United States

Securities and Exchange Commission

Washington, D.C. 20549

SCHEDULE 13D

(Rule 13d-101)

Information to be Included in Statements Filed Pursuant to § 240.13d-1(a) and

Amendments Thereto Filed Pursuant to § 240.13d-2(a)

Under the Securities Exchange Act of 1934

(Amendment No. 6)*

Eidos Therapeutics, Inc.

(Name of Issuer)

Common Stock, par value $0.001

(Title of Class of Securities)

28249H104

(CUSIP Number)

Brian Stephenson

BridgeBio Pharma, Inc.

421 Kipling Street,

Palo Alto, CA 94301

(650) 391-9740

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

August 8, 2019

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of Rule 13d-1(e), Rule 13d-1(f) or Rule 13d-1(g), check the following box.  ☐

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Rule 13d-7(b) for other parties to whom copies are to be sent.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

EXPLANATORY NOTE

This Amendment No. 6 amends the Schedule 13D, filed with the U.S. Securities and Exchange Commission by BridgeBio Pharma, Inc. (the “Reporting Person”) and its predecessor and now wholly-owned subsidiary, BridgeBio Pharma LLC, relating to the Common Stock, par value $0.001 per share (the “Common Stock”), of Eidos Therapeutics, Inc., a Delaware corporation (the “Issuer”), whose principal executive offices are located at 101 Montgomery Street, Suite 2550, San Francisco, California 94104. Except as specifically set forth herein, the Schedule 13D remains unmodified.

Item 3. Source and Amount of Funds or Other Consideration.

Item 3 of the Schedule 13D is supplemented by the addition of the following:

The information set forth in Item 4 of this Amendment No. 6 is incorporated herein by reference.

Item 4. Purpose of Transaction.

On August 8, 2019, the Reporting Person delivered to the board of directors of the Issuer (the “Board”) a letter setting forth a non-binding proposal to acquire all of the outstanding shares of Common Stock of the Issuer that are not owned by the Reporting Person and its subsidiaries for a fixed exchange ratio of 1.30 shares of the Reporting Person for each share of the Issuer (the “Proposal”). A copy of the Proposal is filed herewith as Exhibit 3, and the information set forth in the Proposal is incorporated by reference herein.

The Reporting Person indicated in the Proposal that it expects that a special committee of independent directors appointed by the Board and advised by independent legal and financial advisors (the “Special Committee”) will consider the Proposal and make a recommendation to the Board. The Reporting Person also stated in the Proposal that it will not proceed with the transaction contemplated by the Proposal unless the proposed transaction is approved by the Special Committee and that the proposed transaction will be subject to a non-waivable condition requiring approval by the holders of a majority of the aggregate voting power represented by shares of Common Stock that are not owned by the Reporting Person.

The Proposal may result in one or more of the transactions, events or actions specified in clauses (a) through (j) of Item 4 of Schedule 13D, including, without limitation, an acquisition of additional securities of the Issuer, an extraordinary corporate transaction (such as a merger) involving the Issuer, delisting of the Common Stock from the Nasdaq Global Select Market and other material changes in the Issuer’s business or corporate structure.

No assurances can be given that the transaction contemplated by the Proposal or any other potential transaction involving the Reporting Person and the Issuer will be consummated, or if a transaction is undertaken, as to its terms or timing. The Reporting Person reserves the right to modify or withdraw the Proposal at any time. The Reporting Person reserves the right to formulate other plans or make other proposals which could result in one or more of the transactions, events or actions specified in clauses (a) through (j) of Item 4 of Schedule 13D, and to modify or withdraw any such plan or proposal at any time.

Item 5. Interest in Securities of the Issuer.

Item 5 of the Schedule 13D is amended by restating the items disclosed under (a) – (b) thereof as follows:

BridgeBio Pharma, LLC, a wholly-owned subsidiary of the Reporting Person, is the record holder of 24,575,501 shares of Common Stock. The following sets forth, as of the date of this Schedule 13D, the aggregate number of shares of Common Stock and percentage of Common Stock beneficially owned by the Reporting Person, as well as the number of shares of Common Stock as to which the Reporting Person has the sole power to vote or to direct the vote, shared power to vote or to direct the vote, sole power to dispose or to direct the disposition, or shared power to dispose or to direct the disposition of, as of the date hereof, based on 36,884,175 shares of Common Stock outstanding as of July 30, 2019.

Item 7. Material to be Filed as Exhibits.

Item 7 is amended and supplemented by adding the following at the end thereof:

SIGNATURES

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Date: August 8, 2019

Exhibit 3

August 8, 2019

Board of Directors

Eidos Therapeutics, Inc.

101 Montgomery Street, Suite 2550

San Francisco CA, 94104

Dear Members of the Board of Directors:

BridgeBio Pharma Inc. (“BridgeBio” or “Parent”) is pleased to submit this non-binding proposal to acquire all of the outstanding shares of stock of Eidos Therapeutics, Inc. (the “Company” or “Eidos”) that are not owned by BridgeBio for a fixed exchange ratio of 1.30 BridgeBio shares for each share of Eidos.

We believe that our Proposal represents an extremely attractive value to the Company’s public stockholders. Based on the closing price of BridgeBio shares as of 8/7/2019, the Proposal values each Eidos share at $38.31, which is a 20.9% premium to the closing price of Eidos shares as of 8/7/2019. According to 34 recent precedent minority buy-in deals, the median purchase premium is ~15% for all stock deals (data from Dealogic, public filings, Factset, and Bloomberg). This offer is attractive based both on intrinsic value and comparable considerations.

As stockholders of BridgeBio, the Company’s stockholders would have the opportunity to benefit from and participate in continued upside in Eidos while diversifying their investment through exposure to the broad portfolio of assets being developed by BridgeBio. This may be important to current investors, especially given the dearth of M&A in the cardiovascular area thereby limiting opportunities for liquidity and diversification.

Our Proposal should not be construed as indicating an interest in participating in any alternative change of control transaction involving the Company. BridgeBio, in its capacity as a stockholder of the Company, has no interest in selling control of the Company.

Our Proposal is subject to the approval of the Company’s Board of Directors and the negotiation and execution of mutually acceptable definitive transaction documentation. It is our expectation that a special committee of independent directors appointed by the Company’s Board of Directors will consider our Proposal and make a recommendation to the Company’s Board of Directors. We will not move forward with the Proposal unless it is approved by such a special committee, as advised by independent legal and financial advisors. In addition, our Proposal will be subject to a non-waivable condition requiring the approval of a majority of the aggregate voting power represented by the shares of common stock that are not owned by BridgeBio.    

This Proposal is a non-binding expression of interest only and does not constitute an offer subject to binding acceptance, and we reserve the right to withdraw or modify our Proposal at any time.

421 Kipling Street, Palo Alto, CA 94301 650.391.9969

No legal obligation with respect to the Proposal or any other transaction shall arise unless and until we have executed definitive transaction documentation between us and the Company.

We are available at your convenience to discuss any aspects of our Proposal.

Sincerely,

Brian Stephenson

CFO, BridgeBio Pharma, Inc.

421 Kipling Street, Palo Alto, CA 94301 650.391.9969