RGLS Regulus Therapeutics Inc

(1) Includes 1,285,424 shares of Common Stock (defined in Item 2(d)) issuable upon the exercise of A-1 Warrants (defined in Item 4).

Includes 3,126,710 shares of Common Stock issuable upon the exercise of A-2 Warrants (defined in Item 4).

Includes 762,383 shares of Common Stock issuable upon the exercise of A-3 Warrants (defined in Item 4). Excludes 600,367 shares of Common Stock issuable upon the exercise of A-3 Warrants as a result of the A-3 Warrants Blocker (defined in Item 4).

(1) Includes 1,285,424 shares of Common Stock issuable upon the exercise of A-1 Warrants.

Includes 3,126,710 shares of Common Stock issuable upon the exercise of A-2 Warrants.

Includes 762,383 shares of Common Stock issuable upon the exercise of A-3 Warrants and excludes 600,367 shares issuable upon the exercise of A-3 Warrants as a result of the A-3 Warrants Blocker.

(1) Includes 1,083,457 shares of Common Stock issuable upon the exercise of A-1 Warrants.

Includes 2,635,450 shares of Common Stock issuable upon the exercise of A-2 Warrants.

Excludes 957,489 shares of Common Stock issuable upon the exercise of A-3 Warrants as a result of the A-3 Warrants Blocker.

(1) Includes 1,083,457 shares of Common Stock issuable upon the exercise of A-1 Warrants.

Includes 2,635,450 shares of Common Stock issuable upon the exercise of A-2 Warrants.

Excludes 957,489 shares of Common Stock issuable upon the exercise of A-3 Warrants as a result of the A-3 Warrants Blocker.

(1) Includes 178,494 shares of Common Stock issuable upon the exercise of A-1 Warrants.

Includes 434,190 shares of Common Stock issuable upon the exercise of A-2 Warrants.

Excludes 152,442 shares of Common Stock issuable upon the exercise of A-3 Warrants as a result of the A-3 Warrants Blocker.

(1) Includes 178,494 shares of Common Stock issuable upon the exercise of A-1 Warrants.

Includes 434,190 shares of Common Stock issuable upon the exercise of A-2 Warrants.

Excludes 152,442 shares of Common Stock issuable upon the exercise of A-3 Warrants as a result of the A-3 Warrants Blocker.

(1) Includes 2,368,881 shares of Common Stock issuable upon the exercise of A-1 Warrants.

Includes 5,762,160 shares of Common Stock issuable upon the exercise of A-2 Warrants.

Includes 762,383 shares of Common Stock issuable upon the exercise of A-3 Warrants and excludes 1,557,856 shares of Common Stock issuable upon the exercise of A-3 Warrants as a result of the A-3 Warrants Blocker.

(1) Includes 2,592,572 shares of Common Stock issuable upon the exercise of A-1 Warrants.

Includes 6,306,280 shares of Common Stock issuable upon the exercise of A-2 Warrants.

Includes 762,383 shares of Common Stock issuable upon the exercise of A-3 Warrants and excludes 1,769,772 shares of Common Stock issuable upon the exercise of A-3 Warrants as a result of the A-3 Warrants Blocker.

(1) Includes 2,592,572 shares of Common Stock issuable upon the exercise of A-1 Warrants.

Includes 6,306,280 shares of Common Stock issuable upon the exercise of A-2 Warrants.

Includes 762,383 shares of Common Stock issuable upon the exercise of A-3 Warrants and excludes 1,769,772 shares of Common Stock issuable upon the exercise of A-3 Warrants as a result of the A-3 Warrants Blocker.

(1) Includes 2,592,572 shares of Common Stock issuable upon the exercise of A-1 Warrants.

Includes 6,306,280 shares of Common Stock issuable upon the exercise of A-2 Warrants.

Includes 762,383 shares of Common Stock issuable upon the exercise of A-3 Warrants and excludes 1,769,772 shares of Common Stock issuable upon the exercise of A-3 Warrants as a result of the A-3 Warrants Blocker.

