Introduction:
Although there are more than 6 million prevalent cases of
generalized anxiety disorder (GAD) in the United States alone, a substantial
percentage of newly diagnosed patients do not receive a prescription therapy.
Regulatory approval for GAD is generally as a follow-on indication after
approval for major depressive disorder (e.g., key branded agents include Lexapro
[Forest Laboratories’ escitalopram], Effexor XR [Pfizer’s venlafaxine XR], and
Cymbalta [Eli Lilly’s duloxetine]). In our study of newly diagnosed patients,
we find these agents are generally reserved for later lines of therapy in favor
of generic selective serotonin reuptake inhibitors (SSRIs) and benzodiazepines.
Moreover, year-over-year analysis of newly diagnosed GAD patients reveals that
branded agents have recently moved backward in lines of therapy, likely because
of the increasingly cost-sensitive healthcare environment.
Despite tightening cost restrictions, surveyed primary care
physicians (PCPs) and psychiatrists expect to reduce their use of
benzodiazepines in GAD over the next two years, likely because of the risk of
addiction to these medications. This shift offers an opportunity for agents
with a rapid onset of action (relative to antidepressant therapies) for the
relief of somatic and/or psychiatric symptoms in GAD without the potential for
addiction.
Atypical antipsychotics such as Seroquel/Seroquel XR
(AstraZeneca’s quetiapine/quetiapine XR) and Abilify (Bristol-Myers
Squibb/Otsuka Pharmaceutical’s aripiprazole) are used in later lines of therapy
for the treatment of refractory GAD. However, our drug comparison analysis
indicates that a substantial unmet need remains for therapies treating this
population, particularly for therapies with new mechanisms of action that can
be used either as monotherapy or adjunct therapy to current agents to treat
refractory anxiety.
Using patient-level claims data, as well as insight from 151
surveyed psychiatrists and PCPs, this report determines the share of each key
therapy used in the treatment of GAD by line of therapy, analyzes why key drugs
are chosen over others, and explains how physicians forecast this dynamic will
change over the next two years.
Questions Answered in This Report:
*
Lines of therapy: The GAD market is dominated by generic,
off-label benzodiazepines and generic SSRIs (e.g., citalopram [Forest
Laboratories’ Celexa, generics], sertraline [Pfizer’s Zoloft, generics]). Our
lines of therapy analysis reveals that a considerable percentage of GAD
patients progress to second- and third-line therapy, suggesting these generics
are insufficient to meet the market needs.
Among the major brands approved
for GAD, how much use does each brand get in each line of therapy? Why do
physicians prescribe one major brand other another? What key messages can each
brand use to best expand its market share in GAD?
*
Pathways to key therapies: For brands relegated to later
lines of therapy, longer times before patients progress to these brands mean
smaller patient shares.
How long do patients progressing to Lexapro, Effexor
XR, and Cymbalta remain on their previous therapies? What do the relative times
to progression reveal about these key brands? How are these agents placed
relative to one another in the treatment algorithm for GAD, and how will their
placement evolve over the next two years?
*
Physician behavior: GAD patients are treated by both
psychiatrists and PCPs and can be given different treatments depending on the
type of physician.
Which group of physicians more often prescribes bupropion
(GlaxoSmithKline’s Wellbutrin/Wellbutrin SR/Wellbutrin XL, generics) and why?
For which physicians does cost of drugs factor as a more important reason to
prescribe one drug over another? What are the weaknesses of each agent treating
GAD from the perspective of both psychiatrists and PCPs?
*
Forecast: Benzodiazepines have been a common first-line
therapy for several decades in the treatment of GAD, but surveyed physicians
say that their increasing use of combination therapy in the treatment of GAD
over the next two years will come with a concomitant decrease in the use of
benzodiazepines.
Which drugs and drug classes will see the most increased
use in early lines of therapy? In which lines of therapy do physicians expect
to use new therapies (e.g., PGx Health/Clinical Data, Inc.’s vilazodone, Lundbeck’s
LU-AA21004) with potential in the GAD market? What other changes in medical
practice will influence future patient share and market dynamics? Scope:
Primary research: Quantitative results from our
survey of 151 physicians (75 psychiatrists and 76 PCPs):
- Physician opinion on how drug use differs by patient severity.
- Most influential drug attributes when physicians choose among agents.
- Anticipated changes in the line of therapy in which physicians
use key agents.
Primary patient-level data: Quantitative findings
from our analysis of data covering 61 million lives from 98 geographically
diverse U.S. health plans:
- Quantified lines of therapy analysis showing exact share of each
agent in each line of therapy, including rate of progression between lines and
length of time patients are on each line.
- Progression flowcharts through one year of treatment for newly
diagnosed patients receiving each of the following first line agents: Lexapro,
Effexor XR, Cymbalta, benzodiazepines, citalopram, sertraline,
fluoxetine (Eli Lilly’s Prozac, generics), paroxetine (GlaxoSmithKline’s Paxil,
generics), bupropion (GlaxoSmithKline’s Wellbutrin/Wellbutrin SR/Wellbutrin XL,
generics), venlafaxine IR (Pfizer’s [formerly Wyeth’s] Effexor, generics),
Pristiq (Pfizer/Impax Laboratories’ desvenlafaxine XR), Seroquel, buspirone
(Bristol-Myers Squibb’s BuSpar, generics), mirtazapine (Organon’s Remeron,
generics), gabapentin (Pfizer’s Neurontin, generics), hydroxyzine pamoate
(generics), hydroxyzine hydrochloride (generics), other antiepileptics
(generics), tricyclic agents (generics), and modified cyclics (generics).
- Flowcharts tracking the preceding therapy patterns for patients
taking each of the following key therapies: Lexapro, Effexor XR, Cymbalta, benzodiazepines,
citalopram, sertraline, fluoxetine, paroxetine, venlafaxine IR, Pristiq,
Seroquel, Seroquel XR, Abilify, risperidone, Zyprexa, buspirone, mirtazapine,
and Lyrica (Pfizer’s pregabalin).