A subset of mesothelioma patients may soon be treated with Adcetris, a drug currently used to treat Hodgkin’s disease and large-cell lymphoma.
The possible breakthrough stems from the recent identification of the protein CD30 in a small but distinct percentage of mesothelioma cells lines, providing a new target for treatment of the asbestos-related cancer.
Cancer researchers at Case Western Reserve University in Cleveland first discovered that Adcetris, also known as brentuximab vedotin, effectively slowed the growth of mesothelioma cells that contained CD30.
Lead researcher and hematologist Dr. Afshin Dowlati told Asbestos.com the drug was “very, very active against these cells, and not active against the cells that did not express CD30.”
Molecular Cancer Therapeutics published the report titled, “CD30 Is a Potential Therapeutic Target in Malignant Mesothelioma,” earlier this year.
The U.S. Food and Drug Administration (FDA) approved Adcetris in 2011 under its accelerated approval program. Research performed at the Sylvester Comprehensive Cancer Center in Miami helped the FDA approve the drug for lymphoma.
CD30 is important because it interacts with smaller proteins and acts like a regulator of apoptosis, or programmed cell death. Adcetris, manufactured by Seattle Genetics, is an antibody-drug conjugate designed to target CD30 and change the way it reacts.
Case Western, which is rising to national prominence in mesothelioma research, started by testing 83 different mesothelioma tumor specimens in the laboratory and found 13 that expressed the CD30 protein. Each of the 13 samples was of the epithelioid subtype, which accounts for more than half of all mesothelioma cell lines. These were targeted and produced impressive results.
The other subtypes of mesothelioma are sarcomatoid and biphasic. The three types differ in shape, size and cell structure. Within the epithelioid subtype, there also are different varieties, but no differentiation was made in the study.
“This is just a small step in the right direction,” Dowlati said. “We believe that more profound studies need to be done in the clinic where CD30 can be targeted.”
Although the drug was effective against only a small percentage of the cell lines in the laboratory, it illustrated the way mesothelioma research is evolving, and how doctors are currently thinking when it comes to treatment options.
“All patients aren’t created equal. Mesothelioma isn’t all the same. You identify subtypes, and try to find what works for each one,” Dowlati said. “Different types can be treated in different ways. It’s a very old concept in medicine, but in oncology, it’s really just come to fruition in the last decade. Instead of the same drug for everyone, cancer treatment has to be personalized.”
Mesothelioma is an aggressive, rare cancer diagnosed in 3,000 Americans annually. Some patients live less than six months after being diagnosed, but there are survivors living five years and more.
Oncologists currently cannot explain why a drug that works for one patient, often doesn’t work for another. It underlines the need for more research like that being done at Case Western.
“We don’t know if this drug will work in the clinic,” Dowlati cautioned. “Just because something works in the laboratory, doesn’t mean it will work in the clinic. A lot of questions still need to be answered.”