Clinical Program

Biothera Pharmaceuticals is leveraging its knowledge of Imprime PGG’s mechanism of action and its extensive clinical experience through the IMPRIME cancer immunotherapy clinical trials. Biothera initially is targeting cancer indications with high unmet clinical needs for which the standard of care is evolving toward combination therapy with checkpoint inhibitors. The Company has announced three clinical trials that will evaluate Imprime PGG in combination with pembrolizumab (KEYTRUDA®), Merck’s anti-PD-1 checkpoint inhibitor, in four cancer indications.

In the melanoma, triple negative breast cancer and head and neck cancer Phase 2 studies, Biothera will test for a mechanism-based biomarker
that may help identify patients with the best probability of responding to the combination therapy of Imprime PGG and pembrolizumab.

  Non-Small Cell 
Lung Cancer
Breast Cancer*
Head and Neck 
Phase Phase 1b/2 Phase 2 Phase 2 Phase 2
Combination Therapy Pembrolizumab Pembrolizumab Pembrolizumab Pembrolizumab
Patients 2nd line  
– CPI naive
Progressive disease following CPI treatment Progressive disease following chemotherapy 
– CPI naive
(1) PD following CPI treatment or (2) stable disease after 3+ months on Pembrolizumab
Number of Subjects 36 29 42 87
Primary Endpoint Progression-Free Survival Overall Response Overall Response Overall Response
Additional Endpoints Safety, ORR, OS, 
Immuno-PD markers
Safety, PFS, OS, 
Immuno-PD markers
Safety, PFS, OS, 
Immuno-PD markers
Safety, PFS, OS, 
Immuno-PD markers
Collaboration Partner The Big Ten Cancer Research Consortium Merck Merck Merck
Target Initiation 1Q 2017 1Q 2017 1Q 2017 3Q 2017
Status Recruiting

* Anti-beta glucan antibody (ABA) biomarker > than 20 μg/ml

CPI – Checkpoint Inhibitor
Immuno-PD markers – ImmunoPharmacodynamic markers of innate immune activation
PFS – Progression-Free Survival

ORR – Overall Response Rate
OS – Overall Survival

Imprime PGG’s clinical trials address the following four therapeutic indications:

Melanoma and Triple Negative Breast Cancer (TNBC)

  • Biothera and Merck have entered into a clinical research collaboration to study the combination of Imprime PGG and pembrolizumab in a Phase 2 clinical trial in patients with either advanced melanoma who have progressed on treatment with a checkpoint inhibitor therapy, or with TNBC whose disease has progressed following treatment with one or more lines of therapy for metastatic disease. The study is currently enrolling patients. News release
  • Melanoma is the most dangerous type of skin cancer, and the incidence of melanoma has increased 15 times in the last four decades. Approximately 132,000 cases of melanoma are diagnosed around the world each year.
  • TNBC refers to any breast cancer that does not express estrogen receptor (ER), progesterone receptor (PR) or overexpress the HER2 receptor. Approximately 10%–20% of all breast cancers are TNBC, and have a worse prognosis compared with other breast cancer subtypes.

Non-Small Cell Lung Cancer (NSCLC)

  • The Big Ten Cancer Research Consortium is conducting a Phase 1/b2 clinical trial evaluating Imprime PGG and pembrolizumab in NSCLC patients. The study is open for patient enrollment. Funding is provided by Merck. News release
  • Lung cancer is the most common cancer worldwide, with 1.8 million new cases diagnosed each year; NSCLC accounts for 85% of cases.
  • Because the early stages of NSCLC are associated with few specific symptoms, approximately 70% of cases are not diagnosed until the disease is at an advanced stage and has spread to other parts of the body.

Head and Neck Squamous Cell Cancer (HNSCC)

  • Biothera and Merck are collaborating on a Phase 2 clinical study investigating Imprime PGG and pembrolizumab in head and neck cancer patients. The study will include two distinct cohorts of patients: (1) HNSCC patients with progressive disease following prior treatment with an immune checkpoint inhibitor and (2) patients with stable disease, who have failed to demonstrate an objective response after at least three months of pembrolizumab mono therapy. News release
  • HNSCC is the sixth leading cancer by incident, with more than 550,000 new cases diagnosed each year.

Biomarker & Translational Research

  • Biothera’s advanced translational research capabilities may help elucidate Imprime-induced immune activity
  • Immuno Proof of Concept measures are important early clinical indicators of immune response and potential long-term clinical benefits
  • Pre- and post-Imprime tumor biopsies and blood samples will be analyzed for evidence of:
    • Repolarization of myeloid cells in tumor microenvironment
    • Improved dendritic cell function, including T cell infiltration and activation

Details about the clinical trials evaluating Biothera’s Imprime PGG for a various indications, including trial objectives, patient enrollment criteria and trial site locations, will become available as the trials commence on, a service of the U.S. National Institutes of Health.