- Japan's Mitsubishi Tanabe Pharma has withdrawn an application to get its ALS drug Radicava approved in Europe, citing "unwarranted" data requests from regulators.
- Mitsubishi Tanabe submitted the application last April with data from a six-month study showing functional loss was significantly slower in patients treated with Radicava than placebo. However, regulators raised concerns about the strength of the results, and considered giving Radicava a conditional approval that would require Mitsubishi Tanabe to generate more data.
- In a Thursday statement, the company said regulators wanted a long-term, placebo-controlled study lasting at least one year to assess Radicava's effect on survival. Mitsubishi Tanabe disagreed with that stance and "made the difficult decision" to pull its approval application. It will now "carefully consider" Radicava's future options in the EU.
Radicava (edaravone) already holds approvals in several of the world's largest pharmaceutical markets, including the U.S., Canada and Japan. That track record make the drug's troubles in the EU more pronounced.
There, the regulatory committee tasked with evaluating drugs and recommending approval took issue with the study Mitsubishi Tanabe says clearly shows Radicava's health benefits.
Though the study showed Radicava-treated patients had significantly greater improvements on an ALS functional scale compared to placebo-treated patients, the committee argues there wasn't enough evidence to conclude the drug also had a positive impact on health metrics like breathing and muscle strength or survival.
Regulators noted too that the study, which looked at 137 patients over a 24-week timeframe, was too small and too short. Additionally, they had problems with the way patients were separated into the experimental or placebo arms, since more patients in the Radicava group had less severe ALS when the study kicked off.
"When patients in the placebo group were later switched to Radicava there was no noticeable effect," the committee said in document published May 29.
Mitsubishi Tanabe withdrew its application on May 24. At that time, the committee said it still had some "unresolved issues" with Radicava and believed the drug's benefits didn't outweigh its risks.
In a letter to the committee's chair, Mitsubishi Tanabe said its decision stemmed from the committee opinion on Radicava's risk-benefit profile. The company added that its withdrawal doesn't impact ongoing clinical trials of the drug.
"Mitsubisihi Tanabe Pharma Group will continue to make every effort to deliver edavarone to patients suffering from ALS worldwide by increasing, as far as possible, the number of countries with regulatory approvals based on the current data," the company said in its May 30 statement.
Radicava got an OK from the Food and Drug Administration in May 2017 as a treatment for ALS, also known as amyotrophic lateral sclerosis or Lou Gehrig’s disease.
The disease has been particularly tricky for drugmakers, evidenced by multiple failures seen in clinical testing. Over the last two years, experimental therapies from Cytokinetics, Astellas and Flex Pharma have missed the mark on either efficacy or safety.
In Mitsubishi Tanabe's fiscal year ended March 31, Radicava raked in 27 billion Japanese yen (around $250 million).