Originally published March 8.
By Turna Ray
Expanding their existing collaboration around the MAGE-A3 biomarker, GlaxoSmithKline and Abbott Molecular announced last week that they will work together to develop and commercialize a diagnostic test to select patients for an investigational skin cancer immunotherapy.
GSK is developing a MAGE-A3-targeting antigen-specific cancer immunotherapeutic, or ASCI, for the adjuvant treatment of melanoma. The drug is currently being investigated in a Phase III study, called DERMA, in which participants must have MAGE-A3-expressing melanoma tumors in order to receive the therapy. Under the terms of the agreement with Abbott, the diagnostics firm will provide the MAGE-A3 test for the GSK study.
Before deciding to develop a companion test for GSK's melanoma treatment, the two firms inked a similar deal last July around the MAGE-A3 marker for a non-small cell lung cancer treatment [see PGx Reporter 07-15-2009].
It is likely that GSK and Abbott's collaboration around the MAGE-A3 marker may lead to personalization of other cancer drugs. According to the partners' statement on the melanoma collaboration, Abbott's test will be designed to detect MAGE-A3, a tumor-specific antigen that is expressed in skin cancer, NSCLC, liver and bladder cancer. The MAGE-A3 antigen is not present in normal cells.
GSK's MAGE-A3 ASCI combines tumor antigens selected to increase the body's anti-tumor immune response. Several of GSK's ASCIs are being studied in clinical trials to see if they can reduce patients' risk of tumor recurrence following surgery, or impact tumor growth in an early metastatic setting.
"This is an exciting continuation of our important collaboration with GSK, a leading company in cancer immunotherapy research," said Stafford O'Kelly, head of Abbott's molecular diagnostics business, in a statement. "The agreement is indicative of our commitment to personalized medicine and our focus on developing innovative companion diagnostic tests that can be used to identify patients most likely to benefit from specific cancer therapies."
The companion test being developed by Abbott will be a PCR-based molecular diagnostic that will operate on the company's m2000 instrument platform.
According to an Abbott spokesperson, the company is planning to submit the diagnostic simultaneously with the drug, to the US Food and Drug Administration for pre-market approval.
"We are planning to submit simultaneously with GSK and are working with them directly on this approach," the spokesperson said. "The details and timelines of the submission have not yet been made public." GSK did not respond to questions about this collaboration.
GSK's O'Kelly offered a glimpse into the drug developer's strategy behind drug/diagnostic partnerships at a conference on personalized medicine in Philadelphia last month. According to O'Kelly, in a Rx/Dx collaboration, the therapeutic and the test harbor the same risk in development, since successful administration of the drug is dependent on how well the test works.
Furthermore, O'Kelly expressed the view that a laboratory-developed test is "not acceptable" for companion diagnostic development, and that the same test used in clinical studies should be the test submitted to regulatory authorities for market clearance.
In O'Kelly's view, the earlier the companion test is incorporated into drug development, the better the chances of success.
According to GSK and Abbott, if the development and commercialization efforts go as planned, their drug/diagnostic combination product stands to be the only one of its kind in the skin cancer setting. "There are no nucleic acid-based tests approved by the FDA for use in identifying patients who may derive treatment benefits from targeted skin cancer therapies," the partners said in a statement.
Financial details of the collaboration were not released. "While we believe there are significant commercial opportunities for a clinically validated test, any financial forecasts at this point would be premature," the Abbott spokesperson told Pharmacogenomics Reporter last week.
The American Cancer Society estimates that in 2008 there were more than 8,000 deaths from melanoma and as many as 62,000 new cases of the disease. Published studies show that around 65 percent of melanoma patients' tumors express MAGE-A3.
The Phase III DERMA study, in which GSK's MAGE-A3 ASCI is being evaluated, will recruit 1,300 patients and is currently enrolling. To be eligible, melanoma patients must have stage 3B or 3C disease, have had their tumors resected, and the cancer in their lymph nodes must be detectable without a microscope.