UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

o

Rule 13d-1(b)

x

Rule 13d-1(c)

o

Rule 13d-1(d)

CUSIP No. 45253H101

1.

Names of Reporting Persons
Capital Ventures International

2.

Check the Appropriate Box if a Member of a Group (See Instructions)

(a)

o

(b)

o

3.

SEC Use Only

4.

Citizenship or Place of Organization
Cayman Islands

Number of
Shares
Beneficially
Owned by
Each
Reporting
Person With

5.

Sole Voting Power
0

6.

Shared Voting Power
2,048,854(1)

7.

Sole Dispositive Power
0

8.

Shared Dispositive Power
2,048,854 (1)

9.

Aggregate Amount Beneficially Owned by Each Reporting Person
2,048,854 (1)

10.

Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)  o

11.

Percent of Class Represented by Amount in Row (9)
4.8%

12.

Type of Reporting Person (See Instructions)
CO

CUSIP No. 45253H101

1.

Names of Reporting Persons
Heights Capital Management, Inc.

2.

Check the Appropriate Box if a Member of a Group (See Instructions)

(a)

o

(b)

o

3.

SEC Use Only

4.

Citizenship or Place of Organization
Delaware

Number of
Shares
Beneficially
Owned by
Each
Reporting
Person With

5.

Sole Voting Power
0

6.

Shared Voting Power
2,048,854(1)

7.

Sole Dispositive Power
0

8.

Shared Dispositive Power
2,048,854 (1)

9.

Aggregate Amount Beneficially Owned by Each Reporting Person
2,048,854 (1)

10.

Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)  o

11.

Percent of Class Represented by Amount in Row (9)
4.8%

12.

Type of Reporting Person (See Instructions)
CO

CUSIP No. 45253H101

Item 1.

(a)

Name of Issuer
ImmunoGen, Inc. (the “Company”).

(b)

Address of Issuer’s Principal Executive Offices
128 Sidney Street, Cambridge, MA 02139

Item 2.

(a)

Name of Person Filing
Capital Ventures International and Heights Capital Management, Inc. (each, a “Reporting Person”)

(b)

Address of Principal Business Office or, if none, Residence
CVI:        One Capitol Place, P.O. Box 1787 GT, Grand Cayman Islands, B.W.I.

HCM:     101 California Street, S-3250, San Francisco, CA 94111

(c)

Citizenship
CVI:       Cayman Islands

HCM:     Delaware

(d)

Title of Class of Securities
Common Stock, $.01 par value per share, of the Company (“Common Stock”).

(e)

CUSIP Number
45253H101

Item 3.

If this statement is filed pursuant to §§240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:

(a)

o

Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o).

(b)

o

Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c).

(c)

o

Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c).

(d)

o

Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8).

(e)

o

An investment adviser in accordance with §240.13d-1(b)(1)(ii)(E);

(f)

o

An employee benefit plan or endowment fund in accordance with §240.13d-1(b)(1)(ii)(F);

(g)

o

A parent holding company or control person in accordance with §240.13d-1(b)(1)(ii)(G);

(h)

o

A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);

(i)

o

A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);

(j)

o

Group, in accordance with §240.13d-1(b)(1)(ii)(J).

CUSIP No. 45253H101

Item 4.

Ownership

Provide the following information regarding the aggregate number and percentage of the class of securities of the issuer identified in Item 1.

The information required by Items 4(a) – (c) is set forth in Rows 5 – 11 of the cover page for each Reporting Person hereto and is incorporated herein by reference for each such Reporting Person. The Company’s Quarterly Report on Form 10-Q for the quarterly period ended September 30, 2007 indicates there were 42,635,859 shares of Common Stock outstanding as of October 30, 2007. 

Heights Capital Management, Inc., which serves as the investment manager to Capital Ventures International, may be deemed to be the beneficial owner of all Shares owned by Capital Ventures International. Each of the Reporting Persons hereby disclaims any beneficial ownership of any such Shares, except to the extent of their pecuniary interest therein.

Item 5.

Ownership of Five Percent or Less of a Class

If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following   o.

Item 6.

Ownership of More than Five Percent on Behalf of Another Person

Not applicable

Item 7.

Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company or Control Person

Not applicable

Item 8.

Identification and Classification of Members of the Group

Not applicable

Item 9.

Notice of Dissolution of Group

Not applicable

CUSIP No. 45253H101

Item 10.

Certification

By signing below, I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.

Date:

January 31, 2008

CAPITAL VENTURES INTERNATIONAL

By: Heights Capital Management, Inc. pursuant to a
Limited Power of Attorney, a copy of which is filed as
Exhibit A hereto.

By:

/s/ Todd Silverberg

Todd Silverberg,

Secretary

HEIGHTS CAPITAL MANAGEMENT, INC.

By:

/s/ Todd Silverberg

Todd Silverberg,

Secretary

Dated: February 13, 2006

CAPITAL VENTURES INTERNATIONAL

By: Heights Capital Management, pursuant to a Limited Power of Attorney, a copy of which is filed as Exhibit A to the Schedule 13G.

By:

/s/ Todd Silverberg

Todd Silverberg, Secretary

Dated: February 13, 2006

HEIGHTS CAPITAL MANAGEMENT, INC.

By:

/s/ Todd Silverberg

Todd Silverberg, Secretary