Boundless Bio (BOLD) said Tuesday it has signed a definitive merger agreement with privately held biotech firm Serapha Bio in an all-stock merger.

The company said that when the deal closes, the merged company will operate under the name Serapha Bio and is expected to trade on the Nasdaq stock market under the ticker symbol "AATD."

As part of the merger, Serapha has received commitments for pre-closing private investments of approximately $230 million from a group of investors co-led by RA Capital Management and RTW Investments.

Approximately $138 million of that has already been funded in a Series A financing, according to Boundless Bio.

The remaining $92 million in funding is expected to close about the same time as the merger, the company said.

Before closing, Boundless Bio expects to declare a cash dividend to pre-merger Boundless stockholders.

Shares of Boundless Bio were up 2.1% pre-bell.