Prothena Reports 77% Revenue Decline in Q2 2026, Despite Significant Milestone Payment

Prothena Corporation plc reported significant financial changes in its latest 10-Q filing for the quarter ending June 30, 2026. The company generated total revenue of $1.0 million for the quarter, a decrease of 77% compared to $4.4 million in the same period last year. For the first half of 2026, total revenue surged to $52.1 million, up 619% from $7.2 million in the first half of 2025, primarily due to a $50.0 million milestone payment from Novo Nordisk related to the advancement of coramitug in clinical trials. Collaboration revenue also fell to $1.0 million for the quarter and $2.0 million for the half-year, down from $4.4 million and $7.2 million, respectively, in the previous year.

Operating expenses for Prothena decreased significantly, totaling $22.1 million for the second quarter of 2026, down 75% from $89.0 million in the same quarter of 2025. This decline was driven by reduced research and development costs, which fell to $8.8 million from $40.5 million year-over-year, as well as lower general and administrative expenses. The company reported a net loss of $18.6 million for the quarter, a substantial improvement from a loss of $125.8 million in the prior year. For the first half of 2026, Prothena recorded a net income of $14.1 million, contrasting with a loss of $186.0 million in the same period of 2025.

In terms of strategic developments, Prothena has made notable progress in its clinical pipeline, particularly with its drug candidates targeting neurodegenerative diseases. The company is advancing its investigational therapies, including prasinezumab for Parkinson's disease and coramitug for ATTR amyloidosis, with ongoing clinical trials. The Phase 3 CLEOPATTRA trial for coramitug has been initiated, and the company has received Fast Track designation from the FDA for this candidate. Additionally, Prothena has entered into significant collaboration agreements with Roche and Bristol Myers Squibb, which are expected to provide further financial support through milestone payments and royalties.

Operationally, Prothena's cash and cash equivalents stood at $288.2 million as of June 30, 2026, down from $307.5 million at the end of 2025. The company reported a working capital increase to $280.4 million, attributed to the recent milestone payment from Novo Nordisk. Prothena's total liabilities decreased significantly to $15.7 million from $46.3 million at the end of the previous fiscal year, reflecting a reduction in restructuring liabilities and other current obligations. The company anticipates that its existing cash reserves will be sufficient to meet its operational needs for at least the next twelve months, although it may require additional capital to support ongoing and future clinical development efforts.

Looking ahead, Prothena remains focused on advancing its clinical programs and exploring potential partnerships to enhance its pipeline. The company acknowledges the inherent risks associated with drug development and the need for additional capital to support its growth strategy. Prothena's management is committed to leveraging its scientific expertise and collaborations to drive the development of innovative therapies for neurodegenerative diseases, while also managing its financial resources prudently.