Roche/Chugai's glycine transporter-1 inhibitor bitopertin is poised to be the first approved treatment to adress negative symptoms in schizophrenia, following its forecast launch in the US and Europe in 2016 and in Japan in 2017, say new forecasts.

As a first-in-class agent for these prominent yet underserved symptoms of schizophrenia, bitopertin will garner nearly $1.5 billion in major-market sales in 2022, says the research, from Decision Resources.

"Treatments for negative symptoms, such as abnormalities in emotional expression and social interaction, is one of the top unmet needs in schizophrenia because - although nearly two-thirds of patients experience notable negative symptoms - currently-available antipsychotics have not proven efficacious and reliable in treating such symptoms," notes Decision Resources senior business insights analyst Anne-Elise Tobin.

"Bitopertin has engendered enthusiasm from interviewed key opinion leaders, who say its novel mechanism of action will be beneficial as an adjunctive therapy to current antipsychotics. Because bitopertin will be used adjunctively and thus will not compete directly with other currently-available therapies, it will contribute to market growth over the forecast period," she says.

The launch of depot formulations of two atypical antipsychotics currently available in oral form will lead to an overall increase in the use of depot formulations across the major markets, the study adds. 

In particular, Otsuka/Lundbeck's once-monthly Abilify Maintena (aripiprazole) will provide a more-tolerable option than current depot products, and Janssen's paliperidone palmitate three-month formulation will offer substantial compliance and administration advantages over currently-available once-monthly or twice-monthly depots. Together, these two agents are expected to capture major-market sales of nearly $1.8 billion in 2022, it notes.

The schizophrenia market will grow from $6.3 billion in 2012 to $8.0 billion in 2022, due to the launch of multiple premium-priced emerging therapies, including bitopertin, Abilify Maintena and paliperidone palmitate three-month depot, says Decision Resources. Uptake of emerging projects will offset the impact of expanding generic competition to 2022, including that for three of the four top patient-share market leaders - Eli Lilly's Zyprexa (olanzapine), Bristol-Myers Squibb/Otsuka's Abilify and AstraZeneca/Astellas' Seroquel (quetiapine).

In light of a growing generics presence, emerging schizophrenia treatments will increasingly have to compete with low-cost alternatives of current products, and the entrance of multiple new antipsychotics into this crowded market will require emerging therapies to adequately differentiate themselves from their competitors to ensure uptake and obtain favourable reimbursement status, the report advises.