13D Filing: James E. Flynn and AveXis Inc (AVXS)

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

[Rule 13d-101]

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO §
24.13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO § 240.13D-2(a)

(Amendment No. 3)*

AveXis,
Inc.

(Name
of Issuer)

Common
Stock, par value $0.0001 per share

(Title
of Class of Securities)

05366U100

(CUSIP
Number)

(Name,
Address and Telephone Number of Person Authorized to Receive Notices and Communications)

August
21, 2017

(Date
of Event which Requires Filing of this Statement)

If the filing person
has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing
this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box ☐.

Note: Schedules
filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See § 240.13d-7
for other parties to whom copies are to be sent.

(Continued on following
pages)

(Page 1 of 15 Pages)

* 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).

SCHEDULE 13D

(1) Comprised of 413,611 shares held by Deerfield Special Situations
Fund, L.P., 119,429 shares held by Deerfield Partners, L.P. and 152,000 shares held by Deerfield International Master Fund, L.P.

 SCHEDULE 13D

 SCHEDULE 13D

 SCHEDULE 13D

SCHEDULE 13D

SCHEDULE 13D

(2) Comprised of 413,611 shares held by Deerfield Special Situations
Fund, L.P., 119,429 shares held by Deerfield Partners, L.P., 1,623,089 shares held by Deerfield Private Design Fund III, L.P.,
152,000 shares held by Deerfield International Master Fund, L.P. and 15,931 shares of Common Stock underlying options held by
Jonathan Leff, a partner in Deerfield Management Company, L.P. and a former director of the Issuer.

SCHEDULE 13D

(3) Comprised of 1,623,089 shares held by Deerfield Private
Design Fund III, L.P.

SCHEDULE 13D

(4) Comprised of 413,611 shares held by Deerfield Special Situations
Fund, L.P., 119,429 shares held by Deerfield Partners, L.P., 1,623,089 shares held by Deerfield Private Design Fund III, L.P.,
152,000 shares held by Deerfield International Master Fund, L.P. and 15,931 shares of Common Stock underlying options held by
Jonathan Leff, a partner in Deerfield Management Company, L.P. and a former director of the Issuer.

This Amendment No. 3 (this “Amendment”)
to Schedule 13D amends the Schedule 13D (as previously amended, the “Schedule 13D”) filed by (i) Deerfield Mgmt,
L.P. (“Deerfield Mgmt”), (ii) Deerfield Special Situations Fund, L.P. (“Deerfield Special Situations
Fund”), (iii) Deerfield Management Company, L.P. (“Deerfield Management”), (iv) Deerfield Private
Design Fund III, L.P. (“Deerfield Private Design Fund III”), (v) Deerfield Partners, L.P. (“Deerfield
Partners”), (vi) Deerfield International Master Fund, L.P. (“Deerfield International Master Fund”),
(vii) Deerfield Mgmt III, L.P. (“Deerfield Mgmt III”) and (viii) James E. Flynn, a natural person (“Flynn”
and collectively with Deerfield Mgmt, Deerfield Special Situations Fund, Deerfield Management, Deerfield Private Design Fund III,
Deerfield Partners, Deerfield International Master Fund and Deerfield Mgmt III, the “Reporting Persons”), with
respect to the securities of AveXis, Inc. (the “Company”), on February 19, 2016, as amended by Amendment Nos.
1 and 2 to the Schedule 13D filed on February 2, 2017 and May 31, 2017. Deerfield Special Situations Fund, Deerfield Private Design
Fund III, Deerfield Partners and Deerfield International Master Fund are collectively referred to herein as the “Funds.”

Capitalized terms used herein but not otherwise
defined herein shall have the meanings ascribed to them in the Schedule 13D.

Item 2.        Identity and Background.

Item 2(e) of the Schedule 13D is hereby
amended by adding the following:

On August 21, 2017, Deerfield Management
voluntarily agreed to settle an SEC administrative proceeding relating to alleged violations of Section 204A of the Investment
Advisers Act of 1940 (the “Advisers Act”), without admitting or denying the SEC’s allegations, pursuant to an
order under Section 203(e) and 203(k) of the Advisers Act (the “Order”).  The Order resolved the SEC’s allegations
that Deerfield Management, from 2012 through 2014, violated Section 204A of the Advisers Act by failing to establish, maintain,
and enforce policies and procedures reasonably designed to prevent the misuse of material, nonpublic information, particularly
taking into consideration the nature of Deerfield Management’s business.  The Order alleged that, as part of Deerfield
Management’s research in the healthcare sector, Deerfield Management engaged third party consultants and research firms,
including firms that specialized in providing “political intelligence” regarding upcoming regulatory and legislative
decisions, that Deerfield Management employees based certain trading recommendations on such information, and that hedge funds
advised by Deerfield Management then made those trades.  The Order required Deerfield Management to cease and desist from
committing or causing any violations and any future violations of Section 204A of the Advisers Act, censured Deerfield Management
and provided that Deerfield Management will pay disgorgement and interest of $811,695 and a civil money penalty of $3,946,267.

