 NEWARK, Calif., July 28, 2021 PRNewswire -- Protagonist Therapeutics, Inc. Nasdaq:PTGX Protagonist or the Company today announced its entry into an amended collaboration agreement the Restated Agreement with Janssen Biotech, Inc., one of the Janssen Pharmaceutical Companies of Johnson Johnson, relating to research, development, manufacture and commercialization of multiple oral Interleukin IL-23 receptor antagonist drug candidates. 