13G Filing: Partner Fund Management and Medicines Co (MDCO)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

 

SCHEDULE 13G

(Rule 13d-102)

 

Information Statement Pursuant to Rules 13d-1
and 13d-2

Under the Securities Exchange Act of 1934

(Amendment No. )*

The Medicines Company

(Name of Issuer)

Common stock, par value $0.001 per share

(Title of Class of Securities)

584688105

(CUSIP Number)

April 21, 2017

Date of Event Which Requires Filing of the Statement

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

¨

Rule 13d-1(b)

x

Rule 13d-1(c)

¨

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 disclosures provided in a prior cover page.

The information required on 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).