Updated with new information.
SAN FRANCISCO (TheStreet) -- The use of Seattle Genetics' (SGEN) Adcetris as a maintenance therapy after a stem-cell transplant in "high risk" Hodgkin lymphoma patients led to a 20 percentage point improvement in relapse rates compared to a placebo after two years of follow-up, researchers reported Saturday.
The new Adcetris data comes from a phase III study known as AETHERA, which is being presented in full at the American Society of Hematology annual meeting underway here. Next year, Seattle Genetics intends to seek approval from regulators to expand the use of Adcetris into a larger pool of Hodgkin lymphoma patients based on the AETHERA study results.
The AETHERA study enrolled 327 Hodgkin lymphoma patients who had undergone stem-cell transplant to put their disease into remission but who still had certain characteristics which made them more likely to relapse. Between 30 and 45 days after transplant, the patients were randomized to receive treatment with Adcetris or a placebo for one year.
After two years of followup, 65% of Adcetris patients had no evidence of disease progression compared to 45% of patients treated with a placebo, according to new details from the AETHERA study disclosed Saturday at an ASH-sponsored media briefing.
"This is the first study in lymphoma to demonstrate that the addition of a maintenance drug after transplant can markedly improve patient outcomes," said Dr. Craig Moskowitz of Memorial Sloan Kettering Cancer Center in New York. Moskowitz was the lead investigator in the AETHERA study.
In September, Seattle Genetics first announced the AETHERA study achieved its primary endpoint, showing maintenance therapy with Adcetris led to a 43% reduction in the risk of disease progression compared to placebo.
Despite delaying disease progression, treatment with Adcetris did not prolong survival compared to placebo in the phase III study at this analysis, which the company blames partly on placebo patients "crossing over" to receive Adcetris once their disease progressed. Another survival analysis of the study will be conducted in 2016. Adcetris' safety profile was "generally consistent" with previous studies, the company said.