13G Filing: RA Capital Management and Sunesis Pharmaceuticals Inc (SNSS)

Page 2 of 8 – SEC Filing

CUSIP No. 867328700 13G
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)  ¨
(b)  ¨
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                             0 shares
6. Shared Voting Power                        3,596,8401 shares
7. Sole Dispositive Power                   0 shares
8. Shared Dispositive Power               3,596,8401 shares
9.

Aggregate Amount Beneficially Owned by Each Reporting Person

3,596,8401 shares

10.

Check if the Aggregate Amount
in Row (9) Excludes
                      ¨

Certain Shares (See Instructions)

11.

Percent of Class Represented by Amount in Row (9)

10.4%2

12.

Type of Reporting Person (See Instructions)

IA

_________________________

1 The shares reported herein for the Reporting Person
represent (i) 3,096,840 shares of the Issuer’s Common Stock beneficially owned and (ii) 500,000 shares of the Issuer’s
Common Stock the reporting person has the right to acquire through the exercise of warrants dated October 25, 2017 (“Warrant
Shares”).

2 The number
of shares outstanding for purposes of this percentage calculation assumes (i) 34,248,322 outstanding shares of Common Stock of
the Issuer, based on the Issuer’s Form 10-Q as filed with the Securities and Exchange Commission (“SEC”) on November
2, 2017, plus (ii) the 500,000 Warrant Shares the reporting persons may acquire upon the exercise of warrants.

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