A new antipsychotic drug developed by Lundbeck and Otsuka looks set to debut in the US in August after gaining FDA approval on Friday.
Rexulti (brexpiprazole) is a dopamine D2 and serotonin 5-HT1A partial agonist positioned as a successor to the Otsuka’s big-selling atypical antipsychotic Abilify (aripiprazole), which is sold by Bristol-Myers Squibb in the US but lost patent protection in May.
Rexulti has been approved by the FDA for adults with major depressive disorder (MDD) and schizophrenia, broad indications that will give it an opportunity to become a crossover therapy in central nervous system (CNS) disorders like its parent aripiprazole.
Abilify’s primary use is in schizophrenia and bipolar disorder but it has increasingly been used as an add-on treatment for adults with MDD, and this has helped drive sales growth. There are around 2.4 million people with schizophrenia in the US, but MDD is a much larger patient group numbering some 15m people.
Many patients with MDD do not respond to therapy with single-agent antidepressants and need additional add-in therapies to help control symptoms, according to Michael Thase of the University of Pennsylvania School of Medicine, who worked on the clinical trials of brexpiprazole.
“In the clinical trials that led to the FDA’s approval, adding [Rexulti] to ongoing antidepressant therapy helped MDD patients improve unresolved symptoms of MDD,” he added.
Lundbeck has said it expects Rexulti to grow into a 5bn-plus krone ($750m) product, thanks to the drug’s balanced profile – capturing the space between the antipsychotic drugs such as aripiprazole that have activating side effects – such as agitation and insomnia – and sedating drugs such as quetiapine.
Lundbeck notes that in trials more than 90% of patients completed treatment protocols, which indicate how well brexpiprazole is tolerated and suggests it could offer “best-in-class” tolerability among atypical antipsychotics.
Rexulti’s eventual sales performance is expected to hinge on how successfully Lundbeck and Otsuka can differentiate the new drug from Abilify now that generics are being launch onto the US market.
Otsuka will shortly report second quarter sales of the drug that will give an indication of the impact of the US patent loss on the product. US sales grew 2.5% to $1.1bn in the first quarter of the year and it is currently the 11th biggest-selling drug in the world by global sales.
Meanwhile, Rexulti is one of string of new drugs at Lundbeck – along with the likes of long-acting aripiprazole depot Abilify Maintena (also partnered with Otsuka) and new antidepressant Brintellix (vortioxetine) – which it hopes will restore growth after the loss of patent protection on US blockbuster antidepressant Lexapro/Celexa (escitalopram).
Kåre Schultz, Lundbeck’s chief executive, said: “All treatment options require healthcare providers, patients and caregivers to balance efficacy and tolerability in managing their diseases.
“We are proud to introduce Rexulti to help adult patients living with MDD and schizophrenia.”