F1This amendment is being filed to correct the vesting terms of the options that were granted. 50,000 non-qualified stock options ("Stock Options") convertible solely into common shares of Idera Pharmaceuticals, Inc. (the "Issuer") were granted to Julian C. Baker, a principal of Baker Bros. Advisors LP (the "Adviser") and 50,000 Stock Options were granted to Dr. Kelvin M. Neu, an employee of the Adviser. The Stock Options were granted pursuant to the Issuer's 2013 Stock Incentive Plan, as amended, have a strike price of $1.63 and vest in full on the first anniversary of the date of grant, subject to continued service as a director.
F2Julian C. Baker and Dr. Kelvin M. Neu serve on the Issuer's Board of Directors (the "Board") as representatives of 667, L.P. ("667"), Baker Brothers Life Sciences, L.P. ("Life Sciences"), 14159, L.P. ("14159", and together with 667, and Life Sciences, the "Funds"). Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Kelvin M. Neu do not have any right to any of the Issuer's securities issued as part of their service on the Board and the Funds are entitled to receive all the pecuniary interest in the securities issued. The Funds each own an indirect proportionate pecuniary interest in the Stock Options. Solely as a result of Felix J. Baker's and Julian C. Baker's ownership interest in the general partners of the general partners of the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the stock options (i.e. no direct pecuniary interest).
F3The 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. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are principals 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.

Remarks

Remarks: Julian C. Baker and Dr. Kelvin M. Neu, respectively, a principal and an employee of Baker Bros. Advisors LP (the "Adviser") are directors of Idera Pharmaceuticals, Inc. ("the Issuer"). By virtue of their representation on the Board of Directors of the Issuer, for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, the reporting persons are deemed directors by deputization of the Issuer.