Idenix Pharmaceuticals (IDIX)

[DewDiligence]

Bristol-Myers just issued a ‘Dear Doctor’
letter regarding the Baraclude label change
for HIV co-infection (emphasis in original text):

http://www.fda.gov/medwatch/safety/2007/Baraclude%20DHCP_aug1607.pdf

>>
August 2007

IMPORTANT DRUG WARNING

Dear Healthcare Professional:

Bristol-Myers Squibb would like to inform you that therapy with BARACLUDE® (entecavir) is not recommended for HIV/HBV co-infected patients who are not also receiving highly active antiretroviral therapy (HAART) due to the potential for the development of HIV (human immunodeficiency virus) resistance.

Accordingly, the BARACLUDE Full Prescribing Information has been updated to include the following information in the boxed WARNINGS:

“Limited clinical experience suggests there is a potential for the development of resistance to HIV (human immunodeficiency virus) nucleoside reverse transcriptase inhibitors if BARACLUDE is used to treat chronic hepatitis B virus infection in patients with HIV infection that is not being treated. Therapy with BARACLUDE is not recommended for HIV/HBV co-infected patients who are not also receiving highly active antiretroviral therapy (HAART). See WARNINGS: Co-infection with HIV.”

In addition, the MICROBIOLOGY section of the BARACLUDE Full Prescribing Information has been revised to include the following additional information:

Antiviral Activity against HIV

“A comprehensive analysis of the inhibitory activity of entecavir against a panel of laboratory and clinical human immunodeficiency virus type 1 (HIV-1) isolates using a variety of cells and assay conditions yielded EC50 values ranging from 0.026 to >10mcM; the lower EC50 values were observed when decreased levels of virus were used in the assay. In cell culture, entecavir selected for an M184I substitution in HIV reverse transcriptase at micromolar concentrations, confirming inhibitory pressure at high entecavir concentrations. HIV variants containing the M184V substitution showed loss of susceptibility to entecavir.”

Consistent with clinical practice guidelines for chronic hepatitis B management, the WARNINGS section of the BARACLUDE Full Prescribing Information has been updated with the following information:

"Before initiating BARACLUDE therapy, HIV antibody testing should be offered to all patients. BARACLUDE has not been studied as a treatment for HIV infection and is not recommended for this use."

Other changes in the WARNINGS and PRECAUTIONS sections and PATIENT INFORMATION have been made consistent with the information described above. Please refer to the enclosed BARACLUDE Full Prescribing Information, including boxed WARNINGS, for more information.

…If you have had a patient who experienced an adverse event following, or coincident with the use of BARACLUDE (entecavir), please contact Bristol-Myers Squibb at 1-800-321-1335 or the FDA MedWatch program by phone at 1-800-FDA-1088, by fax at 1-800-FDA-0178, or by mail (MedWatch, 5600 Fishers Lane, Rockville, MD 20852-9787).

Please refer to the accompanying Important Information about BARACLUDE and the enclosed BARACLUDE Full Prescribing Information, including boxed WARNINGS.

Sincerely,

Freda C. Lewis-Hall, M.D.
Senior Vice President, US Medical Affairs
Bristol-Myers Squibb
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