Prothena Q4 Earnings Meet Estimates, Pipeline Progress in Focus

Prothena Corporation PRTA reported fourth-quarter 2025 adjusted loss per share (excluding restructuring costs) of 45 cents, in line with the Zacks Consensus Estimate.

In the year-ago quarter, the company had incurred a loss of $1.08 per share.

Revenues totaled $0.02 million, missing the Zacks Consensus Estimate of $3.0 million. Prothena had recorded revenues of $2.1 million in the year-ago quarter. The top line primarily comprises collaboration revenues from Bristol Myers Squibb BMY.

Over the past year, Prothena’s shares have lost 42% against the industry’s growth of 18.8%.

PRTA’s Q4 Results in Detail

Research and development expenses plunged 71% year over year to $14.6 million, driven by reduced clinical trial, manufacturing, personnel and consulting costs.

General and administrative expenses were $12.6 million, down 25% year over year.

As of Dec. 31, 2025, Prothena had $308.4 million in cash, cash equivalents and restricted cash, compared with $331.7 million as of Sept. 30, 2025. It had no debt.

PRTA’s Full-Year 2025 Results

For 2025, Prothena reported total revenues of $9.7 million, which declined 93% year over year.

For full-year 2025, the company recorded a net loss of $3.97 per share, wider than a loss of $2.27 per share in 2024.

PRTA’s 2026 Guidance

The company expects 2026 net cash burn from operating and investing activities to be in the range of $50 million-$55 million. It expects the year-end cash, cash equivalents and restricted cash midpoint to be approximately $255 million. Net loss for 2026 is projected to be in the $67 million to $72 million range. Prothena expects to earn up to $105 million as clinical milestone payments tied to the advancement of coramitug by Novo Nordisk NVO and PRX019 by BMY in 2026.

Prothena Corporation plc Price and Consensus

Prothena Corporation plc price-consensus-chart | Prothena Corporation plc Quote

PRTA’s Pipeline Updates

Prothena is developing prasinezumab in collaboration with Roche RHHBY for the treatment of Parkinson’s disease.

Roche is evaluating prasinezumab in an ongoing late-stage PARAISO study for early-stage Parkinson's disease, with primary completion expected in 2029. Roche expects peak sales potential of greater than $3.5 billion (unadjusted) of prasinezumab.

Novo Nordisk had earlier acquired Prothena’s clinical-stage antibody, Coramitug (formerly PRX004), a potential first-in-class amyloid depleter antibody for the treatment of ATTR amyloidosis with cardiomyopathy (ATTR-CM).

NVO is evaluating the candidate under a late-stage CLEOPATTRA study for ATTR-CM. The study is expected to be completed by 2029.

Prothena announced the publication of data from Novo Nordisk’s phase II study evaluating coramitug for the treatment of patients with ATTR-CM in November. The phase II data for coramitug supports the ongoing phase III CLEOPATTRA study.

PRTA expects to earn a clinical milestone in the first half of 2026 if the prespecified enrollment criteria are met in the ongoing phase III study by Novo Nordisk. The candidate could earn Prothena up to $1.23 billion in development and sales milestones, including $100 million already received, with additional payments tied to phase III enrollment targets.

Prothena is advancing an early-stage pipeline of programs for several potential neurological indications with Bristol Myers.

BMS-986446 (formerly PRX005) is a best-in-class anti-tau, MTBR-specific antibody for the potential treatment of Alzheimer’s Disease.

BMS-986446 was granted Fast Track designation by the FDA as a treatment for Alzheimer’s disease previously.

Bristol Myers is conducting the phase II TargetTau-1 study in approximately 310 patients with early Alzheimer’s disease and the primary completion is expected in 2027. Bristol Myers Squibb also conducted a phase I open-label single-dose clinical study to assess subcutaneous administration.

PRX019, a potential treatment for neurodegenerative diseases, is also being developed in collaboration with Bristol Myers. BMY in-licensed exclusive global rights to PRX019 in 2024.

Prothena expects to earn a milestone payment by the end of 2026 if Bristol Myers decides to further develop PRX019.

PRTA’s Zacks Rank

PRTA carries a Zacks Rank #3 (Hold) at present. You can see the complete list of today’s Zacks #1 Rank (Strong Buy) stocks here.

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This article originally published on Zacks Investment Research (zacks.com).

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