SC 13D

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D. C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

MOLECULAR INSIGHT PHARMACEUTICALS, INC.

(Name of Issuer)

COMMON STOCK, $0.01 PAR VALUE

(Title of Class of Securities)

60852M104

(CUSIP Number of Class of Securities)

David S. Barlow

640 Lewis Wharf

Boston, Massachusetts 02110

(617) 922 5422

(Name, Address and Telephone Number of Person Authorized
to Receive Notices and Communications)

with copies to:

Greenberg Traurig, LLP One International Place, 20th Floor Boston, Massachusetts 02110 Attention: Jonathan Bell, Esq. Telephone: (617) 310-6038 Greenberg Traurig, LLP One International Place, 20th Floor Boston, Massachusetts 02110 Attention: Mark Berthiaume, Esq. Telephone: (617) 310-6007

January 30, 2009

(Date of Event which Requires Filing of this Statement)

If the filing person has previously filed a Statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D and is filing this Schedule because of Rule 13d-1(e), 13d-1(f) or 13d-1(g), check the following box. x

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Rule 240.13d-7(b) for other parties to whom copies are to be sent.

*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 disclosures provided in a prior cover page.

The information required on 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 (‘‘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. 60852M104 SCHEDULE 13D Page 2 of 6 Pages

1.	NAME OF REPORTING PERSON: David S. Barlow
	I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)
	Not applicable.
2.	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
	(a) o
	(b) x
3.	SEC USE ONLY
4.	SOURCE OF FUNDS
	PF
5.	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e)
	o
6.	CITIZENSHIP OR PLACE OF ORGANIZATION
	United States

NUMBER OF  SHARES  BENEFICIALLY  OWNED BY  EACH REPORTING  PERSON  WITH	7.	SOLE VOTING POWER
		2,735,447(1) (see Item 5)
	8.	SHARED VOTING POWER
		-0- (see Item 5)
	9.	SOLE DISPOSITIVE POWER
		2,735,447(1)  (see Item 5)
	10.	SHARED DISPOSITIVE POWER
		-0- (see Item 5)

11.	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
	2,735,447(1) SHARES OF COMMON STOCK.
12.	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES
	o
13.	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
	10.9% OF COMMON STOCK(2)
14.	TYPE OF REPORTING PERSON
	IN

(1) As of January 30, 2009, David S. Barlow owned (i) 2,695,447 shares of common stock of Molecular Insight Pharmaceuticals, Inc. and (ii) had the right to acquire 40,000 shares of common stock pursuant to certain Employment Stock Options within sixty days of January 30, 2009.

(2) The percentage calculation is based upon the sum of (i) 24,988,157 shares of common stock of Molecular Insight Pharmaceuticals, Inc. issued and outstanding as of November 7, 2008 as reported in a Form 10-Q filed by the company with the Securities and Exchange Commission on November 14, 2008 and (ii) 40,000 shares of common stock that Mr. Barlow has the right to acquire within sixty days of January 30, 2009 pursuant to certain Employment Stock Options.

Page 2 of 6 Pages

SCHEDULE 13D

ITEM 1. SECURITY AND ISSUER

This statement on Schedule 13D (this “Schedule 13D”) relates to the common stock, par value $0.01 per share (the “Common Shares”), of Molecular Insight Pharmaceuticals, Inc., a Massachusetts  corporation (the “Issuer”). The principal executive offices of the Issuer are located at 160 Second Street, Cambridge, Massachusetts 02142.

ITEM 2. IDENTITY AND BACKGROUND

(a) This Schedule 13D is being filed by David S. Barlow, an individual.

(b) Mr. Barlow has a business address of 640 Lewis Wharf, Boston, Massachusetts 02110.

(c) Mr. Barlow’s present principal occupation is independent investor and member of several not for profit boards.

(d) and (e) During the last five years, Mr. Barlow has not been convicted in any criminal proceeding (excluding traffic violations or similar misdemeanors) nor was he a party to a civil proceeding of a judicial or administrative body resulting in a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws, or finding any violations with respect to such laws.

(f) Mr. Barlow is a citizen of the United States of America.

ITEM 3. SOURCE AND AMOUNT OF FUNDS

The Common Shares beneficially owned by Mr. Barlow were acquired through the exercise of employee stock options granted to Mr. Barlow during his employment with the Issuer as its Chief Executive Officer and open market purchases.  The aggregate amount of funds used to purchase all Common Shares beneficially owned by Mr. Barlow was approximately $5,000,000.

The source of funds for the acquisition of the Common Shares beneficially owned by Mr. Barlow was Mr. Barlow’s own funds and a non-interest bearing promissory note payable by Mr. Barlow to the Issuer in the amount of $295,650 with respect to the exercise of an option to purchase restricted Common Shares granted to Mr. Barlow in connection with his original employment agreement with the Issuer. On November 4, 2005, Mr. Barlow repaid this loan in full.

