UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT
PURSUANT TO SECTION 13 OR 15(d) OF THE
SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported) December 17, 2009

VION PHARMACEUTICALS, INC.

(Exact Name of Registrant as Specified in its Charter)

Delaware	000-26534	13-3671221
(State or Other Jurisdiction	(Commission	(IRS Employer
of Incorporation)	File Number)	Identification No.)

4 Science Park, New Haven, CT	06511
(Address of Principal Executive Offices)	(Zip Code)

Registrant’s telephone number, including area code: (203) 498-4210

Not Applicable

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

o Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 1.03 Bankruptcy and Receivership

On December 17, 2009, Vion Pharmaceuticals, Inc. (the “Debtor” or the “Company”) filed a voluntary petition (the “Chapter 11 Petition”) for relief under Chapter 11 of Title 11 of the United States Bankruptcy Code (the “Bankruptcy Code”) in the United States Bankruptcy Court for the District of Delaware (the “Bankruptcy Court”).

Under Chapter 11, certain claims in existence prior to the Debtor’s filing of the petition for relief under the Bankruptcy Code are stayed while the Debtor continues business operations as a debtor-in-possession. The Debtor will continue to operate its business as debtor-in-possession under the jurisdiction of the Bankruptcy Court and in accordance with the applicable provisions of the Bankruptcy Code.

A copy of the press release dated December 17, 2009, announcing the bankruptcy filing is attached hereto as Exhibit 99.1 and is incorporated herein by reference.

Item 2.04 Triggering Events That Accelerate or Increase a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement.

The Chapter 11 bankruptcy filing described in Item 1.03 above constitutes an event of default under the Company’s indenture with U.S. Bank National Association, dated February 20, 2007 (the “Indenture”) relating to the Company’s $60,000,000 7.75% Convertible Senior Notes (the “Notes”). On December 17, 2009, all unpaid principal of, and accrued and unpaid interest and additional interest, if any, on the Notes then outstanding became automatically due and payable. However, the ability of the holders of the Notes to seek remedies to enforce their rights under the Indenture is automatically stayed as a result of the filing of the Chapter 11 petition.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

EXHIBIT NO.		DESCRIPTION
	99.1	Press release dated December 17, 2009

SIGNATURES

     Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	VION PHARMACEUTICALS, INC.
Date: December 17, 2009	By:	/s/ Howard B. Johnson
		Name:	Howard B. Johnson
		Title:	President and Chief Financial Officer

EXHIBIT INDEX

EXHIBIT NO.		DESCRIPTION
	99.1	Press release dated December 17, 2009