| CUSIP
No. 82640U404 |
| 1. |
Names of Reporting Persons. I.R.S.
Identification Nos. of above persons (entities only):
Abingworth LLP
98-0518585 |
| 2. |
Check
the Appropriate Box if a Member of a Group (See Instructions): |
(a)
[ ] |
|
| |
(b) [ ] |
|
| 3. |
SEC
Use Only |
| 4. |
Source of
Funds (See Instructions): WC (See Item 3) |
| 5. |
Check
if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e): [ ] |
| 6. |
Citizenship
or Place of Organization: England |
| |
| |
Number
of |
7.
Sole Voting Power: |
0
|
|
| |
Shares
Beneficially |
8.
Shared Voting Power: |
2,193,626* |
|
| |
Owned
by |
|
|
|
| |
Each Reporting |
9.
Sole Dispositive Power: |
0
|
|
| |
Person
With |
10.
Shared Dispositive Power: |
2,193,626* |
|
| |
|
|
|
| 11. |
Aggregate
Amount Beneficially Owned by Each Reporting Person: |
2,193,626* |
|
| 12. |
Check if the
Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions): [ ] |
| 13. |
Percent
of Class Represented by Amount in Row (11): 8.9%* |
|
|
| 14. |
Type
of Reporting Person (See Instructions): PN |
|
|
| |
|
|
|
|
|
|
|
|
*As of the date hereof,
Abingworth LLP (“Abingworth”) may be deemed to beneficially own an aggregate of 2,193,626 shares of common stock,
par value $0.001 per share (the “Common Stock”), of Sierra Oncology, Inc. (the “Issuer”) consisting
of (i) 1,314,127 shares of Common Stock held directly by Abingworth Bioventures VII, LP (“ABV VII”), (ii) 8,374 shares
of Common Stock issuable upon the exercise of stock options issued to Dr. Andrew Sinclair and (iii) an aggregate of 871,125 shares of
Common Stock issuable upon the exercise of Series A Warrants (the “Series A Warrants”) held by ABV VII. Dr. Andrew
Sinclair, a Partner of Abingworth, was granted options, as director’s compensation, with respect to 14,374 shares of Common Stock,
of which 8,374 shares of Common Stock are exercisable within sixty (60) days of the date hereof (the “Options”). Under
an agreement between Dr. Sinclair and Abingworth, Dr. Sinclair is deemed to hold the Options and any shares of Common Stock issuable
upon the exercise of the Options for the benefit of ABV VII, and must exercise the Options solely upon the direction of Abingworth. As
a result of the foregoing, Abingworth, as the investment manager of ABV VII, may be deemed to beneficially own (i) the 1,314,127 shares
of Common Stock, (ii) the 8,374 shares of Common Stock issuable upon the exercise of the Options and (iii) the 871,125 shares of Common
Stock underlying the Series A Warrants. Thus, for purposes of Rule 13d-3 under the Securities Exchange Act of 1934, as amended, Abingworth
may be deemed to beneficially own 8.9% of the shares of Common Stock of the Issuer deemed issued and outstanding as of the date hereof.
The foregoing beneficial
ownership percentage is based upon 23,665,100 shares of Common Stock outstanding as of March 7, 2022, based on information reported in
the Issuer’s Annual Report on Form 10-K filed with the Securities and Exchange Commission on March 10, 2022.
| CUSIP
No. 82640U404 |
| 1. |
Names of Reporting Persons. I.R.S.
Identification Nos. of above persons (entities only):
Abingworth Bioventures VII, LP
93-1331173 |
| 2. |
Check
the Appropriate Box if a Member of a Group (See Instructions): |
(a)
[ ] |
|
| |
(b) [ ] |
|
| 3. |
SEC
Use Only |
| 4. |
Source of
Funds (See Instructions): WC (See Item 3) |
| 5. |
Check
if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e): [ ] |
| 6. |
Citizenship
or Place of Organization: England |
| |
| |
Number
of |
7.
Sole Voting Power: |
0
|
|
| |
Shares
Beneficially |
8.
Shared Voting Power: |
2,193,626* |
|
| |
Owned
by |
|
|
|
| |
Each Reporting |
9.
Sole Dispositive Power: |
0
|
|
| |
Person
With |
10.
