Organization and Nature of Operations	3 Months Ended
Mar. 31, 2022
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Nature of Operations	Note 1 – Organization and Nature of Operations Description of Business Rain Therapeutics Inc. (“Rain” or the “Company”) was incorporated in the state of Delaware in April 2017. Rain is a late-stage precision oncology company developing therapies that target oncogenic drivers for which the Company is able to genetically select patients the Company believes will be most likely to benefit. This approach includes using a tumor-agnostic strategy to select patients based on their tumors’ underlying genetics rather than histology. Rain’s lead product candidate, milademetan, is a small molecule, oral inhibitor of mouse double minute 2, which may be oncogenic in numerous cancers. In addition to milademetan, the Company is also developing a preclinical program that is focused on inducing synthetic lethality in cancer cells by inhibiting RAD52. The Company operates in one business segment and its principal operations are in the United States, with its headquarters in Newark, California. Reverse Stock Split On April 15, 2021 and April 16, 2021, the Company’s board of directors (the “Board of Directors”) and stockholders, respectively, approved an amended and restated certificate of incorporation of the Company to effect a 1-for-1.0799 reverse stock split of the Company’s common stock. The reverse stock split was effected on April 16, 2021. The Company’s outstanding stock options were also adjusted to reflect the 1-for-1.0799 reverse stock split of the Company’s common stock. Accordingly, all common stock and stock options and related per share amounts in these financial statements have been retroactively adjusted for all periods presented to give effect to the reverse stock split. Outstanding stock options were proportionately reduced and the respective exercise prices, if applicable, were proportionately increased. The reverse stock split resulted in an adjustment to the Series A and Series B convertible preferred stock conversion prices to reflect a proportional decrease in the number of shares of common stock to be issued upon conversion. Initial Public Offering On April 27, 2021, the Company completed its initial public offering (“IPO”) in which the Company issued and sold 7,352,941 shares of common stock at a public offering price of $17.00 per share. On May 11, 2021, the Company issued an additional 492,070 shares of common stock in connection with the exercise of the underwriters’ option to purchase additional shares at the public offering price. The Company’s net proceeds from the sale of shares in the IPO, including the sale of shares pursuant to the exercise of the underwriters’ option to purchase additional shares, was $121.5 million, net of underwriting discounts and commissions, and other offering fees. Immediately prior to the closing of the IPO, 8,344,905 shares of the Company’s convertible preferred stock were exchanged for 7,727,470 shares of non-voting common stock. Upon the closing of the IPO, 7,928,501 shares of the Company’s convertible preferred stock were automatically converted into 7,341,860 shares of common stock. Following the IPO, there were no shares of convertible preferred stock outstanding. Basis of Presentation The accompanying interim unaudited condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) related to a quarterly report on Form 10-Q. Any reference in these notes to applicable guidance is meant to refer to GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) promulgated by the Financial Accounting Standards Board (“FASB”). The year-end balance sheet data was derived from the Company’s audited financial statements but does not include all disclosures required by GAAP. These condensed financial statements should be read in conjunction with the Company’s audited financial statements for the year ended December 31, 2021 included in the Company’s Annual Report on Form 10-K, filed pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended (the Exchange Act). The unaudited financial information for the interim periods presented herein reflects all adjustments which, in the opinion of management, are necessary for a fair presentation of the financial condition and results of operation for the periods presented, with such adjustments consisting only of normal recurring adjustments. Liquidity and Capital Resources The Company has devoted substantially all of its efforts to drug discovery and development, raising capital and building operations. The Company has a limited operating history and has not generated any revenue since its inception, and the sales and income potential of the Company’s business is unproven. The Company has incurred net losses and negative cash flows from operating activities since its inception and expects to continue to incur net losses into the foreseeable future as it continues the development of its product candidates. From inception through March 31, 2022, the Company has funded its operations through net proceeds from its IPO in April 2021, and the issuance of convertible promissory notes and convertible preferred stock. The accompanying condensed financial statements have been prepared assuming the Company will continue as a going concern. Management believes that the Company’s current cash, cash equivalents and short-term investments will provide sufficient funds to enable the Company to meet its obligations for at least twelve months from the filing date of this report.

