13D Filing: Baker Bros. Advisors and Erytech Pharma SA (ADR) (ERYP)

Page 7 of 10

Page 7 of 10 – SEC Filing

CUSIP No.  29604W108 Page   7   of   10   Pages

Pursuant to the Offering, on November 10, 2017, 667, L.P. and
Baker Brothers Life Sciences, L.P. (“Life Sciences” and together with 667, the “Funds”) purchased 308,928
and 2,781,141 ADS of the Issuer, respectively, at the offering price of $23.26 per share, totaling 3,090,069 shares in the aggregate.
Each of the Funds purchased ADS of the Issuer with their working capital.

Prior to the Offering, the Funds held securities of the Issuer
previously purchased in open market transactions directly with a broker dealer and in underwritten public offerings using working
capital of the Funds. The aggregate purchase price of the 1,808,268 Ordinary Shares directly held by Funds was approximately $47.5MM.

The Funds hold securities of the Issuer for investment purposes.
The Reporting Persons or their affiliates may purchase additional securities or dispose of securities in varying amounts and at
varying times depending upon the Reporting Persons’ continuing assessments of pertinent factors, including the availability
of Ordinary Shares or other securities for purchase at particular price levels, the business prospects of the Issuer, other business
investment opportunities, economic conditions, stock market conditions, money market conditions, the attitudes and actions of the
Board and management of the Issuer, the availability and nature of opportunities to dispose of securities of the Issuer and other
plans and requirements of the particular entities. The Reporting Persons may discuss items of mutual interest with the Issuer,
which could include items in subparagraphs (a) through (j) of Item 4 of Schedule 13D.

Depending upon their assessments of the above factors, the Reporting
Persons or their affiliates may change their present intentions as stated above and may make suggestions to the management of the
Issuer regarding corporate financing and strategy, and may acquire or dispose of securities of the Issuer (by means of open market
purchases, privately negotiated purchases, or otherwise).

Except as otherwise disclosed herein, at the present time, the
Reporting Persons do not have any plans or proposals with respect to any extraordinary corporate transaction involving the Issuer
including, without limitation, those matters described in subparagraphs (a) through (j) of Item 4 of Schedule 13D.

Item 5. Interest in Securities of the Issuer.

(a) and (b) Items 7 through 11 and 13 of each
of the cover pages of this Schedule 13D are incorporated herein by reference. Set forth below is the aggregate number of Ordinary
Shares of the Issuer directly held by each of the Funds, including Ordinary Shares owned through American Depositary Shares held
by each of the Funds, and the percentage of the Issuer’s outstanding Ordinary Shares such holdings represent. Each American
Depositary Share represents one Ordinary Shares of the Issuer. The information set forth below is based upon 17,119,681 Ordinary
Shares that will be outstanding following the Offering plus 806,104 additional ADS and/ or ordinary shares issued as part of the
Underwriters option according to information published by the Issuer on November 10, 2017 and November 15, 2017. Such percentage
figures are calculated in accordance with Rule 13d-3 under the Securities Exchange Act of 1934, as amended.

Follow Erytech Pharma S.a. (NASDAQ:ERYP)

Page 7 of 10