Spero Therapeutics (SPRO) investor relations material

Strategic focus and pipeline

• Developing SP001, a third-generation Fc-silent anti-CD40L monoclonal antibody for immune-mediated diseases, with lead indication in IgG4-related disease and expansion into Sjögren's disease and other areas.

• Established operational and public company infrastructure with a cash runway projected into the second half of 2029.

Scientific rationale and mechanism

• CD40L is a validated target with human proof-of-concept in multiple autoimmune diseases; SP001 blocks upstream immune signals sustaining autoimmunity by inhibiting CD40L interactions.

• SP001's mechanism affects both B and T cells, offering potential as a chronic disease-modifying therapy in conditions with high relapse rates.

Clinical development and data

• Completed two healthy volunteer trials and a Phase 1b multiple ascending dose study in Sjögren's disease, showing favorable safety, tolerability, and efficacy signals.

• Phase 1b data demonstrated improvements in disease activity indices (ESSDAI, ESSPRI) and B-cell biomarkers, with a benign safety profile and no serious adverse events reported.

• SP001 showed superior immune suppression in preclinical models compared to leading Phase 3 antibodies.