Clinical Experience

Imprime PGG Early Clinical Experience

We believe that our initial clinical experience serves to de-risk the ongoing development path for Imprime PGG.  Following three Phase 1 studies, defining 4 mg/kg as an appropriate Phase 2 dose, 10 clinical studies were initiated beginning in 2007 in patients with colorectal cancer, non-small cell lung cancer, pancreatic cancer, non-Hodgkins Lymphoma and chronic lymphocytic leukemia.  These studies evaluated Imprime PGG in combination with anti-cancer monoclonal antibodies (Erbitux®, Avastin®, Rituxan®, Campath®), with and without chemotherapies.  In these trials, Imprime PGG was safely administered in all combinations tested and provided indications of antitumor activity.  More than 500 subjects (cancer patients and healthy human volunteers) were treated with Imprime PGG in these studies.

Biothera has chosen not to develop these particular Imprime PGG combination regimens further, due to (1) recent scientific evidence suggesting that the combination of Imprime PGG with CPIs may be a more promising combination strategy, and (2) a more favorable development, regulatory and commercialization pathway with CPIs.  However, we believe these trials provide important data that will guide our clinical development plans and may increase the probability of future clinical success.  Taken together, the historical clinical trials demonstrate:

  1. Safety Profile. Imprime PGG has demonstrated a favorable safety profile in more than 500 subjects.  Imprime PGG has been well-tolerated in clinical studies and can be administered via IV infusion.  Infusion reactions are the most common side effect attributed to Imprime PGG and they are generally manageable.
  2. Clinical Activity. Imprime PGG has demonstrated promising signals of activity in multiple drug combinations and tumor types.
  3. Biomarker Development. We have discovered a mechanism-based, patient selection biomarker through our healthy volunteer clinical studies and retrospective analyses of clinical trials in cancer patients.  We developed a simple pre-treatment blood test that will identify those patients who are most likely to respond to Imprime PGG and are using this biomarker test in three ongoing Phase 2 clinical trials.  We will fully validate the biomarker in future studies as part of our clinical development program.