Filed Pursuant to Rule 424(b)(3)

Registration No. 333-190196

PROSPECTUS SUPPLEMENT NO. 21

(To Prospectus dated September 18, 2013, as amended)

2,298,412 Shares

Tengion, Inc.

This Prospectus Supplement No. 21 supplements the prospectus dated September 18, 2013 (as supplemented or amended to date, the “Prospectus”), which forms a part of our Registration Statement on Form S-1 (Registration Statement No. 333-190196). The Prospectus and this prospectus supplement relate to the disposition from time to time of up to 2,298,412 shares of our common stock, which are held or may be held by the stockholders named in the Prospectus.

This prospectus supplement should be read in conjunction with the Prospectus, which is to be delivered with this prospectus supplement. This prospectus supplement updates, amends and supplements the information included or incorporated by reference in the Prospectus. If there is any inconsistency between the information in the Prospectus and this prospectus supplement, you should rely on the information in this prospectus supplement.

This prospectus supplement is not complete without, and may not be delivered or utilized except in connection with, the Prospectus, including any amendments or supplements to it.

Current Report on Form 8-K

On December 29, 2014, we filed a Current Report on Form 8-K with the Securities and Exchange Commission. The text of such Form 8-K is attached hereto.

Investing in our common stock involves a high degree of risk. Please see the section entitled “Risk Factors” beginning on page 21 of the Prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities, or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus supplement is December 29, 2014.

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 22, 2014

Tengion, Inc.

(Exact name of registrant as specified in its charter)

001-34688

(Commission File Number)

Delaware	20-0214813
(State or other jurisdiction of	(I.R.S. Employer Identification No.)
incorporation)

3929 Westpoint Blvd., Suite G

Winston-Salem, NC 27103

(Address of principal executive offices, with zip code)

(336) 722-5855

(Registrant’s telephone number, including area code)

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 or Receivership.

On December 29, 2014, Tengion, Inc. (the “Company”) commenced a bankruptcy proceeding (the “Chapter 7 Case”) by filing a voluntary petition for relief under the provisions of chapter 7 of title 11 of the United States Code, 11 U.S.C. §§ 101 et seq. (the “Code”) in the United States Bankruptcy Court for the District of Delaware (the “Bankruptcy Court”). The Chapter 7 Case is being administered under case number 14-12829.  As a result of the filing of the Chapter 7 Case, a Chapter 7 trustee will be appointed by the Bankruptcy Court and will assume control of the Company.  The assets of the Company will be liquidated in accordance with the Code.

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

The filing of the Chapter 7 Case constituted an event of default under the terms of the Facility Agreements dated October 2, 2012 and June 28, 2013, each among the Company and lenders party thereto. As of the date hereof, approximately $31.6 million of principal and accrued but unpaid interest remains outstanding under the promissory notes governed by such agreements, which has become immediately due and payable as a result of the filing of the Chapter 7 Case.

Item 5.07. Submission of Matters to a Vote of Security Holders.

On December 22, 2014, the Company held a Special Meeting of Stockholders.  The proposal submitted to a vote of the stockholders was an amendment to the Company’s Fourth Amended and Restated Certificate of Incorporation, as amended, to increase the number of authorized shares of common stock from 10,000,000,000 to 20,000,000,000 shares.  The results of the voting on such proposal are as follows:

For	Against	Abstain
16,688,868	7,843,134	108,945

There were no broker non-votes with respect to this proposal.  This proposal required the affirmative vote of a majority of the Company’s stockholders for approval and, as a result, was not approved.

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.

	TENGION, INC.
Date:  December 29, 2014	By: /s/ A. Brian Davis
	A. Brian Davis
	Chief Financial Officer and Senior Vice President, Finance