Thyrogen Indications, Dosage, Storage, Stability - Thyrotropin Alfa

Thyrogen Indications, Dosage, Storage, Stability - Thyrotropin Alfa

INDICATIONS

Thyrogen (thyrotropin alfa for injection) is indicated for use as an adjunctive diagnostic tool for serum thyroglobulin (Tg) testing with or without radioiodine imaging in the follow-up of patients with well-differentiated thyroid cancer.

Potential Clinical Uses:

1. Thyrogen Tg testing may be used in patients with an undetectable Tg on thyroid hormone suppressive therapy to exclude the diagnosis of residual or recurrent thyroid cancer (see CLINICAL PHARMACOLOGY , Clinical Trials , Thyroglobulin (Tg) Results ).
2. Thyrogen testing may be used in patients requiring serum Tg testing and radioiodine imaging who are unwilling to undergo thyroid hormone withdrawal testing and whose treating physician believes that use of a less sensitive test is justified.
3. Thyrogen testing may be used in patients who are either unable to mount an adequate endogenous TSH response to thyroid hormone withdrawal or in whom withdrawal is medically contraindicated.

Considerations in the Use of Thyrogen:

1. Even when Thyrogen-stimulated Tg testing is performed in combination with radioiodine imaging, there remains a meaningful risk of missing a diagnosis of thyroid cancer or of underestimating the extent of disease. Therefore, thyroid hormone withdrawal Tg testing with radioiodine imaging remains the standard diagnostic modality to assess the presence, location and extent of thyroid cancer.
2. Thyrogen Tg levels are generally lower than, and do not correlate with Tg levels after thyroid hormone withdrawal (see CLINICAL PHARMACOLOGY , Thyroglobulin (Tg) Results ).
3. A newly detectable Tg level or a Tg level rising over time after Thyrogen, or a high index of suspicion of metastatic disease, even in the setting of a negative or low-stage Thyrogen radioiodine scan, should prompt further evaluation such as thyroid hormone withdrawal to definitively establish the location and extent of thyroid cancer. On the other hand, none of the 31 patients studied with undetectable Thyrogen Tg levels (< 2.5 ng/mL) had metastatic disease. Therefore, an undetectable Thyrogen Tg level suggests the absence of clinically significant disease (see CLINICAL PHARMACOLOGY , Clinical Trials ).
4. The decisions whether to perform a Thyrogen radioiodine scan in conjunction with a Thyrogen serum Tg test and whether and when to withdraw a patient from thyroid hormone are complex. Pertinent factors in these decisions include the sensitivity of the Tg assay used, the Thyrogen Tg level obtained, and the index of suspicion of recurrent or persistent local or metastatic disease. In the clinical trials, combination Tg and scan testing did enhance the diagnostic accuracy of Thyrogen in some cases (see CLINICAL PHARMACOLOGY Clinical Trials ).
5. Thyrogen is not recommended to stimulate radioiodine uptake for the purposes of ablative radiotherapy of thyroid cancer.
6. The signs and symptoms of hypothyroidism which accompany thyroid hormone withdrawal are avoided with Thyrogen (see CLINICAL PHARMACOLOGY , Clinical Trials , Quality of Life , Hypothyroid Signs and Symptoms ).

Thyrogen 0.9 mg intramuscularly may be administered every 24 hours for two doses or every 72 hours for three doses.

After reconstitution with 1.2 mL Sterile Water for Injection, a 1.0 mL solution (0.9 mg thyrotropin alfa) is administered by intramuscular injection to the buttock.

For radioiodine imaging, radioiodine administration should be given 24 hours following the final Thyrogen injection. Scanning should be performed 48 hours after radioiodine administration (72 hours after the final injection of Thyrogen).

The following parameters utilized in the second Phase 3 study are recommended for radioiodine scanning with Thyrogen:

• A diagnostic activity of 4 mCi (148 MBq) ¹³¹ l should be used.
• Whole body images should be acquired for a minimum of 30 minutes and/or should contain a minimum of 140,000 counts.
• Scanning times for single (spot) images of body regions should be 10-15 minutes or less if the minimum number of counts is reached sooner (i.e., 60,000 for a large field of view camera, 35,000 counts for a small field of view).

For serum Tg testing, the serum sample should be obtained 72 hours after the final injection of Thyrogen.

INSTRUCTIONS FOR USE

Thyrogen (thyrotropin alfa for injection) is for intramuscular injection to the buttock. The powder should be reconstituted immediately prior to use with 1.2 mL of the diluent provided. Each vial of Thyrogen and each vial of diluent is intended for single use. Discard unused portion of the diluent.

Thyrogen should be stored at 2-8°C (36-46°F). Each vial, after reconstitution with 1.2 mL of the accompanying Sterile Water for Injection, USP, should be inspected visually for particulate matter or discoloration before use. Any vials exhibiting particulate matter or discoloration should not be used.

If necessary, the reconstituted solution can be stored for up to 24 hours at a temperature between 2°C and 8°C, while avoiding microbial contamination.

DO NOT USE Thyrogen after the expiration date on the vial. Protect from light.

Thyrogen (thyrotropin alfa for injection) is supplied as a sterile, non-pyrogenic, lyophilized product. It is available as a kit containing two 1.1 mg vials ( ≥ 4 IU) of Thyrogen® (thyrotropin alfa for injection) and two 10 mL vials of Sterile Water for Injection, USP.

NDC 58468-1849-4

Store at 2-8°C.

Rx ONLY

Thyrogen® (thyrotropin alfa for injection)

Manufactured and Distributed by:
Genzyme Corporation
One Kendall Square
Cambridge, MA 02139
(800) 745-4447

Marketed by:
Knoll Pharmaceutical Company
Genzyme Corporation