Boston Biomedical, Inc. Highlights Phase 1 Data Evaluating Investigational WT1 Cancer Peptide Vaccine DSP-7888 (ombipepimut-S*) in Patients with Advanced Malignancies at SITC 2019

CAMBRIDGE, Mass, November 8, 2019 – Boston Biomedical, Inc. today announced the presentation of new data from a phase 1 study evaluating DSP-7888, an investigational WT1 cancer peptide vaccine, in patients with advanced malignancies. Findings from the phase 1 study investigating the safety, tolerability, and determination of the recommended phase 2 dose of DSP-7888 in patients with recurrent or progressive advanced malignancies will be presented in a poster presentation at the Society for Immunotherapy of Cancer’s (SITC) 34th Annual Meeting, held in National Harbor, Maryland, on November 6-10, 2019. Patients enrolled in the study have progressed on standard therapy, were intolerant to standard therapy, or were patients for whom no standard therapy existed for their cancer.

“The data presented at the SITC Annual Meeting demonstrate our unwavering commitment to advancing a pipeline of novel cancer therapeutics to address unmet patient needs,” said Patricia S. Andrews, Chief Executive Officer, Boston Biomedical, Inc. “We are excited to share more about the progress of our pipeline, including DSP-7888, with the scientific community.”

Findings from the multicenter, open-label, dose-escalation study showed that DSP-7888 was well tolerated, with no dose-limiting toxicities identified in patients with advanced malignancies. In this study, 24 patients received escalating doses of intradermal (n=10) or subcutaneous (n=14) DSP-7888. Of the 24 patients, four had stable disease and 21 patients were evaluable for WT1-specific cytotoxic T-lymphocyte (CTL) detection. In the evaluable population, WT1-specific CTL induction was observed in six of nine intradermal patients (66.7%) and five of 12 subcutaneous patients (41.7%). An intradermal dose of 10.5 mg was determined as the recommended phase 2 dose, consistent with the findings of a separate phase 1/2 study of DSP-7888 in patients with myelodysplastic syndrome. The most frequently observed adverse event was Grade 1 or 2 injection site reaction.1

“We believe the WT1 antigen is a promising target for immunotherapy, as it is expressed across a range of cancer types and plays a key role in the proliferation, differentiation and apoptotic process of cells,” said Alexander Spira, MD, PhD, FACP, lead author, and Director of Virginia Cancer Specialists Research Institute. “The findings from this study support the continuation of evaluating DSP-7888 in advanced cancers.”

The company will also present background information on an ongoing phase 1/2 clinical study evaluating DSP-0509, an investigational toll-like receptor (TLR) 7 agonist, for the treatment of solid tumors.

Below are the details for the Boston Biomedical presentations:

Abstract Title Details Lead Author

Multicenter, open-label, phase 1 study of DSP-7888 Dosing Emulsion (DSP-7888) in patients with advanced malignancies

Abstract #355
November 8, 2019
7:00 a.m. – 8:00 p.m. ET
Poster Presentation

Alexander Spira, MD, PhD,
FACP, Virginia Cancer
Specialists Research Institute and The US Oncology Network

A first-in-human phase 1/2, multicenter trial of toll-like receptor (TLR) 7 agonist DSP-0509 as monotherapy and in combination with pembrolizumab in adult patients with advanced solid tumors

Abstract #426
November 9, 2019
7:00 a.m. – 8:00 p.m. ET
Poster Presentation

Shadia Jalal, MD,
Indiana University School of Medicine

About DSP-7888 (ombipepimut-S*)

DSP-7888 is an investigational 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.

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). DSP-7888 is currently being investigated in two monotherapy studies: a phase 1/2 trial in myelodysplastic syndrome (MDS) (NCT02436252) and a phase 1/2 trial in pediatric patients with relapsed or refractory high grade gliomas (NCT02750891). 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).

About DSP-0509

DSP-0509 is an investigational synthetic toll-like receptor (TLR) 7 agonist. In preclinical models, DSP-0509 was shown to promote the cytokine induction and cytotoxic T lymphocyte activation mediated by agonistic effect of TLR 7 expressed in plasmacytoid dendritic cells. DSP-0509 is hypothesized to sustain the immune-mediated anticancer activity by induction of immune system memory cells and is currently being evaluated in a phase 1/2 clinical trial in patients with advanced solid tumors (NCT03416335).

About Boston Biomedical, Inc.

Boston Biomedical, Inc. is a developer of novel cancer therapeutics with the goal of significantly improving patient outcomes. The company’s most advanced research programs are focused on investigational agents that inhibit multiple oncogenic pathways, including cancer stemness pathways, and modifying immune responses.

Headquartered in Cambridge, Massachusetts, Boston Biomedical, Inc. is an indirect, wholly-owned subsidiary of Sumitomo Dainippon Pharma Co., Ltd., a pharmaceutical company based in Japan. Boston Biomedical works closely with its parent company, Sumitomo Dainippon Pharma, and Tolero Pharmaceuticals, also a wholly owned subsidiary, to expedite the discovery, development and commercialization of novel treatment options.

Additional information about the company and its pipeline can be found at www.BostonBiomedical.com.

Disclaimer Regarding Forward-Looking Statements

The forward-looking statements in this press release are based on management’s assumptions and beliefs in light of information presently available and involve both known and unknown risks and uncertainties. Any forward-looking statements set forth in this press release speak only as of the date of this press release. We do not undertake to update any of these forward-looking statements to reflect events or circumstances that occur after the date hereof. Information concerning pharmaceuticals (including compounds under development) contained within this material is not intended as advertising or medical advice.

For general inquiries:
Boston Biomedical, Inc.
617-674-6800

For media inquiries:
Rachel Newman
Spectrum™
404-865-3603
rnewman@spectrumscience.com

References

1Spira A, et al., Multicenter, open-label, phase 1 study of DSP-7888 Dosing Emulsion (DSP-7888) in patients with advanced malignancies. 2019. SITC. Abstract #355.