SYNLOGIC, INC. — Director's Dealing 2015

Oct 1, 2015

SEC Form 3 — Initial Statement of Beneficial Ownership

Issuer: Mirna Therapeutics, Inc. (MIRN)
CIK: 0001527599
Period of Report: 2015-09-30

Reporting Person: Alleva Lawrence M (Director)

Holdings (Derivative)

Security	Exercise Price	Expiration	Underlying	Shares	Ownership
Series D Preferred Stock	$0.00		Common Stock (3818)		Indirect
Stock Option (Right to Buy)	$7.80	2024-11-05	Common Stock (13333)		Direct
Stock Option (Right to Buy)	$6.15	2025-03-01	Common Stock (2666)		Direct
Stock Option (Right to Buy)	$6.45	2025-06-04	Common Stock (8000)		Direct

Footnotes

F1: Each share of Series D Preferred Stock will automatically convert on a one-to-one basis into Common Stock immediately prior to the consummation of the Issuer's initial public offering.

F2: The securities are immediately convertible.

F3: The expiration date is not relevant to the conversion of these securities.

F4: The shares are held by the Lawrence M. Alleva Profit Sharing Plan.

F5: The option vests with respect to 20% of the shares subject thereto on September 10, 2014, with the remaining shares vesting with respect to 1/8 of the remaining shares subject thereto on each six month anniversary thereafter, subject to the Reporting Person continuing to provide services to the Issuer through each such vesting date.

F6: The option vests with respect to 20% of the shares subject thereto on January 1, 2015, with the remaining shares vesting with respect to 1/8 of the remaining shares subject thereto on each six month anniversary thereafter, subject to the Reporting Person continuing to provide services to the Issuer through each such vesting date.

F7: The option vests with respect to 20% of the shares subject thereto on May 1, 2015, with the remaining shares vesting with respect to 1/8 of the remaining shares subject thereto on each six month anniversary thereafter, subject to the Reporting Person continuing to provide services to the Issuer through each such vesting date.