Sumitomo Dainippon Pharma Oncology Announces First Patient Dosed in Phase 2 Dose-Expansion Portion of Study Evaluating Investigational WT1 Immunotherapeutic Cancer Vaccine DSP-7888 (ombipepimut-S*) in Patients with Ovarian Cancer

On October 27, 2020 Sumitomo Dainippon Pharma Oncology, Inc., a developer of novel cancer therapeutics, reported the first patient has been dosed in the Phase 2 expansion portion of the study evaluating DSP-7888, an investigational immunotherapeutic cancer vaccine that targets Wilms Tumor 1 (WT1), in combination with checkpoint inhibitor pembrolizumab, in patients with platinum-resistant ovarian cancer (PROC) (Press release, Sumitomo Dainippon Pharma, OCT 27, 2020, View Source [SID1234569167]).

Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:

Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing

                  Schedule Your 30 min Free Demo!

The Phase 1b/2 open-label, multicenter study consists of two parts. The Phase 1b portion evaluated the safety and tolerability of the combination of DSP-7888 with a PD-1 checkpoint inhibitor in adult patients with solid tumors. Based on the known high prevalence of WT1 in ovarian cancer and the findings from the Phase 1b portion of this study, the Phase 2 part will evaluate the antitumor activity of DSP-7888 in combination with pembrolizumab in patients with PROC.

"Patients with platinum-resistant ovarian cancer have a high unmet need with limited treatment options; therefore, we are excited to advance the study of DSP-7888 plus pembrolizumab and evaluate its role and potential benefits," said Patricia S. Andrews, Chief Executive Officer and Global Head of Oncology, Sumitomo Dainippon Pharma Oncology (SDP Oncology). "Furthermore, we look forward to better understanding how these combined mechanisms may be able to sensitize this patient population to immunomodulators and improve clinical benefits."

The primary objective for the Phase 2 portion of the study is to evaluate the preliminary antitumor activity of DSP-7888 in combination with pembrolizumab in terms of the objective response rate (ORR) in patients with PROC. Secondary objectives of the Phase 2 portion of the study are to evaluate the preliminary clinical activity of DSP-7888 in combination with pembrolizumab in terms of duration of response (DOR), disease control rate (DCR), progression-free survival (PFS), 6-month PFS rate and overall survival (OS) in this patient population. Additional secondary objectives of the Phase 2 portion of the study include evaluating ORR, DCR and PFS per iRECIST of DSP-7888 administered in combination with pembrolizumab in patients with PROC. Exploratory objectives of the Phase 2 portion of the study include determining the progression-free survival ratio (PFSr) as an evaluation of treatment benefit of DSP-7888 administered with pembrolizumab.

Ovarian cancer is the fifth leading cause of cancer-related deaths among women in the United States.1 Patients with ovarian cancer who relapse within six months of completing first-line therapy are classified as being "platinum resistant" and typically have low response rates to subsequent chemotherapy, with a median survival under a year.2 Therefore, more efficient treatment methods are warranted to improve the survival of patients with ovarian cancer. In addition, the majority of ovarian cancer patients with serous histology are positive with WT1 in their tumors.3

The trial is being conducted at sites in the United States. Additional information on this trial, including comprehensive inclusion and exclusion criteria, can be accessed at www.ClinicalTrials.gov (NCT03311334).

About DSP-7888 (ombipepimut-S*)

DSP-7888 is an investigational immunotherapeutic cancer vaccine containing two peptides that induce WT1-specific cytotoxic T lymphocytes (WT1-CTL) and helper T cells to attack WT1-expressing cancerous cells found in various types of hematologic and solid tumors. Researchers have identified that by adding helper T cell inducing peptides, improved outcomes may be achieved compared to a killer peptide treatment regimen alone.4

DSP-7888 is currently being investigated in combination with bevacizumab in a Phase 2 trial in patients with recurrent or progressive glioblastoma (NCT03149003) and in a Phase 1/2 trial in combination with nivolumab or pembrolizumab in patients with advanced solid tumors (NCT03311334). In 2017, the U.S. Food and Drug Administration granted Orphan Drug Designations for DSP-7888 in MDS and brain cancer.

*Adegramotide/nelatimotide is also assigned as the international nonproprietary name (INN).