Nature of Business and Basis of Presentation	12 Months Ended
Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business and Basis of Presentation	(1) Nature of Business and Basis of Presentation Organization Cullinan Oncology, Inc., together with its consolidated subsidiaries ("Cullinan" or "the Company"), is a clinical-stage biopharmaceutical company focused on modality-agnostic targeted oncology. Cullinan’s predecessor company, Cullinan Pharmaceuticals, LLC was formed in September 2016 and was subsequently renamed Cullinan Oncology, LLC ("LLC") in November 2017. The LLC’s wholly-owned subsidiary, Cullinan Management, Inc. ("Management"), was formed in September 2016 and became the surviving entity in a reverse merger with the LLC in January 2021. In February 2021, Management changed its name to Cullinan Oncology, Inc. The Company completed the sale of its entire equity interest in its partially-owned subsidiary, Cullinan Pearl Corp. ("Cullinan Pearl"), to Taiho Pharmaceutical Co., Ltd (“Taiho”) in June 2022. Refer to Note 3 for additional details relating to the transaction. The sale of the Company's equity interest in Cullinan Pearl did not meet the criteria to be reported as a discontinued operation under the accounting principles generally accepted in the United States ("U.S. GAAP"). Therefore, prior period consolidated financial statements and disclosures have not been retroactively restated to reflect the impact of the sale of the Company’s equity interest in Cullinan Pearl. Reorganization, Reverse Stock Split and Initial Public Offering In January 2021, the Company completed its initial public offering ("IPO") in which it issued and sold 13,685,000 shares of its common stock, including 1,785,000 shares sold pursuant to the full exercise of the underwriters’ option to purchase additional shares, at a price to the public of $21.00 per share. The shares began trading on the Nasdaq Global Select Market on January 8, 2021 under the symbol “CGEM”. The net proceeds received by the Company from the offering were $264.5 million, after deducting underwriting discounts, commissions and other offering expenses. Immediately prior to the effectiveness of the Company’s registration statement, the Company completed its reorganization, whereby the LLC merged with and into Management and Management was the surviving entity (the "Reorganization"). Management was the registrant in the IPO. Liquidity The Company has incurred operating losses, with the exception of the one-time gain on the sale of Cullinan Pearl in 2022, and negative cash flows from operations since its inception and expects to continue to generate operating losses for the foreseeable future. The Company’s ultimate success depends on the outcome of its research and development activities as well as the ability to commercialize the Company’s product candidates. The Company is subject to a number of risks including, but not limited to, the need to obtain adequate additional funding for the ongoing and planned clinical development of its product candidates. Due to the numerous risks and uncertainties associated with pharmaceutical products and development, the Company is unable to accurately predict the timing or amount of funds required to complete development of its product candidates, and costs could exceed the Company’s expectations for a number of reasons, including reasons beyond the Company’s control. In June 2022, the Company completed the sale of the Company’s equity interest in its partially-owned subsidiary, Cullinan Pearl, to Taiho for an upfront payment of $275.0 million. Refer to Note 3 for additional details relating to the transaction. Since inception, the Company has funded its operations primarily through the sale of equity securities and from licensing or selling the rights to its product candidates. The Company expects that its cash, cash equivalents and short-term investments of $467.3 million and long-term investments and interest receivable of $82.8 million as of December 31, 2022, will be sufficient to fund its operating expenses and capital expenditure requirements through the next twelve months from the date of issuance of these consolidated financial statements.

Nature of Business and Basis of Presentation

12 Months Ended

Dec. 31, 2022

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Nature of Business and Basis of Presentation

(1)

Nature of Business and Basis of Presentation

Organization

Cullinan Oncology, Inc., together with its consolidated subsidiaries ("Cullinan" or "the Company"), is a clinical-stage biopharmaceutical company focused on modality-agnostic targeted oncology. Cullinan’s predecessor company, Cullinan Pharmaceuticals, LLC was formed in September 2016 and was subsequently renamed Cullinan Oncology, LLC ("LLC") in November 2017. The LLC’s wholly-owned subsidiary, Cullinan Management, Inc. ("Management"), was formed in September 2016 and became the surviving entity in a reverse merger with the LLC in January 2021. In February 2021, Management changed its name to Cullinan Oncology, Inc.

The Company completed the sale of its entire equity interest in its partially-owned subsidiary, Cullinan Pearl Corp. ("Cullinan Pearl"), to Taiho Pharmaceutical Co., Ltd (“Taiho”) in June 2022. Refer to Note 3 for additional details relating to the transaction. The sale of the Company's equity interest in Cullinan Pearl did not meet the criteria to be reported as a discontinued operation under the accounting principles generally accepted in the United States ("U.S. GAAP"). Therefore, prior period consolidated financial statements and disclosures have not been retroactively restated to reflect the impact of the sale of the Company’s equity interest in Cullinan Pearl.

Reorganization, Reverse Stock Split and Initial Public Offering

In January 2021, the Company completed its initial public offering ("IPO") in which it issued and sold 13,685,000 shares of its common stock, including 1,785,000 shares sold pursuant to the full exercise of the underwriters’ option to purchase additional shares, at a price to the public of $21.00 per share. The shares began trading on the Nasdaq Global Select Market on January 8, 2021 under the symbol “CGEM”. The net proceeds received by the Company from the offering were $264.5 million, after deducting underwriting discounts, commissions and other offering expenses.

Immediately prior to the effectiveness of the Company’s registration statement, the Company completed its reorganization, whereby the LLC merged with and into Management and Management was the surviving entity (the "Reorganization"). Management was the registrant in the IPO.

Liquidity

The Company has incurred operating losses, with the exception of the one-time gain on the sale of Cullinan Pearl in 2022, and negative cash flows from operations since its inception and expects to continue to generate operating losses for the foreseeable future. The Company’s ultimate success depends on the outcome of its research and development activities as well as the ability to commercialize the Company’s product candidates. The Company is subject to a number of risks including, but not limited to, the need to obtain adequate additional funding for the ongoing and planned clinical development of its product candidates. Due to the numerous risks and uncertainties associated with pharmaceutical products and development, the Company is unable to accurately predict the timing or amount of funds required to complete development of its product candidates, and costs could exceed the Company’s expectations for a number of reasons, including reasons beyond the Company’s control.

In June 2022, the Company completed the sale of the Company’s equity interest in its partially-owned subsidiary, Cullinan Pearl, to Taiho for an upfront payment of $275.0 million. Refer to Note 3 for additional details relating to the transaction.

Since inception, the Company has funded its operations primarily through the sale of equity securities and from licensing or selling the rights to its product candidates. The Company expects that its cash, cash equivalents and short-term investments of $467.3 million and long-term investments and interest receivable of $82.8 million as of December 31, 2022, will be sufficient to fund its operating expenses and capital expenditure requirements through the next twelve months from the date of issuance of these consolidated financial statements.