[
]
|
Rule
13d-1(b)
|
|
[X]
|
Rule
13d-1(c)
|
|
[
]
|
Rule
13d-1(d)
|
CUSIP
No. 004225108
|
13G
|
Page
2
of 7
Pages
|
||||
|
1.
|
Names
of Reporting Persons.
I.R.S.
Identification Nos. of above persons (entities only).
RA
Capital Management, LLC
|
||||
2.
|
Check
the Appropriate Box if a Member of a Group (See
Instructions)
|
|||||
(a)
|
o | |||||
(b)
|
o | |||||
3.
|
SEC
Use Only
|
|||||
4.
|
Citizenship
or Place of
Organization Massachusetts
|
|||||
Number
of
Shares
Beneficially
Owned
by
Each
Reporting
Person
With
|
5.
|
Sole
Voting
Power 3,224,296
|
||||
6.
|
Shared
Voting
Power 0
|
|||||
7.
|
Sole
Dispositive
Power 3,224,296
|
|||||
8.
|
Shared
Dispositive
Power 0
|
|||||
9.
|
Aggregate
Amount Beneficially Owned by Each Reporting Person
3,224,296
|
|||||
10.
|
Check
if the Aggregate Amount in Row (9) Excludes o
Certain
Shares (See Instructions)
|
|||||
11.
|
Percent
of Class Represented by Amount in Row (9)
6.2%
|
|||||
12.
|
Type
of Reporting Person (See Instructions)
IA
|
|||||
CUSIP
No. 004225108
|
13G
|
Page
3
of 7
Pages
|
||||
|
1.
|
Names
of Reporting Persons.
I.R.S.
Identification Nos. of above persons (entities only).
Peter
Kolchinsky
|
||||
2.
|
Check
the Appropriate Box if a Member of a Group (See
Instructions)
|
|||||
(a)
|
o | |||||
(b)
|
o | |||||
3.
|
SEC
Use Only
|
|||||
4.
|
Citizenship
or Place of
Organization United
States
|
|||||
Number
of
Shares
Beneficially
Owned
by
Each
Reporting
Person
With
|
5.
|
Sole
Voting
Power 3,224,296
|
||||
6.
|
Shared
Voting
Power 0
|
|||||
7.
|
Sole
Dispositive Power 3,224,296
|
|||||
8.
|
Shared
Dispositive
Power 0
|
|||||
9.
|
Aggregate
Amount Beneficially Owned by Each Reporting Person
3,224,296
|
|||||
10.
|
Check
if the Aggregate Amount in Row (9) Excludes o
Certain
Shares (See Instructions)
|
|||||
11.
|
Percent
of Class Represented by Amount in Row (9)
6.2%
|
|||||
12.
|
Type
of Reporting Person (See Instructions)
IN
|
|||||
CUSIP
No. 004225108
|
13G
|
Page
4
of 7
Pages
|
||||
|
1.
|
Names
of Reporting Persons.
I.R.S.
Identification Nos. of above persons (entities only).
RA
Capital Healthcare Fund, L.P.
|
||||
2.
|
Check
the Appropriate Box if a Member of a Group (See
Instructions)
|
|||||
(a)
|
o | |||||
(b)
|
o | |||||
3.
|
SEC
Use Only
|
|||||
4.
|
Citizenship
or Place of
Organization Delaware
|
|||||
Number
of
Shares
Beneficially
Owned
by
Each
Reporting
Person
With
|
5.
|
Sole
Voting
Power 1,612,156
|
||||
6.
|
Shared
Voting
Power 0
|
|||||
7.
|
Sole
Dispositive Power 1,612,156
|
|||||
8.
|
Shared
Dispositive
Power 0
|
|||||
9.
|
Aggregate
Amount Beneficially Owned by Each Reporting Person
1,612,156
|
|||||
10.
|
Check
if the Aggregate Amount in Row (9) Excludes o
Certain
Shares (See Instructions)
|
|||||
11.
|
Percent
of Class Represented by Amount in Row (9)
3.1%
|
|||||
12.
|
Type
of Reporting Person (See Instructions)
PN
|
|||||
CUSIP
No. 004225108
|
Page
5 of 7
|
CUSIP
No. 004225108
|
Page
6 of 7
|
CUSIP No. 004225108
|
Page
7 of 7
|
DATE:
January 20, 2011
|
|
RA
CAPITAL HEALTHCARE FUND, L.P.
|
|
By:
RA Capital Management, LLC
General Partner |
|
By:
/s/ Peter Kolchinsky
|
|
Peter
Kolchinsky
|
|
Manager
|
|
RA
CAPITAL MANAGEMENT, LLC
|
|
By:
/s/ Peter Kolchinsky
|
|
Peter
Kolchinsky
|
|
Manager
|
|
PETER
KOLCHINSKY
|
|
/s/
Peter Kolchinsky
|
RA
CAPITAL HEALTHCARE FUND, L.P.
|
|
By:
RA Capital Management, LLC
General Partner |
|
By:
/s/ Peter Kolchinsky
|
|
Peter
Kolchinsky
|
|
Manager
|
|
RA
CAPITAL MANAGEMENT, LLC
|
|
By:
/s/ Peter Kolchinsky
|
|
Peter
Kolchinsky
|
|
Manager
|
|
PETER
KOLCHINSKY
|
|
/s/
Peter Kolchinsky
|