13G Filing: EcoR1 Capital and Marinus Pharmaceuticals Inc (MRNS)

Item

1.

(a)

Name of Issuer Marinus Pharmaceuticals, Inc.

(b)

Address of Issuer’s Principal Executive Offices 170 N. Radnor Chester Rd, Suite 250, Radnor, PA 19087

Item

2.

(a)

The names of the persons filing this statement are: EcoR1 Capital Fund Qualified, L.P. (“Qualified Fund”); EcoR1 Capital, LLC (“EcoR1”) and Oleg Nodelman (“Nodelman”) (collectively, the “Filers”).

 

Qualified Fund is filing this statement
jointly with the other Filers, but not as a member of a group and it expressly disclaims membership in a group. In addition, filing
this Schedule 13G on behalf of Qualified Fund should not be construed as an admission that it is, and it disclaims that it is,
a beneficial owner, as defined in Rule 13d-3 under the Act, of any of the Stock covered by this Schedule 13G.

 

Each Filer also disclaims beneficial
ownership of the Stock except to the extent of that person’s pecuniary interest therein.

 

(b)

The principal business office of the Filers is located at: 409 Illinois Street, San Francisco, CA 94158

(c)

For citizenship of Filers, see Item 4 of the cover sheet for each Filer.

(d)

This statement relates to shares of common stock, par value $0.001 per share

of the Issuer (the “Stock”).

(e)

The CUSIP number of the Issuer is: 56854Q101.