Organization and Description of Business	6 Months Ended
Jun. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Description of Business	Note 1. Organization and description of business Eidos Therapeutics, Inc., or the Company, was incorporated as an S corporation in the state of Delaware on August 6, 2013. The Company is advancing a drug candidate, acoramidis (formerly AG10) to treat transthyretin, or TTR, amyloidosis, or ATTR, which leads to organ damage, loss of organ function and eventual death from abnormal buildup of protein deposits predominantly in the heart and peripheral nervous system. acoramidis is an orally-administered small molecule designed to potently stabilize tetrameric TTR, thereby halting at its outset the series of molecular events that give rise to ATTR. The Company has been primarily engaged in business planning, research and development, recruiting personnel, and raising capital. The Company is headquartered in San Francisco, California and it operates as one operating segment. The Company is currently enrolling patients in a Phase 3 clinical trial of acoramidis in patients with ATTR cardiomyopathy and planning a second Phase 3 clinical trial in patients with ATTR polyneuropathy. Due to the global outbreak of SARS-CoV-2, the novel strain of coronavirus that causes Coronavirus disease 19 (COVID-19), the Company has experienced impacts on its clinical trials, including delays in clinical site activations and enrollment of patients. The Company continues to actively monitor the situation and may take further precautionary and preemptive actions as may be required by federal, state or local authorities or that the Company determines are in the best interests of public health and safety and that of its patient community, employees, partners, suppliers and stockholders. Depending on the full impact and prevalence of COVID-19 over time, the Company currently expects enrollment of the Phase 3 clinical trial in ATTR-CM to be completed in the first half of 2021 and initiation of the Phase 3 clinical trial in ATTR-PN to occur in the second half of 2020. Liquidity The Company has incurred net losses from operations since inception and has an accumulated deficit of $154.8 million as of June 30, 2020. The Company’s ultimate success depends on the outcome of its research and development activities. The Company expects to incur additional losses in the future and it anticipates the need to raise additional capital to fully implement its business plan. Through June 30, 2020, the Company has financed its operations through private placements of redeemable convertible preferred stock, convertible promissory notes, an initial public offering (IPO) of common stock, at-the-market offerings of common stock and a licensing agreement with a third-party. On August 2, 2019, the Company filed a Registration Statement on Form S-3, as amended (the “2019 Shelf”) with the SEC in relation to the registration of common stock, preferred stock, debt securities, warrants and units of any combination thereof. The Company also simultaneously entered into an Open Market Sale Agreement (the “2019 Sales Agreement”) with Jefferies LLC and SVB Leerink LLC (each a “Sales Agent” and together, the “Sales Agents”), to provide for the offering, issuance and sale by the Company of up to an aggregate offering price of $100.0 million of its common stock from time to time in “at-the-market” offerings under the 2019 Shelf and subject to the limitations thereof. The Company will pay to the Sales Agent cash commissions of up to 3.0 percent of the gross proceeds of sales of common stock under the 2019 Sales Agreement. The Company issued 834,368 shares of common stock and received $48.1 million in net proceeds under the 2019 Sales Agreement through June 30, 2020. Based on current business plans and assuming no additional financing, the Company believes that its existing cash and cash equivalents will be sufficient to fund its cash requirements through at least the next twelve months from the date of these financial statements. The Company will need to obtain additional financing in the future and may seek financing through the issuance of its common stock, through other equity or debt financings or through collaborations or partnerships with other companies. The amount and timing of the Company’s future funding requirements will depend on many factors, including the pace and results of the Company’s clinical development efforts for acoramidis and other research and development activities. In addition, the Company is closely monitoring ongoing developments in connection with the COVID-19 pandemic, which may negatively impact its financial and operating results. The Company will continue to assess its operating expenses and cash and cash equivalents and, if circumstances warrant, the Company will make appropriate adjustments to its operating plan. The Company may not be able to raise additional capital on terms acceptable to the Company, or at all, and any failure to raise capital as and when needed would compromise the Company’s ability to execute on our business plan and the Company may have to significantly delay, scale back, or discontinue the development of acoramidis or curtail any efforts to expand the Company’s product pipeline.

