Exhibit A

JOINT FILING AGREEMENT

The undersigned agree that this Schedule 13G Amendment No. 1 dated February 12, 2025 relating to the Common Stock, par value $0.001 per share, of Marinus Pharmaceuticals, Inc. shall be filed on behalf of the undersigned.

SOFINNOVA INVESTMENTS, INC.

By: /s/ James Healy

Name: James Healy

Title:   Director

SOFINNOVA BIOEQUITIES GP LLC

By: /s/ Eric Delbridge

Name: Eric Delbridge

Title:   Managing Member

JAMES HEALY

By: /s/ James Healy

ERIC DELBRIDGE

By: /s/ Eric Delbridge