X0306 4 2019-07-01 0 0000861838 IDERA PHARMACEUTICALS, INC. IDRA 0001263508 BAKER BROS. ADVISORS LP 860 WASHINGTON STREET 3RD FLOOR NEW YORK NY 10014 0 0 1 0 0001580575 Baker Bros. Advisors (GP) LLC 860 WASHINGTON STREET 3RD FLOOR NEW YORK NY 10014 0 0 1 0 0001087940 BAKER FELIX 860 WASHINGTON STREET 3RD FLOOR NEW YORK NY 10014 0 0 1 0 0001087939 BAKER JULIAN 860 WASHINGTON STREET, 3RD FLOOR NEW YORK NY 10014 0 0 1 0 Common Stock 21929 D Common Stock 21929 D Common Stock 2019-07-01 4 A 0 2964 2.61 A 350721 I See footnotes Common Stock 2019-07-01 4 A 0 2964 2.61 A 4290995 I See footnotes Common stock ("Common Stock") of Idera Pharmaceuticals, Inc. (the "Issuer") directly held by Julian C. Baker. Common Stock directly held by Felix J. Baker. 2,964 shares of Common Stock issued to Dr. Kelvin M. Neu, a full-time employee of Baker Bros. Advisors LP (the "Adviser") pursuant to the 2013 Stock Incentive Plan (the "Stock Incentive Plan") of the Issuer in lieu of director retainer fees of $7,736. The shares of Common Stock are fully vested. Dr. Neu previously served on the Issuer's board of directors (the "Board") as a representative of the 667, L.P. ("667") and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). Dr. Neu also previously served on the Compensation Committee of the Board for which he received additional director retainer fees. Julian C. Baker, a Managing Member of Baker Bros. Advisors (GP) LLC (the "Adviser GP") also previously served on the Board as a representative of the Funds. Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Neu do not have any right to the pecuniary interest in the Issuer's securities issued in lieu of director retainer fees for previous service on the Board and the Funds are entitled to an indirect proportionate pecuniary interest in the securities issued in lieu of director fees. The Funds each owns an indirect proportionate pecuniary interest in the shares of Common Stock. After giving effect to the transaction reported herein and as a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I directly held by 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP),LLC, due to Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667. Includes beneficial ownership of 32,930 shares issued pursuant to the Stock Incentive Plan in lieu of director retainer fees of which the fund may be deemed to own a portion. After giving effect to the transaction reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I directly held by Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences. Includes beneficial ownership of 32,930 shares issued pursuant to the Stock Incentive Plan in lieu of director retainer fees of which the fund may be deemed to own a portion. The 2,964 shares are reported for each of the Funds as each has an indirect pecuniary interest. The Adviser serves as the investment adviser to the Funds. In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held by the Funds. The Adviser GP is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held by the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held by the Funds. Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose. By: Baker Bros. Advisors LP, Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing 2019-07-03 By: Baker Bros. Advisors (GP) LLC, Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing 2019-07-03 /s/ Felix J. Baker 2019-07-03 /s/ Julian C. Baker 2019-07-03