Security	Date	Code	Shares	Price	A/D	Owned after	D/I	Nature of ownership
Common Stock^{F1,F2,F3,F6,F7}	Apr 3, 2017	A	8,487	$2.43	A	1,026,437	I	See footnote
Common Stock^{F1,F2,F4,F6,F7}	Apr 3, 2017	A	8,487	$2.43	A	9,331,989	I	See footnote
Common Stock^{F1,F2,F5,F6,F7}	Apr 3, 2017	A	8,487	$2.43	A	133,666	I	See footnote

Table II — derivative securities

No Table II lines on this filing.

Explanation of responses

F13,600 shares of common stock (the "Common Stock") issued to Julian C. Baker and 4,887 shares of Common Stock issued to Dr. Kelvin M. Neu, respectively, a principal and an employee of Baker Bros. Advisors LP (the "Adviser") pursuant to the Issuer's 2013 Stock Incentive Plan (the "Stock Incentive Plan") in lieu of director retainer fees of $8,750 and $11,875, respectively. The shares of Common Stock are fully vested. Julian C. Baker and Dr. Neu serve on the Issuer's Board of Directors (the "Board") as representatives of the Funds (as defined below). Dr. Neu also serves on the Compensation Committee of the Board for which he receives additional director retainer fees.
F2Pursuant 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 and the Funds (as defined below)are entitled to an indirect proportionate pecuniary interest in the securities issued in lieu of director fees. 667, L.P. ("667"), Baker Brothers Life Sciences, L.P. ("Life Sciences") and 14159, L.P. ("14159", and together with 667, and Life Sciences, the "Funds") each owns an indirect proportionate pecuniary interest in the shares of Common Stock. Solely as a result of their 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 shares of Common Stock issued in lieu of director retainer fees (i.e., no direct pecuniary interest).
F3As a result of Felix J. Baker's and Julian C. Baker's ownership interest in Baker Biotech Capital (GP), LLC, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in 1,026,437 shares of common stock of the Issuer beneficially owned 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 98,561 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.
F4As a result of Felix J. Baker's and Julian C. Baker's ownership interest in Baker Brothers Life Sciences Capital (GP), LLC, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest 9,331,989 shares of common stock of the Issuer beneficially owned 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 98,561 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.
F5As a result of Felix J. Baker's and Julian C. Baker's ownership interest in 14159 Capital (GP), LLC, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in 133,666 shares of common stock of the Issuer beneficially owned by 14159, a limited partnership of which the sole general partner is 14159 Capital, L.P., a limited partnership of which the sole general partner is 14159 Capital (GP), LLC, due to 14159 Capital, L.P.'s right to receive an allocation of a portion of the profits from 14159. Includes beneficial ownership of 98,561 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.
F6The 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.
F7The disclosure of the grant of Common Stock reported on this form is the sum of two grants totaling 8,487 shares. The 8,487 shares are reported for each of the Funds as each has an indirect pecuniary interest.

Remarks

Remarks: Julian C. Baker and Dr. Kevin 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. The same reporting persons had previously filed with Julian C. Baker as the lead reporting person; commencing with this filing, Baker Bros. Advisors LP will be listed as the lead reporting person to improve clarity. The change in lead reporting person does not reflect any change in pecuniary interest amongst the reporting persons.