EXHIBIT 99.1

                                                           Contact: Abe Wischnia
                                         Senior Director, Investor Relations and
                                                        Corporate Communications
                                                                    858-550-7850

              LIGAND AND ORGANON REACH AGREEMENT ON TERMINATION AND
                   RETURN OF RIGHTS ON AVINZA(R) CO-PROMOTION

         SAN DIEGO, CA - January 17, 2006 -- Ligand Pharmaceuticals Incorporated
(Pink Sheets: LGND) announced today that it has signed an agreement with Organon
USA, Inc. that terminates the AVINZA(R)  co-promotion  agreement between the two
companies and returns AVINZA rights to Ligand.
         The  effective  date of the  termination  agreement is January 1, 2006,
however the parties  have agreed to continue to  cooperate  during a  transition
period ending September 30, 2006 to promote the product.  That transition period
co-operation  includes  a minimum  number of  product  sales  calls per  quarter
(100,000  for  Organon and 30,000 for Ligand  with an  aggregate  of 375,000 and
90,000  respectively  for the  transition  period) as well as the  transition of
ongoing  promotions,  managed care  contracts,  clinical  trials and Key Opinion
Leader  relationships  to Ligand.  During the transition  period Ligand will pay
Organon an amount equal to 23 percent of AVINZA net sales as reported by Ligand.
Ligand  will also pay and be  responsible  for the design and  execution  of all
clinical, advertising and promotion expenses and activities.
         "We are pleased to reach this  agreement on AVINZA with  Organon  which
better  aligns the  strategic  and  financial  interests  of both parties to the
realities of each party's business and situation today," said David E. Robinson,
Ligand  chairman,  president  and CEO.  "This  new  agreement  will  give us the
flexibility  to explore all  strategic  alternatives  for AVINZA and Ligand with
various potential strategic partners in the coming months."
         Michael Novinski, president of Organon USA, Inc., said, "This agreement
aligns with Organon's  strategic and financial  interests  today to better focus
our resources on our current and future product portfolio.  At the same time, we
remain  committed to a smooth  transition in the near term  including  continued
sales  calls  and  transition  activities  on  AVINZA.  We look  forward  to its
continuing  success given our long-term  financial interest to earn a return for
our shareholders on our investments in AVINZA over the past three years."



         The  companies  have  resolved  their  disagreement   concerning  prior
co-promote  fees and Ligand will pay Organon $14.75 million by January 30, 2006.
In consideration  of the early  termination and return of rights under the terms
of the agreement,  Ligand will  unconditionally pay Organon $37.75 million on or
before  October 15, 2006.  Ligand will further pay Organon  $10.0  million on or
before  January 15, 2007,  provided  that Organon has made its minimum  required
level of sales calls. Under certain conditions, including change of control, the
cash payments will accelerate.  In addition, after the termination,  Ligand will
make  quarterly  royalty  payments to Organon equal to 6.5 percent of AVINZA net
sales  through  December  31, 2012 and  thereafter  six percent  through  patent
expiration, currently anticipated to be November of 2017.
         ABOUT AVINZA
         AVINZA (oral morphine sulfate  extended-release  capsules) is the first
true once-a-day  treatment for chronic  moderate-to-severe  pain in patients who
require  continuous,  around-the-clock  opioid therapy for an extended period of
time.  Approved by the FDA in March 2002, AVINZA consists of two components:  an
immediate-release    component   that   rapidly    achieves   plateau   morphine
concentrations  in plasma,  and an  extended-release  component  that  maintains
plasma concentrations  throughout a 24-hour dosing interval.  Ligand co-promotes
AVINZA with Organon Pharmaceuticals USA Inc. in the United States.
         ABOUT LIGAND
         Ligand discovers,  develops and markets new drugs that address critical
unmet medical  needs of patients in the areas of cancer,  pain,  skin  diseases,
men's and women's hormone-related diseases,  osteoporosis,  metabolic disorders,
and  cardiovascular  and  inflammatory   diseases.   Ligand's  proprietary  drug
discovery and development  programs are based on its leadership position in gene
transcription technology, primarily related to intracellular receptors. For more
information, go to www.ligand.com.



         CAUTION REGARDING FORWARD-LOOKING STATEMENTS
         This  news  release  contains  forward-looking  statements  within  the
meaning of section 21E of the Securities Exchange Act of 1934, as amended,  that
involve risks and  uncertainties and reflect Ligand's judgment as of the date of
this  release.  These  statements  include  those  related  to the  terms of the
co-promotion  termination agreement,  future AVINZA sales efforts, the number of
sales calls during the transition period,  AVINZA's market position and Ligand's
exploration of strategic alternatives.  Actual events or results may differ from
our  expectations.  For  example,  there can be no  assurance  that the expected
number of sales  calls will  actually be made  during the  transition  period or
thereafter or that those made will lead to additional AVINZA prescriptions, that
AVINZA's  position in the market will not decline,  that the  termination of the
co-promotion  agreement  will  have any  beneficial  effect  on Ligand or on the
exploration of strategic  alternatives.  Additional information concerning these
and other risk factors  affecting Ligand can be found in prior press releases as
well as in public periodic filings with the Securities and Exchange  Commission,
available  via  www.ligand.com.  Ligand  disclaims  any intent or  obligation to
update these  forward-looking  statements beyond the date of this release.  This
caution is made  under the safe  harbor  provisions  of the  Private  Securities
Litigation Reform Act of 1995.
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