13G Filing: Perceptive Advisors and Avadel Pharmaceuticals PLC (AVDL)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

SCHEDULE 13G

Under the Securities Exchange Act of 1934

(Amendment No.     )*

Avadel
Pharmaceuticals plc

(Name of Issuer)

Ordinary
shares, nominal value $0.01 per share

(Title of Class of Securities)

05337M 10 4¹

(CUSIP Number)

November 1, 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:

☐

Rule 13d-1(b)

☒

Rule 13d-1(c)

☐

Rule 13d-1(d)

*	The remainder of this cover page shall be filled out for a reporting persons 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).

1	Represents the CUSIP number for the American Depositary Shares, each representing one ordinary share, nominal value $0.01 per share.