Organization and Nature of Operations

3 Months Ended

Mar. 31, 2022

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Note 1 – Organization and Nature of Operations

Description of Business

Rain Therapeutics Inc. (“Rain” or the “Company”) was incorporated in the state of Delaware in April 2017. Rain is a late-stage precision oncology company developing therapies that target oncogenic drivers for which the Company is able to genetically select patients the Company believes will be most likely to benefit. This approach includes using a tumor-agnostic strategy to select patients based on their tumors’ underlying genetics rather than histology. Rain’s lead product candidate, milademetan, is a small molecule, oral inhibitor of mouse double minute 2, which may be oncogenic in numerous cancers. In addition to milademetan, the Company is also developing a preclinical program that is focused on inducing synthetic lethality in cancer cells by inhibiting RAD52. The Company operates in one business segment and its principal operations are in the United States, with its headquarters in Newark, California.

Reverse Stock Split

On April 15, 2021 and April 16, 2021, the Company’s board of directors (the “Board of Directors”) and stockholders, respectively, approved an amended and restated certificate of incorporation of the Company to effect a 1-for-1.0799 reverse stock split of the Company’s common stock. The reverse stock split was effected on April 16, 2021. The Company’s outstanding stock options were also adjusted to reflect the 1-for-1.0799 reverse stock split of the Company’s common stock. Accordingly, all common stock and stock options and related per share amounts in these financial statements have been retroactively adjusted for all periods presented to give effect to the reverse stock split. Outstanding stock options were proportionately reduced and the respective exercise prices, if applicable, were proportionately increased. The reverse stock split resulted in an adjustment to the Series A and Series B convertible preferred stock conversion prices to reflect a proportional decrease in the number of shares of common stock to be issued upon conversion.

Initial Public Offering

On April 27, 2021, the Company completed its initial public offering (“IPO”) in which the Company issued and sold 7,352,941 shares of common stock at a public offering price of $17.00 per share. On May 11, 2021, the Company issued an additional 492,070 shares of common stock in connection with the exercise of the underwriters’ option to purchase additional shares at the public offering price. The Company’s net proceeds from the sale of shares in the IPO, including the sale of shares pursuant to the exercise of the underwriters’ option to purchase additional shares, was $121.5 million, net of underwriting discounts and commissions, and other offering fees.

Immediately prior to the closing of the IPO, 8,344,905 shares of the Company’s convertible preferred stock were exchanged for 7,727,470 shares of non-voting common stock. Upon the closing of the IPO, 7,928,501 shares of the Company’s convertible preferred stock were automatically converted into 7,341,860 shares of common stock. Following the IPO, there were no shares of convertible preferred stock outstanding.

Basis of Presentation

The accompanying interim unaudited condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) related to a quarterly report on Form 10-Q. Any reference in these notes to applicable guidance is meant to refer to GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) promulgated by the Financial Accounting Standards Board (“FASB”). The year-end balance sheet data was derived from the Company’s audited financial statements but does not include all disclosures required by GAAP. These condensed financial statements should be read in conjunction with the Company’s audited financial statements for the year ended December 31, 2021 included in the Company’s Annual Report on Form 10-K, filed pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended (the Exchange Act). The unaudited financial information for the interim periods presented herein reflects all adjustments which, in the opinion of management, are necessary for a fair presentation of the financial condition and results of operation for the periods presented, with such adjustments consisting only of normal recurring adjustments.

Liquidity and Capital Resources

The Company has devoted substantially all of its efforts to drug discovery and development, raising capital and building operations. The Company has a limited operating history and has not generated any revenue since its inception,

and the sales and income potential of the Company’s business is unproven. The Company has incurred net losses and negative cash flows from operating activities since its inception and expects to continue to incur net losses into the foreseeable future as it continues the development of its product candidates. From inception through March 31, 2022, the Company has funded its operations through net proceeds from its IPO in April 2021, and the issuance of convertible promissory notes and convertible preferred stock.

The accompanying condensed financial statements have been prepared assuming the Company will continue as a going concern. Management believes that the Company’s current cash, cash equivalents and short-term investments will provide sufficient funds to enable the Company to meet its obligations for at least twelve months from the filing date of this report.