Drugs to Watch: Mental Health Conditions

The FDA is reviewing two novel therapies for mental health. The first is Lykos Therapeutics’ (formerly MAPS Public Benefit Corp.) new drug application for midomafetamine to treat patients with PTSD. The target action date is Aug. 11, 2024. If approved, this would be the first psychedelic-assisted therapy for post-traumatic stress disorder.

PTSD is a mental health condition affecting about 13 million Americans each year, yet currently available treatments provide only modest efficacy; there are high treatment discontinuation rates.

Midomafetamine is 3,4-methylenedioxymethamphetamine (MDMA) — commonly known as ecstasy — a class of psychoactive compounds. It is classified as a Schedule I drug by the Drug Enforcement Agency, which means it has the highest potential for abuse and potential to create psychological or physical dependence.

The new drug application (NDA) submission included data from two phase 3 studies. Both met the primary end point and the key secondary end point. In one trial, 45 of 52 (86.5%) patients treated with midomafetamine achieved a clinically meaningful benefit, and
37 of 52 (71.2%) patients no longer met criteria for PTSD by study end.

Common treatment-related side effects included mild increases in blood pressure and pulse. Midomafetamine did not appear to increase the risk of suicidal ideation.

IPD Analytics LLC predicts the wholesale acquisition cost will be between $5,000 and $10,000 per drug course and the drug will be administered by physicians.

In the area of schizophrenia, KarXT (xanomeline/trospium), if approved would be a new approach to treating adults with schizophrenia. The FDA has assigned a Prescription Drug User Fee Act (PDUFA) date of Sept. 26, 2024.

Developed by Karuna Therapeutics Inc., KarXT acts on two muscarinic receptors — M1 and M4 — in the brain that are thought to improve positive, negative and cognitive symptoms of schizophrenia. Unlike existing treatments, KarXT does not directly block dopamine receptors.

Schizophrenia affects about 24 million people worldwide. About 30% of people with schizophrenia do not respond to therapy, with an additional 50% experiencing only a partial improvement in symptoms or side effects.

The NDA submission includes data from three placebo-controlled trials in which KarXT met its primary end point, demonstrating improvements in symptoms of schizophrenia.

In a final review, officials from the Institute for Clinical and Economic Review (ICER) rated the health benefit of KarXT as promising but found there is a lack of long-term data. ICER has determined KarXT would be cost-effective if priced between $16,000 and $20,000 per year.

IPD Analytics predicts the wholesale acquisition cost will likely be between $20,000 and $30,000. In March 2024, Bristol Myers Squibb acquired Karuna for an estimated $14 billion.

Last week, Bristol Myers Squibb announced new data from the EMERGENT clinical trial program. KarXT demonstrated a favorable long-term metabolic profile where most patients experienced stability or improvements on metabolic parameters over 52 weeks of treatment. At the time of the data cutoff of Aug. 18, 2023, the interim pooled data analysis included 718 patients who received at least one dose of KarXT, with 134 patients having completed one year of treatment.

In the pooled analysis from the long-term EMERGENT studies, 62% of patients reported at least one treatment-related adverse event. The most common treatment-related adverse events were nausea, vomiting, constipation, dry mouth, dyspepsia, dizziness, hypertension, and diarrhea.

The overall discontinuation rate was 53% and primary reasons for discontinuation included withdrawn consent (19%), treatment-related adverse events (15%), participant lost to follow-up (8%), and participant failed to adhere to protocol requirements (7%).