Item 5.        Interest in Securities of the Issuer.

Items 5(a), (b) and (c) of the Schedule 13D are hereby amended
and restated in their entirety as follows:

(a)

(1)       Deerfield
Mgmt

Percentage of shares: 2.15%*

(2)       Deerfield
Management

Percentage of shares: 7.28%*

(3)       Deerfield
Special Situations Fund

Number of shares: 413,611

Percentage of shares: 1.30%*

(4)       Deerfield
Private Design Fund III

Number of shares: 1,623,089

Percentage of shares: 5.08%*

(5)       Deerfield
Partners

Number of Shares: 119,429

Percentage of Shares: 0.37%*

(6)       Deerfield
International Master Fund

Number of Shares: 152,000

Percentage of Shares: 0.48%*

(7)       Deerfield
Mgmt III

Percentage of shares: 5.08%*

(8)       Flynn

Percentage of shares: 7.28%*

*Percentage beneficial ownership reported herein reflects 31,925,446
shares of Common Stock outstanding as of August 10, 2017, as reported in the Company’s Quarterly Report on Form 10-Q for
the quarterly period ended June 30, 2017.

(b)

(1)        Deerfield
Mgmt

Sole power to vote or direct the vote: 0

Shared power to vote or direct the vote:
685,040

Sole power to dispose or to direct the disposition:
0

Shared power to dispose or direct the disposition:
685,040

(2)       Deerfield
Management

Sole power to vote or direct the vote: 0

Shared power to vote or direct the vote:
2,324,060

Sole power to dispose or to direct the disposition:
0

Shared power to dispose or direct the disposition:
2,324,060

(3)       Deerfield
Special Situations Fund

Sole power to vote or direct the vote: 0

Shared power to vote or direct the vote:
413,611

Sole power to dispose or to direct the disposition:
0

Shared power to dispose or direct the disposition:
413,611

(4)       Deerfield
Private Design Fund III

Sole power to vote or direct the vote: 0

Shared power to vote or direct the vote:
1,623,089

Sole power to dispose or to direct the disposition:
0

Shared power to dispose or direct the disposition:
1,623,089

(5)       Deerfield
Partners

Sole power to vote or direct the vote: 0

Shared power to vote or direct the vote:
119,429

Sole power to dispose or to direct the disposition:
0

Shared power to dispose or direct the disposition:
119,429

(6)       Deerfield
International Master Fund

Sole power to vote or direct the vote: 0

Shared power to vote or direct the vote:
152,000

Sole power to dispose or to direct the disposition:
0

Shared power to dispose or direct the disposition:
152,000

(7)       Deerfield
Mgmt III

Sole power to vote or direct the vote: 0

Shared power to vote or direct the vote:
685,040

Sole power to dispose or to direct the disposition:
0

Shared power to dispose or direct the disposition:
685,040

(8)       Flynn

Sole power to vote or direct the vote: 0

Shared power to vote or direct the vote:
2,324,060

Sole power to dispose or to direct the disposition:
0

Shared power to dispose or direct the disposition:
2,324,060

Flynn is the sole member of the general
partner of each of Deerfield Mgmt, Deerfield Mgmt III and Deerfield Management. Deerfield Mgmt is the general partner, and Deerfield
Management is the investment advisor, of Deerfield Special Situations Fund, Deerfield Partners and Deerfield International Master
Fund. Deerfield Mgmt III is the general partner, and Deerfield Management is the investment advisor, of Deerfield Private Design
Fund III.

(c) No Reporting Person has effected any
transactions in the Company’s securities within the past sixty days. The changes in the percentage of Common Stock beneficially
owned by each Reporting Person reflected in this Amendment have resulted solely from an increase in the number of shares of Common
Stock outstanding, a change in the number of shares of Common Stock underlying the vested portion of options held by Jonathan Leff
for the benefit of Deerfield Management and purchases that occurred prior to such sixty-day period.

Item 7. Material to be Filed as Exhibits

Item 7 of the Schedule 13D is hereby
amended by adding the following:

SIGNATURE

After reasonable inquiry
and to the best of their knowledge and belief, the undersigned certify that the information set forth in this statement is true,
complete and correct.

Dated: August 22, 2017