The Endocannabinoid System
The endocannabinoid system regulates multiple processes in the body to restore homeostasis through the interplay of its receptors and their ligands. This system is in many animals (including humans), and its role extends to the central nervous system, the immune system, metabolism and more. It is involved in inflammation, fibrosis, wound healing, energy regulation, behavior, memory, pain, reproduction and cell growth and differentiation. The extensive involvement of the endocannabinoid system in regulating vital processes in the body is the basis for new opportunities to develop medicines to treat human illnesses.
At Corbus, we are targeting the two main cannabinoid G-protein-coupled receptors (GPCRs): the cannabinoid receptor type 1 (CB1) is widely expressed throughout the body and especially in the nervous system while the cannabinoid receptor type 2 (CB2) is highly expressed in activated cells of the immune system. By rationally designing novel small molecules that bind to these receptors and modulate their activity, Corbus is developing compounds that could treat cancer, and inflammatory, fibrotic, and metabolic disorders.
Research demonstrates that targeting CB2 in the immune system reduces inflammation and inhibits or halts fibrosis. CB2 is preferentially expressed on activated immune cells and found on other cell types, such as fibroblasts, muscle cells, endothelial cells, and cancer cells.
Corbus’ most advanced compound lenabasum is an oral, small molecule that selectively activates CB2. Biologic activities of lenabasum have been shown in animal models and humans, and include activation of the resolution of inflammation, reducing inflammatory mediators, and limiting fibrosis. Lenabasum has had an acceptable safety profile in studies to date. Approximately 1,300 subjects have received lenabasum. The most common adverse events related to lenabasum are dizziness, headache and fatigue.
Key Lenabasum Studies
|Target (Program)||Phase||Trial Size N Dosed||Status|
|Dermatomyositis||3||176||• Topline data expected Q2 2021|
|SLE||2||100||• Ongoing, topline data expected second half of 2021|
|Systemic Sclerosis||3||363||• Primary efficacy endpoint
(ACR CRISS score) not met
• FVC changes seen in sub-
population in post-hoc analysis
• Acceptable safety profile
• Waiting for DM data before
deciding next steps
|Cystic Fibrosis||2b||425||Primary efficacy endpoint
(pulmonary exacerbation rate)
was not met
• Acceptable safety profile
• Not planning additional studies
Cancer is a leading cause of death worldwide
Among patients who respond to CPIs, disease progression often occurs due to resistance mechanisms. Significant unmet need remains for greater and more durable responses to CPIs.
There is a growing body of published data demonstrating the complex role the endocannabinoid system plays in cancer.
CB2 is expressed by cancer cells themselves and activated immune cell, fibroblasts, and endothelial cells in the tumor microenvironment (TME). CB2-dependent pathways can inhibit the ability of cancers to grow and metastasize, providing beneficial effects on the immune system and the tumor stroma. Results from cell and animal studies demonstrate that activating CB2 counteracts tumor growth, promotes tumor apoptosis and reduces the ability of tumors to evade the immune system.
Corbus’ CB2 agonists inhibit growth of multiple human cancer cell types, including breast, lung, colon, and glioblastoma cancer cells. These compounds induce caspases involved in apoptotic cell death. Initial studies in a xenograft cancer model using the triple negative breast cancer cell line MDA-MB-468 show dose-dependent and time-dependent inhibition of tumor growth.
Our CB2 agonists represent an entirely novel approach in cancer treatment and have demonstrated activity against tumor cells in vitro, and several show activity as monotherapy in animal models of solid tumors.
Phase 1 testing is planned to start at the end of 2022.