Gerngross Tillman U. Form 3 Arsanis / Tillman U. Gerngross ownership change

SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person^*

Gerngross Tillman U.

(Last) (First) (Middle)

C/O ARSANIS, INC.

890 WINTER STREET, SUITE 230

(Street)

WALTHAM MA 02451

(City) (State) (Zip)

2. Date of Event Requiring Statement (Month/Day/Year)
11/15/2017

3. Issuer Name and Ticker or Trading Symbol
Arsanis, Inc. [ ASNS ]

4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

5. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock	102,549	D

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Option (right to buy)	(1)	04/18/2023	Common Stock	26,809	1.85	D
Stock Option (right to buy)	(2)	07/19/2026	Common Stock	38,675	9.39	D
Series D Convertible Preferred Stock	(3)	(3)	Common Stock	90,272	(3)	D

Explanation of Responses:

1. This option fully vested on September 1, 2014.

2. This option was granted on July 20, 2016, and vests over four years, with 25% of the original 38,675 shares underlying the option having vested on July 20, 2017 and 2.0833% of the original 38,675 shares vesting monthly thereafter, subject to continued service.

3. The Series D Convertible Preferred Stock is convertible into Common Stock on a 0.29300-for-one basis into the number of shares of Common Stock shown in column 3 at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

Remarks:

Exhibit Index: 24.1 Power of Attorney

	/s/ Mike Gray, attorney-in-fact	11/15/2017
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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