13G Filing: Perceptive Advisors and Sierra Oncology Inc. (SRRA)

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The Master Fund directly holds 3,655,186 shares of Common Stock. Perceptive Advisors serves as
the investment manager to the Master Fund and may be deemed to beneficially own the securities directly held by the Master Fund. Mr. Edelman is the managing member of Perceptive Advisors and may be deemed to beneficially own the securities
directly held by the Master Fund.

Item 5.

Ownership of Five Percent or Less of a Class.

If this statement is being filed
to report the fact that as of the date hereof the Reporting Persons have ceased to be the beneficial owner of more than five percent of the class of securities, check the following ☐.

Item 6.

Ownership of More than Five Percent on Behalf of Another Person.

Not
applicable.

Item 7.

Identification and Classification of the SubsidiaryWhich Acquired the Security Being Reported on by the Parent Holding Company or Control Person.

Not applicable.

Item 8.

Identification and Classification of Members of the Group.

Not applicable.

Item 9.

Notice of Dissolution of Group.

Not applicable.

Item 10.

Certification.

By signing below I certify that, to the best of my knowledge and
belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as
a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11.