Protagonist Therapeutics Inc (PTGX): RA Capital Management Acquires 6.8% Stake

Item 1.

(a) Name of Issuer: Protagonist
Therapeutics, Inc. (the “Issuer”).

(b) Address of the Issuer’s Principal Executive
Offices: 521 Cottonwood Drive, Suite 100, Milpitas, CA 95035.

 

Item 2.

(a) Name of Person
Filing: This joint statement on Schedule 13G is being filed by Peter Kolchinsky, RA Capital Management, LLC (“Capital”),
and RA Capital Healthcare Fund, L.P. (the “Fund”). Mr. Kolchinsky, Capital and the Fund are collectively referred to
herein as the “Reporting Persons.” Capital is the general partner of the Fund and serves
as investment adviser for a separately managed account (the “Account”). Mr. Kolchinsky is the manager of Capital. As
the investment adviser to the Fund and the Account, Capital may be deemed a beneficial owner, for purposes of Section 13(d) of
the Securities Exchange Act of 1934 (the “Act”), of any securities of the Issuer owned by the Fund or the Account.
As the manager of Capital, Mr. Kolchinsky may be deemed a beneficial owner, for purposes of Section 13(d) of the Act, of any securities
of the Issuer beneficially owned by Capital. Capital is a registered investment adviser within the meaning of Rule 13d-1(b)(1)(ii)(E)
and Rule 16a-1(a)(v), and Mr. Kolchinsky is a parent or control person of Capital within the meaning of Rule 13d-1(b)(1)(ii)(G)
and Rule 16a-1(a)(1)(vii). Capital and Mr. Kolchinsky disclaim beneficial ownership of the securities reported in this Schedule
13G Statement (the “Statement”) other than for the purpose of determining their obligations under Section 13(d) of
the Act, and neither the filing of the Statement nor the filing of this Amendment shall not be deemed an admission that either
Capital or Mr. Kolchinsky is or was the beneficial owner of such securities for any other purpose.

(b) Address of
Principal Business Office: The principal business office of the Reporting Persons is c/o RA Capital Management, LLC, 20 Park
Plaza, Suite 1200, Boston, MA 02116.

(c) Citizenship:
Capital is a Massachusetts limited liability company. The Fund is a Delaware limited partnership. Mr. Kolchinsky is a United States
citizen.

(d) Title and Class
of Securities: Common stock (“Common Stock”) of the Issuer.

(e) CUSIP Number:
74366E102

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:

Not applicable.

Item 4. Ownership:

 

(a)	Amount Beneficially Owned: See the response(s) to Item 9 on the attached cover page(s).
(b)	Percent of Class: See the response(s) to Item 11 on the attached cover page(s).