Pandion Therapeutics to be Acquired by Merck

Merck and Watertown-based Pandion Therapeutics, a clinical-stage biotech developing novel therapeutics targeting autoimmune diseases, have agreed that Merck will acquire Pandion for $60 per share or approximately $1.85 billion. The transaction is expected to close in the first half of 2021.

Pandion is advancing a pipeline of precision immune modulators targeting critical immune control nodes. The company’s lead candidate, PT101, is an engineered IL-2 mutein fused to a protein backbone designed to selectively activate and expand regulatory T cells (Tregs) for the potential treatment of ulcerative colitis and other autoimmune diseases. In autoimmune diseases, the immune system inappropriately attacks a host’s cells, and targeting Tregs could allow the immune system to regain control and return to homeostasis.

Tregs act as a control node within the immune system and can inhibit the activity of several different pro-inflammatory immune cell types. Tregs are critical for self-tolerance, or the ability of the immune system to recognize a hosts’ cells and not produce an immune attack against them. Defects in Tregs result in multi-organ inflammation and their dysfunction is associated with many autoimmune diseases. Multiple third-party clinical trials suggest that expansion of Tregs by low-dose IL-2 can benefit patients with autoimmune diseases.

PT101 has completed a Phase 1a clinical trial, which achieved its primary objective of safety and tolerability. In the trial, PT101 demonstrated proof of mechanism by selectively expanding Tregs in healthy volunteers. (Source: Merck Website, 25 February, 2021)