LA JOLLA, CA—The EZH1/2 inhibitor DS-3201b could be a novel therapeutic option for non-Hodgkin lymphoma (NHL), according to a speaker at the 10th Annual T-cell Lymphoma Forum.
DS-3201b was considered well tolerated in a phase 1 study of Japanese patients with relapsed/refractory NHL.
In addition, DS-3201b demonstrated activity against B- and T-cell lymphomas, producing an overall response rate of 59%.
Kunihiro Tsukasaki, MD, PhD, of Saitama Medical University in Moroyama, Saitama, Japan, presented these results at the meeting.
The trial was sponsored by Daiichi Sankyo Co., Ltd.
Dr Tsukasaki presented data on 18 patients with relapsed/refractory NHL.
The 12 B-cell lymphoma patients had follicular lymphoma (n=5), diffuse large B-cell lymphoma (n=3), MALT lymphoma (n=2), nodal marginal zone lymphoma (n=1), and lymphoplasmacytic lymphoma (n=1).
The 6 patients with T-cell lymphoma had peripheral T-cell lymphoma not otherwise specified (n=2), angioimmunoblastic T-cell lymphoma (n=2), and adult T-cell leukemia/lymphoma (n=2).
The patients’ median age was 67 (range, 44-75), and 10 were female. All patients had an ECOG performance status of 0 (72%) or 1 (28%).
Patients had a median of 2 prior chemotherapy regimens (range, 1-8).
For this study, they received DS-3201b at 150 mg (n=7), 200 mg (n=9), or 300 mg (n=2). They received the drug once daily in 28-day cycles until they progressed or experienced unacceptable toxicity.
DLTs and AEs
Dose-limiting toxicities (DLTs) were evaluated in cycle 1. All 18 patients were evaluable for DLT assessment.
There were 4 treatment-emergent adverse events (AEs) that met the definition of DLTs:
- 3 cases of grade 4 platelet count decrease (n=1 at 200 mg, n=2 at 300 mg)
- 1 case of grade 3 anemia requiring blood transfusion (at 300 mg).
All 4 DLTs led to treatment interruption.
There were 5 serious AEs reported in 3 patients. Only one of these—pneumocystis jiroveci pneumonia—was considered related to DS-3201b.
Hematologic AEs included decreases in platelets (grade 1-4), lymphocytes (grade 1-4), neutrophils (grade 2-4), and white blood cells (grade 2-3), as well as anemia (grade 1-3).
Other AEs (all grade 1/2) included dysgeusia, alopecia, diarrhea, decreased appetite, alanine aminotransferase increase, aspartate aminotransferase increase, nasopharyngitis, rash, and dry skin.
No deaths had been reported as of the data cutoff last November.
Seventeen patients were evaluable for response.
The overall response rate was 59%, with 1 patient achieving a complete response (CR) and 9 achieving a partial response (PR). Four patients had stable disease (SD), and 3 progressed.
Among the T-cell lymphoma patients, 1 had a CR, 4 had PRs, and 1 progressed. The complete responder had angioimmunoblastic T-cell lymphoma, and the patient who progressed had adult T-cell leukemia/lymphoma.
Among the B-cell lymphoma patients, 5 had PRs, 4 had SD, and 2 progressed.
Dr Tsukasaki said DS-3201b has demonstrated early clinical activity and therefore has the potential to be a novel therapeutic option for B-cell and T-cell lymphomas. However, further evaluation is warranted to determine the optimal dosing regimen and target diseases.