Polish biotech JPP Biologics reports positive Phase I data for first-in-class biologic for immune diseases

The Polish biotech focuses on innovative antibody therapeutics, and the reported results set JJP-1212 as a potential first-in-class antagonist of CD89 (also called FcαRI), a key receptor for immunoglobulin A (IgA). The programme targets autoimmune, inflammatory, and fibrotic diseases in which pathogenic IgA autoantibodies play a central role. “JJP‑1212 is a first-in-class versatile anti‑CD89 antagonist with the potential to be developed across a family of IgA‑mediated indications, tapping into a $70B+ market by 2030 with blockbuster sales potential,” said Pawel Szczepanski, JJP Biologics CEO and Chairman of the Management Board, in an email to European Biotechnology Magazine.

The Phase I trial, conducted in healthy volunteers, met all primary endpoints. According to the company, JJP-1212 demonstrated a favourable safety and tolerability profile, alongside predictable pharmacokinetics and clear pharmacodynamic activity. No dose-limiting toxicities were reported, and adverse events were mild to moderate. In addition, the data demonstrate the feasibility of both intravenous and subcutaneous administration, providing flexibility for later-stage clinical development.

“The first patient trial for JJP‑1212 is already underway in Linear IgA Disease, a rare IgA‑mediated blistering skin disorder for which JJP‑1212 holds EMA orphan medicinal product designation,” said Szczepanski.

Targeting IgA-driven disease mechanisms

The JJP-1212 programme focuses on blocking CD89 (FcαRI), the receptor for immunoglobulin A (IgA). As the company explains, when IgA autoantibodies form immune complexes and then bind to the CD89 receptor on immune cells, they trigger strong inflammatory responses. By binding to CD89, JJP-1212 blocks IgA engagement and prevents downstream activation of CD89-positive immune cells. This inhibits the release of chemoattractant molecules, limits epitope spreading and suppresses other inflammatory activation pathways that can lead to severe tissue damage. Despite strong academic evidence, CD89 has so far remained an underexplored target in drug development.

First mover advantage in a niche field

JJP-1212 is designed to block IgA-CD89 signalling, thereby reducing downstream immune activation in CD89-expressing immune cells, including monocytes, macrophages, eosinophils and, most notably, neutrophils.

Neutrophils are key components of the innate immune system but have historically been underrepresented as therapeutic targets in drug development. Growing evidence, however, identifies them as major drivers of disease pathology across a range of inflammatory and autoimmune conditions.

The reported Phase I data confirmed that JJP-1212 engages its target in humans and modulates the intended biological pathway.

Broader pipeline and Polish biotech momentum

Beyond immunology, JJP Biologics is also advancing JJP-1008, an oncology-focused antibody programme targeting CD270 (HVEM), a non-conventional immune checkpoint involved in tumour immune evasion. According to the company’s website, analogous to the PD-1/PD-L1 axis, where tumour PD-L1 expression is used as a companion diagnostic, JJP Biologics has identified HVEM as a tumour-specific marker associated with poor prognosis and an immunosuppressive tumour microenvironment. Still in preclinical development, JJP-1008 is designed to selectively block inhibitory HVEM interactions while preserving activating signalling, thereby converting high HVEM expression from a disadvantage into a therapeutic opportunity. The company’s pipeline reflects a strategy of focusing on novel, high-risk, high-reward targets that have strong biological rationale but limited industry competition.

“Both JJP‑1212 and JJP‑1008 are proprietary JJP Biologics antibodies, discovered and developed within our R&D organization in Poland,” said Szczepanski.

Alongside the growing maturity of the Polish biotechnology sector, which has increasingly moved from early research toward clinical-stage innovation, JJP Biologics joins an expanding group of Central and Eastern European companies demonstrating the ability to develop first-in-class biologics to international standards. “JJP 1212 is in fact the first new biological entity to be completely developed within the Polish biotechnology sector, which is something we are very proud of,” said Szczepanski.

Note: this article has been updated to include quotes from Szczepanski on January 7, 2026, at 5:56 PM.