Prolium Bioscience launched on Tuesday with $50 million in series A funding from RTW Investments to advance a T-cell engager (TCE) across several autoimmune diseases. In-licensed from KeyMed Biosciences and InnoCare Pharma, Prolium's sole asset is PR-203, a CD20/CD3–targeting TCE. The newco has global rights to the candidate in all indications outside cancer, and ex-Asia rights in oncology.With Chinese Phase I/II data in non-Hodgkin lymphoma already generated for PR-203, the deal is yet another example of Western drugmakers picking up early-stage therapeutic programmes from China, particularly bispecifics (see – Spotlight On: Bispecifics dominate among cross-border I&I deals). In the lymphoma study, PR-203 achieved an overall response rate of 82% and a complete response rate of 59%.Autoimmune aspirationsThough PR-203 already has some supporting cancer data under its belt, Prolium is first exploring its potential in the autoimmune space. The company has kicked off a safety study in healthy volunteers and plans to start a Phase I/II study of PRO-203 in systemic sclerosis in the second quarter; additional trials in B-cell driven diseases are also expected to launch this year. Separately, an investigator-initiated study is evaluating the TCE in five patients with treatment-refractory, advanced systemic lupus erythematosus and lupus nephritis."Prolium’s team is executing impressively to generate substantial data readouts of PRO-203 in several autoimmune disorders within the next two years," said Peter Fong, president of RTW.By engaging CD20 on B cells and CD3 on T cells, PRO-203 is designed to trigger T-cell dependent cellular cytotoxicity, thus depleting B cells. According to CEO Scott Requadt, CD20 is the most-validated target in B-cell driven autoimmune diseases."T-cell engagers are the next frontier in treating autoimmune disease, with the potential to achieve deep B-cell depletion in tissues, like CAR-T, without many of the challenges of CAR-T," he added.