ITEM 4. PURPOSE OF TRANSACTION

On January 30, 2009, Mr. Barlow delivered to the board of directors of the Issuer (the “Board”) the letter filed herewith as Exhibit 1, which is incorporated herein by reference. Mr. Barlow desires to continue to engage in discussions with management of the Issuer and members of the Board concerning the business, operations and future plans of the Issuer, as well as measures Mr. Barlow believes will improve shareholder value for the benefit of the Issuer’s stockholders. Such measures include, without limitation, the exploration of strategic alternatives to maximize the value of the Issuer.

Page 3 of 6 Pages

Except as set forth in this Item 4, Mr. Barlow has no plans or proposals which relate to, or could result in, any of the matters referred to in paragraphs (a) through (j), inclusive, of the instructions to Item 4 of Schedule 13D. Mr. Barlow, at any time and from time to time, may review or reconsider his position and/or change his purpose and/or formulate plans or proposals with respect thereto. Depending on various factors including, without limitation, the Issuer’s financial position and business strategy, the price levels of the Common Shares, conditions in the securities markets and general economic and industry conditions, Mr. Barlow may in the future take such actions with respect to his investment in the Issuer as he deems appropriate including, without limitation, seeking Board representation; making proposals to the Issuer concerning changes to the capitalization, ownership structure or operations of the Issuer; engaging in communications with one or more shareholders of the Issuer, one or more officers of the Issuer and/or one or more members of the Board, regarding, among other items, its business, operations, policies, management, structure, operations or capitalization; purchasing additional Common Shares; selling some or all of his Common Shares; and/or changing his intention with respect to any and all matters referred to in this Item 4.

ITEM 5. INTERESTS IN SECURITIES OF THE ISSUER

(a) As of January 30, 2009, Mr. Barlow beneficially owns 2,735,447 Common Shares, which include (i) 2,695,447 Common Shares owned by Mr. Barlow and (ii) 40,000 Common Shares that Mr. Barlow has the right to acquire within sixty days of January 30, 2009 pursuant to certain Employment Stock Options.  The Common Shares beneficially owned by Mr. Barlow represent approximately 10.9% of the Issuer’s outstanding Common Shares, which percentage is based upon (i) 24,988,157 Common Shares issued and outstanding as of November 7, 2008 as reported in a Form 10-Q filed by the Issuer with the Securities and Exchange Commission on November 14, 2008 and (ii) 40,000 Common Shares that Mr. Barlow has the right to acquire within sixty days of January 30, 2009 pursuant to certain Employment Stock Options (the “Issued and Outstanding Shares”).

(b) Mr. Barlow has sole voting and dispositive power over the Common Shares beneficially owned by him.

(c) Mr. Barlow has engaged in the following transactions in the Issuer’s Common Shares during the last 60 days:

Transaction	Trade Date	Common Shares	Price per Share
Exercise of Employee Stock Option	12/29/08	14,583	$1.20
Exercise of Employee Stock Option	12/29/08	20,666	$4.80
Exercise of Employee Stock Option	12/29/08	46,000	$4.80

Page 4 of 6 Pages

(d) No person (other than Mr. Barlow) is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the Common Shares beneficially owned by Mr. Barlow.

(e) Not applicable.

ITEM 6. CONTRACTS, ARRANGEMENTS, UNDERSTANDINGS OR RELATIONSHIPS WITH RESPECT TO SECURITIES OF THE ISSUER.

None.

ITEM 7. MATERIAL TO BE FILED AS EXHIBITS.

Exhibit 1 – Letter from David S. Barlow to the Board of Directors of Molecular Insight Pharmaceuticals, Inc., dated January 30, 2009.

Page 5 of 6 Pages

SIGNATURE

After reasonable 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.

DATED: January 30, 2009
	/s/ David S. Barlow
	David S. Barlow

Page 6 of 6 Pages

EX-99.1

David S. Barlow

640 Lewis Wharf

Boston, Massachusetts 02110

January 30, 2009

The Board of Directors

Molecular Insight Pharmaceuticals, Inc.

160 Second Street

Cambridge, Massachusetts 02142

Board Members:

I own approximately 11% of the outstanding shares of Common Stock Molecular Insight Pharmaceuticals, Inc.  I am writing to express my grave concern at your mismanagement of the Company’s business and investor relations process which has caused considerable damage to my investment and that of other shareholders.  I fear that, unless you take immediate action to reverse your current course, this damage will continue for the long term.

