Page 8 of 10 – SEC Filing
| CUSIP No. 45168K306 | Page 8 of 10 Pages |
| Holder | Shares of Common Stock | 2018 Warrants | May 2020 Warrants | September 2020 Warrants | 2021 Warrants | |||||||||||||||
| 667, L.P. | 1,723,224 | 2,250,846 | 1,752,291 | 465,230 | 172,406 | |||||||||||||||
| Baker Brothers Life Sciences, L.P. | 16,438,080 | 17,626,445 | 13,722,245 | 3,620,051 | 1,938,274 | |||||||||||||||
| 14159, L.P. | 35,105 | 439,036 | 341,791 | 90,694 | 48,070 | |||||||||||||||
| Total | 18,196,409 | 20,316,327 | 15,816,327 | 4,175,975 | 2,158,750 | |||||||||||||||
The Prefunded Warrants are only exercisable to the extent that
after giving effect to such exercise the holders thereof and their affiliates would beneficially own, for purposes of Rule 13d-3
under the Securities Exchange Act of 1934, as amended, no more than 4.999% of the outstanding shares of Common Stock of the Issuer.
The 2018 Warrants are only exercisable to the extent that after giving effect to such exercise the holders thereof and their affiliates
would beneficially own, for purposes of Rule 13d-3 under the Securities Exchange Act of 1934, as amended, no more than 19.99% of
the outstanding shares of Common Stock of the Issuer. As a result of this restriction, the number of shares that may be issued
upon exercise of the Warrants by the above holders may change depending upon changes in the outstanding shares of Common Stock.
The Adviser GP, Felix J. Baker and Julian C. Baker as principals
of the Adviser GP, and the Adviser may be deemed to be beneficial owners of securities of the Issuer directly held by the Funds,
and may be deemed to have the power to vote or direct the vote of and the power to dispose or direct the disposition of such securities.
The Reporting Persons disclaim beneficial ownership of the securities
held by each of the Funds, and this Amendment No. 2 shall not be deemed an admission that the Reporting Persons are the beneficial
owners of such securities for purposes of Section 13(d) or for any other purpose.
The Adviser GP, and Felix J. Baker and Julian C. Baker as principals
of the Adviser GP, may be deemed to have the power to vote or direct the vote of and the power to dispose or direct the disposition
of the Stock Options held by Julian C. Baker and Dr. Neu.
(c) Except as described in this Amendment No. 2, none of the
Reporting Persons has effected any transaction in the securities of the Issuer during the past 60 days.
(d) Certain securities of the Issuer are held directly by 667,
a limited partnership the sole general partner of which is Baker Biotech Capital, L.P., a limited partnership the sole general
partner of which is Baker Biotech Capital (GP), LLC. Julian C. Baker and Felix J. Baker are the controlling members of Baker Biotech
Capital (GP), LLC.
Certain securities of the Issuer are held directly by Life Sciences,
a limited partnership the sole general partner of which is Baker Brothers Life Sciences Capital, L.P., a limited partnership the
sole general partner of which is Baker Brothers Life Sciences Capital (GP), LLC. Julian C. Baker and Felix J. Baker are the controlling
members of Baker Brothers Life Sciences Capital (GP), LLC.
Certain securities of the Issuer are held directly by 14159,
a limited partnership the sole general partner of which is 14159 Capital, L.P., a limited partnership the sole general partner
of which is 14159 Capital (GP), LLC. Julian C. Baker and Felix J. Baker are the controlling members of 14159 Capital (GP), LLC.
(e) Not applicable.
