BOTHELL — Seattle Genetics gained approval Thursday for its drug Adcetris to be used to treat a rare disfiguring blood cancer of the skin.
A study found that Adcetris showed far more positive results for test patients than the current drugs in use for cutaneous T-cell lymphoma, said Seattle Genetics CEO Clay B. Siegall.
“It’s such a dramatic difference when we showed the data to doctors they were gasping,” Siegall said. “They were giving these other drugs to patients and they weren’t really helping.”
Cutaneous T-cell lymphoma affects about 2,000 people a year in the U.S. People who have the cancer can have 30, 40 or 50 nodules — abnormal tissue — develop on their skin. There are limited treatment options and no known cure.
Adcetris has been used to treat 40,000 patients with Hodgkin lymphoma and other lymphomas since 2011. Seattle Genetics expects $600 million in global sales this year, Siegall said.
Adcetris targets lymphoma cells and delivers a payload to kill the cancer. The key is the drug is attracted to a protein called CD30 that manifests on lymphoma.
The study conducted on cutaneous T-cell lymphoma involved 131 patients — with half in a control group being treated by one of two existing drugs and the other half being treated with Adcetris. While it’s a small number of patients, the study was statistically meaningful, Siegall said.
The study showed that patients treated with existing medication showed positive results 12.5 percent of the time. Patients who received Adcetris saw positive results 56 percent of the time.
“It was four times the level of response,” Siegall said.
The study did not measure survival rates; that’s something that could be looked at in future studies. The study focused on primary cutaneous anaplastic large cell lymphoma and CD30-expressing mycosis fungoides, the most common subtypes of cutaneous T-cell lymphoma. That’s about 70 percent of cutaneous T-cell lymphoma.
The FDA approval is for second-line treatment, meaning that patients must first be treated with one of the existing drugs.
While the news is welcome for people afflicted with the cancer, Seattle Genetics is hoping to gain another FDA approval in the near future.
It has been put on the fast track to receive approval for Adcetris to be used as front-line treatment with chemotherapy for patients with advanced classical Hodgkin lymphoma. Right now, Adcetris is currently used as second- or third-line treatment when other drugs fail.
If that happens, Seattle Genetics’ signature drug could be used far more in treatments around the U.S. The FDA is evaluating the results of a study called Echelon-1 to determine if Adcetris can be used as a front-line treatment.
“When Wall Street looks at Seattle Genetics the biggest thing they look at is E1 trial for front-line Hodgkin lymphoma,” Siegall said.
Jim Davis: 425-339-3097; jdavis@heraldnet.com; @HBJnews.
