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): September 26, 2008

Penwest Pharmaceuticals Co.

(Exact Name of Registrant as Specified in Charter)

Washington	000-23467	91-1513032
(State or Other Jurisdiction	(Commission	(IRS Employer
of Incorporation)	File Number)	Identification No.)

39 Old Ridgebury Road, Suite 11
Danbury, Connecticut	06810-5120
(Address of Principal Executive Offices)	(Zip Code)

Registrant’s telephone number, including area code: (877) 736-9378

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))

TABLE OF CONTENTS

Item 8.01. Other Events

     On September 26, 2008, Penwest Pharmaceuticals Co. (the “Company”) filed a registration statement on Form S-3 with the SEC. This shelf registration statement covers the issuance and sale by the Company of any combination of common stock, preferred stock, debt securities and warrants having an aggregate purchase price of up to $75 million. The new shelf registration statement is intended to replace the Company’s current $75 million shelf registration statement, which was filed in July 2005 and is scheduled to expire on December 1, 2008 under SEC rules. Upon the effectiveness of the new shelf registration statement, the offering of securities under the July 2005 shelf registration statement will be deemed terminated.

     The new shelf registration statement has not yet become effective. The securities covered by the shelf registration statement may not be sold, nor may any offers to buy such securities be accepted prior to the time the registration statement becomes effective. This report does not constitute an offer to sell or the solicitation of an offer to buy any securities of the Company and these securities cannot be sold in any state in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of such state.

SIGNATURE

     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.

	PENWEST PHARMACEUTICALS CO.
Date: September 26, 2008	By:	/s/ Benjamin L. Palleiko
		Benjamin L. Palleiko
		Senior Vice President, Corporate Development and Chief Financial Officer