- Coadministration with Esomeprazole Does Not Affect Blood Levels of
LEXIVA -
CAMBRIDGE, Mass. and RTP, N.C., Nov. 18 /PRNewswire-FirstCall/ --
GlaxoSmithKline (NYSE: GSK) and Vertex Pharmaceuticals Incorporated
(Nasdaq: VRTX) today announced that the U.S. Food and Drug Administration
(FDA) approved GSK's application to add clinical data to the prescribing
information for LEXIVA(R) (fosamprenavir calcium), an HIV protease inhibitor
(PI). The newly added information shows that simultaneous administration of
LEXIVA in combination with esomeprazole (Nexium(R)) does not result in
lowering of blood levels for LEXIVA. This update is based on a study showing
that blood levels of LEXIVA remained unchanged when patients took LEXIVA and
20 mg once-daily esomeprazole simultaneously. Drug interactions that result
in lower PI blood levels may increase the risk for virologic failure in
patients treated with HIV protease inhibitors.
LEXIVA is indicated for the treatment of HIV infection in adults in
combination with other antiretroviral medications. The following points
should be considered when initiating therapy with LEXIVA plus ritonavir (RTV)
(LEXIVA/r) in PI-experienced patients: the PI-experienced patient study was
not large enough to reach a definitive conclusion that LEXIVA/r and
lopinavir/ritonavir are clinically equivalent. Once-daily administration of
LEXIVA plus RTV is not recommended for PI-experienced patients. LEXIVA is the
first PI to offer flexible dosing options with no food or fluid restrictions.
Among HIV-positive patients, heartburn, gastroesophageal reflux disease
and ulcers are common disorders. A recent survey of 200 HIV-positive patients
found that nearly 80 percent of patients have used an over the counter (OTC)
acid-reducing agent and 39 percent have used a prescription proton pump
inhibitor (PPI).(1) In the month prior to the survey, 28 percent reported
using an antacid, 25 percent used a prescription PPI and 13 percent used an
OTC acid-reducing agent including OTC PPIs.
"To avoid potential drug interactions, it is important that patients talk
with their health care professional about any medications, even over-the-
counter products, they are taking," said Mark Shaefer, Pharm. D., acting vice
president, HIV, Infectious Disease Medicine Development Center at GSK. "With
this update, patients know that they can take a proton pump inhibitor
simultaneously with LEXIVA without affecting blood levels of LEXIVA."
LEXIVA was co-discovered by GlaxoSmithKline and Vertex Pharmaceuticals
Incorporated.
The new prescribing information includes data from study APV10031, a
randomized, open-label, cross-over study in 48 healthy adults. Subjects
received 20 mg of esomeprazole alone for seven days followed by the addition
of 1400 mg LEXIVA BID (twice-a-day) or 700 mg LEXIVA boosted with 100 mg
ritonavir (r) BID for 14 days at the same time with their dose of
esomeprazole. This was followed by a 21- to 28-day washout period and then
participants were given unboosted or boosted LEXIVA for 14 days. Results
indicated that blood levels of LEXIVA were not changed when taken
simultaneously with esomeprazole compared to LEXIVA administered without
esomeprazole. Blood levels of esomeprazole were increased by 55 percent when
taken with 1400 mg LEXIVA BID.
Proton pump inhibitors such as esomeprazole reduce levels of stomach acid
and are used to treat several stomach problems including heartburn. Over-the-
counter antacids also reduce levels of stomach acid and, when coadministered
with LEXIVA, did not significantly affect the blood levels of LEXIVA.
Important Safety Information about LEXIVA
HIV medicines do not cure HIV infection/AIDS or prevent passing HIV to
others.
LEXIVA is contraindicated in patients with previously demonstrated,
clinically significant hypersensitivity to any of the components of this
product or to amprenavir. Hyperglycemia, new onset or exacerbations of
diabetes mellitus, and spontaneous bleeding in hemophiliacs have been reported
with protease inhibitors.
Redistribution/accumulation of body fat including central obesity,
dorsocervical fat enlargement (buffalo hump), peripheral wasting, facial
wasting, breast enlargement and "cushingoid appearance" have been observed in
patients receiving antiretroviral therapy. The causal relationship, mechanism
and long-term consequences of these events are currently unknown.
LEXIVA should be used with caution in patients with a known sulfonamide
allergy.
