ThZeal - The Zeal

SC 13G 1 d61123_sc13g.txt SCHEDULE 13G SECURITIES AND EXCHANGE COMMISSION Washington, D. C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. __) REPLIGEN CORPORATION (Name of Issuer) Common Stock, $.01 par value per share (Title and Class of Securities) 759916109 (CUSIP Number) October 27, 2004 (Date of Event which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this schedule is filed: |_| Rule 13d-1(b) |X| Rule 13d-1(c) |_| Rule 13d-1(d) *The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page. The information required in the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 (the "Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes). ------------------- ----------------- CUSIP No. 759916109 Page 2 of 8 Pages ------------------- ----------------- -------------------------------------------------------------------------------- 1. NAME OF REPORTING PERSONS S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS IB PARTNERS MANAGEMENT, INC., IRS number 74-3092655, ,as general partner on behalf of the following limited partnerships and on behalf of managed accounts: InvestBio Partners, L.P., IRS number 74-3092654, and InvestBio Short Term Opportunity Fund, L.P., IRS number 20-1477796. -------------------------------------------------------------------------------- 2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) |_| (b) |_| -------------------------------------------------------------------------------- 3. SEC USE ONLY -------------------------------------------------------------------------------- 4. CITIZENSHIP OR PLACE OF ORGANIZATION Delaware -------------------------------------------------------------------------------- NUMBER OF 5. SOLE VOTING POWER SHARES 1,583,878 ----------------------------------------------------------------- BENEFICIALLY 6. SHARED VOTING POWER OWNED BY 0 ----------------------------------------------------------------- EACH 7. SOLE DISPOSITIVE POWER REPORTING 1,583,878 ----------------------------------------------------------------- PERSON 8. SHARED DISPOSITIVE POWER WITH 0 -------------------------------------------------------------------------------- 9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 1,583,878 -------------------------------------------------------------------------------- 10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* |_| -------------------------------------------------------------------------------- 11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 5.3% -------------------------------------------------------------------------------- 12. TYPE OF REPORTING PERSON* IB Partners Management, Inc.- CO InvestBio Partners, L.P. and InvestBio Short Term Opportunity Fund- PN -------------------------------------------------------------------------------- 2 ------------------- ----------------- CUSIP No. 759916109 Page 3 of 8 Pages ------------------- ----------------- Item 1(a). Name of Issuer: Repligen Corporation Item 1(b). Address of Issuer's Principal Executive Offices: 41 Seyon Street, Bldg. 1, Suite 100, Waltham, MA 02453 Item 2(a). Name of Person Filing: (i) IB Partners Management, Inc. (ii) InvestBio Partners, L.P. (iii) InvestBio Short Term Opportunity Fund, L.P. Item 2(b). Address of Principal Business Office or, if None, Residence: 500 Fifth Avenue, 56th Fl., New York, NY 10110 Item 2(c). Citizenship: Not Applicable. Item 2(d). Title of Class of Securities: Common Stock, $.01 par value. Item 2(e). CUSIP Number: 759916109 Item 3. If this statement is filed pursuant to Rule 13d-1(b), or 13d-2(b) or (c), check whether the person filing is a: (a) |_| Broker or Dealer registered under Section 15 of the Act. (b) |_| Bank as defined in Section 3(a)(6) of the Act. (c) |_| Insurance Company as defined in Section 3(a)(19) of the Act. (d) |_| Investment Company registered under Section 8 of the Investment Company Act. (e) |_| Investment Adviser registered in accordance with Rule 13d-1(b)(1)(ii)(E). 3 ------------------- ----------------- CUSIP No. 759916109 Page 4 of 8 Pages ------------------- ----------------- (f) |_| Employee Benefit Plan or Endowment Fund in accordance with Rule 13d-1(b)(1)(ii)(F). (g) |_| Parent Holding Company or control person in accordance with Rule 13d-1(b)(1)(ii)(G). (h) |_| A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act. (i) |_| 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. (j) |_| Group, in accordance with Rule 13d-1(b)(1)(ii)(J). If this Statement is filed pursuant to Rule 13d-1(c), check this box [X]. Item 4. Ownership. (a) Amount beneficially owned: 1,583,878 (b) Percent of Class: 5.3% (c) Number of Shares as to which the person has: (i) Sole power to vote or to direct the vote: 1,583,878 (ii) Shared power to vote or to direct the vote: 0 (iii) Sole power to dispose or to direct the disposition of: 1,583,878 (iv) Shared Power to dispose or to direct the disposition of: 0 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. |_|. 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. Not Applicable. 4 ------------------- ----------------- CUSIP No. 759916109 Page 5 of 8 Pages ------------------- ----------------- Item 8. Identification and Classification of Members of the Group. See Exhibit A Item 9. Notice of Dissolution of Group. Not Applicable. 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. SIGNATURE Date: November 5, 2004 IB PARTNERS MANAGEMENT, INC., By: /s/ Scott L. Mathis ------------------------------ Name: Scott L. Mathis Title: President INVESTBIO PARTNERS, L.P. and INVESTBIO SHORT TERM OPPORTUNITY FUND, L.P. By: IB PARTNERS MANAGEMENT, INC., General Partner By: /s/ Scott L. Mathis ------------------------------ Name: Scott L. Mathis Title: President 5 EXHIBIT A IDENTIFICATION AND CLASSIFICATION OF JOINT FILERS Pursuant to Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, the reporting persons making this joint filing are identified and classified as follows:

6 EXHIBIT B JOINT FILING AGREEMENT PURSUANT TO RULE 13d-1(k)(1) This agreement is made pursuant to Rule 13d-1(k)(1) under the Securities and Exchange Act of 1934 (the "Act") by and among the parties listed below, each referred to herein as a "Joint Filer." The Joint Filers agree that a statement of beneficial ownership as required by Sections 13(g) or 13(d) of the Act and the Rules thereunder maybe filed on each of their behalf on Schedule 13G or 13D, as appropriate, and that said joint filing may thereafter be amended by further joint filings. The Joint Filers state that they each satisfy the requirements for making a joint filing under Rule 13d-1(k) (1). IB PARTNERS MANAGEMENT, INC., By: /s/ Scott L. Mathis ------------------------------ Name: Scott L. Mathis Title: President INVESTBIO PARTNERS, L.P. and INVESTBIO SHORT TERM OPPORTUNITY FUND, L.P. By: IB PARTNERS MANAGEMENT, INC., General Partner By: /s/ Scott L. Mathis ------------------------------ Name: Scott L. Mathis Title: President 7 EXHIBIT C DISCLAIMER OF BENEFICIAL OWNERSHIP Repligen Corporation Common Stock 1,583,878 shares IB Partners Management, Inc. disclaims beneficial ownership as to all shares beneficially owned for Section 13(g) filing purposes by InvestBio Partners, L.P., InvestBio Short Term Opportunity Fund, L.P. and managed accounts. 8