The impact of genericisation in the unipolar depression market is set to be tempered by continued uptake of novel antidepressants and antipsychotics, says new research.

The expanding use of two recently-approved therapies – Lundbeck/Takeda Pharmaceutical’s Brintellix (vortioxetine) and Actavis/Pierre Fabre’s Fetzima (levomilnaceprin ER) – plus the forecast launch of Otsuka Pharmaceutical/Lundbeck’s brexpiprazole, will offset a steep near-term decline in sales resulting from patent expiries for the two key drugs prescribed for unipolar depression  - Eli Lilly/Shionogi’s Cymbalta/Xeristar (duloxetine) and Bristol-Myers Squibb/Otsuka Pharmaceutical’s Abilify (aripiprazole), says the research, from Decision Resources.

It also expects newer antidepressant therapies to be prescribed as third- and fourth-line treatments for patients whose depressive symptoms are inadequately addressed by generic selective serotonin reuptake inhibitors (SSRIs) and/or serotonin and norephinephrine reuptake inhibitors (SNRIs), or for patients who cannot tolerate available therapies. 

And it sees the continued growing use of atypical antipsychotics as adjunctive treatment in patients with a poor response to antidepressants, in the absence of more efficacious alternatives. In particular, the launch of generic aripiprazole during the study period will drive greater use of the drug in this capacity to 2023.

Also during the forecast period, Brillintex will experience moderate uptake as a later-line alternative in treatment non-responders, says DR. Extensive trial data shows the drug may confer improvements in cognition – a significant advantage over other antidepressants – and that it offers a low risk of weight gain and sexual dysfunction. Even as a later-line option, Brillintex’s relative high price will drive its peak-year sales in major markets to over $2.4 billion in 2022, it forecasts.

Despite extensive generic availability of early-line antidepressants and increasingly restrictive reimbursement environments across the major markets, opportunities remain for novel antidepressants, because a sizeable proportion of the drug-treated population responds suboptimally to available monoaminergic-targeted drugs, says DR.

The launch of generic versions of Cymbalta/Xeristar and Abilify will not only result in a dramatic near-term drop in sales due to extensive and rapid uptake of generics, but will also create market access pressures for the newer agents launching in these classes - Fetzima and brexpiprazole, respectively, it forecasts.

Treatment-resistant depression (major depressive disorder that does not respond to at least two adequate courses of antidepressant therapy) has and will continue to be the arena of greatest unmet need in the treatment of depression over the next 10 years, says Decision Resources group analyst Alana Simorellis.

“An agent proven to be more effective than current agents in treatment-resistant patients would be welcomed by physicians and would likely be used as part of combination therapy,” she forecasts.