Insider 'Big Buy' Amid Earnings Turnaround: Could Hidden Parkinson's and Alzheimer's Beneficiaries Emerge?

Prothena Corp. Public Ltd. Co. (NASDAQ: PRTA) returned to profitability in the first quarter of 2026, posting net income of $32.7 million after receiving a $50 million Phase III milestone payment from Novo Nordisk for its ATTR cardiomyopathy candidate, correlateg.

By cutting research-and-development and selling, general and administrative expenses, Prothena slashed its 2026 cash-burn forecast from $50–55 million to $18–23 million. The company now expects to end the year with about $273 million in cash, and as of March 31 it held $330.3 million in cash and restricted cash with no debt.

Prothena’s board has authorized a share-repurchase program of up to $100 million through the end of 2026. Director William P. Scully recently bought 100,000 common shares on the open market for roughly $980,000, noticeably increasing his stake.

Investors have been drawn to Prothena’s Q1 results, which significantly beat Wall Street estimates, and to the U.S. FDA’s Fast Track designation for Novo Nordisk’s correlateg. These developments have shone a spotlight on Prothena’s co-development pipeline with its partners.

Major pharmaceutical companies are moving quickly in neurodegenerative and amyloid diseases by leveraging Prothena’s assets. Roche is advancing Phase III trials of prasinezumab for Parkinson’s disease and presented long-term follow-up data at the 2026 AD/PD conference, while Bristol Myers Squibb secured FDA Fast Track status for its Alzheimer’s candidate BMS-986446 (PRX005).

Prothena is a late-stage biotech focused on developing antibody therapies that target protein misfolding and aggregation. Through licensing and co-development agreements with Novo Nordisk, Roche and Bristol Myers Squibb, Prothena aims to generate royalties and milestone payments across Parkinson’s, Alzheimer’s and ATTR amyloid cardiomyopathy.

The U.S. biotech sector—which faces high interest rates and clinical-trial risks—remains volatile. Partnerships with big pharma and regulatory Fast Track designations are viewed as key factors influencing company valuations and future fundraising prospects.