13G Filing: Great Point Partners and PTC Therapeutics Inc. (PTCT)

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

Schedule 13G

Under the Securities Exchange Act of
1934

(Amendment No. )*

PTC Therapeutics Inc.

(Name of Issuer)

Common Stock

(Title of Class of Securities)

69366J200

(CUSIP Number)

June 6, 2017

(Date of Event which Requires Filing of
this Statement)

Check the appropriate box to designate the
rule pursuant to which this Schedule is filed:

x	Rule 13d-1(b)
o	Rule 13d-1(c)
o	Rule 13d-1(d)

*The remainder of this
cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of
securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover
page.

The information required in the remainder
of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of
1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions
of the Act (however, see the Notes).

Persons who respond to the collection of
information contained in this form are not required to respond unless the form displays a currently valid OMB control number.