Trimeris Inc. and Neokimia Inc. entered a collaboration to discover and develop small-molecule fusion inhibitors of the human immunodeficiency virus.

Sherbrooke, Quebec-based Neokimia will provide Trimeris on a nonexclusive basis a library of small-molecule HIV gp41 fusion protein targets for Trimeris to screen.

“If we’re fortunate enough to identify hits in those initial screens, Trimeris will work with Neokimia to identify focus libraries around those hits to improve their potency, their specificity and their drug-like characteristics,” Michael Recny, vice president of corporate development at Trimeris, said. “That will progress hopefully through to the development of a clinical candidate.”

Any new discoveries would be expected to complement Durham, N.C.-based Trimeris’ existing fusion inhibitors. In April, Trimeris reported positive Phase III results from its lead fusion inhibitor, T-20.

Fusion inhibitors work by inhibiting fusion of HIV with host cells before the virus enters the cell and can start the replication process. Most HIV drugs work after HIV already has entered the cell.

The collaboration with Neokimia is for an undetermined period of time, but Trimeris retains the contractual right to end the agreement after a specific amount of time, Recny said.

“We’re certainly pleased to work with Neokimia, because we think they bring a unique library of compounds,” Recny said.

Neokimia President and CEO Caroline Fortier said she thinks Trimeris wanted to work with her four-year-old company because of the power of the Neokimia platform.

“We have a chemistry-based platform where our molecules have increased bioactivity,” she said. “Second of all, they have been designed to interact with large molecules [like the fusion inhibitors]. Thirdly, we’re probably the only chemistry-based drug discovery company that has a library of compounds for which we know not only the chemical structure, but also the 3-dimensional structure. So we can modulate that 3-dimensional structure to have better affinity with targets.”

The companies will jointly fund research up to the point where a development candidate is discovered. Trimeris then would be responsible for all clinical development and regulatory and commercial activities on a worldwide basis. Neokimia would be entitled to payments based on the achievement of certain development and commercial milestones, and royalties on net product sales.

Depending on their resources at the time, Neokimia would have the option to jointly fund clinical development for compounds through the end of Phase I trials in exchange for increased royalties on sales, Recny said.

Recny said they are looking for inhibitors that hopefully would be complementary to Trimeris’ existing HIV fusion inhibitors.

Trimeris still is on track to file a new drug application in the early part of the second half of this year for T-20, based on the earlier positive results from the Phase III trial, he said. T-20 is being developed by Trimeris and Hoffmann-La Roche Inc., of Nutley, N.J. T-20 was given fast-track designation by the FDA. The drug, which was given in combination with an individualized antiretroviral treatment regimen in the trial, is injected subcutaneously twice daily. Trimeris maintains that fusion inhibitors such as T-20 offer benefits because they do not act within a cell, thereby reducing the likelihood of side effects and drug-drug interactions, and offer simplified dosing. (See BioWorld Today, April 19, 2002.)

Trimeris also has T-1249, a second fusion inhibitor with fast-track designation from the FDA, in Phase I/II trials.

Trimeris’ stock (NASDAQ:TRMS) fell $1.28 Friday to close at $45.04.