Pfizer Inc. announced that the Japanese
Ministry of Health, Labour and Welfare approved Lyrica (pregabalin)
capsules for the treatment of peripheral neuropathic pain. This
follows the recent approval in Japan of Lyrica for the treatment of
postherpetic neuralgia on April 16, 2010. Lyrica is the first
medication approved for peripheral neuropathic pain in Japan where it
is co-promoted with Eisai Co., Ltd.
"Neuropathic pain remains an
under-diagnosed condition in many parts of the world, in large part
due to low awareness and understanding of the condition and the fact
that there are few proven treatment options available," said
Steve Romano, M.D., vice president, Medical Affairs Head, Primary
Care Business Unit at Pfizer. "This approval reinforces the
benefit that Lyrica can bring to appropriate patients suffering from
peripheral neuropathic pain."
Peripheral neuropathic pain, or
peripheral nerve pain, is a difficult-to-treat chronic pain
condition. It is initiated or caused by a primary lesion or
dysfunction in the peripheral nervous system. The pain symptoms that
patients experience are often described as burning, tingling or
shock-like sensations. Peripheral neuropathic pain may be triggered
by a variety of medical conditions including nerve injury, sciatica,
fibromyalgia, diabetes, infection (herpes zoster), cancer, HIV
infection and HIV treatment. Research has shown that patients with
neuropathic pain are often prescribed medications that have no
demonstrated efficacy in treating this type of pain or have
significant side effects.
The Lyrica approval was based on ten
phase 3 double-blind studies including eight Western studies and two
studies in Japan. The first study in Japan was previously reviewed
by the Japanese regulatory authorities in support of the postherpetic
neuralgia indication in April 2010. The second study in Japan was
conducted to support the peripheral neuropathic pain indication and
was a comparative study of Lyrica and placebo in Japanese patients
with diabetic peripheral neuropathy. Results showed that Lyrica
reduced symptoms of peripheral neuropathic pain as early as week one
of treatment for some patients and maintained those improvements for
the duration of the 13-week study. Although the exact mechanism of
Lyrica is unknown, it is believed to calm neurons that cause
neurologic pain.
This phase 3 double-blind diabetic
peripheral neuropathic study conducted in Japan included a total of
314 patients: 135 on placebo, 134 on Lyrica 300mg per day and 45 on
Lyrica 600mg per day. Both Lyrica treatments reduced pain scores
during the comparative study from baseline: -1.94 for Lyrica 600mg,
-1.82 for Lyrica 300mg and -1.20 for placebo based on an 11-point
numeric rating scale.
The most common adverse events in the
Japanese peripheral neuropathic study were somnolence (24.5%),
dizziness (22.5%), and edema (17.2%).
Lyrica is currently approved in 110
countries and regions globally. In the United States, Lyrica
(pregabalin) capsules CV is approved by the US Food and Drug
Administration (FDA) for the management of neuropathic pain
associated with diabetic peripheral neuropathy, postherpetic
neuralgia, fibromyalgia and as adjunctive therapy for adult patients
with partial onset seizures.
Treatment with Lyrica may cause
dizziness, somnolence, peripheral edema or blurred vision. Other
most common adverse reactions include dry mouth, weight gain,
constipation, euphoric mood, balance disorder, increased appetite and
thinking abnormally. There have been post-marketing reports of
angioedema and hypersensitivity. Like other anti-epileptic drugs,
Lyrica may cause suicidal thoughts or actions in a very small number
of people.