13D Filing: James E. Flynn and Homology Medicines Inc (FIXX)

On April 2, 2018, in connection with the
closing of the IPO, each share of the Preferred Stock automatically converted into 0.1900057 shares of Common Stock (after giving
effect to a 1-for-5.263 reverse stock split in connection with the IPO). The number of shares of Common Stock acquired by the Reporting
Persons upon such conversion was:

In addition, in connection with the IPO,
each of Deerfield Private Design Fund III and Deerfield Partners acquired 625,000 shares of Common Stock for $16.00 per share.
The aggregate purchase price paid by Deerfield Private Design Fund III and Deerfield Partners for such shares was $10,000,000.00
and $10,000,000.00, respectively. Deerfield Private Design Fund III and Deerfield Partners utilized their respective working capital
to purchase the shares of Common Stock reported herein.

Shares of Common Stock beneficially owned
by the Reporting Persons are or may be held from time to time by the applicable Fund in margin accounts established with their
respective brokers or banks, and a portion of the purchase price for the Common Stock may have been obtained through margin borrowing.
Common Stock positions held in margin accounts may be pledged as collateral security for the repayment of debit balances in the
margin accounts.

The information set forth in Items 3 and
6 is incorporated herein by reference.

The Reporting Persons have acquired the
shares reported herein for investment purposes. Cameron Wheeler, Ph.D., an employee of Deerfield Management, was appointed to serve
on the Company’s board of directors prior to the IPO and continues to serve in such capacity.

Depending on various factors and subject
to the obligations described herein, the Reporting Persons may take such actions with respect to their investments in the Company
as they deem appropriate, including, without limitation, purchasing additional shares of Common Stock or other financial instruments
related to the Company or selling some or all of their beneficial or economic holdings, engaging in hedging or similar transactions
with respect to the securities relating to the Issuer and/or otherwise changing their intention with respect to any and all matters
referred to in Item 4 of Schedule 13D.

On July 28, 2017, prior to the IPO Deerfield
Private Design Fund III, Deerfield Healthcare Innovations Fund, the Company and other investors entered into an Amended and Restated
Investors’ Rights Agreement of the Company (the “Investor Rights Agreement”), the terms of which are described
in Item 6 below.