SC TO-T/A

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE TO

Amendment No. 4

Tender Offer Statement under Section 14(d)(1) or 13(e)(1)
of the Securities Exchange Act of 1934

Biosite Incorporated

(Name of Subject Company (Issuer))

Inca Acquisition, Inc.
Inverness Medical Innovations, Inc.

(Name of Filing Persons (Offerors))

Common Stock, $0.01 par value

(Title of Class of Securities)
090945106
(CUSIP Number of Class of Securities)

Ron Zwanziger
President and Chief Executive Officer
Inverness Medical Innovations, Inc.
51 Sawyer Road, Suite 200
Waltham, Massachusetts 02453
(781) 647-3900

(Name, address and telephone number of person authorized
to receive notices and communications on behalf of filing persons)

Copy to:

Scott F. Duggan, Esq.
Goodwin Procter LLP
Exchange Place
Boston, Massachusetts 02109
(617) 570-1000

CALCULATION OF FILING FEE

Transaction Valuation*	Amount of Filing Fee**
$1,603,420,070	$49,225.00

*	Estimated for purposes of calculating the filing fee only. This calculation assumes the purchase of 17,334,271 shares of the Common Stock of Biosite Incorporated at the tender offer price of $92.50 per share.
**	The amount of the filing fee, calculated in accordance with the Securities Exchange Act of 1934, as amended, equals $30.70 per million of transaction value.

þ Check the box if any part of the fee is offset as provided by Rule 0-11(a)(2) and identify the filing with which the offsetting fee was previously paid. Identify the previous filing by registration statement number, or the Form or Schedule and the date of its filing.

Amount Previously Paid: $49,225.00	Filing Party: Inverness Medical Innovations, Inc.
Form or Registration No. Schedule TO	Date Filed: May 29, 2007

o	Check the box if the filing relates solely to preliminary communications made before the commencement of a tender offer.
	Check the appropriate boxes below to designate any transactions to which the statement relates:
x	third-party tender offer subject to Rule 14d-1. issuer tender offer subject to Rule 13e-4.
o	going-private transaction subject to Rule 13e-3.
o	amendment to Schedule 13D under Rule 13d-2.
	Check the following box if the filing is a final amendment reporting the results of the tender offer: o

     This Amendment No. 4 (this “Amendment”) amends and supplements the Tender Offer Statement on Schedule TO (the “Schedule TO”) originally filed with the Securities and Exchange Commission (the “SEC”) on May 29, 2007, as amended by Amendment No. 1 on May 30, 2007, Amendment No. 2 on June 5, 2007, and Amendment No. 3 on June 7, 2007 relating to the offer by Inca Acquisition, Inc., a Delaware corporation (the “Purchaser”) and a wholly-owned subsidiary of Inverness Medical Innovations, Inc. (“Inverness”) to purchase all of the issued and outstanding shares of common stock, par value $0.01 per share, including the associated right to purchase series A participating preferred stock, par value $0.01 per share, (collectively, the “Shares”), of Biosite Incorporated, a Delaware corporation (“Biosite”), at a purchase price of $92.50 per share, plus, if the first time the Shares are accepted for payment (the “Acceptance Time”) shall not have occurred on or prior to July 2, 2007, an additional $0.015205 per Share for each day during the period commencing on July 3, 2007, through the Acceptance Time, less any applicable withholding taxes (the “Offer Price”), upon the terms and subject to the conditions set forth in the Offer to Purchase, dated May 29, 2007 (the “Offer to Purchase”), and in the related Letter of Transmittal (the “Letter of Transmittal”). Capitalized terms used and not otherwise defined in this Amendment shall have the meanings assigned to such terms in the Offer to Purchase or in the Schedule TO. This Amendment is being filed on behalf of Inverness and the Purchaser.

Items 4 and 11 of the Schedule TO, to the extent such Items incorporate by reference the information contained in the Offer, are hereby amended and supplemented as follows:

Section 15—“Certain Legal Matters” of the Offer to Purchase is hereby amended and supplemented by adding the following sentence after the second paragraph under the subsection captioned “Antitrust Matters”:

“On June 7, 2007, Inverness issued a press release announcing that the waiting period required under the HSR Act expired without a request for additional information with respect to the Offer and the Merger.”

