FDA Grants Orphan Drug Designation for Investigational WT1 Cancer Peptide Vaccine DSP-7888

Boston Biomedical announced the U.S. Food and Drug Administration (FDA) has granted Orphan Drug Designation (ODD) for DSP-7888, an investigational cancer peptide vaccine, for the treatment of myelodysplastic syndrome (MDS). MDS is a group of rare blood disorders characterized by abnormal development of blood cells within the bone marrow.

Currently being studied in phase 1/2 clinical trials, DSP-7888 contains peptides to induce Wilms' tumor gene 1 (WT1)-specific cytotoxic T lymphocytes (CTL) and helper T cells, which attack WT1-expressing cancerous cells found in various types of hematologic and solid cancers. The National Cancer Institute ranked WT1 as the number one priority target for cancer immunotherapy.

Approximately 10,000 to 15,000 people are newly diagnosed with MDS in the U.S. annually. It is estimated that one third of MDS patients can develop acute myeloid leukemia (AML), a rapidly growing cancer of bone marrow cells. The FDA's ODD program provides special status and development incentives for drugs and biologics which are intended for the safe and effective treatment, diagnosis or prevention of rare diseases/disorders that affect fewer than 200,000 people in the U.S.

"Receiving an Orphan Drug Designation for DSP-7888 reinforces our dedication to helping address an unmet medical need for people with myelodysplastic syndrome, where other therapies are still needed," said Patricia S. Andrews, Chief Executive Officer, Boston Biomedical. "We are committed to uncovering the potential therapeutic benefit of cancer peptide vaccines, and we look forward to advancing the clinical development of this first-in-class compound."

The first clinical data for DSP-7888, from a phase 1/2 study in patients with MDS who progressed on or after first-line azacitidine (AZA) treatment, were presented at the 2016 American Society of Hematology Annual Meeting and Exposition. In the phase 1 portion of the study, DSP-7888 was well-tolerated in MDS patients, and the data also showed preliminary signs of clinical activity.

This is the third ODD the company has received in the last two years, and is the first one for DSP-7888.

DSP-7888 is an investigational cancer peptide vaccine containing peptides that induce Wilms' tumor gene 1 (WT1)-specific cytotoxic T lymphocytes (CTL) and helper T cells, which attack WT1-expressing cancerous cells found in various types of hematologic and solid cancers. By adding helper T cell-inducing peptides, improved efficacy may be achieved compared to a killer peptide treatment regimen alone.

DSP-7888 is currently being investigated in three monotherapy studies: a phase 1/2 study in myelodysplastic syndrome (MDS) (NCT02436252), a phase 1/2 study in pediatric patients with relapsed or refractory high grade gliomas (NCT02750891), and a phase 1 study in advanced malignancies (NCT02498665). DSP-7888 will also be evaluated in combination with bevacizumab in a phase 2 study in patients with recurrent or progressive glioblastoma; the study is currently recruiting patients (NCT03149003).