New Antipsychotic That Causes Less Weight Gain Gets FDA Approval - Everyday Health

The U.S. Food and Drug Administration (FDA) announced the approval of a once-daily atypical antipsychotic drug, Lybalvi (olanzapine and samidorphan), to treat adults with schizophrenia and adults with bipolar I disorder.

According to its manufacturer, Alkermes, the combination of olanzapine and samidorphan causes significantly less weight gain than traditional Zyprexa (olanzapine), one of the most widely prescribed antipsychotic drugs for treating schizophrenia and bipolar I disorder.

"The weight gain on olanzapine has limited its use in patients, due to reluctance of healthcare providers to prescribe it and as a result of patients discontinuing the medication. This is unfortunate since olanzapine is one of the most effective antipsychotics on the market," says René S. Kahn, MD, PhD, who is a professor and chair of the department of psychiatry and behavioral health system at the Icahn School of Medicine at Mount Sinai in New York City. Dr. Kahn was one of the researchers who studied the effects of Lybalvi in clinical trials.

"Lybalvi combines the efficacy of olanzapine with limited weight gain, and thus provides an important alternative to olanzapine monotherapy," Kahn adds.

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What Is Lybalvi? Safety, Effectiveness, and Side Effects

The new approval is based on the results of the ENLIGHTEN-1 and ENLIGHTEN-2 studies. In ENLIGHTEN-1, which was published in the March–April issue of the Journal of Clinical Psychiatry, adults with acutely exacerbated (or worsened) schizophrenia who completed four weeks of treatment with Lybalvi experienced significant improvements compared with those who received placebo.

In ENLIGHTEN-2, a phase 3 study published in August 2020 in the American Journal of Psychiatry, researchers assessed the impact of Lybalvi on weight gain compared with olanzapine alone. Over the course of 24 weeks, the researchers found that Lybalvi had similar effectiveness while causing significantly less weight gain and smaller increases in waist size compared with olanzapine alone.

Lybalvi, which is taken by mouth, was found to be well tolerated in both studies. According to Lybalvi's website, the most common side effects in adults with schizophrenia were weight gain, sleepiness, dry mouth, and headache.

In adults with bipolar I disorder, common side effects when using Lybalvi included constipation, weakness, dry mouth, dizziness, and increased appetite. In adults with bipolar I disorder who took Lybalvi along with lithium or valproate, side effects included dry mouth, back pain, memory and speaking issues, weight gain, and dizziness. Lybalvi should not be used by people who are taking opioids or going through acute opioid withdrawal.

Lybalvi is anticipated to be available for patients in late 2021, Alkermes said in a press release.

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Weight Gain: A Common Side Effect of Antipsychotic Meds

Antipsychotic drugs like Lybalvi and olanzapine play a key role in managing conditions like schizophrenia, but as Kahn mentioned, they often come with significant side effects like weight gain. A review of 307 studies that assessed weight change with antipsychotic treatment, which was published in PLOS ONE, showed that the majority of antipsychotic medications are associated with some degree of weight gain when used long term. The amount of weight gain caused by each drug ranged from mild to severe, the researchers wrote.

Weight gain associated with antipsychotic medication can play a role in a variety of problems ranging from a worse quality of life to an increased risk of cardiovascular disease and death. There is also a greater likelihood that patients who are prescribed these medications may fail to stick with them, according to an August 2017 article published in the journal Nonpsychiatric Disease and Treatment.

The authors of the August 2017 article wrote that the risk of weight gain "appears to be highest with olanzapine and clozapine [another antipsychotic drug that can be used to treat people with schizophrenia]," and tends to happen quickly after starting antipsychotic treatment and continue over time. Strategies to address weight gain, such as dietary counseling, exercise programs, and cognitive and behavioral interventions, appear to have "modest effects," the authors stated, adding that although switching medication is an option, it can lead to a relapse in one's illness.

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