RA Capital Management Bets Another $20 Million On Kala Pharmaceuticals Inc.

CUSIP No. 483119103

This Amendment No. 1 amends and supplements
the statement on Schedule 13D (the “Statement”) originally filed with the Securities and Exchange Commission on February
14, 2018 by the Reporting Persons with respect to the Common Stock, $0.001 par value (the “Common Stock”), of Kala
Pharmaceuticals, Inc. (the “Issuer”).   Unless otherwise defined herein, capitalized terms used in this
Amendment No. 1 shall have the meanings ascribed to them in the initial Statement.

Item 3. Source and Amount of Funds or Other Consideration

Item 3 of the Statement is hereby amended
and supplemented as follows:

On October 3, 2018, the Reporting Persons purchased
2,424,242 shares of Common Stock of the Issuer for $19,999,996.50. The shares were purchased with working capital.

Item 4. Purpose of Transaction

 

Item 4 is hereby supplemented as follows:

The Reporting Persons acquired the Common Stock
referred to in Item 3 for investment purposes and not with an intent, purpose or effect of changing control of the Issuer.

 

Item 5. Interest in Securities of the Issuer

(a) and (b) See Items 7-11 of the cover pages
and Item 2 above.

(c) The following table lists the Reporting
Persons’ transactions in Common Stock that were effected during the sixty day period prior to the filing of this Schedule
13D:

Transaction		Date		No. Shares		Price
Purchase		3-Oct-2018		2,000,301* and 423,941		$	8.25

Shares marked with an * were acquired by the
Fund. The remaining shares were acquired for the Account.

(d) Not applicable.

(e) Not applicable.

Item 7. Material to Be Filed as Exhibits

Exhibit 1

Joint Filing Agreement by and among the Reporting Persons is incorporated herein by reference to Exhibit 1 to the Schedule 13D filed by the Reporting Persons with the Securities and Exchange Commission on February 14, 2018.