By Clinical Informatics News Staff

January 21, 2015 | QIAGEN’s circulating tumor DNA companion diagnostic for lung cancer has been granted CE-IVD marking in 30 European countries, the company announced. The diagnostic is designed as a companion for Astra Zeneca’s IRESSA for non-small cell lung cancer patients.

The liquid biopsy is adapted from QIAGEN’s therascreen EGFR test for detecting EGFR mutation status in solid lung tumor samples. The new diagnostic determines EGFR mutation status by testing for 21 mutations in circulating nucleic acids in blood tests.

The technology is not new. QIAGEN’s QIAamp Circulating Nucleic Acid Kit for DNA purification was launched in 2009. “It’s the gold standard, I think it’s fair to say, for isolating this kind of free DNA,” said Christoph Menzel, Associate Director Global Product Management at QIAGEN. “It is also used in the non-invasive prenatal testing space very heavily.”

But this marks the first regulatory registration of a liquid biopsy lung cancer companion diagnostic. The European Medicines Agency just extended the drug label of IRESSA to include the detection of EGFR mutations in circulating tumor DNA obtained from a blood sample.  

The new application is the result of a long-standing relationship between QIAGEN and AstraZeneca. The two companies announced their intention to develop a liquid biopsy companion diagnostic for IRESSA in July 2014.

IRESSA (gefitinib), the oral monotherapy anti-cancer treatment from AstraZeneca, is an epidermal growth factor receptor-tyrosine kinase (EGFR-TK) inhibitor that acts to block signals for cancer cell growth and survival.

In 2009, IRESSA was approved in Europe as a first-line treatment for adult patients with NSCLC with activating mutations of EGFR-TK. The therascreen EGFR test as a tissue-based companion diagnostic was approved by the FDA in July 2013 and in China in May 2014.  

Solid tumor sampling is the standard of care, and in about 80% of cases, solid tumor tissue is available for EGFR mutation testing, said Menzel. IRESSA can be prescribed to patients whose tumors have activating mutations, but for the rest of patients, where the tissue samples is not available for biopsy, it’s not clear if the drug should be administered.

“In 20% of cases you cannot do [a tumor biopsy] for various reasons,” Menzel explained, “For example in a metastatic state you cannot get access to the sample, you have a very tiny biopsy… it’s not enough to do all the testing for lung cancer diagnostics and then you do not have anything from the tissue to do molecular tests for targeted therapies. These patients are not benefitting from it.”

The new approval will give those patients an EGFR testing option.

Menzel also conceded that some studies have suggested that liquid biopsy tests may be useful in addressing tumor heterogeneity. “Currently this is not part of our intended use,” he said, “but there are definitely studies saying that there is heterogeneity in the tissue samples that can give problems and with plasma samples you have more homogeneity.”