FDA Issues AbbVie Complete Response Letter for ABBV-951 in Parkinson Disease

This is a developing story and will be updated with new information as it becomes available.
According to a new announcement, the FDA has again issued a complete response letter (CRL) to AbbVie's new drug application (NDA) for ABBV-951 (foscarbidopa/foslevodopa) for the treatment of motor fluctuations in adults with advanced Parkinson disease (PD).¹

In the CRL, the agency cited observations identified during inspection of a third-party manufacturer listed in the NDA. The inspection at the facility did not involve ABBV-951 or any of the company's medicine. The CRL did not identify any issues in terms of safety, efficacy, or labeling of ABBV-951, including the device. Furthermore, the letter did not request that the company perform additional efficacy and safety studies related to the drug or device-related testing.

"There remains a tremendous unmet need for treatment options for patients living with advanced PD in the United States," Roopal Thakkar, MD, senior vice president, chief medical officer, global therapeutics, AbbVie, said in a statement.¹ "We are focused on working with the FDA to bring this important therapy to patients as soon as possible."

In May 2023, the FDA issued the first CRL to AbbVie for its investigational 24-hour continuous foscarbidopa/foslevodopa pump. In the CRL, the agency requested additional information on the pump as part of its review, but did not request AbbVie to conduct additional efficacy and safety trials related to the drug.²

The NDA was based on the phase 3 M15-736 study (NCT04380142), a double-blind, double-dummy trial in which treatment with the therapeutic resulted in increased ON time by 2.72 hours over a 12-week period to 0.97 hours for oral levodopa/carbidopa (LD/CD). Comprising of 130 adults with advanced PD, the trial randomly assigned individuals 1:1 to either ABBV-951 solution as a continuous infusion under the skin plus oral placebo capsules for LD/CD or ABBV-951 as a subcutaneous infusion plus oral capsules containing LD/CD encapsulated tablets.²

If approved, this would mark AbbVie’s second major regulatory success for patients with PD in the last 7 years. In 2015, the FDA approved Duopa, the first and, to date, only treatment providing 16 continuous hours of LD/CD to help control motor fluctuations in advanced PD. The eternal suspension is administered using a small, portable pump that delivers LD/CD directly into the small intestine through a tube placed during an outpatient procedure.³

ABBV-951 also showed a good safety profile in the phase 3 study, with most of the reported adverse events (AEs) either mild or moderate in a nature. Serious AEs occurred in 8% ABBV-951 group compared with 6% in the LD/CD group. Notably, there as 1 death recorded in the study, believed to be from a treatment-emergent AE while in the LD/CD group. At week 12, ABBV-951-treated patients showed a decrease of 2.75 hours in OFF time, with changes observed as early as the first week. In comparison, those in the oral LD/CD group demonstrated decreases of 0.96 hours during the same stretch (P = .0054).

REFERENCES
1. AbbVie Provides U.S. Regulatory Update on ABBV-951 (Foscarbidopa/Foslevodopa). News Release. Published June 25, 2024. Accessed June 25, 2024. https://news.abbvie.com/2024-06-25-AbbVie-Provides-U-S-Regulatory-Update-on-ABBV-951-Foscarbidopa-Foslevodopa
2. AbbVie provides regulatory update on ABBV-951 (foscarbidopa/foslevodopa) new drug application. News release. AbbVie. March 22, 2023. Accessed June 25, 2024. https://news.abbvie.com/article_display.cfm?article_id=12567
3. Soileau MJ, Aldred J, Budur K, et al. Safety and efficacy of continous subcutaneous foslevodopa-foscarbidopa in patients with advanced Parkinson’s disease: a randomized, double-blind, active-controlled, phase 3 trial. Lancet Neurol. 2022;21(12):1099-1109. doi:10.1016/S1474-4422(22)00400-8.