Common Stock and Noncontrolling Interest in Subsidiaries	12 Months Ended
Dec. 31, 2022
Common Stock And Noncontrolling Interest In Subsidiaries [Abstract]
Common Stock and Noncontrolling Interest in Subsidiaries	(8) Common Stock and Noncontrolling Interests in Subsidiaries Common Stock Each share of common stock entitles the holder to one vote and to receive dividends when and if declared by the board of directors of the Company. No dividends have been declared through December 31, 2022. Noncontrolling Interests in Subsidiaries Certain subsidiaries issue common stock in connection with licensing agreements and to employees, directors and consultants pursuant to subsidiary equity incentive plans. The holders of subsidiary common stock are entitled to one vote per share. The holders of subsidiary common stock are entitled to receive dividends when and if declared by the subsidiaries’ board of directors and distributions in either case only after the payment of all preferential amounts required to be paid to the holders of shares of preferred stock of the respective subsidiary. Cullinan Amber In June 2021, the Company purchased 3.0 million shares of Series A preferred stock from Cullinan Amber, and MIT received 0.2 million shares of common stock from Cullinan Amber pursuant to the MIT License Agreement. In June 2022, the Company purchased 6.0 million shares of Series A preferred stock from Cullinan Amber, and MIT received 0.3 million shares of common stock from Cullinan Amber pursuant to the MIT License Agreement. In November 2022, the Company purchased 10.0 million shares of Series A preferred stock from Cullinan Amber, MIT received 0.5 million shares of common stock from Cullinan Amber pursuant to the MIT License Agreement, and a scientific advisor received 0.2 million shares of common stock from Cullinan Amber pursuant to an equity-based compensation agreement. As of December 31, 2022, the Company held common shares and Series A preferred stock that represented 94% of Cullinan Amber's outstanding equity. As of December 31, 2022, noncontrolling interests collectively held common shares that represented 6% of Cullinan Amber's outstanding equity. In 2022 and 2021, $0.4 million and less than $0.1 million of losses, respectively, were attributed to the noncontrolling interests of Cullinan Amber. Cullinan Florentine In July 2021, the Company purchased 7.5 million shares of Series B preferred stock from Cullinan Florentine Corp.("Cullinan Florentine"). In July 2022, the Company purchased 3.75 million shares of Series B preferred stock from Cullinan Florentine. As of December 31, 2022, the Company held common shares, Series A preferred stock and Series B preferred stock that represented 96% of Cullinan Florentine's outstanding equity. As of December 31, 2022, noncontrolling interests collectively held common shares that represented 4% of Cullinan Florentine's outstanding equity. In each of 2022 and 2021, no losses were attributed to the noncontrolling interests of Cullinan Florentine. Cullinan MICA In June 2021, the Company purchased 5.4 million shares of Series A senior preferred stock from Cullinan MICA Corp. ("Cullinan MICA"), and certain other existing investors purchased 0.7 million shares of Series A senior preferred stock from Cullinan MICA for $0.9 million. In March 2022, the Company purchased 6.7 million shares of Series A senior preferred stock from Cullinan MICA, and certain other existing investors purchased 0.9 million shares of Series A senior preferred stock from Cullinan MICA for $1.2 million. In October 2022, the Company purchased 1.5 million shares of Cullinan MICA's Series A senior preferred stock, 2.0 million shares of Cullinan MICA's Series A junior preferred stock, and 11.5 million shares of Cullinan MICA's Series A-2 junior preferred stock from two of Cullinan MICA’s other stockholders for $30.7 million. In November 2022, the Company purchased 0.4 million shares of Cullinan MICA's common stock and 0.9 million of options for Cullinan MICA's common stock from five of Cullinan MICA’s other stockholders for $2.6 million. The Company also exercised its options to purchase 0.9 million shares of common stock from Cullinan MICA. As of December 31, 2022, the Company held 95% of the fully-diluted shares outstanding of Cullinan MICA, including 96% of its Series A preferred stock. As of December 31, 2022, noncontrolling interests collectively owned 5% of the fully-diluted shares outstanding of Cullinan MICA, including 4% of its Series A preferred stock. In 2022 and 2021, $1.2 million and $1.1 million of losses, respectively, were attributed to the noncontrolling interests of Cullinan MICA. Prior to being acquired by the Company, the Cullinan MICA board of directors authorized the grant of stock options to employees, directors of, consultants and other key persons to the entity. In October 2022, the Cullinan MICA board of directors authorized the acceleration of vesting for approximately 0.3 million stock options. The vesting acceleration was determined to be a cancellation of the prior award with a concurrent grant of a replacement award and was accounted for as a modification resulting in $0.6 million in incremental equity-based compensation expense. As of December 31, 2022, Cullinan MICA had approximately 0.2 million stock options held by noncontrolling interests that were outstanding and exercisable with a weighted-average exercise price of $0.22 per share. Cullinan Pearl In June 2022, the Company sold its equity interest in its partially-owned subsidiary, Cullinan Pearl, to Taiho. Refer to Note 3 for additional details relating to the transaction. Prior to the sale, the Company accounted for the noncontrolling interest using the HLBV method. In 2022 and 2021, $0.3 and $0.7 million of losses, respectively, were attributed to the noncontrolling interests of Cullinan Pearl.