Regulus Therapeutics Inc., a Delaware corporation (the “Issuer”).

4224 Campus Point Court, Suite 210

San Diego, California 92121

Biotechnology Value Fund, L.P. (“BVF”)

44 Montgomery St., 40th Floor

San Francisco, California 94104

Citizenship: Delaware

BVF I GP LLC (“BVF GP”)

44 Montgomery St., 40th Floor

San Francisco, California 94104

Citizenship: Delaware

Biotechnology Value Fund II, L.P. (“BVF2”)

44 Montgomery St., 40th Floor

San Francisco, California 94104

Citizenship: Delaware

BVF II GP LLC (“BVF2 GP”)

44 Montgomery St., 40th Floor

San Francisco, California 94104

Citizenship: Delaware

Biotechnology Value Trading Fund OS LP (“Trading Fund OS”)

PO Box 309 Ugland House

Grand Cayman, KY1-1104

Cayman Islands

Citizenship: Cayman Islands

BVF Partners OS Ltd. (“Partners OS”)

PO Box 309 Ugland House

Grand Cayman, KY1-1104

Cayman Islands

Citizenship: Cayman Islands

BVF GP Holdings LLC (“BVF GPH”)

44 Montgomery St., 40th Floor

San Francisco, California 94104

Citizenship: Delaware

BVF Partners L.P. (“Partners”)

44 Montgomery St., 40th Floor

San Francisco, California 94104

Citizenship: Delaware

BVF Inc.

44 Montgomery St., 40th Floor

San Francisco, California 94104

Citizenship: Delaware

Mark N. Lampert (“Mr. Lampert”)

44 Montgomery St., 40th Floor

San Francisco, California 94104

Citizenship: United States

Each of the foregoing is referred to as a “Reporting Person” and collectively as the “Reporting Persons.”

Common Stock, par value $0.001 per share (the “Common Stock”)

75915K200

The Reporting Persons hold 2,592,572 A-1 Warrants (the “A-1 Warrants”) exercisable for an aggregate of 2,592,572 shares of Common Stock. The A-1 Warrants are exercisable for a period of five years following the date of issuance and have an exercise price of $1.08 per share. The A-1 Warrants may not be exercised if, after such exercise, the Reporting Persons would beneficially own, as determined in accordance with Section 13(d) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), more than 9.99% of the number of shares of Common Stock then issued and outstanding (the “A-1 Warrants Blocker”). As of the close of business on December 31, 2021, the A-1 Warrants Blocker limits the aggregate exercise of A-1 Warrants by the Reporting Persons to 2,592,572 out of the 2,592,572 shares of Common Stock underlying the A-1 Warrants owned by the Reporting Persons in the aggregate. In providing beneficial ownership described herein, the Reporting Persons have assumed that all A-1 Warrants owned by each of BVF, BVF2 and Trading Fund OS and held in a certain Partners managed account (the “Partners Managed Account”) would be exercised.

The Reporting Persons hold 6,306,280 A-2 Warrants (the “A-2 Warrants”) exercisable for an aggregate of 6,306,280 shares of Common Stock. The A-2 Warrants are exercisable for a period of five years following the date of issuance and have an exercise price of $6.66 per share. The A-2 Warrants may not be exercised if, after such exercise, the Reporting Persons would beneficially own, as determined in accordance with Section 13(d) of the Exchange Act, more than 9.99% of the number of shares of Common Stock then issued and outstanding (the “A-2 Warrants Blocker”). As of the close of business on December 31, 2021, the A-2 Warrants Blocker limits the aggregate exercise of A-2 Warrants by the Reporting Persons to 6,306,280 out of the 6,306,280 shares of Common Stock underlying the A-2 Warrants owned by the Reporting Persons in the aggregate. In providing beneficial ownership described herein, the Reporting Persons have assumed that all A-2 Warrants owned by each of BVF, BVF2 and Trading Fund OS and held in the Partners Managed Account would be exercised.