On June 7, 2007, Inverness issued a press release announcing the termination of the waiting period under the HSR Act, a copy of which is filed as Exhibit (a)(5)(F) hereto and is incorporated by reference.

Miscellaneous

Item 12 of the Statement is hereby amended and supplemented to include the following:

     “(a)(5)(F) Press Release issued by Inverness Medical Innovations, Inc. on June 7, 2007.”

SIGNATURES

     After due inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

INCA ACQUISITION, INC.
By:	/s/ Jay McNamara
Name:	Jay McNamara
Title:	Assistant Secretary

INVERNESS MEDICAL INNOVATIONS, INC.
By:	/s/ Jay McNamara
Name:	Jay McNamara
Title:	Senior Counsel – Corporate and Finance

Date: June 7, 2007

INDEX TO EXHIBITS

(a)(1)(A)	Offer to Purchase, dated as of May 29, 2007.*
(a)(1)(B)	Letter of Transmittal.*
(a)(1)(C)	Notice of Guaranteed Delivery.*
(a)(1)(D)	Letter to Brokers, Dealers, Banks, Trust Companies and other Nominees.*
(a)(1)(E)	Letter to Clients for use by Brokers, Dealers, Banks, Trust Companies and other Nominees.*
(a)(1)(F)	Guidelines for Certification of Taxpayer Identification Number on Substitute Form W-9.*
(a)(1)(G)	Summary Advertisement published on May 29, 2007.*
(a)(5)(A)	Press Release issued by Inverness Medical Innovations, Inc. on May 9, 2007 (incorporated by reference to the Schedule TO-C filed by Inverness Medical Innovations, Inc. on May 9, 2007).*
(a)(5)(B)	Press Release issued by Inverness Medical Innovations, Inc. on May 11, 2007 (incorporated by reference to the Schedule TO-C filed by Inverness Medical Innovations, Inc. on May 11, 2007).*
(a)(5)(C)	Joint press release issued by Inverness Medical Innovations, Inc. and Biosite Incorporated, dated May 17, 2007 (incorporated by reference to the Schedule TO-C filed by Inverness Medical Innovations, Inc. on May 18, 2007).*
(a)(5)(D)	Press Release issued by Inverness Medical Innovations, Inc. on May 29, 2007.*
(a)(5)(E)	Presentation given to Biosite employees on May 30, 2007.*
(a)(5)(F)	Press Release issued by Inverness Medical Innovations, Inc. on June 7, 2007.
(b)(1)	Commitment Letter dated May 14, 2007, by and among General Electric Capital Corporation, UBS Loan Finance LLC and Inverness Medical Innovations, Inc. (incorporated by reference to Exhibit 99.2 to the Current Report on Form 8-K filed by Inverness Medical Innovations, Inc. on May 15, 2007) (superceded in its entirety by Exhibit (b)(3)).*
(b)(2)	Commitment Letter dated May 14, 2007, by and among UBS Loan Finance LLC, UBS Securities LLC, General Electric Capital Corporation and Inverness Medical Innovations, Inc. (incorporated by reference to Exhibit 99.3 to the Current Report on Form 8-K filed by Inverness Medical Innovations, Inc. on May 15, 2007) (superceded in its entirety by Exhibit (b)(3)).*
(b)(3)	Commitment Letter dated June 5, 2007, by and among UBS Loan Finance LLC and General Electric Capital Corporation and Inverness Medical Innovations, Inc.*
(d)(1)	Agreement and Plan of Merger, dated as of May 17, 2007, by and among Inverness Medical Innovations, Inc., the Purchaser and Biosite Incorporated (incorporated by reference to Exhibit 2.1 to the Current Report on Form 8-K filed by Inverness Medical Innovations, Inc. on May 18, 2007).*

* previously filed

EX-99.(A)(5)(F)

Exhibit (a)(5)(F)

FOR IMMEDIATE RELEASE

For Inverness:

Media Contacts:
Matt Benson 415-618-8750
Maggie Pisacane 212-687-8080
Sard Verbinnen & Co

Investor Relations Contact:
Doug Guarino 781-647-3900

For Biosite:

Investor Relations Contact:
Nadine Padilla 858-805-2820

INVERNESS AND BIOSITE ANNOUNCE EXPIRATION OF HART-SCOTT-RODINO WAITING PERIOD

WALTHAM, Mass. and SAN DIEGO, Calif., June 7, 2007 — Inverness Medical Innovations, Inc. (Amex: IMA) and Biosite Incorporated (Nasdaq: BSTE) today announced that the waiting period required under the Hart-Scott-Rodino Antitrust Improvements Act of 1976 with respect to Inverness’ proposed acquisition of Biosite pursuant to a cash tender offer of $92.50 per share has expired without a request for additional information.