Common Stock and Noncontrolling Interest in Subsidiaries

12 Months Ended

Dec. 31, 2022

Common Stock And Noncontrolling Interest In Subsidiaries [Abstract]

Common Stock and Noncontrolling Interest in Subsidiaries

(8)

Common Stock and Noncontrolling Interests in Subsidiaries

Common Stock

Each share of common stock entitles the holder to one vote and to receive dividends when and if declared by the board of directors of the Company. No dividends have been declared through December 31, 2022.

Noncontrolling Interests in Subsidiaries

Certain subsidiaries issue common stock in connection with licensing agreements and to employees, directors and consultants pursuant to subsidiary equity incentive plans. The holders of subsidiary common stock are entitled to one vote per share. The holders of subsidiary common stock are entitled to receive dividends when and if declared by the subsidiaries’ board of directors and distributions in either case only after the payment of all preferential amounts required to be paid to the holders of shares of preferred stock of the respective subsidiary.

Cullinan Amber

In June 2021, the Company purchased 3.0 million shares of Series A preferred stock from Cullinan Amber, and MIT received 0.2 million shares of common stock from Cullinan Amber pursuant to the MIT License Agreement.

In June 2022, the Company purchased 6.0 million shares of Series A preferred stock from Cullinan Amber, and MIT received 0.3 million shares of common stock from Cullinan Amber pursuant to the MIT License Agreement.

In November 2022, the Company purchased 10.0 million shares of Series A preferred stock from Cullinan Amber, MIT received 0.5 million shares of common stock from Cullinan Amber pursuant to the MIT License Agreement, and a scientific advisor received 0.2 million shares of common stock from Cullinan Amber pursuant to an equity-based compensation agreement.

As of December 31, 2022, the Company held common shares and Series A preferred stock that represented 94% of Cullinan Amber's outstanding equity. As of December 31, 2022, noncontrolling interests collectively held common shares that represented 6% of Cullinan Amber's outstanding equity.

In 2022 and 2021, $0.4 million and less than $0.1 million of losses, respectively, were attributed to the noncontrolling interests of Cullinan Amber.

Cullinan Florentine

In July 2021, the Company purchased 7.5 million shares of Series B preferred stock from Cullinan Florentine Corp.("Cullinan Florentine").

In July 2022, the Company purchased 3.75 million shares of Series B preferred stock from Cullinan Florentine.

As of December 31, 2022, the Company held common shares, Series A preferred stock and Series B preferred stock that represented 96% of Cullinan Florentine's outstanding equity. As of December 31, 2022, noncontrolling interests collectively held common shares that represented 4% of Cullinan Florentine's outstanding equity.

In each of 2022 and 2021, no losses were attributed to the noncontrolling interests of Cullinan Florentine.

Cullinan MICA

In June 2021, the Company purchased 5.4 million shares of Series A senior preferred stock from Cullinan MICA Corp. ("Cullinan MICA"), and certain other existing investors purchased 0.7 million shares of Series A senior preferred stock from Cullinan MICA for $0.9 million.

In March 2022, the Company purchased 6.7 million shares of Series A senior preferred stock from Cullinan MICA, and certain other existing investors purchased 0.9 million shares of Series A senior preferred stock from Cullinan MICA for $1.2 million.

In October 2022, the Company purchased 1.5 million shares of Cullinan MICA's Series A senior preferred stock, 2.0 million shares of Cullinan MICA's Series A junior preferred stock, and 11.5 million shares of Cullinan MICA's Series A-2 junior preferred stock from two of Cullinan MICA’s other stockholders for $30.7 million.

In November 2022, the Company purchased 0.4 million shares of Cullinan MICA's common stock and 0.9 million of options for Cullinan MICA's common stock from five of Cullinan MICA’s other stockholders for $2.6 million. The Company also exercised its options to purchase 0.9 million shares of common stock from Cullinan MICA.

As of December 31, 2022, the Company held 95% of the fully-diluted shares outstanding of Cullinan MICA, including 96% of its Series A preferred stock. As of December 31, 2022, noncontrolling interests collectively owned 5% of the fully-diluted shares outstanding of Cullinan MICA, including 4% of its Series A preferred stock.

In 2022 and 2021, $1.2 million and $1.1 million of losses, respectively, were attributed to the noncontrolling interests of Cullinan MICA.

Prior to being acquired by the Company, the Cullinan MICA board of directors authorized the grant of stock options to employees, directors of, consultants and other key persons to the entity. In October 2022, the Cullinan MICA board of directors authorized the acceleration of vesting for approximately 0.3 million stock options. The vesting acceleration was determined to be a cancellation of the prior award with a concurrent grant of a replacement award and was accounted for as a modification resulting in $0.6 million in incremental equity-based compensation expense. As of December 31, 2022, Cullinan MICA had approximately 0.2 million stock options held by noncontrolling interests that were outstanding and exercisable with a weighted-average exercise price of $0.22 per share.

Cullinan Pearl

In June 2022, the Company sold its equity interest in its partially-owned subsidiary, Cullinan Pearl, to Taiho. Refer to Note 3 for additional details relating to the transaction.

Prior to the sale, the Company accounted for the noncontrolling interest using the HLBV method. In 2022 and 2021, $0.3 and $0.7 million of losses, respectively, were attributed to the noncontrolling interests of Cullinan Pearl.