Organization and Description of Business

6 Months Ended

Jun. 30, 2020

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Organization and Description of Business

Note 1. Organization and description of business

Eidos Therapeutics, Inc., or the Company, was incorporated as an S corporation in the state of Delaware on August 6, 2013. The Company is advancing a drug candidate, acoramidis (formerly AG10) to treat transthyretin, or TTR, amyloidosis, or ATTR, which leads to organ damage, loss of organ function and eventual death from abnormal buildup of protein deposits predominantly in the heart and peripheral nervous system. acoramidis is an orally-administered small molecule designed to potently stabilize tetrameric TTR, thereby halting at its outset the series of molecular events that give rise to ATTR. The Company has been primarily engaged in business planning, research and development, recruiting personnel, and raising capital. The Company is headquartered in San Francisco, California and it operates as one operating segment.

The Company is currently enrolling patients in a Phase 3 clinical trial of acoramidis in patients with ATTR cardiomyopathy and planning a second Phase 3 clinical trial in patients with ATTR polyneuropathy. Due to the global outbreak of SARS-CoV-2, the novel strain of coronavirus that causes Coronavirus disease 19 (COVID-19), the Company has experienced impacts on its clinical trials, including delays in clinical site activations and enrollment of patients. The Company continues to actively monitor the situation and may take further precautionary and preemptive actions as may be required by federal, state or local authorities or that the Company determines are in the best interests of public health and safety and that of its patient community, employees, partners, suppliers and stockholders. Depending on the full impact and prevalence of COVID-19 over time, the Company currently expects enrollment of the Phase 3 clinical trial in ATTR-CM to be completed in the first half of 2021 and initiation of the Phase 3 clinical trial in ATTR-PN to occur in the second half of 2020.

Liquidity

The Company has incurred net losses from operations since inception and has an accumulated deficit of $154.8 million as of June 30, 2020. The Company’s ultimate success depends on the outcome of its research and development activities. The Company expects to incur additional losses in the future and it anticipates the need to raise additional capital to fully implement its business plan. Through June 30, 2020, the Company has financed its operations through private placements of redeemable convertible preferred stock, convertible promissory notes, an initial public offering (IPO) of common stock, at-the-market offerings of common stock and a licensing agreement with a third-party.

On August 2, 2019, the Company filed a Registration Statement on Form S-3, as amended (the “2019 Shelf”) with the SEC in relation to the registration of common stock, preferred stock, debt securities, warrants and units of any combination thereof. The Company also simultaneously entered into an Open Market Sale Agreement (the “2019 Sales Agreement”) with Jefferies LLC and SVB Leerink LLC (each a “Sales Agent” and together, the “Sales Agents”), to provide for the offering, issuance and sale by the Company of up to an aggregate offering price of $100.0 million of its common stock from time to time in “at-the-market” offerings under the 2019 Shelf and subject to the limitations thereof. The Company will pay to the Sales Agent cash commissions of up to 3.0 percent of the gross proceeds of sales of common stock under the 2019 Sales Agreement. The Company issued 834,368 shares of common stock and received $48.1 million in net proceeds under the 2019 Sales Agreement through June 30, 2020.

Based on current business plans and assuming no additional financing, the Company believes that its existing cash and cash equivalents will be sufficient to fund its cash requirements through at least the next twelve months from the date of these financial statements. The Company will need to obtain additional financing in the future and may seek financing through the issuance of its common stock, through other equity or debt financings or through collaborations or partnerships with other companies. The amount and timing of the Company’s future funding requirements will depend on many factors, including the pace and results of the Company’s clinical development efforts for acoramidis and other research and development activities. In addition, the Company is closely monitoring ongoing developments in connection with the COVID-19 pandemic, which may negatively impact its financial and operating results. The Company will continue to assess its operating expenses and cash and cash equivalents and, if circumstances warrant, the Company will make appropriate adjustments to its operating plan. The Company may not be able to raise additional capital on terms acceptable to the Company, or at all, and any failure to raise capital as and when needed would compromise the Company’s ability to execute on our business plan and the Company may have to significantly delay, scale back, or discontinue the development of acoramidis or curtail any efforts to expand the Company’s product pipeline.