The expiration of the Hart-Scott-Rodino waiting period has satisfied one of the conditions to the closing of the tender offer. The tender offer and withdrawal rights are currently scheduled to expire at 12:00 midnight, New York City time, on Monday, June 25, 2007 (the end of the day on Monday), unless extended.

Advisors:
UBS Investment Bank is acting as financial advisor to Inverness as well as serving as dealer manager for the proposed tender offer. Covington Associates is acting as financial advisor to Inverness and Goldman, Sachs & Co. is acting as financial advisor to Biosite. Goodwin Procter LLP is serving as legal counsel to Inverness and Cooley Godward Kronish LLP and Potter Anderson & Corroon LLP are serving as legal counsel to Biosite.

# # #

About Inverness:
Inverness Medical Innovations, Inc. is a leading developer of advanced diagnostic devices and is presently exploring new opportunities for its proprietary electrochemical and other technologies in a variety of professional diagnostic and consumer-oriented applications including immuno-diagnostics with a focus on women’s health, cardiology and infectious disease. The Company’s new product development

efforts, as well as its position as a leading supplier of consumer pregnancy and fertility/ovulation tests and rapid point-of-care diagnostics, are supported by the strength of its intellectual property portfolio. Inverness is headquartered in Waltham, Massachusetts.

For additional information on Inverness Medical Innovations, Inc., please visit our website at www.invernessmedical.com.

About Biosite:
Biosite Incorporated is a leading bio-medical company commercializing proteomics discoveries for the advancement of medical diagnosis. The company’s products contribute to improvements in medical care by aiding physicians in the diagnosis of critical diseases and health conditions. The Biosite Triage(R) rapid diagnostic tests are used in more than 70 percent of U.S. hospitals and in more than 60 international markets. Information on Biosite can be found at www.biosite.com.

Additional Information About the Proposed Transaction and Where to Find It:

This press release is neither an offer to purchase nor a solicitation of an offer to sell shares of Biosite. Stockholders of Biosite are urged to read the relevant tender offer documents because they contain important information that stockholders should consider before making any decision regarding tendering their shares. Inverness and its acquisition subsidiary have filed tender offer materials with the U.S. Securities and Exchange Commission (SEC), and Biosite has filed a Solicitation/Recommendation Statement with respect to the offer. The tender offer materials (including an Offer to Purchase, a related Letter of Transmittal and certain other offer documents) and the Solicitation/Recommendation Statement contain important information, which should be read carefully before any decision is made with respect to the tender offer. The Offer to Purchase, the related Letter of Transmittal and certain other offer documents, as well as the Solicitation/Recommendation Statement, are available to all stockholders of Biosite at no expense to them. The tender offer materials and the Solicitation/Recommendation Statement are available for free at the SEC’s website at http://www.sec.gov. In addition, stockholders are able to obtain a free copy of these documents from (i) Inverness by mailing requests for such materials to: Investor Relations Department, 51 Sawyer Road, Suite 200, Waltham, MA 02453 and (ii) Biosite by mailing requests for such materials to: Investor Relations, Biosite Incorporated, 9975 Summers Ridge Road, San Diego, California 92121. In addition to the Offer to Purchase, the related Letter of Transmittal and certain other offer documents, as well as the Solicitation/Recommendation Statement, Biosite and Inverness file annual, quarterly and special reports, proxy statements and other information with the SEC. You may read and copy any reports, statements or other information filed by Biosite or Inverness at the SEC public reference room at 100 F Street, N.E., Washington, D.C. 20549. Please call the SEC at 1-800-SEC-0330 for further information on the public reference room. Biosite’s and Inverness’ filings with the SEC are also available to the public from commercial document-retrieval services and at the website maintained by the SEC at http://www.sec.gov.