TriSalus Life Sciences announced a definitive merger agreement with Westminster Health Acquisition Corporation that will take the oncology-focused medical device company public and fund Phase III trials for its pressure-enabled drug delivery platform. The transaction values TriSalus at approximately $315 million pro forma enterprise value, with the combined entity expected to trade on Nasdaq under ticker TLSI by Q3 2025.
The Westminster SPAC held $69 million in trust as of December 2024, supplemented by a $40 million PIPE led by existing TriSalus shareholders including Longitude Capital and Santen Pharmaceutical. TriSalus disclosed $22 million in current cash, putting total pro forma liquidity near $131 million before transaction expenses. The company burned approximately $35 million in 2024 across three ongoing clinical programs, suggesting an 18-month runway at current spend before needing additional capital. Westminster's sponsor, led by former Cigna executive David Cordani, waived earnout provisions and accepted a reduced promote structure that releases shares only above $12.50 post-merger price thresholds.
TriSalus manufactures the Pressure-Enabled Drug Delivery system, a catheter-based platform that creates transient increases in intratumoral pressure to enhance chemotherapy penetration in solid tumors. The technology bypasses systemic toxicity by delivering existing oncology drugs directly into the tumor vasculature under controlled pressure gradients. The company holds 37 issued patents covering pressure modulation mechanics and has 510(k) clearance for the delivery catheter as a vascular access device. Current trials focus on hepatocellular carcinoma and pancreatic cancer, where the platform combines with standard-of-care agents like gemcitabine and cisplatin. Enrollment in the PERIO-03 liver cancer study reached 187 patients across 22 sites as of January 2025, with interim survival data expected in Q4 2025.
The SPAC route returns after biotech de-SPAC transactions dropped 91% between 2021 and 2023, with only four healthcare SPAC mergers closing in 2024 compared to 63 in 2021. TriSalus represents a shift toward later-stage assets with visible catalysts rather than pre-revenue platform plays. The company reported $2.1 million in 2024 revenue from international device sales and physician training fees, a modest but real commercial footprint. Management disclosed $180 million in cumulative equity raised since the 2019 spinout from AngioDynamics, which retained a 12% stake now worth approximately $38 million at merger valuation. The filing shows TriSalus paying AngioDynamics a 3.5% royalty on future product sales, capped at $25 million lifetime.
Allocators should track three sequences. The Westminster shareholder vote occurs approximately 45 days post-S-4 effectiveness, likely mid-May 2025, with redemption rates determining final cash to balance sheet. PERIO-03 interim analysis reads out in Q4 2025 and will either validate the pressure-modulation thesis with survival data or send the stock below cash value if endpoints miss. The company must initiate its pancreatic cancer pivotal trial by Q1 2026 to maintain Longitude Capital's $15 million milestone tranche, creating a forced capital deployment clock. Separate from the merger, TriSalus maintains an exclusive distribution agreement with Guerbet SA covering 14 European markets, generating mid-single-digit percentage royalties that hit TriSalus books with a one-quarter lag.
AngioDynamics announced in its January 2025 earnings call that it would monetize the retained TriSalus position within six months post-merger, adding 7 million shares of potential selling pressure to a float that will total approximately 38 million shares at close. The lockup agreement permits AngioDynamics to sell 25% of its stake every 90 days starting 180 days post-close, meaning 1.75 million shares become available in Q1 2026 regardless of stock performance.