FDA Should Not Approve Drug That Is Likely to Cause Life-Threatening Lung Toxicity
(NewDesignWorld Press Center) - Washington, D.C. – A proposed new drug to treat acute agitation in patients with schizophrenia and bipolar disease should not be approved by the Food and Drug Administration (FDA) because the drug has been shown to cause significant, life-threatening lung toxicity and fails to provide any significant benefits in comparison to currently available, FDA-approved alternative drugs, Public Citizen said in a letter sent today to the agency.
The drug, loxapine inhalation powder (also known as Adasuve), manufactured by Alexza Pharmaceuticals, is the first inhaled form of an antipsychotic for use in schizophrenic or bipolar patients. Loxapine already is approved in a capsule form for long-term treatment of schizophrenia, but Alexza is seeking approval for an inhaled form that would be administered for acute agitation as frequently as every two hours as needed, up to a maximum of three doses per day. Action by the FDA on the drug is expected to occur by May 4.
But the drug can cause significant abnormalities in lung function and high rates of pulmonary adverse events – such as bronchospasm, chest discomfort, wheezing and shortness of breath – particularly in patients with asthma and chronic obstructive pulmonary disease COPD (also known as chronic bronchitis and emphysema). Because there is a high rate of smoking in patients with schizophrenia and bipolar disorder, which leads to the development of asthma and COPD, such patients would be particularly prone to developing serious lung toxicity from inhaled loxapine.
In fact, in one safety study testing inhaled loxapine in patients with asthma, approximately 60 percent of the patients had clinically significant abnormalities developed immediately after a single dose of the drug, and approximately 20 percent could not receive a planned second dose because of adverse respiratory events. In a different safety study, which examined the drug in patients with COPD, results were similar.
“Even a single dose of inhaled loxapine resulted in significant pulmonary toxicity in safety trials designed to evaluate inhaled loxapine,” said Dr. Michael Carome, deputy director of Public Citizen’s Health Research Group. “The risks of this drug greatly outweigh its limited benefits. Allowing it to be marketed, even at a single dose, would result in many preventable injuries and deaths.”
FDA reviewers expressed serious concerns about the potential for life-threatening pulmonary toxicity with inhaled loxapine and even questioned the benefits offered by the drug. One FDA reviewer was skeptical whether conclusions from the clinical trials could be extrapolated to the real-word setting – particularly in psychiatric emergency room settings, which likely would be a common setting for use, the letter said. Another reviewer doubted whether inhaled loxapine offered any advantages over current FDA-approved treatments for these patients.
Indeed, one FDA official stated that, in order for the drug to be approved, the company should “be required to submit adequate data on a formulation of the Staccato Loxapine product that demonstrates a lack of pulmonary toxicity.” Such data do not exist.
“As the FDA’s own analysis demonstrated, there is no reasonable justification for approving this drug, and doing so would recklessly endanger patients’ lives,” Carome said.