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Murine monoclonal antibodies (MAbs) are foreign proteins, and their administration can induce HAMA. While limited data exist concerning the clinical significance of HAMA, the presence of HAMA may interfere with murine-antibody based immunoassays, or could compromise the efficacy of diagnostic or therapeutic murine antibody-based agents and increase the risk of adverse reactions. For these reasons, patients should be informed that the use of this product could adversely affect the future ability to diagnose recurrence of their tumor, the ability to perform certain other laboratory tests, or to use other murine-based products. Patients should be advised to discuss prior use of murine-antibody based products with their physicians (see Heterologous Protein Administration, below).
Heterologous Protein Administration
Indium In 111 ProstaScint® (capromab pendetide) has been shown to induce HAMA to murine IgG infrequently and with low peak levels after single administration. HAMA levels were detected (at > 8 ng/mL) by RIA after single infusion in 8% (20/239) of patients, while 1% of patients had levels greater than 100 ng/mL. In addition, serum HAMA levels were detected by RIA after repeat infusion in 19% (5/27) of the patients.
While limited data exist concerning the clinical significance of HAMA, detectable serum levels can alter the clearance and tissue biodistribution of MAbs. The development of persistently elevated serum HAMA levels could compromise the efficacy of diagnostic or therapeutic murine antibody-based agents. In repeat administration trials, 93% (65/70) of the evaluable repeat infusions were associated with normal tissue distribution of the MAb conjugate. Pre-infusion serum HAMA levels were generally not predictive of altered distribution.
When considering the administration of Indium In 111 ProstaScint® to patients who have previously received other murine antibody-based products, physicians should be aware of the potential for assay interference and increased clearance and altered biodistribution, which may interfere with the quality or sensitivity of the imaging study. Prior to administration of murine antibodies, including Indium In 111 ProstaScint® (capromab pendetide), the physician should review the patient history to determine whether the patient has previously received such products.
Last reviewed on RxList: 7/9/2012
This monograph has been modified to include the generic and brand name in many instances.
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