The Reporting Persons hold 2,532,155 A-3 Warrants (the “A-3 Warrants”) exercisable for an aggregate of 2,532,155 shares of Common Stock. The A-3 Warrants are exercisable for a period of five years following the date of issuance and have an exercise price of $0.7464 per share. The A-3 Warrants may not be exercised if, after such exercise, the Reporting Persons would beneficially own, as determined in accordance with Section 13(d) of the Exchange Act, more than 9.99% of the number of shares of Common Stock then issued and outstanding (the “A-3 Warrants Blocker”). As of the close of business on December 31, 2021, the A-3 Warrants Blocker limits the aggregate exercise of A-3 Warrants by the Reporting Persons to 762,383 out of the 2,532,155 shares of Common Stock underlying the A-3 Warrants owned by the Reporting Persons in the aggregate. In providing beneficial ownership described herein, the Reporting Persons have assumed that the A-3 Warrants held by BVF to acquire 762,383 shares of Common Stock would be exercised, which would bring the Reporting Persons to the aggregate 9.99% limitation, and the remaining A-3 Warrants exercisable into 600,367 shares of Common Stock owned by BVF, A-3 Warrants exercisable into 957,489 shares of Common Stock owned by BVF2, A-3 Warrants exercisable into 152,442 shares of Common Stock owned by Trading Fund OS and the A-3 Warrants exercisable into 59,474 shares of Common Stock held in the Partners Managed Account, would not be exercised due to the A-3 Warrants Blocker.

As of the close of business on December 31, 2021, (i) BVF beneficially owned 5,174,517 shares of Common Stock, including 1,285,424 shares of Common Stock issuable upon the exercise of the A-1 Warrants held by it, 3,126,710 shares of Common Stock issuable upon the exercise of the A-2 Warrants held by it and 762,383 shares of Common Stock issuable upon the exercise of the A-3 Warrants held by it, and excluding 600,367 shares of Common Stock issuable upon the exercise of A-3 Warrants held by it; (ii) BVF2 beneficially owned 3,718,907 shares of Common Stock, including 1,083,457 shares of Common Stock issuable upon the exercise of the A-1 Warrants held by it and 2,635,450 shares of Common Stock issuable upon the exercise of the A-2 Warrants held by it, and excluding 957,489 shares of Common Stock issuable upon the exercise of A-3 Warrants held by it; and (iii) Trading Fund OS beneficially owned 612,684 shares of Common Stock, including 178,494 shares of Common Stock issuable upon the exercise of the A-1 Warrants held by it and 434,190 shares of Common Stock issuable upon the exercise of the A-2 Warrants held by it, and excluding 152,442 shares of Common Stock issuable upon the exercise of A-3 Warrants held by it.

BVF GP, as the general partner of BVF, may be deemed to beneficially own the 5,174,517 shares of Common Stock beneficially owned by BVF.

BVF2 GP, as the general partner of BVF2, may be deemed to beneficially own the 3,718,907 shares of Common Stock beneficially owned by BVF2.

Partners OS, as the general partner of Trading Fund OS, may be deemed to beneficially own the 612,684 shares of Common Stock beneficially owned by Trading Fund OS.

BVF GPH, as the sole member of each of BVF GP and BVF2 GP, may be deemed to beneficially own the 8,893,424 shares of Common Stock beneficially owned in the aggregate by BVF and BVF2.

Partners, as the investment manager of BVF, BVF2 and Trading Fund OS, and the sole member of Partners OS, may be deemed to beneficially own the 9,661,235 Shares beneficially owned in the aggregate by BVF, BVF2 and Trading Fund OS and held in the Partners Managed Account, including 155,127 shares of Common Stock held in the Partners Managed Account, which includes 45,197 shares of Common Stock issuable upon the exercise of A-1 Warrants held in the Partners Managed Account and 109,930 shares of Common Stock issuable upon the exercise of the A-2 Warrants held in the Partners Managed Account, and excluding 59,474 shares of Common Stock issuable upon the exercise of A-3 Warrants held in the Partners Managed Account.

