Telbivudine Label Adds Resistance Warning

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Telbivudine Label Adds Resistance Warning

SUMMARY: Package labeling for the hepatitis B drug telbivudine (Tyzeka) was

recently changed to add information about the risk of drug resistance and a

recommendation for monitoring after 6 months of treatment.

The nucleoside analog telbivudine has demonstrated good activity against

hepatitis B virus (HBV), but as with most drugs in its class, the virus can

develop drug resistance that compromises long-term efficacy.

Below is the edited text of a recent advisory from the U.S. Food and Drug

Administration (FDA) describing label changes providing more details about the

risk of resistance and recommendations for how to prevent it.

Labeling Changes to Tyzeka (Telbivudine) 600 mg Tablets and Oral Solution 100

mg/5 mL Reflect Risk of Resistance-Associated Substitutions

April 1, 2011 -- FDA has approved changes in product labeling for Tyzeka

(telbivudine) 600 mg tablets and Tyzeka (telbivudine) oral solution 100 mg/5 mL

related to a higher risk of developing resistance-associated substitutions in

treated patients.

Indications and Usage-Under Section 1.1 Chronic Hepatitis B

The following points should be considered when initiating therapy with Tyzeka:

For HBeAg-positive patients, Tyzeka should only be initiated in patients with

HBV DNA less than 9 log10 copies/mL and ALT greater than or equal to 2x Upper

Limit of Normal (ULN) prior to treatment.

For HBeAg-negative patients, Tyzeka should only be initiated in patients with

HBV DNA less than 7 log10 copies/mL prior to treatment.

On-treatment response should guide continued therapy [see Dosage and

Administration (2.1) and Microbiology (12.4)].

Dosage and Administration-Under Section 2.1 Adults and Adolescents (16 years of

age and older):

Due to higher rates of resistance that may develop with longer-term treatment

among patients with incomplete viral suppression, treatment should only be

initiated, if pre-treatment HBV DNA and ALT measurements are known, in the

following patient populations:

For HBeAg-positive patients, HBV DNA should be less than 9 log10 copies/mL and

ALT should be greater than or equal to 2x ULN prior to treatment with Tyzeka.

For HBeAg-negative patients, HBV DNA should be less than 7 log10 copies/mL prior

to treatment with Tyzeka.

HBV DNA levels should be monitored at 24 weeks of treatment to assure complete

viral suppression (HBV DNA less than 300 copies/mL). Alternate therapy should be

initiated for patients who have detectable HBV DNA after 24 weeks of treatment.

Optimal therapy should be guided by further resistance testing.

Dosage and Administration-Under Section 2.4-Duration of Therapy:

For patients with incomplete viral suppression (HBV DNA greater than or equal to

300 copies/mL) after 24 weeks of treatment, alternate therapy should be

instituted. HBV DNA should be monitored every 6 months to assure continued

response. If patients test positive for HBV DNA at any time after their initial

response, alternate treatment should be instituted. Optimal therapy should be

guided by resistance testing.

For more information on the role of Tyzeka in the treatment of hepatitis, please

see the American Association for the Study of Liver Diseases (AASLD) Practice

Guidelines for Management of Chronic Hepatitis B.

4/5/11

Source

R Klein and K Struble (FDA). Labeling Changes to Tyzeka (Telbivudine) 600 mg

Tablets and Oral Solution 100 mg/5 mL Reflect Risk of Resistance-Associated

Substitutions. FDA Hepatitis Update. April 1, 2011.