Hookipa Pharma Cancels Merger with Poolbeg, Signaling Shift in Biotech M&A Landscape

In a surprising turn of events, US-based immunotherapeutics company Hookipa Pharma has called off its planned merger with UK rare disease firm Poolbeg Pharma. The decision, announced on February 20, 2025, marks a significant shift in the biotech merger and acquisition landscape that had been gaining momentum since the beginning of the year.

Merger Reversal

Hookipa Pharma initially announced its intention to acquire Poolbeg Pharma on January 2, 2025, through an all-stock transaction. The proposed deal would have resulted in Poolbeg shareholders owning approximately 55% of the merged entity, with Hookipa shareholders retaining the remaining 45%. As part of the agreement, Poolbeg was set to delist from the UK's AIM exchange and become a subsidiary of Nasdaq-listed Hookipa.

The merger was accompanied by plans for a $30 million private placement fundraise, orchestrated by Hookipa to provide the combined company with sufficient capital to advance its pipeline. However, this additional funding would have altered the ownership percentages outlined in the initial agreement.

Market Implications

The cancellation of this high-profile merger raises questions about the current state of biotech M&A activity. Industry analysts are closely watching to see if this decision signals a broader trend of caution in the sector or if it's an isolated incident based on company-specific factors.

Hookipa's Recent Challenges

The merger termination comes on the heels of a challenging 2024 for Hookipa Pharma. The New York-based company faced setbacks, including a round of layoffs following Roche's decision to withdraw from a collaboration on the HB-700 program, which targets KRAS-mutated cancers.

Despite these challenges, Hookipa had been moving forward with its HB-700 program, with interim phase 1 data expected in the first half of 2026. The cancellation of the Poolbeg merger raises questions about the future of this program and Hookipa's overall strategic direction.