Page 6 of 10 – SEC Filing
| CUSIP No. 45168K306 | Page 6 of 10 Pages |
Amendment No. 2 to Schedule 13D
This Amendment No. 2 to Schedule 13D amends and supplements
the previously filed Schedules 13D filed by Baker Bros. Advisors LP (the “Adviser”), Baker Bros. Advisors (GP), LLC
(the “Adviser GP”), Julian C. Baker and Felix J. Baker (collectively the “Reporting Persons”). Except as
supplemented herein, such statements, as heretofore amended and supplemented, remain in full force and effect.
The Adviser GP is the sole general partner of the Adviser. Pursuant
to the management agreements, as amended, among the Adviser, Baker Brothers Life Sciences, L.P. (“Life Sciences”),
14159, L.P. (“14159”), and 667, L.P. (“667”, and together with Life Sciences and 14159, the “Funds”)
and their respective general partners, the Funds respective general partners relinquished to the Adviser all discretion and authority
with respect to the investment and voting power of the securities held by the Funds, and thus the Adviser has complete and unlimited
discretion and authority with respect to the Funds’ investments and voting power over investments.
| ITEM 4. | Purpose of the Transaction. |
Item 4 of Amendment No. 2 is supplemented and superseded, as
the case may be, as follows:
On
March 5, 2018, Life Sciences, 667 and 14159 increased to 19.99% the beneficial ownership limitation (“Beneficial Ownership
Limitation”) on the warrants to acquire common stock of Idera Pharmaceuticals, Inc. (“the Issuer”) at
an exercise price of $0.47 per share with an expiration date of May 7, 2018 (the “2018
Warrants”). The Beneficial Ownership Limitation had limited exercise of the 2018 Warrants to the extent that giving effect
to such exercise would not cause the holders thereof and their affiliates to beneficially own, for purposes of Rule 13d-3 under
the Exchange Act, in excess of 4.999% of the outstanding shares of Common Stock of the Issuer. The increase in the Beneficial Ownership
Limitation becomes effective 61 days after March 5, 2018
Julian C. Baker, a principal of the Adviser, and Dr. Kelvin
M. Neu, an employee of the Adviser, serve on the Board of Directors of the Issuer (the “Board”), as representatives
of the Funds. Dr. Neu serves as Chairman of the Compensation Committee. Julian C. Baker and Dr. Neu hold 55,042 and 73,684 shares
of Common Stock, respectively, received as compensation for service on the Board. Additionally, Julian C. Baker and Dr. Neu each
hold options to purchase shares of Common Stock (“Stock Options”) received for their service on the Board. Each of
Julian C. Baker and Dr. Neu holds 225,000 Stock Options, of which 157,500 are vested or will vest within 60 days hereof.
The policy of the Funds and the Adviser does not permit principals
or employees of the Adviser to receive compensation for serving as a directors of the Issuer and the Funds are instead entitled
to the pecuniary interest in the Stock Options or shares of Common Stock received as director compensation. Julian C. Baker and
Dr. Neu have no voting or dispositive power and no pecuniary interest in the Stock Options and Common Stock received as compensation
for their service on the Board. Other than through their control of the Adviser, Felix J. Baker and Julian C. Baker have neither
voting nor dispositive power and have no direct pecuniary interest in the Stock Options or Common Stock received as directors compensation
held by Julian C. Baker and Dr. Neu.
The Adviser has voting and investment power over the Stock Options and Common Stock received as director
compensation held by Julian C. Baker and Dr. Neu.
