13G Filing: Granite Point Capital and Marinus Pharmaceuticals Inc (MRNS)

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Page 12 of 13 – SEC Filing

EXHIBIT 1

JOINT FILING AGREEMENT
PURSUANT TO RULE 13d-1(k)

The undersigned acknowledge and agree that the foregoing statement
on Schedule 13G is filed on behalf of each of the undersigned and that all subsequent amendments to this statement on Schedule
13G shall be filed on behalf of each of the undersigned without the necessity of filing additional joint filing agreements. The
undersigned acknowledge that each shall be responsible for the timely filing of such amendments, and for the completeness and accuracy
of the information concerning him or it contained herein and therein, but shall not be responsible for the completeness and accuracy
of the information concerning the others, except to the extent that he or it knows or has reason to believe that such information
is inaccurate.

DATE: July 18, 2017

GRANITE POINT CAPITAL MASTER FUND, L.P.
By:  Granite Point Capital L.L.C., its general partner
/s/ David Bushley
Name:  David Bushley
Title: Chief Operating Officer
GRANITE POINT CAPITAL PANACEA GLOBAL HEALTHCARE FUND
By:  Granite Point Capital L.L.C., its general partner
/s/ David Bushley
Name:  David Bushley
Title: Chief Operating Officer
GRANITE POINT CAPITAL SCORPION FOCUSED IDEAS FUND
By:  Granite Point Capital L.L.C., its general partner
/s/ David Bushley
Name:  David Bushley
Title: Chief Operating Officer
GRANITE POINT CAPITAL L.L.C.
/s/ David Bushley
Name:  David Bushley
Title: Chief Operating Officer

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