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* NeoMed Innovation V L.P. (Last) (First) (Middle) 13 CASTLE STREET (Street) ST HELIER Y9 JE4 5UT (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) 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) Form filed by One Reporting Person X 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)

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
Series B Convertible Preferred Stock	(1)	(1)	Common Stock	246,682	(1)	D(4)
Series C Convertible Preferred Stock	(2)	(2)	Common Stock	41,878	(2)	D(4)
Series D Convertible Preferred Stock	(3)	(3)	Common Stock	279,079	(3)	D(4)

1. Name and Address of Reporting Person* NeoMed Innovation V L.P. (Last) (First) (Middle) 13 CASTLE STREET (Street) ST HELIER Y9 JE4 5UT (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* NeoMed Management (Jersey) Ltd (Last) (First) (Middle) 13 CASTLE STREET (Street) ST HELIER Y9 JE4 5UT (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* NeoMed Innovation V Ltd (Last) (First) (Middle) 13 CASTLE STREET (Street) ST HELIER Y9 JE4 5UT (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. The Series B Convertible Preferred Stock is convertible into Common Stock on a 0.44650-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.

2. The Series C Convertible Preferred Stock is convertible into Common Stock on a 0.49832-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.

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.

4. The reported securities are held of record by NeoMed Innovation V L.P. NeoMed Management (Jersey) Limited is the Investment Manager to NeoMed Innovation V L.P. NeoMed Innovation V Limited is the general partner of Neomed Innovation V L.P. By virtue of such relationships, NeoMed Management (Jersey) Limited and NeoMed Innovation V Limited may be deemed to have voting and investment power with respect to the shares held by NeoMed Innovation V L.P. Each of NeoMed Management (Jersey) Limited and NeoMed Innovation V Limited disclaims beneficial ownership of the shares held by NeoMed Innovation V L.P., except to the extent of its or his pecuniary interest therein, if any.

Remarks:

Exhibit Index: 24.1 Power of Attorney 24.2 Power of Attorney 24.3 Power of Attorney

	/s/ Mike Gray, as attorney-in-fact on behalf of NeoMed Innovation V L.P.	11/15/2017
	/s/ Mike Gray, as attorney-in-fact on behalf of NeoMed Management (Jersey) Limited	11/15/2017
	/s/ Mike Gray, as attorney-in-fact on behalf of NeoMed Innovation V Limited	11/15/2017
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
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