13D Filing: Redmile Group and Alder Biopharmaceuticals Inc (ALDR)

CUSIP No.: 014339105

(1) The source of funds was working capital of the entities for which
Redmile Group, LLC is the investment manager/adviser listed in items (i)
through (viii) of footnote (2) below.

(2) The aggregate amount of shares of Common Stock beneficially
owned by the Reporting Persons is comprised of the following: (i) 1,062,676
shares of Common Stock and 46,596 shares of Class A-1 Preferred Stock held by
Redmile Capital Fund, LP, (ii) 262,671 shares of Common Stock and 204,772
shares of Class A-1 Preferred Stock held by Redmile Capital Offshore Fund II,
Ltd., (iii) 154,403 shares of Common Stock and 7,594 shares of Class A-1
Preferred Stock held by Redmile Capital Offshore Fund (ERISA), Ltd., (iv)
2,129,754 shares of Common Stock and 95,210 shares of Class A-1 Preferred Stock
held by Redmile Capital Offshore Fund, Ltd., (v) 47,400 shares of Common Stock and
112,847 shares of Class A-1 Preferred Stock held by Redmile Strategic Master
Fund, LP, (vi) 2,143,630 shares of Common Stock and 258,249 shares of Class A-1
Preferred Stock held by MM LS Opportunities Master Fund, L.P., (vii) 434,439
shares of Common Stock held by Map 20 Segregated Portfolio, a segregated
portfolio of LMA SPC, and (viii) 270,793 shares of Common Stock held by P
Redmile Ltd. Redmile Group, LLC is the investment manager/adviser to each of
the private investment vehicles and separately managed accounts listed in items
(i) through (viii) and, in such capacity, exercises sole voting and investment
power over all of the shares held by such vehicles and accounts and may be
deemed to be the beneficial owner of these shares. Jeremy C. Green serves as
the managing member of Redmile Group, LLC and also may be deemed to be the
beneficial owner of these shares. Redmile Group, LLC and Mr. Green each
disclaim beneficial ownership of these shares, except to the extent of its or
his pecuniary interest in such shares, if any. The Class A-1 Preferred Stock is
initially convertible into shares of Common Stock on a one-for-ten basis.
Pursuant to the Certificate of Designation, the Issuer may not effect any
conversion of the Class A-1 Preferred Stock, and a holder of the Class A-1
Preferred Stock does not have the right to convert any portion of the Class A-1
Preferred Stock held by such holder, to the extent that, after giving effect to
the conversion set forth in a notice of conversion, such conversion would
result in such holder, together with such holder’s affiliates, and any persons
acting as a group together with such holder or affiliates, beneficially owning
in excess of the Beneficial Ownership Limitation. The 6,807,876 shares of
Common Stock reported as beneficially owned by the Reporting Persons in this
Schedule 13D represents 9.99% of the outstanding shares of Common Stock
(calculated in accordance with footnote (3) below).

(3) Percent of class calculated based on an aggregate of 67,844,820 shares
of Common Stock issued and outstanding as of February 21, 2018, as reported by
the Issuer in the Form 10-K, plus 302,110 shares of Common Stock issuable upon
conversion of 30,211 shares of Class A-1 Preferred Stock, which, due to the
Beneficial Ownership Limitation, is the maximum number of shares of Class A-1
Preferred Stock that could be converted to Common Stock as of February 21,
2018.