Irinotecan

Pharmacogenomic Information in the Context of the FDA-Approved Drug Label*

The FDA recommends, but does not require, genetic testing prior to initiating treatment with irinotecan.

Excerpt from the irinotecan drug label:

"Individuals who are homozygous for the UGT1a1*28 allele (UGT1A1 7/7 genotype) are at increased risk for neutropenia following initiation of CAMPTOSAR treatment...When administered in combination with other agents, or as a single-agent, a reduction in the starting dose by at least one level of CAMPTOSAR should be considered for patients known to be homozygous for the UGT1A1*28 allele."

Patients homozygous for the UGT1A1*28 allele, a genetic polymorphism present in approximately 10% of the North American population that leads to reduced UGT1A1 enzyme activity, are at increased risk for neutropenia resulting from treatment with irinotecan. Individuals heterozygous for the UGT1A1 allele may be at increased risk for neutropenia. UGT1A1 catalyzes the conjugation of the highly active irinotecan metabolite SN-38 to the less-active SN-38 glucuronide.

The irinotecan drug label was updated on 5/2010 to include more studies supporting the association of UGT1A1*28 and neutropenia risk, and information about laboratory testing of UGT1A1. For the complete drug label text with sections containing pharmacogenetic information highlighted, see the Irinotecan drug label PDF.

Pharmacogenomic Testing

The information below is provided for educational purposes only and does not constitute an endorsement of any listed test or manufacturer.

¹ Entries in this column link to test manufacturer's website.
² Information in this column was found using searches of the entire FDA website (http://www.fda.gov/search.html), searches of the FDA CDRH CLIA database (http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfClia/Search.cfm), or searches of the FDA CDRH Premarket Approval Database (http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfPMA/pma.cfm).

Table updated 4/15/2009.

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