Compensation Letter, dated February 11, 2022, from the Registrant to Ruhi Khan

I am pleased to announce that the Caribou Board of Directors has approved a bonus based on the Company’s achievements in 2021. You will receive a one-time payment of $26,650, less applicable withholding taxes, on February 22, 2022. Congratulations! Your base salary is $410,000 and your target bonus will be 40% in 2022 for your role as Chief Business Officer. Your current manager is Rachel Haurwitz.

2021 was a pivotal year for the Company as we signed a license and collaboration agreement with AbbVie, closed the Series C financing, and became a publicly traded company. Additionally, as publicly disclosed in July, the first patient was dosed in Caribou’s Phase 1 ANTLER clinical trial for our allogeneic anti-CD19 CAR-T cell therapy (CB-010). The other members of the Board and I are grateful to you for your hard work and your achievements in 2021. Caribou has the exciting and challenging opportunity to transform the field of medicine with our product candidates. Only through the continued collective efforts of the herd will we achieve our ambitious 2022 goals.

Nothing in this letter shall be construed as a guarantee of employment, your employment remains at-will, and the Company reserves the right to change your title, reporting structure, base salary, target bonus, or other benefits at any time. Thank you again for your contributions to the Company’s accomplishments in 2021. Please let Cindy know if you wish to contribute to your 401(k) account from your bonus payment.

I am excited about all we will accomplish together in 2022!