8-K

                       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



                                DECEMBER 10, 1999
                   (Date of Report - earliest event reported)



                         TRIANGLE PHARMACEUTICALS, INC.
               (Exact name of registrant as specified in charter)


        DELAWARE                   000-21589                   56-1930728
(State of incorporation           (Commission                 (IRS Employer
    or organization)              File Number)              Identification No.)

     4 University Place, 4611 University Drive, Durham, North Carolina 27707


        Registrant's telephone number, including area code: (919)493-5980


                                      NONE
         --------------------------------------------------------------
         (Former name or former address, if changed since last report.)



Item 5.  OTHER EVENTS.

         On December 10, 1999, we issued a press release announcing that the
Food and Drug Administration, following extensive discussions with us, advised
us that we would need to conduct one or possibly two additional Phase III
studies in order to prove that regimens containing Coactinon(R) are equivalent
or superior to current first line regimens used to treat HIV-infected patients.
The press release has been filed as an exhibit to this Current Report on Form
8-K.







Item 7.  EXHIBITS.


        99.1 Press Release dated December 10, 1999.









                                    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 thereunto duly authorized.



                                TRIANGLE PHARMACEUTICALS, INC.




DATE:  December 17, 1999        By: /s/ David W. Barry
                                    ---------------------------------
                                    Name: David W. Barry, M.D.
                                    Title:  Chairman and Chief Executive Officer







                         TRIANGLE PHARMACEUTICALS, INC.

                                    FORM 8-K

                                  EXHIBIT INDEX


EXHIBIT
NUMBER             DOCUMENT DESCRIPTION
- -------            --------------------

99.1               Press Release dated December 10, 1999.

EX-99.1

EXHIBIT 99.1

CONTACT:
Peter A. Arakelian                                    Douglas MacDougall
Director of Investor and Public Relations             Priscilla Harlan
Triangle Pharmaceuticals, Inc.                        Feinstein Kean Healthcare
(919) 493-5980                                        (617) 577-8110
www.tripharm.com                                      www.fkhealth.com


For Immediate Release
- ---------------------

          TRIANGLE PHARMACEUTICALS ANNOUNCES THAT ADDITIONAL PHASE III
               STUDIES FOR COACTINON(R) (EMIVIRINE) ARE REQUIRED

DURHAM, N.C. - DECEMBER 10, 1999 - Triangle Pharmaceuticals, Inc. (Nasdaq: VIRS)
today announced that the Food and Drug Administration (FDA), following extensive
discussions with the Company, has advised Triangle that it would need to conduct
one or possibly two additional Phase III studies in order to prove that regimens
containing Coactinon are equivalent or superior to current first line regimens
used to treat HIV-infected patients.

Over the first half of 2000, Triangle Pharmaceuticals will review the results of
an ongoing study, MKC-401, which compares the use of Coactinon in conjunction
with stavudine and Coviracil(R) (emtricitabine) with a regimen of abacavir,
stavudine and Coviracil. This study will determine whether the profile of
Coactinon justifies the initiation of additional studies.

David W. Barry, M.D., Chairman and Chief Executive Officer of Triangle,
commented, "It is always disappointing to learn that the requirement of
additional studies will lead to delay or discontinuation of the development of a
drug candidate, but we believe it is a wise decision to allocate our resources
to those drug candidates which we believe offer the most significant incremental
benefit to patients suffering from HIV or hepatitis B infection. The
reallocation of resources will provide greater support for the continuing
development of our other drugs, including Coviracil, for which we plan to submit
a New Drug Application (NDA) in late 2000."

Triangle Pharmaceuticals, Inc., is a specialty pharmaceutical company engaged in
the development of new antiviral drug candidates, with a particular focus on
therapies for the human immunodeficiency virus, including the acquired
immunodeficiency syndrome (AIDS), and hepatitis B virus (HBV). Triangle drug
candidates under development for HIV and/or HBV include Coactinon(R)
(emivirine), Coviracil(R) (emtricitabine), DAPD, L-FMAU and DMP-450. More
information about Triangle's portfolio, management and product development
strategy is available on Triangle Pharmaceuticals' website at
HTTP://WWW.TRIPHARM.COM.

Statements in this press release may constitute forward-looking statements and
are subject to numerous risks and uncertainties, including the failure to
successfully complete pivotal clinical trials,



the Company's future capital needs, the inability to commercialize Coviracil(R)
(emtricitabine) and DAPD due to patent rights held by third parties, the
Company's ability to obtain additional funding (including contingent contractual
milestones), patent protection and required regulatory approvals for its drug
candidates, the development of competitive products by others, the cost of
coactive therapy and the extent to which coactive therapy achieves market
acceptance, the Company's success in identifying new drug candidates, acquiring
rights to the candidates on favorable terms and developing any candidates to
which the Company acquires any rights, and these and other risks detailed from
time to time in the Company's filings with the Securities and Exchange
Commission. The actual results may differ materially from those projected in
this press release. The Company disclaims any obligations to update the
statements in this press release.