnolence, decreased
appetite, anxiety and specific male sexual function disorders.

Full prescribing information and Medication Guide are available at 

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1 Pfizer, Inc. Data on file. 

2 American Psychiatric Association. Practice Guideline for the Treatment of
Patients with Major Depressive Disorder. Third Edition. Arlington, VA, American
Psychiatric Association, 2010. 

3 Kessler RC, Berglund P, Demler O, et al. The epidemiology of major depressive
disorder: results from the National Comorbidity Survey Replication (NCS-R).
JAMA. 2003; 289(23):3095-3105. 

4 American Psychiatric Association: Diagnostic and Statistical Manual of Mental
Disorders, Fourth Edition, Text Revision. Washington, DC, American Psychiatric
Association, 2000. 

5 PRISTIQ® (desvenlafaxine) Extended Release Tablets Prescribing Information,
Pfizer, Inc. Philadelphia, PA.

Pfizer Inc.
Jennifer Kokell, 212-733-2596
Suzanne Harnett, 212-733-8009

Copyright Business Wire 2013

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