Solstice Oncology

Solstice Oncology announced $225M in Series A financing on September 9, 2026. Solstice Oncology launched with a $225 million Series A led by RA Capital Management to advance porustobart, a neoadjuvant immuno-oncology therapy.

Round details

The financing includes backing from RA Capital Management, Canaan Partners, Forbion. The company did not publish a valuation with the announcement.

• Round: Series A
• Capital announced: $225M
• Headquarters: Boston, MA

How the company plans to use the capital

The announcement did not state how the proceeds will be used. The release said Solstice is advancing its lead candidate porustobart, with a Phase 2 colon cancer trial expected to open for enrollment early in the fourth quarter of 2026 and data from that trial expected in the second half of 2027.

Why this matters for GTM teams

The round was led by RA Capital Management for a clinical-stage immuno-oncology company built around the neoadjuvant treatment setting, where the company said it sees the greatest opportunity to improve cure rates and long-term survival.

Fresh capital is often an operational signal rather than a buying signal by itself. Teams should validate the company’s hiring pattern, product launches, geographic expansion, and technology priorities before choosing the message and timing of outreach.

Source and methodology

This report is based on the company’s announcement and records the disclosed amount, round, investors, location, and stated use of funds. SalesTools Research does not estimate undisclosed valuation or revenue figures.

Primary source: Solstice Oncology Series A announcement.