Salarius Pharmaceuticals, Inc. — Director's Dealing 2015

Feb 5, 2015

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Flex Pharma, Inc. (FLKS)
CIK: 0001615219
Period of Report: 2015-02-03

Reporting Person: Westphal Christoph H (Director, President and CEO)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2015-02-03	Common Stock	C	1868067	$0.00	Acquired	1868067	Indirect
2015-02-03	Common Stock	C	516697	$0.00	Acquired	2384764	Indirect

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2015-02-03	Series A Preferred Stock	$0.00	C	8000000	Disposed		Common Stock (8000000)	Indirect
2015-02-03	Series B Preferred Stock	$0.00	C	2212756	Disposed		Common Stock (2212756)	Indirect

Footnotes

F1: The shares automatically converted on a 4.2825-for-1 basis into shares of the Issuer's Common Stock upon the closing of a Qualified Public Offering (as defined in the Amended and Restated Certificate of Incorporation).

F2: Longwood Fund II GP, LLC is the ultimate General Partner of Longwood Fund II, L.P. Christoph Westphal, M.D., Ph.D., Richard Aldrich and Michelle Dipp, M.D., Ph.D. (collectively, the "Managers") are managers of Longwood Fund II GP, LLC, and, as such, may be deemed to have shared voting and dispositive power with respect to the issuer's securities held by Longwood Fund II, L.P. (the "Longwood Shares"). Each of the Managers disclaim beneficial ownership of the Longwood Shares, except to the extent of their respective pecuniary interest therein, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of the shares for purposes of Section 16 or for any other purpose.

F3: N/A.

F4: The shares have no expiration date.