CUSIP No. 02155H200
1
|
NAMES OF REPORTING PERSONS
Baker Bros. Advisors LP
|
2
|
CHECK
THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions)
|
(a) ¨
(b)
¨
|
3
|
SEC USE ONLY
|
4
|
CITIZENSHIP OR PLACE OF ORGANIZATION
Delaware
|
NUMBER OF
SHARES
BENEFICIALLY
OWNED BY
EACH
REPORTING
PERSON
WITH
|
5
|
SOLE VOTING POWER
1,884,451
|
6
|
SHARED VOTING POWER
-0-
|
7
|
SOLE DISPOSITIVE POWER
1,884,451
|
8
|
SHARED DISPOSITIVE POWER
-0-
|
9
|
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
1,884,451
|
10
|
CHECK
BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
(See Instructions)
|
¨
|
11
|
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
5.1% (1)
|
12
|
TYPE OF REPORTING PERSON (See Instructions)
IA, PN
|
|
(1)
|
Based on 37,142,946 shares of Common Stock (“Common Stock”)
of Altimmune, Inc. (the “Issuer”) outstanding as of December 31, 2020, as reported in the Issuer’s
Form S-3 filed with the Securities and Exchange Commission (“SEC”) on December 31, 2020.
|
CUSIP No. 02155H200
1
|
NAMES
OF REPORTING PERSONS
Baker Bros. Advisors (GP) LLC
|
2
|
CHECK
THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions)
|
(a) ¨
(b)
¨
|
3
|
SEC USE ONLY
|
4
|
CITIZENSHIP OR PLACE OF ORGANIZATION
Delaware
|
NUMBER OF
SHARES
BENEFICIALLY
OWNED BY
EACH
REPORTING
PERSON
WITH
|
5
|
SOLE VOTING POWER
1,884,451
|
6
|
SHARED VOTING POWER
-0-
|
7
|
SOLE DISPOSITIVE POWER
1,884,451
|
8
|
SHARED DISPOSITIVE POWER
-0-
|
9
|
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
1,884,451
|
10
|
CHECK
BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
(See Instructions)
|
¨
|
11
|
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
5.1% (1)
|
12
|
TYPE
OF REPORTING PERSON (See Instructions)
HC, OO
|
|
(1)
|
Based on 37,142,946 shares of Common Stock of the Issuer outstanding
as of December 31, 2020, as reported in the Issuer’s Form S-3 filed with the SEC on December 31, 2020.
|
CUSIP No. 02155H200
1
|
NAMES
OF REPORTING PERSONS
Felix J. Baker
|
2
|
CHECK
THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions)
|
(a) ¨
(b)
¨
|
3
|
SEC USE ONLY
|
4
|
CITIZENSHIP OR PLACE OF ORGANIZATION
United States
|
NUMBER OF
SHARES
BENEFICIALLY
OWNED BY
EACH
REPORTING
PERSON
WITH
|
5
|
SOLE VOTING POWER
1,884,451
|
6
|
SHARED VOTING POWER
-0-
|
7
|
SOLE DISPOSITIVE POWER
1,884,451
|
8
|
SHARED DISPOSITIVE POWER
-0-
|
9
|
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
1,884,451
|
10
|
CHECK
BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
(See Instructions)
|
¨
|
11
|
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
5.1% (1)
|
12
|
TYPE
OF REPORTING PERSON (See Instructions)
IN, HC
|
|
(1)
|
Based on 37,142,946 shares of Common Stock of the Issuer outstanding
as of December 31, 2020, as reported in the Issuer’s Form S-3 filed with the SEC on December 31, 2020.
|
CUSIP No. 02155H200
1
|
NAMES
OF REPORTING PERSONS
Julian C. Baker
|
2
|
CHECK
THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions)
|
(a) ¨
(b)
¨
|
3
|
SEC USE ONLY
|
4
|
CITIZENSHIP OR PLACE OF ORGANIZATION
United States
|
NUMBER OF
SHARES
BENEFICIALLY
OWNED BY
EACH
REPORTING
PERSON
WITH
|
5
|
SOLE VOTING POWER
1,884,451
|
6
|
SHARED VOTING POWER
-0-
|
7
|
SOLE DISPOSITIVE POWER
1,884,451
|
8
|
SHARED DISPOSITIVE POWER
-0-
|
9
|
AGGREGATE
AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
1,884,451
|
10
|
CHECK
BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
(See Instructions)
|
¨
|
11
|
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
5.1% (1)
|
12
|
TYPE
OF REPORTING PERSON (See Instructions)
IN, HC
|
|
(1)
|
Based on 37,142,946 shares of Common Stock of the Issuer outstanding
as of December 31, 2020, as reported in the Issuer’s Form S-3 filed with the SEC on December 31, 2020.
|
Schedule 13G
|
Item 1(a)
|
Name of Issuer:
|
Altimmune, Inc.
(the “Issuer”)
|
Item 1(b)
|
Address of Issuer’s Principal Executive Offices:
|
910
Clopper Road, Suite 201S
Gaithersburg,
Maryland 20878
|
Item 2(a)
|
Name of Person Filing:
|
This Schedule 13G is being filed jointly by the Baker
Bros. Advisors LP (the “Adviser”), Baker Bros. Advisors (GP) LLC (the “Adviser GP”), Felix J. Baker and
Julian C. Baker (collectively, the “Reporting Persons”).
|
Item 2(b)
|
Address of Principal Business Office or, if None, Residence:
|
The business address of each of
the Reporting Persons is:
c/o Baker Bros. Advisors LP
860 Washington Street, 3rd
Floor
New York, NY 10014
(212) 339-5690
The Adviser is a limited partnership organized under
the laws of the State of Delaware. The Adviser GP is a limited liability company organized under the laws of the State of Delaware.
