Bristol Myers Squibb's Cobenfy, a recently approved schizophrenia drug, has shown mixed results in longer-term studies, highlighting the complexities of treating this severe mental illness. While some patients experienced significant improvements, high dropout rates raise concerns about long-term adherence and effectiveness.
Trial Outcomes and Patient Perspectives
The drug, approved in September, acts differently from existing schizophrenia treatments by targeting a different receptor that indirectly blocks dopamine release. The new data, presented at the Psych Congress meeting in Boston, comes from two longer studies following initial encouraging five-week trials.
One study focused on severely ill patients, with a concerning 78% dropout rate, leaving only 35 participants for final analysis. However, among those who completed the year-long trial, 69% showed a meaningful improvement in their symptoms. The second study, involving more stable patients, had a 51% dropout rate, with 283 patients completing the trial. In this group, 30% experienced a meaningful benefit.
Interviews with study participants revealed varying experiences. Some reported a reduction in auditory hallucinations, while others found the drug ineffective. An independent research team found that, after six months, 36 participants said they would continue taking Cobenfy if given the option, while 10 said they would not.
Expert Commentary and Clinical Implications
Dr. Greg Mattingly of Washington University School of Medicine in St. Louis, a consultant for Bristol Myers Squibb and a researcher on one of the studies, noted that the dropout rates were typical for schizophrenia studies. Dr. John Krystal of Yale University, who has researched other schizophrenia drugs but was not involved in these studies, pointed out that only 10% to 20% of participants dropped out due to side effects, which he considered "pretty good." He suggested that fewer or milder side effects could improve treatment adherence, potentially reducing substance use, homelessness, and unemployment associated with untreated mental illness.
Cost and Access Considerations
A significant concern is the estimated yearly cost of Cobenfy, which is $22,500, compared to $540 for a generic antipsychotic. Experts like Dr. Krystal worry that insurers may require patients to try cheaper alternatives first, potentially delaying access to Cobenfy. Cheaper generic options like clozapine are available, but clozapine requires a cumbersome blood testing program to monitor for a rare but potentially fatal side effect.
Comparing Cobenfy to Existing Treatments
Patients and families are eager to see data comparing Cobenfy to clozapine, which is considered one of the best treatments for schizophrenia. Some patients have found success with clozapine, managing side effects like weight gain with additional medications. The value proposition of Cobenfy will likely depend on its ability to demonstrate superior efficacy or tolerability compared to existing options.
