o
|
Rule 13d-1(b)
|
x
|
Rule 13d-1(c)
|
o
|
Rule 13d-1(d)
|
CUSIP No. 817337405
|
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 5,169,800
|
||||
|
||||||
6.
|
Shared Voting Power 0
|
|||||
|
||||||
7.
|
Sole Dispositive Power 5,169,800
|
|||||
|
||||||
8.
|
Shared Dispositive Power 0
|
|||||
|
||||||
9.
|
Aggregate Amount Beneficially Owned by Each Reporting Person
5,169,800
|
|||||
|
||||||
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)
5.20%
|
|||||
|
||||||
12.
|
Type of Reporting Person (See Instructions)
IA
|
|||||
|
CUSIP No. 817337405
|
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 5,169,800
|
||
|
||||
6.
|
Shared Voting Power 0
|
|||
|
||||
7.
|
Sole Dispositive Power 5,169,800
|
|||
|
||||
8.
|
Shared Dispositive Power 0
|
|||
|
||||
9.
|
Aggregate Amount Beneficially Owned by Each Reporting Person
5,169,800
|
|||
|
||||
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)
5.20%
|
|||
|
||||
12.
|
Type of Reporting Person (See Instructions)
IN
|
|||
|
CUSIP No. 817337405
|
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 2,717,516
|
||||
|
||||||
6.
|
Shared Voting Power 0
|
|||||
|
||||||
7.
|
Sole Dispositive Power 2,717,516
|
|||||
|
||||||
8.
|
Shared Dispositive Power 0
|
|||||
|
||||||
9.
|
Aggregate Amount Beneficially Owned by Each Reporting Person
2,717,516
|
|||||
|
||||||
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)
2.74%
|
|||||
|
||||||
12.
|
Type of Reporting Person (See Instructions)
PN
|
|||||
|
||||||
CUSIP No. 817337405
|
|
Page 5 of 7
|
Item 3.
|
If this statement is filed pursuant to §§240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
|
Item 4.
|
Ownership:
|
CUSIP No. 817337405
|
|
Page 6 of 7
|
Item 5.
|
Ownership of Five Percent or Less of a Class:
|
Item 6.
|
Ownership of More than Five Percent on Behalf of Another Person:
|
Item 7.
|
Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company or Control Person:
|
Item 8.
|
Identification and Classification of Members of the Group:
|
Item 9.
|
Notice of Dissolution of Group:
|
Item 10.
|
Certification:
|
CUSIP No. 817337405
|
|
Page 7 of 7
|
DATE: DECEMBER 9, 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 |