The two new agreements build upon the ongoing collaboration between the two companies for the novel antipsychotic RGH-188, which is currently undergoing initial trials in schizophrenia patients.
The first new collaboration will focus upon a group of compounds that target the NMDA 2B receptor and will be developed for the treatment of chronic pain and other CNS conditions.
RGH-896 is an orally active selective NR2B antagonist in Phase II development. NR2B is predominantly expressed on pain processing neuronal pathways. By blocking NR2B, RGH-896 and related compounds block pain signalling without interacting with other NMDA receptor subtypes thus potentially improving therapeutic index and side effect profile.
Pre-clinical data with RGH-896 and related compounds support development in neuropathic pain and possibly other chronic pain conditions.
Forest and Richter intend to initiate a Phase IIb study in neuropathic pain in the United Stated in the second half of 2006.
Under the terms of the agreement, Forest will pay Richter undisclosed upfront and milestone payments in addition to royalties and will have exclusive rights in the US and Canada.
The two companies will jointly fund the development program. RGH-896 has patent applications that provide patent protection until at least 2022.
"The teams of Forest and Richter have established a working relationship in the past year on RGH-188, a potential antipsychotic. This served as a catalyst for the two new projects, one at an early research stage, mGluR1/5, and the other, RGH-896, in early Phase II," said Erik Bogsch, CEO of Gedeon Richter.
"The human studies will take several years before their submission to the regulatory agencies. The success of the compounds obviously will depend on the results of this extensive testing."
The other collaboration will focus upon a group of compounds that target the group 1 metabotropic glutamate receptors (mGLUR1/5).
Group 1 metabotropic glutamate receptors (mGluR1 and 5) are G-protein coupled receptors (GPCRs) that are activated by the excitatory neurotransmitter glutamate. These receptors are distinct from other glutamate receptors, e.g. ionotropic NMDA and AMPA receptors.
The terms of the new agreement will see Richter and Forest advance leads to clinical trials within the next two to three years. Forest will pay Richter undisclosed upfront and milestone payments in addition to royalties and will have exclusive rights in North America.
Richter will retain exclusive rights in Europe and countries of the former Soviet Union. The two companies will share rights in all other territories.
The neuropathic pain market in the United States is estimated to exceed $2 Billion dollars annually. Currently available therapies are inadequate with room to improve efficacy, tolerability and dosing regimens.
There is also an unmet need in other chronic pain conditions such as chronic osteoarthritis pain and low back pain which afflict a large number of patients and for which there are no wholly adequate therapies.
A novel medication that is effective and well tolerated could expand this market and may have significant commercial potential.