8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 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)

November 5, 2008

OPTIMER PHARMACEUTICALS, INC.

(Exact name of registrant as specified in its charter)

Delaware	001-33291	33-0830300
(State or other jurisdiction of incorporation)	(Commission File Number)	(IRS Employer Identification No.)

10110 Sorrento Valley Road, Suite C

San Diego, CA  92121

(Address of principal executive offices, including zip code)

(858) 909-0736

(Registrant’s telephone number, including area code)

N/A

(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 2.02    Results of Operations and Financial Condition.

On November 5, 2008, the Company issued a press release announcing its unaudited financial results for the third quarter ended September 30, 2008.  A copy of this press release is attached hereto as Exhibit 99.1.

This information and the exhibits hereto are being furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liability of that section, nor shall they be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

Item 9.01     Financial Statements and Exhibits.

(d)  Exhibits.

Exhibit No.	Description
99.1	Press Release dated November 5, 2008.

2

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.

	OPTIMER PHARMACEUTICALS, INC.
By:	/s/ John D. Prunty
	John D. Prunty Chief Financial Officer (Duly Authorized Officer and Principal Financial and Accounting Officer)

Date:  November 5, 2008

3

EX-99.1

Exhibit 99.1

Optimer Pharmaceuticals Reports Third Quarter 2008 Financial Results

SAN DIEGO – November 5, 2008 - - Optimer Pharmaceuticals, Inc. (Nasdaq:OPTR) today announced its financial results for the third quarter ended September 30, 2008. Optimer reported a net loss for the third quarter of 2008 of $9.2 million, or $0.31 per share, compared to a net loss of $6.5 million, or $0.28 per share, for the same period in 2007.  Research and development expenses in the third quarter of 2008 were $7.9 million compared to $5.5 million in the third quarter of 2007.  The increase was primarily due to expenses related to OPT-80 and Prulifloxacin Phase 3 clinical trials.

As of September 30, 2008, Optimer held cash, cash equivalents and investments of $47.6 million.

“Our financial results for the quarter were in line with our expectations.  Also during the quarter, we completed enrollment in the second Prulifloxacin Phase 3 study for the treatment of infectious diarrhea and we had a very strong presence at the ICAAC/IDSA infectious disease conference,” said Michael N. Chang, Ph.D., Optimer’s President and Chief Executive Officer. “We presented the full analysis data from our first Prulifloxacin Phase 3 study and sponsored a medical education symposium on CDI with a panel of infectious disease experts. We are rapidly approaching our next key milestone – data from our first OPT-80 Phase 3 trial for the treatment of CDI.”

Recent Corporate Highlights

·The full data analysis from the first of two Phase 3 clinical studies of Prulifloxacin was featured at this year’s joint meeting of the Annual Interscience Conference on Antimicrobial Agents and Chemotherapy/Infectious Disease Society of America (ICAAC/IDSA) in October 2008. Data presented by Herbert DuPont, M.D., primary researcher and Director, Center for Infectious Diseases at the University of Texas School of Public Health, showed that Prulifloxacin shortened recovery time in patients suffering from travelers’ diarrhea, a form of infectious diarrhea.

·Optimer completed enrollment in the second of two Phase 3 clinical trials examining the safety and efficacy of Prulifloxacin for the treatment of travelers’ diarrhea.

·At the ICAAC/IDSA meeting, Optimer sponsored a symposium of top infectious disease experts who spoke about the ‘Current Treatments and Challenges’ of Clostridium difficile infection.

About Optimer Pharmaceuticals

Optimer Pharmaceuticals, Inc. is a biopharmaceutical company focused on discovering, developing and commercializing innovative anti-infective products for the treatment of serious infections. Optimer has two late-stage anti-infective

product candidates.  OPT-80 is being developed for the treatment of Clostridium difficile infection, the most common hospital-acquired diarrhea.  Prulifloxacin is an antibiotic being developed for the treatment of travelers’ diarrhea, a form of infectious diarrhea.  Additional information can be found at http://www.optimerpharma.com.

Forward-looking Statements

Statements included in this press release that are not a description of historical facts are forward-looking statements, including without limitation all statements related to the development of OPT-80 and Prulifloxacin, and the timing of clinical trials and anticipated results and regulatory activities. Words such as “believes,” “anticipates,” “plans,” “expects,” “intend,” “will,” “goal” and similar expressions are intended to identify forward-looking statements. The inclusion of forward-looking statements should not be regarded as a representation by Optimer that any of its plans will be achieved. Actual results may differ materially from those set forth in this release due to the risks and uncertainties inherent in Optimer’s business including, without limitation, risks relating to: the timing, progress and likelihood of success of its product research and development programs, the timing and status of its preclinical and clinical development of potential drugs and other risks detailed in Optimer’s filings with the Securities and Exchange Commission.

Contacts

Optimer Pharmaceuticals, Inc.

Christina Donaghy, Corporate Communications Manager

John D. Prunty, Chief Financial Officer & VP Finance

858-909-0736

Porter Novelli Life Sciences

Jason I. Spark, Vice President

619-849-6005

Optimer Pharmaceuticals, Inc.

Consolidated Statements of Operations

(unaudited)

	Three Months Ended September 30,						Nine Months Ended September 30,
	2008			2007			2008			2007
Revenues:
Research grants	$	239,212		$	44,493		$	844,675		$	241,793
Collaborative research agreements	—			271,555			50,000			431,555
Total revenues	239,212			316,048			894,675			673,348
Operating expenses:
Research and development	7,877,906			5,496,136			21,003,764			35,964,496
Marketing	415,916			387,424			1,695,400			1,238,492
General and administrative	1,544,925			1,362,052			4,803,422			3,969,695
Total operating expenses	9,838,747			7,245,612			27,502,586			41,172,683
Loss from operations	(9,599,535		)	(6,929,564		)	(26,607,911		)	(40,499,335		)
Interest income and other, net	411,352			454,230			1,426,386			1,391,731
Net loss	$	(9,188,183	)	(6,475,334		)	$	(25,181,525	)	(39,107,604		)
Basic and diluted net loss per share	$	(0.31	)	$	(0.28	)	$	(0.89	)	$	(1.94	)
Shares used to compute basic and diluted net loss per share	29,253,693			23,154,266			28,377,733			20,143,478

Optimer Pharmaceuticals, Inc.

Condensed Consolidated Balance Sheets

	September 30 2008		December 31, 2007
	(unaudited)
ASSETS
Current assets:
Cash and cash equivalents	$	24,102,746	$	3,191,814
Short-term investments	22,362,491		55,613,785
Prepaid expenses and other current assets	837,035		967,994
Total current assets	47,302,272		59,773,593
Restricted cash	170,000		—
Property and equipment, net	648,024		705,374
Long-term investments	1,150,000		—
Other assets	332,787		306,573
Total assets	$	49,603,083	$	60,785,540
LIABILITIES AND STOCKHOLDERS’ EQUITY
Current liabilities:
Accounts payable	$	3,127,941	$	2,602,152
Accrued expenses	2,614,186		4,998,025
Total current liabilities	5,742,127		7,600,177
Deferred rent	266,976		281,894
Commitments and contingencies	—		—
Stockholders’ equity	43,593,980		52,903,469
Total liabilities and stockholders’ equity	$	49,603,083	$	60,785,540