This section highlights FDA-related milestones and regulatory updates for drugs developed by Prothena (PRTA).
Over the past two years, Prothena has reported clinical trial outcomes, regulatory submissions, approvals, and other FDA events for drugs and therapies such as
Birtamimab and Prasinezumab. For definitions of regulatory abbreviations such as NDA, BLA, or PDUFA, see the event status legend.
Birtamimab - FDA Regulatory Timeline and Events
Birtamimab is a drug developed by Prothena for the following indication: AL Amyloidosis.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- Birtamimab
- Announced Date:
- May 23, 2025
- Indication:
- AL Amyloidosis
Announcement
Prothena Corporation plc announced the Phase 3 AFFIRM-AL clinical trial evaluating birtamimab in patients with AL amyloidosis did not meet its primary endpoint (HR=0.915, p-value=0.7680).
AI Summary
Prothena Corporation plc announced that the Phase 3 AFFIRM-AL clinical trial evaluating birtamimab in patients with AL amyloidosis did not meet its primary endpoint. The trial showed a hazard ratio of 0.915 with a p-value of 0.7680, meaning that birtamimab did not improve time to all-cause mortality compared to standard care. Secondary endpoints, including the 6-minute walk test and a physical health score, were also not met. As a result, Prothena will discontinue the development of birtamimab and halt the open-label extension of the AFFIRM-AL trial.
The decision to stop the program is part of a broader plan to decrease ongoing operating expenses and reduce the company’s organizational size. Prothena plans to provide further updates in June regarding its efforts to adjust spending and explore additional business options.
Read Announcement- Drug:
- Birtamimab
- Announced Date:
- April 15, 2024
- Indication:
- AL Amyloidosis
Announcement
Prothena Corporation plc announced the publication related to the mechanism of action, pharmacological characteristics, and clinical utility of birtamimab, a potential best-in-class anti-amyloid treatment for AL amyloidosis.
AI Summary
Prothena Corporation plc recently announced the publication of a study in Leukemia & Lymphoma that explains how birtamimab works and its potential role as a best-in-class anti-amyloid treatment for AL amyloidosis. The newly released article details the drug’s mechanism of action by showing how birtamimab binds to a unique epitope exposed on misfolded light chain proteins. This selective binding allows the antibody to neutralize toxic light chain aggregates and clear the amyloid deposits that build up in vital organs, potentially preventing organ damage and failure.
The publication also highlights the pharmacological characteristics and clinical utility of birtamimab, underscoring its innovative approach compared to current therapies. These insights may guide further research and clinical investigation into improving treatment outcomes for patients suffering from this severe, progressive disease.
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Prasinezumab - FDA Regulatory Timeline and Events
Prasinezumab is a drug developed by Prothena for the following indication: Parkinson's disease.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- Prasinezumab
- Announced Date:
- June 16, 2025
- Indication:
- Parkinson's disease
Announcement
Prothena Corporation plc announced partner Roche will advance prasinezumab, an investigational anti-alpha-synuclein antibody, into Phase III development in early-stage Parkinson's disease.
AI Summary
Prothena Corporation plc announced that partner Roche will move forward with advancing prasinezumab into Phase III development for early-stage Parkinson’s disease. Prasinezumab is an investigational antibody that targets aggregated alpha-synuclein—a protein believed to drive the progression of Parkinson’s. Data from the Phase IIb PADOVA study, along with ongoing open-label extension studies, showed that prasinezumab may provide additional benefits on top of current symptomatic treatments. The studies noted promising trends, including a potential delay in motor progression and early signs of impacting the underlying disease biology. This development represents an important step toward creating the first disease-modifying treatment option for Parkinson’s, a condition that affects millions worldwide and has high unmet medical needs. By progressing to Phase III trials, this partnership hopes to further explore prasinezumab’s potential in slowing down the progression of Parkinson’s disease.
Read Announcement- Drug:
- Prasinezumab
- Announced Date:
- December 19, 2024
- Indication:
- Parkinson's disease
Announcement
Prothena Corporation plc announced results from the Phase IIb PADOVA study conducted by partner Roche investigating prasinezumab in 586 people with early-stage Parkinson's disease, treated for a minimum of 18 months while on stable symptomatic treatment.
AI Summary
Prothena Corporation plc announced promising results from the Phase IIb PADOVA study conducted by Roche for prasinezumab in 586 early-stage Parkinson's patients. Participants were treated for at least 18 months while continuing stable symptomatic therapy. The study showed a numerical delay in motor progression and positive trends across several secondary and exploratory endpoints. Notably, the primary endpoint—time to confirmed motor progression—demonstrated a trend favoring prasinezumab, especially in the subgroup of patients already receiving levodopa, indicating a potential clinical benefit in slowing disease advancement.
The treatment was well tolerated with no new safety concerns observed. Roche plans to further evaluate the data and collaborate with health authorities to determine the next steps for prasinezumab’s development as a potential disease-modifying therapy for Parkinson’s disease.
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