The citizenship of each of Julian C. Baker and Felix J. Baker is the United States of America.
|
Item 2(d)
|
Title of Class of Securities
|
Common Stock, par value $0.0001 per share (“Common
Stock”).
02155H200
|
Item 3.
|
If this statement is filed pursuant to §§240.13d-1(b) or (c), check whether the person filing is a:
|
(a) ¨ Broker
or dealer registered under Section 15 of the Exchange Act.
(b) ¨ Bank as
defined in section 3(a)(6) of the Exchange Act.
(c) ¨ Insurance
company as defined in section 3(a)(19) of the Exchange Act.
(d) ¨ Investment
company registered under section 8 of the Investment Company Act of 1940.
(e) x An investment
adviser in accordance with Rule 13d-1(b)(1)(ii)(E).
(f) ¨ An employee
benefit plan or endowment fund in accordance with Rule 13d-1(b)(1)(ii)(F).
(g) x A parent
holding company or control person in accordance with Rule 13d-1(b)(1)(ii)(G).
(h) ¨ A savings
association as defined in Section 3(b) of the Federal Deposit Insurance Act.
(i) ¨ A church
plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940.
(j) ¨ Group,
in accordance with Rule 13d-1(b)(1)(ii)(J).
Items 5 through 9 and 11 of each of the cover
pages to this Schedule 13G are incorporated herein by reference. Set forth below is the aggregate number of shares of
Common Stock directly held by each of Baker Brothers Life Sciences, L.P. (“Life Sciences”) and 667, L.P.
(“667”, and together with Life Sciences, the “Funds”) which may be deemed to be indirectly
beneficially owned by the Reporting Persons, as well as Common Stock that may be acquired upon exercise of pre-funded
warrants with no expiration date with an exercise price of $0.0001 per share of Common Stock (“Pre-Funded
Warrants”), subject to the limitations on exercise described below.
The information set forth below is based on 37,142,946 shares
of Common Stock outstanding as of December 31, 2020, as reported in the Issuer’s Prospectus filed with the Securities
and Exchange Commission (“SEC”) on December 31, 2020. Such percentage figures are calculated in accordance with
Rule 13d-3 under the Securities Exchange Act of 1934, as amended.
Holder
|
|
Number of Shares of Common Stock we own or have the right to acquire within 60 days
|
|
|
Percent of Class Outstanding
|
|
667, L.P.
|
|
|
147,315
|
|
|
|
0.4
|
%
|
Baker Brothers Life Sciences, L.P.
|
|
|
1,737,136
|
|
|
|
4.7
|
%
|
Total
|
|
|
1,884,451
|
|
|
|
5.1
|
%
|
The Pre-Funded Warrants are only exercisable to the extent that
after giving effect to such exercise the holders thereof, their affiliates and any person who are members of a Section 13(d) group
with the holders or its affiliates would beneficially own in the aggregate, for purposes of Rule 13d-3 under the Exchange Act,
no more than 4.99% of the outstanding Common Stock (“Maximum Percentage”). By written notice to the Issuer, the Funds
may from time to time increase or decrease the Maximum Percentage applicable to that Fund to any other percentage not in excess
of 19.99%. Any such increase will not be effective until the 61st day after such notice is delivered to the Issuer. As
a result of this restriction, the number of shares of Common Stock that may be issued upon exercise of the Pre-Funded Warrants
by the above holders may change depending upon changes in the outstanding Common Stock.
Pursuant to the management agreements, as amended, among the
Adviser, the Funds and their respective general partners, the Funds’ respective general partners relinquished to the Adviser
all discretion and authority with respect to the investment and voting power of the securities held by the Funds and thus the Adviser
has complete and unlimited discretion and authority with respect to the Funds’ investments and voting power over investments.
The Adviser GP, Felix J. Baker and Julian C. Baker as managing
members of the Adviser GP, and the Adviser may be deemed to be beneficial owners of securities of the Issuer directly held by the
Funds.
|
Item 5.
|
Ownership of Five Percent or Less of a Class.
|
If this statement is being filed to report
the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the
class of securities, check the following [ ]. N/A
|
Item
6.
|
Ownership of More than
Five Percent on Behalf of Another Person.
|
N/A
|
Item 7.
|
Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding
Company or Control Person.
|
The information in Item
4 is incorporated herein by reference.
|
Item 8.
|
Identification and Classification of Members of the Group.
|
N/A
|
Item 9.
|
Notice of Dissolution of Group.
|
N/A
By signing below I certify that, to the best of my knowledge
and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired
and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and
were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.
SIGNATURE
After reasonable inquiry and to the best of my knowledge and
belief, I certify that the information set forth in this statement is true, complete and correct.
February 16, 2021
|
BAKER BROS. ADVISORS LP
By: Baker Bros. Advisors (GP) LLC, its general partner
|
|
|
|
|
By:
|
/s/ Scott L. Lessing
|
|
|
Name: Scott L. Lessing
Title: President
|
|
BAKER BROS. ADVISORS (GP) LLC
|
|
|
|
|
By:
|
/s/ Scott L. Lessing
|
|
|
Name: Scott L. Lessing
Title: President
|
|
/s/ Julian C. Baker
|
|
Julian C. Baker
|
|
|
|
/s/ Felix J. Baker
|
|
Felix J. Baker
|