Pfizer-Backed Dren Nets $65M to Advance Lead Asset to Clinic

Courtesy of Getty Images

Courtesy of Getty Images

Dren Bio announced the completion a of $65M Series B financing round. New investors include Pfizer, ArrowMark Partners and Revelation Partners.

Foster City, California-based Dren Bio has completed a Series B financing round worth $65 million. The round was co-led by Aisling Capital and HBM Healthcare Investments. New investors include Pfizer, ArrowMark Partners and Revelation Partners.

It seems appropriate that Pfizer would get in on the company’s new round. In January, Pfizer and Dren inked a research collaboration and license deal to discover and develop therapeutic bispecific antibodies for select oncology targets. The partners are leveraging Dren’s proprietary Targeted Myeloid Engager and Phagocytosis Platform.

Under the terms of that deal, Pfizer paid Dren $25 million upfront in cash, while Dren is eligible for more than $1 billion in various biobucks payments based on development, regulatory and commercial milestones. Pfizer has the option of licensing products out of the collaboration.

The Targeted Myeloid Engager and Phagocytosis Platform engages a receptor selectively expressed on myeloid cells. These include monocytes, macrophages and dendritic cells. Specific myeloid cells, for example, Tumor-Associated Macrophages (TAMs), exist in the tumor microenvironment where they act to suppress the immune system. As a result, they are often linked to worse clinical outcomes.

The company’s tech platform repolarizes TAMs and engages them together with dendritic cells to execute targeted phagocytosis, antigen presentation, and as a result, T cell activation. In short, the platform antibodies are designed to expand immunotherapy’s therapeutic benefit while potentially creating more durable clinical responses. And it does it by killing specific cells that dampen the immune system.

At the time, Nenad Tomasevic, Ph.D., chief executive officer of Dren, said, “This agreement highlights Dren Bio’s expertise in therapeutic antibody development and marks the first collaboration using our proprietary platform to harness myeloid cells in disease, offering a differentiated approach with the potential to provide revolutionary therapies to patients across a broad array of therapeutic areas.”

With the funds from the Series A round, Dren has raised more than $156 million. The Series A round raised $60 million in October 2020. As part of the Series B financing, Dr. Andrew Schiff, M.D., of Aisling Capital and Dr. Chandra P. Leo, M.D., of HBM Partners, will join the company’s board of directors.

“We are truly grateful for all the support we continue to receive from such an outstanding syndicate of investors,” Tomasevic said. “This financing comes at the perfect time as we prepare to initiate the first clinical trial evaluating DR-01, our lead asset, in patients with Large Granular Lymphocytic leukemia or cytotoxic lymphomas in mid-2022. In addition to advancing DR-01, the proceeds from this latest round will also enable us to further expand the development of our internal pipeline using our proprietary Targeted Myeloid Engager and Phagocytosis Platform.”

DR-01 is engineered to precisely eliminate a subset of immune cells. This comes from the company’s enhanced antibody-dependent cellular cytotoxicity (ADCC) program. The type of cell it kills “possesses intrinsic cytotoxic potential and is responsible for a multitude of hematologic malignancies.” The initial target is leukemia and lymphoma cells with NK or CD8 T cell types.

In addition to testing the drug in blood cancers, Dren plans to test it in auto-immune indications driven by the cytotoxic immune cells.

Of the Series B, Schiff said, “We were thoroughly impressed by Dren Bio’s diversified R&D portfolio that encompasses two distinct therapeutic antibody programs including their attractive proprietary platform. We are excited by the opportunity to support Dren Bio in progressing on their mission to deliver revolutionary therapies to patients with severe unmet needs, starting with difficult-to-treat cancers.”