Lexington, MA-based Concert Pharmaceuticals announced today that it has moved three novel drug candidates forward in its pipeline—one of which earned it a $4 million milestone payment from GlaxoSmithKline (NYSE: [[ticker:GSK]]). The European drug giant allied with Concert on an HIV program in 2009, and the molecule, called CTP-298, is now the lead compound in that program.
Glaxo has pledged up to $1 billion in equity and milestone payments to Concert based on the success of its program, which centers on making longer-acting versions of approved HIV treatments by swapping out certain hydrogen atoms in drugs with deuterium atoms. With this last milestone payment, Concert has reaped a total of $50 million from the deal so far.
Concert’s goal is to use its deuterium platform to modify atazanavir, one of the most widely used HIV treatments, which is in the drug class known as protease inhibitors. Currently, atazanavir is commonly given with a boosting agent called ritonavir, which prevents it from getting destroyed by enzymes in the body before it has a chance to be effective. Eliminating the need for ritonavir would simplify the HIV regimen for patients—a big selling point, says Concert CEO Roger Tung.
“Ritonavir is one more pill to remember,” Tung says. “And it’s not a totally benign agent. It causes some patients to get nauseous and it has cardiovascular risk factors. Our goal is to create a drug that can be dosed once a day, without a boosting agent.”
Originally, Concert and Glaxo were counting on a different molecule, CTP-518, to be the lead contender in the HIV program. But CTP-298 “stood out as being preferable” in early human trials, Tung says.
What’s more, Tung says, CTP-298 has the potential to be useful in combination with Glaxo’s experimental treatment called GSK-572, which is an integrase inhibitor that’s now in Phase 3 trials. “Our eventual goal is to have a fixed-dose combo,” Tung says. He adds that Concert and Glaxo have been inspired by the success
