Note 9. Related Party Transactions

Research Collaboration Agreement with TCGFB, Inc.

In October 2024, the Company entered into a strategic research collaboration with a privately-held company, TCGFB, Inc., or TCGFB, to discover antibody therapeutics targeting transforming growth factor beta, or TGF-β, for the potential treatment of patients with idiopathic pulmonary fibrosis, or TCGFB Collaboration. Under the terms of the agreement, the Company provided antibody discovery services, and TCGFB owned all TGF-β product related intellectual property. In exchange for the Company’s research services, TCGFB paid a fixed monthly service fee, plus any third-party costs, and issued the Company a warrant exercisable for up to 3.4 million shares of TCGFB common stock at an exercise price of $0.0001 per share. The warrant was recognized as warrant asset once the vesting restrictions were lifted. In October 2025, the Company received a notice from TCGFB to terminate the TCGFB Collaboration effective as of November 13, 2025. Neither TCGFB nor the Company incurred any termination penalties. Due to the dissolution of TCGFB, the Company wrote off the recognized warrant asset in December 2025.

TCGFB was founded and was controlled by entities affiliated with The Column Group. The agreement constituted a related party transaction because entities affiliated with The Column Group hold more than 5% of the Company’s common stock and Dr. Kutzkey, a member of the Company’s board of directors, serves as Managing Partner of The Column Group.

During the three and six months ended June 30, 2025, the Company recognized $1.0 million and $2.0 million, respectively, as research service revenue – related party for the services rendered, consisting of the fixed cash consideration of $0.8 million and $1.5 million, respectively, and the variable noncash consideration of $0.2 million and $0.5 million, respectively. There was no research service revenue recognized for the three and six months ended June 30, 2026.

Sublease

In April 2024, the Company entered into a related party transaction with Nura Bio, Inc., or Nura Bio, to sublease approximately 6,102 square feet of the Company’s office and laboratory space. The sublease term was initially on a month-to-month basis and the monthly base rent is approximately $35,000, escalating at 3% per annum. In July 2025 and June 2026, the Company and Nura Bio executed sublease extension agreements, each of which extended the lease term by an additional 12 months, resulting in a lease term until May 2027. Nura Bio is also responsible for its share of real estate taxes, utilities and other operating expenses applicable to the subleased space. During the three and six months ended June 30, 2026, the Company recognized sublease income of $0.2 million and $0.4 million, respectively, as reductions to operating expenses. During the three and six months ended June 30, 2025, the Company recognized sublease income of $0.2 million and $0.3 million, respectively, as reductions to operating expenses. Tim Kutzkey, Ph.D., a member of the Company’s board of directors, serves as the chairman of the board of directors of Nura Bio. Dr. Kutzkey also serves as Managing Partner of The Column Group, LLC, which is the general partner of certain limited partnerships which are significant stockholders of Nura Bio. The Column Group holds more than 5% of the Company’s common stock. Therefore, the agreement constitutes a related party transaction.