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

CUSIP No.  05366U100

13D/A

Page 10 of 15 Pages

This Amendment No. 2 (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 No.
1 to the Schedule 13D filed on February 2, 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 4.        Purpose of the Transaction

Item 4 of the Schedule 13D is hereby amended by adding the
following:

As previously disclosed by the Company, Jonathan Leff, a partner
of Deerfield Management, did not stand for re-election to the Company’s board of directors at the Company’s 2017 annual
meeting of stockholders (the “Annual Meeting”). Accordingly, Mr. Leff’s term as a director expired on May 30,
2017, the date of the Annual Meeting.

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

Number of shares:

613,611 (comprised of shares held by Deerfield Special Situations Fund, Deerfield Partners and Deerfield International Master Fund)

Percentage
of shares: 2.21%*

(2)        Deerfield
Management

Number of shares:

2,252,128 (comprised of shares held by Deerfield Special Situations Fund, Deerfield Private Design Fund III, Deerfield Partners and Deerfield International Master Fund, and 15,428 shares underlying options held by Jonathan Leff, to the extent such options are vested)

Percentage
of shares: 8.10%*