FDA Issues Second CRL for Parkinson’s Therapy

The FDA has issued a complete response letter (CRL) for Supernus Pharmaceuticals’ new drug application for SPN-830. SPN-830 is an apomorphine infusion device under review to treat short-term, intermittent “off” episodes in people with Parkinson’s disease. The infusion device would create a continuous treatment with apomorphine.

“We will work with the FDA to address the CRL and to successfully resubmit our SPN-830 NDA,” Jack Khattar, president and CEO of Supernus, said in a news release.

Agency officials indicated there were two areas that require additional review by the FDA or additional information to be provided to the FDA. The first area relates to product quality. Supernus recently submitted additional product quality data to the FDA that it has not yet reviewed.

The second relates to the master file for the infusion device, which is proprietary to the device manufacturer. Supernus officials plan to discuss with the device manufacturer the provision of the requested information and the steps required for the resubmission of the NDA for SPN-830.

No clinical safety or efficacy issues were identified as a requirement for approval.

This is the second CRL for SPN-830. The FDA had issued a complete response letter in October 2022 asking for additional information related to the infusion device and the need for inspection of manufacturing facilities. The FDA completed in February 2024 preapproval inspection of the device manufacturer’s facility.

Supernus markets Apokyn, an injection form of apomorphine but in February 2022, a first generic was approved. Sales of Apokyn for the full year 2023 were $75 million, which was unchanged from 2022.

The company also markets Gocovri (amantadine) to treat dyskinesia in patients with Parkinson’s disease receiving levodopa-based therapy. Dyskinesia is a movement disorder that in patients with Parkinson’s disease is due to overstimulation of dopamine receptors. GoCovri is also indicated as an adjunctive treatment for patients with Parkinson’s who are taking levodopa/carbidopa. In 2023, Gocovri generated net sales of $120 million, up 15% from 2022.

At an investor call in March 2024, official expressed confidence in the potential of SPN-830, with projected peak sales of between $200 million and $300 million.

SPN-830 demonstrated a 2.47 hours per day reduction in off time compared with placebo in the TOLEDO study, which was published in The Lancet Neurology in 2018.