[
]
|
Rule
13d-1(b)
|
[X]
|
Rule
13d-1(c)
|
[
]
|
Rule
13d-1(d)
|
CUSIP
No. 00253U305
|
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)
|
|
(b) o
|
||
3.
|
SEC
Use Only
|
|
4.
|
Citizenship
or Place of
Organization Massachusetts
|
|
Number
of
|
5.
|
Sole
Voting
Power 1,418,724
|
Shares
|
||
Beneficially
|
6.
|
Shared
Voting
Power 0
|
Owned
by
|
||
Each
Reporting
|
7.
|
Sole
Dispositive
Power 1,418,724
|
Person
With
|
||
8.
|
Shared
Dispositive
Power 0
|
|
9.
|
Aggregate
Amount Beneficially Owned by Each Reporting Person
|
|
1,418,724
|
||
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)
|
|
5.02%
|
||
12.
|
Type
of Reporting Person (See Instructions)
|
|
IA
|
||
CUSIP
No. 00253U305
|
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)
|
|
(b) o
|
||
3.
|
SEC
Use Only
|
|
4.
|
Citizenship
or Place of
Organization United
States
|
|
Number
of
|
5.
|
Sole
Voting
Power 1,418,724
|
Shares
|
||
Beneficially
|
6.
|
Shared
Voting
Power 0
|
Owned
by
|
||
Each
Reporting
|
7.
|
Sole
Dispositive
Power 1,418,724
|
Person
With
|
||
8.
|
Shared
Dispositive
Power 0
|
|
9.
|
Aggregate
Amount Beneficially Owned by Each Reporting Person
|
|
1,418,724
|
||
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)
|
|
5.02%
|
||
12.
|
Type
of Reporting Person (See Instructions)
|
|
IN
|
||
CUSIP
No. 00253U305
|
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)
|
|
(b) o
|
||
3.
|
SEC
Use Only
|
|
4.
|
Citizenship
or Place of
Organization Delaware
|
|
Number
of
|
5.
|
Sole
Voting
Power 825,657
|
Shares
|
||
Beneficially
|
6.
|
Shared
Voting
Power 0
|
Owned
by
|
||
Each
Reporting
|
7.
|
Sole
Dispositive
Power 825,657
|
Person
With
|
||
8.
|
Shared
Dispositive
Power 0
|
|
9.
|
Aggregate
Amount Beneficially Owned by Each Reporting Person
|
|
825,657
|
||
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)
|
|
2.92%
|
||
12.
|
Type
of Reporting Person (See Instructions)
|
|
PN
|
||
CUSIP
No. 00253U305
|
Page 5
of 7
|
CUSIP
No. 00253U305
|
Page 6
of 7
|
CUSIP
No. 00253U305
|
Page 7
of 7
|