FDA Clears Lab Test Monitoring Hemophilia B via FIX Activity

CRYOcheck Chromogenic Factor IX reported to be only such test cleared by FDA

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by Steve Bryson, PhD |

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The U.S. Food and Drug Administration (FDA) has cleared CRYOcheck Chromogenic Factor IX assay, a test intended to be used by clinical labs to detect a deficiency in factor IX (FIX), the cause of hemophilia B.

The chromogenic, or color-based, test developed by Precision BioLogic is reported to be the only FDA-cleared FIX assay on the market, and it also can be used to monitor the effectiveness of hemophilia B treatments.

“Precision BioLogic provides tools to help laboratory professionals make the best decisions, faster,” Paul Empey, Precision’s CEO and president, said in a company press release. “Recognizing the need for FDA-cleared chromogenic assays, Precision BioLogic developed CRYOcheck Chromogenic Factor IX to meet the needs of today’s clinical laboratories.”

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Lab test to monitor hemophilia B and treatment effectiveness

Hemophilia B is a genetic condition caused by missing or defective FIX, a blood clotting protein, which can lead to excessive bleeding episodes.

Standard hemophilia treatments include FIX replacement therapies that provide patients with an alternative version of FIX derived from an external source. Some of these therapies have an extended half-life, meaning they remain active in the bloodstream for a longer time, requiring fewer infusions. Gene therapy, which is based on the principle of replacing the defective gene that encodes for FIX with a functional copy to restore the production of a working factor, also can treat the disease.

According to the National Hemophilia Foundation (NHF), limitations are evident in current blood clotting tests to monitor treatment effectiveness, especially that of newer therapies. To address these limitations, the NHF’s Medical and Scientific Advisory Council issued a recommendation supporting more chromogenic tests in clinical labs.

“With the emergence of new therapies, including extended half-life FIX replacements and gene therapy, there has never been a stronger need for accurate, reliable hemophilia tests,” Empey said.

CRYOcheck Chromogenic Factor IX is validated for use on automated blood-clotting analyzers, with a test range from 0% to 200% of FIX activity using one calibration curve. According to the company, the test remains precise even at low levels of FIX activity.

CRYOcheck comes frozen in a ready-to-use format. Reagents can be quickly thawed and then cold stored for up to two days, or refrozen for up to one month, to maximize efficiency while minimizing lab waste.

The company launched the test in several countries last year, including Canada, the EU, the U.K., Australia, and New Zealand. A Chromogenic Factor VIII assay for diagnosing and monitoring hemophilia A is also available.