Date: 12-Jun-2021

Valemetostat Data At EHA Shows Promising Durable Tumor Response In Patients With Peripheral T-Cell Lymphoma And Adult T-Cell Leukemia/Lymphoma

  • Oral presentation highlights data from phase 1 study of valemetostat showing promising clinical activity in patients with relapsed/refractory PTCL and ATL
  • Pivotal phase 2 study VALENTINE-PTCL01 underway globally to further evaluate efficacy and safety of valemetostat in similar patient population
 

TOKYO & MUNICH & BASKING RIDGE, N.J.--(BUSINESS WIRE)-- New data from Daiichi Sankyo Company, Ltd. (hereafter, Daiichi Sankyo) for valemetostat, a potential first-in-class specific and potent dual inhibitor of EZH1 and EZH2, showed promising and durable tumor response in patients with relapsed/refractory peripheral T-cell lymphoma (PTCL) and adult T-cell leukemia/lymphoma (ATL).1,2 The data were reported today during an oral presentation (Abstract #S218) at the Annual Congress of the European Hematology Association (#EHA2021).

PTCL is a group of rare and heterogenous malignancies, including ATL, which represent about 10-15% of all non-Hodgkin lymphomas (NHL).3 The majority of patients with PTCL experience disease progression following initial treatment with a multi-drug chemotherapy-based regimen, and median overall survival following relapse is approximately 5.8 months.4 New innovative treatment strategies are needed to improve survival in these patients.

In this first-in-human phase 1 study of valemetostat in B-cell and T-cell NHL, data were reported at EHA in the subset of patients with relapsed/refractory PTCL and ATL. The objective response rate (ORR), based on investigator’s assessment, was 54.5% (CI 95%: 38.8-69.6) in 44 patients with PTCL including 12 complete responses (CRs) and 12 partial responses (PRs). A median duration of response (DOR) of 56.00 weeks (CI 95%: 44.43-NE) and a median progression-free survival (PFS) of 52.00 weeks (CI 95%: 16.14-NE) were observed after a median follow-up of 19.93 weeks (range: 3.1-68.1).

The ORR in 14 patients with ATL was 57.1% (CI 95%: 28.9-82.3), with four CRs and four PRs. Median DOR and PFS were not estimable for patients with ATL after a median follow-up of 23.07 weeks (range: 3.3-125.0). Twelve patients with PTCL and six patients with ATL remained on treatment with valemetostat at the time of data cutoff on November 2, 2020.

The safety profile of valemetostat in patients with PTCL and ATL (n=58) was similar with that seen across all patients with NHL (n=77). Grade 3 or higher treatment emergent adverse events (TEAEs) occurred in 54 of 77 NHL patients (70.1%) and included neutrophil count decrease (23.4%), lymphocyte count decrease (22.1%), platelet count decrease (16.9%), white blood cell count decrease (15.6%), anemia (11.7%), diarrhea (1.3%) and alanine aminotransferase (ALT) increase (1.3%). Dose interruption or reductions due to TEAEs occurred in 41.6% (n=32) and 10.4% (n=8) of all patients with NHL, respectively.

“The proportion of patients who responded to valemetostat and the durability of responses observed in this trial are very encouraging for patients with PTCL, including ATL, which remains one of the most significant areas of unmet need in the treatment of hematologic cancers,” said Shigeru Kusumoto, MD, Associate Professor, Department of Hematology and Oncology, Nagoya City University Graduate School of Medical Sciences, Japan. “Because both EZH1 and EZH2 play important roles for the pathophysiology of PTCL and ATL, dual targeting of EZH1 and EZH2 with valemetostat may be an innovative approach for these difficult-to-treat diseases.”

“We are committed to translating the novel mechanism of valemetostat into a potential treatment option for patients with PTCL and ATL in various regions around the world where these types of blood cancers are most prevalent,” said Ken Takeshita, MD, Global Head of Research and Development, Daiichi Sankyo. “Based on the promising clinical activity seen in this phase 1 study, we have initiated VALENTINE-PTCL01, a global pivotal study that will further evaluate the efficacy and safety of valemetostat in patients with relapsed or refractory PTCL including ATL.