LA JOLLA, CALIF. — Results from the COMPLETE registry suggest newer single agents may be more effective than combination chemotherapy for patients with relapsed/refractory peripheral T-cell lymphoma (PTCL).
Complete response (CR) rates and median survival times were significantly better among patients who received single agents than among those who received combination therapy.
Although researchers don’t know what is driving these differences in outcomes, they did find that outcomes were best among patients who received single-agent brentuximab vedotin (BV), and a disproportionate number of patients received BV.
The researchers also found that patients who received single-agent therapy were more likely to proceed to stem cell transplant.
Therefore, it’s still unclear if single-agent treatment is superior to combination therapy for relapsed/refractory PTCL, according to Robert Stuver, MD, of Beth Israel Deaconess Medical Center in Boston.
Dr. Stuver presented data from the COMPLETE (Comprehensive Oncology Measures for Peripheral T-cell Lymphoma Treatment) registry at the annual T-cell Lymphoma Forum.
The registry () enrolled patients newly diagnosed with PTCL. Dr. Stuver presented results among patients who had relapsed after, or were refractory to, upfront therapy and went on to receive single-agent therapy or any combination regimen excluding those single agents. Outcome data were collected for 5 years or until death.
Patients and treatment
There were 26 patients in the combination treatment group — 10 with PTCL not otherwise specified (NOS), 6 with angioimmunoblastic T-cell lymphoma (AITL), 5 with natural killer T-cell lymphoma (NKTL), 3 with anaplastic large-cell lymphoma (ALCL), 1 with enteropathy-associated T-cell lymphoma (EATL), and 1 with hepatosplenic T-cell lymphoma (HSTCL).
Patients in the combination group received gemcitabine-based therapy (n = 10), ifosfamide-based therapy (n = 7), platinum-based therapy (n = 4), CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone)-like therapy (n = 1), DHAP (dexamethasone, high-dose cytarabine, and cisplatin; n = 1), and other combinations (n = 3).
There were 31 patients in the single-agent group – 13 with PTCL-NOS, 7 with ALCL, 5 with AITL, 2 with EATL, 2 with NKTL, and 2 with HSTCL.
These patients were treated with BV (n = 12), romidepsin (n = 8), pralatrexate (n = 5), alisertib (n = 3), bendamustine (n = 1), denileukin diftitox (n = 1), and lenalidomide (n = 1).
The CR rates were significantly higher among patients who received single-agent treatment than among those who received combination therapy — 41.4% (12/31) and 19.2% (5/26), respectively (P = .02). The partial response rates were 17.2% (5/31) and 26.9% (7/26), respectively. Rates of stable disease were 3.4% (1/31) and 30.8% (8/26), respectively.
Complete responders in the single-agent arm were treated with BV (n = 7), romidepsin (n = 2), pralatrexate (n = 1), alisertib (n = 1), and bendamustine (n = 1). Four of the patients treated with BV had ALCL.
“We had an enrichment of patients treated with brentuximab,” Dr. Stuver said. “So the obvious question this begs is, ‘Are the favorable results that were seen for single agents over combination therapy solely due to patients treated with brentuximab?’ ”
To investigate, Dr. Stuver and his colleagues compared responses among patients who received BV with patients who received other single agents or combination therapies.
The CR rate was 58.3% (7/12) among BV recipients, 29.4% (5/17) among patients who received other single agents, and 19.2% (5/26) among patients who received combination therapy.
“The takeaway here is that, when you do divide the single-agent group into BV and other single agents, you’re seeing that BV is doing much better than every other group,” Dr. Stuver said. “And all the other single agents are doing somewhat similarly to the combination group, although there’s still a 10% difference, 29% versus 19%.”