While the decline in the public markets is well known, Molecular Insight’s performance significantly lags behind its peers and other relevant indices.  More specifically, since September 25, 2008 Molecular Insight’s stock has, as of January 27, 2009, declined 61.1%, compared to a 18.9% decline for the BTK (Amex Biotech) index and a 15.7% decrease in the NBI (Nasdaq Biotech) index. Of further concern, MIPI has declined 34.2% since it announced positive Zemiva clinical data on December 23, 2008, compared to a 3.2% and 1.1% increasein the BTK and NBI indices, respectively, over the same period.  Given this unacceptable performance, I am requesting your considered response to the following significant issues by February 9, 2009.

I. The Company remains without an experienced CEO, despite having initiated a CEO search approximately six months ago and publicly stating so on September 25, 2008.  This ongoing leadership vacuum has raised significant concerns among investors and has decreased confidence in the Company’s potential, thereby contributing to record low stock prices.  The Company’s failure to have completed a timely and successful CEO search also raises questions regarding the Board’s attention and commitment to a professional, well planned and effectively executed transition to new leadership. Please advise me of your plan regarding the recruitment of a new CEO.

II. The Company has failed to design and implement an effective investor relations program under its new interim leadership as evidenced by: (1) the absence of new analyst coverage, (2) the lack of any meaningful new institutional investors, (3) Jefferies’ analyst’s reduction in the Company’s 12 month per share price target from $20 to $10 only days after the Company’s December conference call regarding the positive Zemiva clinical data, (4) a decrease in the Company’s stock price during and after the January JP Morgan conference, (5) a steady decline in daily trading volume over the last four months and (6) a significant reduction in investor meetings with the Company’s interim CEO as compared to Company practice prior to September 25, 2008.  Please advise as to your plan to correct this unacceptable performance and more fully engage with the investment community.

III. The Company has failed to design and implement an effective external corporate communications program to increase public awareness of the Company and its significant potential, which would increase interest in, and demand for, its stock.  Related evidence includes the Company’s discontinuation of its relationship with a public relations firm particularly noted for its ability to achieve media placements in leading healthcare and business publications.  Prior to its termination, the agency had arranged interviews, held this past summer, with the Company’s CEO and key media vehicles such as Business Week, Forbes and Bloomberg which focused on Zemiva, the Company’s unique cancer portfolio and its pursuit of orphan drugs.  This and other groundwork could have been leveraged to generate positive media coverage, in general, and in connection with the public announcement of the much anticipated Zemiva clinical results.

In addition, by delaying the release of the Zemiva clinical results until the week of Christmas, the Company virtually guaranteed minimal media coverage and communication to current and future investors. Interim leadership abandoned the comprehensive plan to leverage the opportunity presented by the Zemiva results to enhance shareholder value, yet apparently did not implement an alternative plan beyond a press release and a poorly received conference call.  This passive approach resulted in a disappointing response to the Zemiva news, as the Company’s stock has fallen 34% since this successful major milestone was announced.  This drop cannot credibly be blamed on market conditions as related biopharmaceutical indices have performed far better over the same time period.

While it appears the Company’s leadership does not believe investing responsibly in external communications for this, or perhaps any, pre-revenue company is worthwhile, one must then ask if this board and management believe increasing awareness of, and interest in, Molecular Insight helps stimulate investor demand for the Company’s stock, and therefore its price.  If so, what is your plan?  If not, please articulate how positive data and milestones achieved will be translated into enhancing shareholder value, as your approach to leverage the positive Zemiva data clearly failed. Investors need to be informed of your external communications plan and see evidence of its successful execution.

IV. It appears the Board and management are content to simply live with the Company’s record low stock price as an inevitable and unavoidable consequence of the severe economic downturn. By taking this position you are not only harming investors but also limiting the Company’s strategic options in the near and medium term; those options include merging with other companies and raising additional capital on acceptable terms. I am greatly concerned that your current path will necessitate a Company financing disadvantageous to current stockholders.

Whether your failure to build value from the excellent progress of the Company is due to a lack of experienced leadership or a conscious decision by the Board and interim management, the net result is the significant loss in value to shareholders. I urge you to consider whether, once you have taken the steps necessary to enhance the Company’s current stock price, the Company should pursue its strategic alternatives.

If you believe the Board and senior management cannot positively affect the Company’s valuation, particularly following the achievement of major milestones, I request you revisit your charge and ability to perform as Company fiduciaries. A strategy of simply waiting for the overall market to recover is unacceptable.

I trust you realize every member of the Board has fiduciary responsibilities to the shareholders of the Company, of which I represent a significant percentage. Given the alarming decrease in the Company’s value that cannot credibly be attributed to externalities, please make my concerns and requests your highest priority.

I look forward to receiving a written response on or before February 9, 2009.

Sincerely,

/s/ David S. Barlow

David S. Barlow