BAKER BROS. ADVISORS LP bought MDGL

Footnotes

The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $382.00 to $382.36, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.; Baker Bros. Advisors LP (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 directly by the Funds or for the benefit of 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 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 directly by the Funds or for the benefit of 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 directly by the Funds or for the benefit of the Funds.; Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by or held for the benefit of 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.; Includes beneficial ownership of 3,825 shares of Common Stock received from vested restricted stock units of the Issuer (each an "RSU") each previously granted to Julian C. Baker and Dr. Raymond Cheong in their capacity as directors of the Issuer.; Pursuant to the policies of the Adviser, the Adviser has voting and dispositive power over the non-qualified stock options exercisable solely into Common Stock ("Stock Options"), RSUs and any Common Stock received as a result of the exercise of Stock Options or vesting of RSUs.; Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the Board and the Funds are entitled to an indirect proportionate pecuniary interest in such securities. The Funds each own an indirect proportionate pecuniary interest in the Stock Options and RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the Stock Options, RSUs and any Common Stock acquired upon the exercise of Stock Options or vesting of RSUs (i.e. no direct pecuniary interest) issued as compensation for such service on the board of directors of the Issuer.; After giving effect to the transactions 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 held directly by or held for the benefit of 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 their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.