A quiver of arrows for immune disorders: Pandion scores $80M in fresh funding
Scientists began with making recombinant versions of naturally-occurring human proteins, then graduated to monoclonal antibodies. Now, rather than replicating moieties within the body, researchers are modifying these molecules to have precise biology in a functional manner.
This technology, referred to as bispecific antibodies, is already being employed to fight cancer. In early 2018, Pandion Therapeutics was born to reverse-engineer the science into the realm of autoimmune and inflammatory disorders.

Monoclonal antibodies are designed to inhibit a pathway, but Pandion is taking a molecule that the body creates, and engineering it for the biology that we want, said company chief Rahul Kakkar in an interview.
As the company shepherds its lead therapy into patients, on Wednesday it raised a meaty $80 million in a fresh round of financing.
Pandion, which counts Astellas as a partner, has created components that can be mixed and matched to create molecules that have both the biologic and the chemical therapeutic properties that we want, Kakkar explained.
“The way I like to think about it is our molecules represent arrows, within a quiver of arrows that represents our pipeline,” he said. “So each of these arrows has an arrowhead. The arrowhead is an engineered variant of something our bodies naturally use to control the immune system.”
The arrowhead in the company’s lead program — PT101 — is a mutated variant of interleukin two. Naturally, the body uses IL-2 to expand regulatory T cells and to enhance conventional pro-inflammatory T cells. Pandion’s IL-2 two has been engineered to be highly specific for regulatory T cells, but to have no effect on the other cells. The therapy is currently being evaluated in healthy volunteers — and if all goes well, come 2021, the compound will be tested in ulcerative colitis patients.
The arrowhead is in charge of the biology, but the tail gives the arrowhead pharmacotherapeutic properties that we want. “So we can marry an FC fusion, for instance, which gives half-life extension, so then that arrowhead resides within the systemic circulation, has systemic immune-modulatory properties and behaves like an injectable biologic,” Kakkar said.
The next juncture, which Pandion has under development, is creating a bifunctional or bispecific, so the tail end actually has a function, rather than just half-life extension.
“That tail…is designed as a tether or a dock, where it binds the arrowhead within an organ of interest so we can, therefore, guide the arrowhead into specific organ systems,” Kakkar said. “So, for instance, we can guide it into the beta cells of the pancreas, which is where our collaboration with Astellas focuses.”
The word Pandion is the genus name for the osprey (or a sea hawk), a brown-and-white bird of prey. Spreading its wings, it swoops down to water surfaces to seize unsuspecting fish using its talons. “The image of a very precise hit with wingspread basically looks like an antibody binding to a very specific localization in geography and so that’s exactly what our molecules do particularly in the bispecific format,” said Kakkar.
The Series B was led by Access Biotechnology, Boxer Capital, RA Capital and OrbiMed and included the participation of Polaris Partners, Versant Ventures, Roche Venture Fund, SR One, JDRF T1D Fund and BioInnovation Capital. The Boston-based startup raised $58 million in January 2018.
Despite the disruptions faced by the ongoing coronavirus pandemic, since the biotech industry is considered essential in Boston, the company continues to work on its compounds, although all non-lab personnel are working remotely.
“Frankly speaking, the need of patients suffering from autoimmune disease continues and so as long as that need is there, we continue to be focused on executing on our goals,” Kakkar said.
That being said, working from home is hardly a walk in the park. ” I think we’re all supporting each other as best we can, but I think it’s a challenge for everyone.”