Company: PRTA
Filing Date: 2025-11-06
Form Type: 10-Q
Source: 0001559053-25-000044
Chunk: 34

Company: PROTHENA CORP PUBLIC LTD CO
Filing Date: 2025-11-06
Form: 10-Q
Item: Part I, Item 2
Chunk 34
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446 or placebo intravenously (“ IV”) and were followed for up to two months. The results of the trial found all three dose level cohorts of BMS-986446 to be generally safe and well tolerated, meeting the Phase 1 SAD trial primary objective. None of the treatment emergent adverse events (“ TEAE”) were serious. No clinically relevant changes were observed in other safety parameters. BMS-986446 also met key pharmacokinetic (“ PK”) and immunogenicity secondary endpoints. Plasma drug concentrations of BMS-986446 increased in a dose-proportional manner. Furthermore, BMS-986446 exposure in cerebrospinal fluid (“ CSF”) was measured in the high dose cohort and based on the robust exposure of BMS-986446 in the CSF (day 29 CSF:Plasma ratio=0.2%), substantial target engagement is expected in the CNS. BMS-986446 had a desirable immunogenicity profile with no persistent BMS-986446-induced antidrug antibodies (“ ADA”s) observed.

A multiple ascending dose (MAD) portion of the Phase 1 clinical trial was ongoing at the time BMS acquired the global rights to the program and control of the Phase 1 trial.

In the second quarter of 2025, BMS initiated a Phase 1 clinical trial to assess drug levels, tolerability and absolute biological availability of single subcutaneous dose of BMS-986446 in healthy participants. This is a Phase 1, randomized, open-label, parallel, single-dose clinical trial to assess the pharmacokinetics, tolerability, and absolute bioavailability of subcutaneous administration of BMS-986446, an anti-MTBR tau monoclonal antibody, in approximately 46 healthy participants.

PRX019 for the Potential Treatment of Neurodegenerative Diseases

PRX019 is an investigational antibody for the potential treatment of neurodegenerative diseases in development in collaboration with BMS.

In December 2023, the FDA cleared the IND application for PRX019. In May 2024, we entered into an exclusive global license agreement for PRX019 and we received an associated option exercise fee of $80.0 million. We are eligible to receive development, regulatory, and sales milestone payments of up to $617.5 million as well as tiered royalties on annual, worldwide net sales.

In November 2024, we announced that we had initiated a Phase 1 first-in-human clinical trial to evaluate the safety,