Shared Dispositive Power: |
2,193,626* |
|
| |
|
|
|
| 11. |
Aggregate
Amount Beneficially Owned by Each Reporting Person: |
2,193,626* |
|
| 12. |
Check if the
Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions): [ ] |
| 13. |
Percent
of Class Represented by Amount in Row (11): 8.9%* |
|
|
| 14. |
Type
of Reporting Person (See Instructions): PN |
|
|
| |
|
|
|
|
|
|
|
|
*As of the date hereof,
Abingworth Bioventures VII, LP (“ABV VII”) may be deemed to beneficially own an aggregate of 2,193,626 shares of common
stock, par value $0.001 per share (the “Common Stock”), of Sierra Oncology, Inc. (the “Issuer”)
consisting of (i) 1,314,127 shares of Common Stock held directly by ABV VII, (ii) 8,374 shares of Common Stock issuable upon the exercise
of stock options issued to Dr. Sinclair and (iii) an aggregate of 871,125 shares of Common Stock issuable upon the exercise of Series
A Warrants (the “Series A Warrants”) held by ABV VII. Dr. Andrew Sinclair, a Partner of Abingworth, was granted options,
as director’s compensation, with respect to 14,374 shares of Common Stock, of which 8,374 shares of Common Stock are exercisable
within sixty (60) days of the date hereof (the “Options”). Under an agreement between Dr. Sinclair and Abingworth
LLP (“Abingworth”), Dr. Sinclair is deemed to hold the Options and any shares of Common Stock issuable upon the exercise
of the Options for the benefit of ABV VII, and must exercise the Options solely upon the direction of Abingworth. As a result of the
foregoing, ABV VII, may be deemed to beneficially own (i) the 1,314,127 shares of Common Stock, (ii) the 8,374 shares of Common Stock
issuable upon the exercise of the Options and (iii) the 871,125 shares of Common Stock underlying the Series A Warrants. Thus, for purposes
of Rule 13d-3 under the Securities Exchange Act of 1934, as amended, ABV VII may be deemed to beneficially own 8.9% of the shares of
Common Stock of the Issuer deemed issued and outstanding as of the date hereof.
The foregoing beneficial
ownership percentage is based upon 23,665,100 shares of Common Stock outstanding as of March 7, 2022, based on information reported in
the Issuer’s Annual Report on Form 10-K filed with the Securities and Exchange Commission on March 10, 2022.
Explanatory
Note
This
Amendment No. 3 (this “Amendment”) amends and supplements the Schedule 13D filed on behalf of the Reporting Persons
with the Securities and Exchange Commission on February 10, 2020, Amendment No. 1 thereto filed with the Securities and Exchange Commission
on November 5, 2021 and Amendment No. 2 thereto filed with the Securities and Exchange Commission on February 10, 2022 (collectively, the
“Schedule 13D”). Except as specifically provided herein, this Amendment does not modify or amend any of the information
previously reported in the Schedule 13D. Capitalized terms used and not otherwise defined herein shall have the meanings ascribed to
such terms in the Schedule 13D. Information given in response to each item shall be deemed incorporated by reference in all other items,
as applicable.
Item
5. Interest in Securities of the Issuer
Item 5 of the Schedule
13D is amended and supplemented, as the case may be, as follows:
As
of the date hereof, Abingworth may be deemed to beneficially own an aggregate of 2,193,626 shares of Common Stock of the Issuer consisting
of (i) 1,314,127 shares of Common Stock held by ABV VII, (ii) 8,374 shares of Common Stock issuable upon the exercise of the Options
issued to Dr. Andrew Sinclair and (iii) an aggregate of 871,125 shares of Common Stock issuable upon the exercise of the Series A Warrants
held by ABV VII. Dr. Sinclair is a Partner of Abingworth. Under an agreement between Dr. Sinclair and Abingworth, Dr. Sinclair is deemed
to hold the Options and any shares of Common Stock issuable upon the exercise of the Options for the benefit of ABV VII, and must exercise
the Options solely upon the direction of Abingworth.
As
a result of the foregoing, Abingworth, as the investment manager of ABV VII, may be deemed to beneficially own (i) the 1,314,127 shares
of Common Stock held by ABV VII, (ii) the 8,374 shares of Common Stock issuable upon exercise of the Options issued to Dr. Andrew Sinclair
and (iii) the 871,125 shares of Common Stock underlying the Series A Warrants held by ABV VII. Thus, for purposes of Rule 13d-3 under
the Securities Exchange Act of 1934, as amended, Abingworth may be deemed to beneficially own 8.9% of the shares of Common Stock of the
Issuer deemed issued and outstanding as of the date hereof.
The
foregoing beneficial ownership percentage is based upon 23,665,100 shares of Common Stock outstanding as of March 7, 2022, based on information
reported in the Issuer’s Annual Report on Form 10-K filed with the Securities and Exchange Commission on March 10, 2022.
Except
as described herein, since the last Schedule 13D filed on February 10, 2022, there were no other purchases or sales of shares of Common
Stock, or securities convertible into or exchangeable for shares of Common Stock, by the Reporting Persons or any person or entity for
which the Reporting Persons possess voting or dispositive control over the securities thereof.
Item
7. Material to be Filed as Exhibits
The
following exhibit is incorporated into this Schedule 13D:
| |
Exhibit
1
|
Joint
Filing Agreement, dated February 10, 2020, signed by each of the Reporting Persons (incorporated
by reference to Exhibit 1 to the Schedule 13D filed with the Securities and Exchange Commission
on February 10, 2020).
|
Signature
After reasonable inquiry
and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.
Dated: March 21, 2022
ABINGWORTH BIOVENTURES
VII, LP
By: Abingworth LLP,
its Manager
By: /s/ John Heard
Name: John
Heard
Title: Authorized
Signatory
ABINGWORTH
LLP
By: /s/ John Heard
Name: John
Heard
Title: Authorized
Signatory
Attention: Intentional
misstatements or omissions of fact constitute Federal criminal violations (See 18 U.S.C. 1001).