Japan Designates Valemetostat for Accelerated Development to Treat PTCL

The Japan Ministry of Health, Labour and Welfare (MHLW) has granted Sakigake Designation to valemetostat, an investigational treatment for adult patients with relapsed or refractory peripheral T-cell lymphoma (PTCL).

The designation is given to promising therapies and aims to accelerate their development and review process, as well as reduce review time from the standard 12 months to six months.

The decision was based on preliminary data from an ongoing Phase 1 trial (NCT02732275) assessing valemetostat in patients with non-Hodgkin’s lymphoma — including PTCL — who failed to respond or whose disease returned after standard therapy.

The study, still recruiting participants at the National Cancer Center Hospital in Tokyo, is set to include 45 patients to determine the best valemetostat dose for Phase 2 testing as well as preliminary signs of efficacy.

Preliminary results from the first 17 patients showed that more than half the patients (58.8%) responded to treatment, including one complete response — the total disappearance of cancer signs. Valemetostat stabilized the disease in four additional patients.

The therapy, however, showed particularly better response rates in T-cell lymphomas (83.3%) than in B-cell lymphomas (45.5%), the company reported. Both patients with PTCL responded to treatment.

Among the 18 patients evaluable for safety, the most common treatment-related adverse events were those affecting blood cells, including anemia, low platelet counts, and low numbers of white blood cells, called lymphocytes and neutrophils.

Other treatment-related adverse events included an abnormal sense of taste, hair loss, diarrhea, reduced appetite, inflammation of the respiratory tract, increase in liver enzymes, rash, and dry skin.

Those findings were presented in 2017 at the American Society of Hematology (ASH) Annual Meeting in the poster “First-in-Human Study of the EZH1/2 Dual Inhibitor DS-3201b in Patients with Relapsed or Refractory Non-Hodgkin Lymphomas — Preliminary Results.”

Valemetostat, developed by Japanese pharmaceutical company Daiichi Sankyo, is a potent inhibitor of EZH1 and EZH2, two enzymes whose activity promotes tumor development and progression in several cancers, including non-Hodgkin’s lymphoma.

“There is a need for new and novel treatment approaches for patients with peripheral T-cell lymphoma, a group of heterogenous diseases for which relapse rates tend to be high and options beyond systemic chemotherapy are limited,” Kaszushi Araki, valemetostat global team leader at Daiichi Sankyo, said in a press release.

“We look forward to working closely with the Japan Ministry of Health, Labour and Welfare to optimize development of valemetostat and to potentially offer a new, first-in-class targeted therapy option for patients with various subtypes of relapsed/refractory PTCL, including those that are more common in Japan,” Araki said.