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. 5)*

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)

November
13, 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 197,960 shares held by Deerfield Special Situations
Fund, L.P., 160,143 shares held by Deerfield Partners, L.P. and 111,286 shares held by Deerfield International Master Fund, L.P.

 SCHEDULE 13D

 SCHEDULE 13D

 SCHEDULE 13D

SCHEDULE 13D

SCHEDULE 13D

(2) Comprised of 197,960 shares held by Deerfield Special Situations
Fund, L.P., 160,143 shares held by Deerfield Partners, L.P., 1,077,997 shares held by Deerfield Private Design Fund III, L.P.
and 111,286 shares held by Deerfield International Master Fund, L.P.

SCHEDULE 13D

(3) Comprised of 1,077,997 shares held by Deerfield Private
Design Fund III, L.P.

SCHEDULE 13D

(4) Comprised of 197,960 shares held by Deerfield Special Situations
Fund, L.P., 160,143 shares held by Deerfield Partners, L.P., 1,077,997 shares held by Deerfield Private Design Fund III, L.P.
and 111,286 shares held by Deerfield International Master Fund, L.P.

This Amendment No. 5 (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, 2, 3 and 4 to the Schedule 13D filed on February 2, 2017, May 31, 2017, August 22, 2017 and September 8, 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.

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

(a)

(1)       Deerfield
Mgmt

Number of shares: 469,389
(comprised of shares held by Deerfield Special Situations Fund, Deerfield Partners and Deerfield International Master Fund)

Percentage of shares: 1.47%*

(2)        Deerfield
Management

Number of shares: 1,547,386
(comprised of shares held by Deerfield Special Situations Fund, Deerfield Private Design Fund III, Deerfield Partners and Deerfield
International Master Fund)

Percentage of shares: 4.84%*

(3)        Deerfield
Special Situations Fund

Number of shares: 197,960

Percentage of shares: 0.62%*

(4)       Deerfield
Private Design Fund III

Number of shares: 1,077,997

Percentage of shares: 3.37%*

(5)       Deerfield Partners

Number of Shares: 160,143

Percentage of Shares: 0.50%*

(6)       Deerfield
International Master Fund

Number of Shares: 111,286

Percentage of Shares: 0.35%*

(7)       Deerfield
Mgmt III

Number of shares: 1,077,997
(comprised of shares held by Deerfield Private Design Fund III)

Percentage of shares: 3.37%*

(8)       Flynn

Number of shares: 1,547,386
(comprised of shares held by Deerfield Special Situations Fund, Deerfield Partners, Deerfield International Master Fund, Deerfield
Private Design Fund III)

Percentage of shares: 4.84%*

*Percentage beneficial ownership reported herein reflects 31,976,418
shares of Common Stock outstanding as of November 8, 2017, as reported in the Company’s Quarterly Report on Form 10-Q for
the quarterly period ended September 30, 2017.

(b)

(1)        Deerfield
Mgmt

Sole power to vote or direct the vote: 0

Shared power to vote or direct the vote:
469,389

Sole power to dispose or to direct the disposition:
0

Shared power to dispose or direct the disposition:
469,389

(2)       Deerfield
Management

Sole power to vote or direct the vote: 0

Shared power to vote or direct the vote:
1,547,386

Sole power to dispose or to direct the disposition:
0

Shared power to dispose or direct the disposition:
1,547,386

(3)       Deerfield
Special Situations Fund

Sole power to vote or direct the vote: 0

Shared power to vote or direct the vote:
197,960

Sole power to dispose or to direct the disposition: 0

Shared power to dispose or direct the disposition:
197,960

(4)       Deerfield
Private Design Fund III

Sole power to vote or direct the vote: 0

Shared power to vote or direct the vote:
1,077,997

Sole power to dispose or to direct the disposition:
0

Shared power to dispose or direct the disposition:
1,077,997

(5)       Deerfield
Partners

Sole power to vote or direct the vote: 0

Shared power to vote or direct the vote:
160,143

Sole power to dispose or to direct the disposition:
0

Shared power to dispose or direct the disposition:
160,143

(6)       Deerfield
International Master Fund

Sole power to vote or direct the vote: 0

Shared power to vote or direct the vote:
111,286

Sole power to dispose or to direct the disposition:
0

Shared power to dispose or direct the disposition:
111,286

(7)       Deerfield
Mgmt III

Sole power to vote or direct the vote: 0

Shared power to vote or direct the vote:
1,077,997

Sole power to dispose or to direct the disposition:
0

Shared power to dispose or direct the disposition:
1,077,997

(8)       Flynn

Sole power to vote or direct the vote: 0

Shared power to vote or direct the vote:
1,547,386

Sole power to dispose or to direct the disposition:
0

Shared power to dispose or direct the disposition:
1,547,386

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) Transactions in the Common Stock effected
by the Reporting Persons in the last sixty (60) days are set forth on Schedule A to this Amendment. All of the transactions reflected
in Schedule A to this Amendment were effected in open market transactions on the Nasdaq Global Select Market in the ordinary course
of the applicable Reporting Person’s business.

(e)  As of September 15, 2017, the
Reporting Persons ceased to beneficially own more than five percent of the Common Stock.

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: November 13, 2017

Schedule A

* Each price per share reported in the “Price per Share”
column of this Schedule A is a weighted average price. The Reporting Persons undertake to provide to the staff of the Securities
and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges
set forth in the “Price Range” column of this Schedule A.

** The shares were sold in multiple transactions at prices
within the price range indicated.