Severe or life-threatening skin reactions were reported in less than 1
percent of 700 patients treated with LEXIVA in clinical studies, including one
case of Stevens-Johnson syndrome.
Skin rashes (all grades, without regard to causality) occurred in
approximately 19 percent of patients treated with LEXIVA in the pivotal
efficacy studies. This led to the discontinuation of LEXIVA in less than 1
percent of patients.
During the initial phase of treatment, patients responding to
antiretroviral therapy may develop an inflammatory response to indolent or
residual opportunistic infections.
LEXIVA is contraindicated with ergot derivatives, cisapride, pimozide,
midazolam and triazolam. If LEXIVA is coadministered with ritonavir,
flecainide and propafenone are also contraindicated. Caution should be used
when coadministering medications that are substrates, inhibitors or inducers
of CYP3A4, or potentially toxic medications that are metabolized by CYP3A4.
Serious and/or life-threatening drug interactions could occur between LEXIVA
and amiodarone, lidocaine (systemic), tricyclic antidepressants and quinidine.
Concentration monitoring of these agents is recommended if these agents are
used concomitantly with LEXIVA. LEXIVA should not be coadministered with
rifampin, St. John's wort, lovastatin, simvastatin or delavirdine. Particular
caution should be used when prescribing phosphodiesterase (PDE-5) inhibitors
for erectile dysfunction (e.g., sildenafil or vardenafil) in patients
receiving LEXIVA. This list of potential drug interactions is not complete.
Treatment with LEXIVA/r has resulted in increases in the concentration of
triglycerides. Triglyceride and cholesterol testing should be performed prior
to initiating therapy with LEXIVA and at periodic intervals during therapy.
The most common adverse events seen in clinical trials with LEXIVA were
diarrhea, nausea, vomiting, headache and rash.
About Vertex
Vertex Pharmaceuticals Incorporated is a global biotechnology company
committed to the discovery and development of breakthrough small molecule
drugs for serious diseases. The Company's strategy is to commercialize its
products both independently and in collaboration with major pharmaceutical
companies. Vertex's product pipeline is principally focused on viral
diseases, inflammation, autoimmune diseases and cancer. Vertex co-promotes the
HIV protease inhibitor, LEXIVA, with GlaxoSmithKline.
About GlaxoSmithKline
GlaxoSmithKline is one of the world's leading research-based
pharmaceutical and healthcare companies and an industry leader in HIV research
and therapies. The company is engaged in basic research programs designed to
investigate new targets to treat HIV. For full prescribing information please
go to http://www.LEXIVA.com.
GSK's Bridges to Access program can help provide qualified individuals
with access to GSK's antiretroviral medications, as well as help identify
insurance or other support for medications. Patients may be eligible for this
program if they are not eligible for prescription drug benefits through any
other private or public insurer, payer or program. In 2004, GlaxoSmithKline
donated more than $372.5 million worth of prescription drugs to 475,000
patients. For more information, visit http://www.bridgestoaccess.gsk.com or
call 1-866-PATIENT.
Nexium is a registered trademark of the AstraZeneca group of companies.
Vertex Safe Harbor Statement
This press release may contain forward-looking statements. While
management makes its best efforts to be accurate in making forward-looking
statements, such statements are subject to risks and uncertainties that could
cause Vertex's actual results to vary materially. These risks and
uncertainties include those risks listed under Risk Factors in Vertex's Form
10-K filed with the Securities and Exchange Commission on March 16, 2005.
Vertex Contacts:
Michael Partridge, Director, Corporate Communications, (617) 444-6108
Lora Pike, Manager, Investor Relations, (617) 444-6755
Zachry Barber, Specialist, Media Relations, (617) 444-6470
GSK Contact:
Mary Faye Dark, 919-483-2839
(1) HIV+ Patient Survey, Ziment Chronic Disease Sufferers Panel, April-May
2004.
SOURCE Vertex Pharmaceuticals Incorporated
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Related links:
http://www.vrtx.com
Company News On-Call:
http://www.prnewswire.com/comp/938395.html
CONTACT:
Michael Partridge, Director, Corporate
Communications, +1-617-444-6108, Lora Pike, Manager, Investor
Relations, +1-617-444-6755, or Zachry Barber, Specialist, Media
Relations, +1-617-444-6470, all of Vertex Pharmaceuticals
Incorporated; or Mary Faye Dark of GlaxoSmithKline,
+1-919-483-2839
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