BVF Inc., as the general partner of Partners, may be deemed to beneficially own the 9,661,235 shares of Common Stock beneficially owned by Partners.

Mr. Lampert, as a director and officer of BVF Inc., may be deemed to beneficially own the 9,661,235 shares of Common Stock beneficially owned by BVF Inc.

The foregoing should not be construed in and of itself as an admission by any Reporting Person as to beneficial ownership of any shares of Common Stock owned by another Reporting Person. BVF GP disclaims beneficial ownership of the shares of Common Stock beneficially owned by BVF. BVF2 GP disclaims beneficial ownership of the shares of Common Stock beneficially owned by BVF2. Partners OS disclaims beneficial ownership of the shares of Common Stock beneficially owned by Trading Fund OS. BVF GPH disclaims beneficial ownership of the shares of Common Stock beneficially owned by BVF and BVF2. Each of Partners, BVF Inc. and Mr. Lampert disclaims beneficial ownership of the shares of Common Stock beneficially owned by BVF, BVF2 and Trading Fund OS and held in the Partners Managed Account, and the filing of this statement shall not be construed as an admission that any such person or entity is the beneficial owner of any such securities.

The following percentages are based on a denominator that is the sum of (i) 87,047,832 shares of Common Stock outstanding as of November 5, 2021 as set forth in the Issuer’s

Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on November 12, 2021 and (ii) certain or all of the 2,592,572 shares of Common Stock issuable upon the exercise of A-1 Warrants, 6,306,280 shares of Common Stock issuable upon the exercise of A-2 Warrants, as applicable, and (iii) with regard to BVF, BVF GP, BVF GPH, Partners, BVF Inc. and Mr. Lampert, 762,383 shares of Common Stock issuable upon the exercise of A-3 Warrants, as applicable.

As of the close of business on December 31, 2021, (i) BVF beneficially owned approximately 5.6% of the outstanding shares of Common Stock, (ii) BVF2 beneficially owned approximately 4.1% of the outstanding shares of Common Stock, (iii) Trading Fund OS beneficially owned less than 1% of the outstanding shares of Common Stock, (iv) BVF GP may be deemed to beneficially own approximately 5.6% of the outstanding shares of Common Stock, (v) BVF2 GP may be deemed to beneficially own approximately 4.1% of the outstanding shares of Common Stock, (vi) Partners OS may be deemed to beneficially own less than 1% of the outstanding shares of Common Stock, (vii) BVF GPH may be deemed to beneficially own approximately 9.3% of the outstanding shares of Common Stock, and (viii) each of Partners, BVF Inc. and Mr. Lampert may be deemed to beneficially own approximately 9.99% of the outstanding shares of Common Stock (less than 1% of the outstanding shares of Common Stock are held in the Partners Managed Account).

See Cover Pages Items 5-9.

See Cover Pages Items 5-9.

See Cover Pages Items 5-9.

See Cover Pages Items 5-9.

Not Applicable.

BVF GP, BVF GPH, Partners, BVF Inc. and Mr. Lampert share voting and dispositive power over the shares of Common Stock beneficially owned by BVF. BVF GPH, Partners, BVF Inc. and Mr. Lampert share voting and dispositive power over the shares of Common Stock beneficially owned by BVF2. Partners, BVF Inc. and Mr. Lampert share voting and dispositive power over the shares of Common Stock beneficially owned by Trading Fund OS and held in the Partners Managed Account.

Not Applicable.

See Exhibit 99.1 to Amendment No. 4 to the Schedule 13G filed with the Securities and Exchange Commission on February 14, 2020.

Not Applicable.

By signing below each of the undersigned certifies that, to the best of its knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.

SIGNATURE

After reasonable inquiry and to the best of his knowledge and belief, each of the undersigned certifies that the information set forth in this statement is true, complete and correct.

Dated: February 14, 2022