Key elements for this partnership to succeed include crossing regulatory hurdles in the U.S. and building awareness.
DxS and AstraZeneca have agreed to collaborate to make a companion diagnostic available for use with Iressa, the latter’s treatment for non-small-cell lung cancer (NSCLC). DxS’ TheraScreen®: EGFR29 Mutation Kit will be offered as a test to identify the mutation status of a patient’s EGFR oncogene, which would determine their eligibility for the drug.
Iressa is approved in the EU for locally advanced or metastatic NSCLC with activating mutations of EGFR-TK. In the U.S., however, labeling for Iressa restricts its use to “patients with cancer who in the opinion of their treating physician are currently benefiting or have previously benefited from Iressa treatment.” FDA does not yet have any mandates on testing for the relevant EGFR mutations.
Regarding expected uptake in the EU, “Market education and awareness is a huge theme of the AstraZeneca/DxS collaboration,” asserts Peter Collins, svp of business development for DxS. There is no absolute requirement for oncologists to use the DxS test, but it is essential that patients do need an EGFR test, and hence helping oncologists understand the benefits of the tool will be important, he says.
Making sure doctors know that this test exists and how to get it will be a big part of its success, Collins adds. And of course, market acceptance of Iressa will be a factor.
Rollout will occur on a territory by territory basis in the EU. “We will work together with local AstraZeneca affiliates to ensure that doctors and labs who want to use our test are able to do so,” Collins remarks.
Once the test is available on an FDA-approved platform, the company will be able to launch in the U.S. Another element is getting label changes for the drug to include the benefit seen in patients with certain EGFR mutations, which, according to Collins, could take another two to three years.
Iressa acts by inhibiting the tyrosine kinase enzyme in EGFR, thus blocking the transmission of signals. Out of nine NSCLC patients who responded to Iressa, eight had EGFR mutations, according to a study at the Massachusetts General Hospital and the Dana-Farber Cancer Institute. No mutations were detected among the seven patients who did not respond to the drug. Research also has linked mutant EGFR to higher activation. Additionally, mutated receptors were 10 times more sensitive to Iressa.
DxS has a global distribution deal with Roche Molecular Diagnostics for its TheraScreen range of diagnostic kits. DxS has a global distribution deal with Roche Molecular Diagnostics for its TheraScreen range of diagnostic kits. Also its TheraScreen: K-RAS Mutation Kit is used as a diagnostic for Amgen’s Vectibix® and Erbitux® from Merck Serono and Bristol-Myers Squibb, both colorectal cancer treatments.