EXHIBIT 10.1

CYTOGEN CORPORATION
1999 STOCK OPTION PLAN
FOR NON-EMPLOYEE DIRECTORS


1.       Purpose; Effective Date.

(a)  The  purposes  of  this  Plan  are to  further  the  interests  of  Cytogen
Corporation  (the "Company") by retaining the services of persons now serving as
non-employee Directors of the Company,  attracting and retaining the services of
persons  capable of serving on the Board of  Directors  of the  Company,  and by
providing  such persons with an incentive  that aligns their  interests with the
interests of the Company's shareholders.

(b) This Plan will become  effective on approval of the Plan by the  affirmative
vote of the majority of shares  present in person or  represented  by proxy at a
meeting of the shareholders of the Company and cast on the proposal for approval
of the Plan.

2.       Definitions.

Whenever used in this Plan, the following terms will have the meanings set forth
in this Section:

 "Board of Directors" means the Board of Directors of the Company.

 "Code" means the United States Internal Revenue Code of 1986, as amended.

"Common Stock" means the common stock, par value $.0l per share, of the Company.

"Date of Grant" means with respect to any Option the date the Option will become
effective under the provisions of this Plan.

"Disability" means inability of a Director to engage in any substantial  gainful
activity by reason of a  medically  determinable  physical or mental  impairment
which  reasonably  can be expected to last for a  continuous  period of not less
than six months.

"Eligible  Director"  means,  as of any time,  a person who is a director of the
Company but is not then an Employee.

"Employee"  means  any  person  employed  by  the  Company  (including,  without
limitation,  a person employed by the Company who is also an officer or director
of the Company).

"Exchange Act" means the Securities Exchange Act of 1934, as amended,  and rules
and regulations promulgated thereunder.

"Exercise Price" means with respect to any Option the price per share which must
be paid upon exercise of the Option.

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"Fair Market Value" means (i) if the Common Stock is traded in a market in which
actual  transactions  are  reported,  the  average of the high and low prices at
which the Common  Stock is reported to have traded on the  relevant  date in all
markets  on which  trading in the Common  Stock is  reported,  or if there is no
reported sale of the Common Stock on the relevant  date, the mean of the highest
reported bid price and lowest  reported  asked price for the Common Stock on the
relevant date,  (ii) if the Common Stock is Publicly  Traded but only in markets
in which there is no reporting of actual  transactions,  the mean of the highest
reported bid price and the lowest  reported  asked price for the Common Stock on
the relevant  date,  or (iii) if the Common Stock is not  Publicly  Traded,  the
value of a share  of  Common  Stock as  determined  by the  most  recent  annual
valuation  prepared  by an  independent  expert at the  request  of the Board of
Directors.

"Major  Event"  means when (i) the Company  enters  into one or more  definitive
agreements to merge or consolidate the Company with or into another corporation,
or to sell or otherwise  dispose of all or  substantially  all of the  Company's
assets,  or to effect any other  transaction,  consolidation  or  reorganization
having similar results or effect; (ii) any person other than the Company makes a
tender or  exchange  offer for more than 50% of Common  Stock  pursuant to which
purchases  of any amount of Common Stock are made;  or (iii) stock  representing
more than 50% of the voting power of the Company is acquired by any person other
than the  Company  in any one or more  transactions  occurring  in any  24-month
period.

"Option" means any option granted under this Plan.

"Option Agreement" means an agreement,  in such form as may be determined by the
Board of Directors or the  Committee,  executed and  delivered by the Company to
the holder of any Option with respect to that option.

"Option Shares" means, with respect to any Option,  the maximum number of shares
of Common Stock which may be acquired under the option prior to its expiration.

"Plan" means the Cytogen Corporation 1999 Directors Stock Option Plan.

 "Publicly  Traded" means, with respect to any class of stock, that the class of
stock is required to be registered  under Section 12 of the Securities  Exchange
Act of 1934,  as  amended,  or that stock of that class has been sold within the
preceding 12 months in an underwritten public offering.

"Termination  of  Service"  means the time when a Director  ceases to serve as a
Director for any reason,  including without limitation by reason of resignation,
retirement, removal, death or Disability.

3. Administration of the Plan.

(a) The Compensation Committee of the Board of Directors will be responsible for
the  administration  of this Plan.  The  Committee  shall consist of two or more
non-employee  directors  of the  Company  who meet the  definition  of  "outside
director"  under the provisions of Section 162(m) of the Code and the definition

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of  "non-employee  director" under the provisions of the Exchange Act. No member
of the  Committee  shall have been within one year prior to  appointment  to, or
while  serving on, the  Committee  granted or awarded  equity  securities of the
Company  pursuant to this or any other plan of the Company  except to the extent
that  participation in any such plan or receipt of any such grant or award would
not adversely affect the Committee member's status as a "non-employee  director"
or as an "outside director".

(b) The Committee shall (i) determine or provide for the terms and conditions of
grant Agreements,  and all election and other forms,  which terms and conditions
shall not be inconsistent with this Plan, (ii) interpret the Plan and (iii) make
all other  decisions  relating to the  operation of the Plan.  The Committee may
adopt such rules or  guidelines as it deems  appropriate  to implement the Plan.
The Committee's  determinations under the Plan shall be final and binding on all
persons.

(c) No member  of the Board of  Directors  or of any  committee  of the Board of
Directors shall be liable for any act or omission of the Board or any committee,
or of any other member of the Board or any committee, or for any act or omission
on his own part, in connection  with the  administration  of this Plan unless it
resulted from the member's own willful misconduct.

4.       Persons Eligible to Receive options.

Options shall be granted only to Eligible Directors.

5.       Stock Subject to the Plan.

The maximum  number of shares of Common Stock as to which Options may be granted
under this Plan is 500,000 shares,  subject to adjustment as provided in Section
8. If any option expires or is cancelled, surrendered or forfeited without being
exercised in full,  the number of shares as to which the option is not exercised
will once again become shares as to which new Options may be granted. The Common
Stock  which is issued on exercise of Options  may be  authorized  but  unissued
shares or shares which have been issued and reacquired by the Company.

6.       Grants of Options.

(a)  The  grants  of  options   under   this  Plan   shall  be   automatic   and
non-discretionary.  Each Option shall be exercisable on the terms and subject to
the  conditions  specified in Section 7. No Option granted under this Plan shall
be an "incentive stock option" within the meaning of Section 422A of the Code.

(b) Effective on approval of the Plan by the shareholders, each person who is on
that date an Eligible Director shall be granted an Option to purchase twenty one
thousand (21,000) shares of Common Stock (the "Initial Option").

(c) Each person who is  appointed  a director  of the Company  after the date of
approval of the Plan by the Shareholders and is an Eligible  Director as of such
date shall be granted an Option to purchase a pro rata  portion of ten  thousand

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(10,000) shares of Common Stock,  based upon the number of full months remaining
from the date of election until the one year anniversary  month of the preceding
annual meeting, as of the effective date of their appointment.

(d) On the day following each annual meeting of the stockholders of the Company,
commencing  with the 2000  annual  meeting,  each  person who is on that date an
Eligible  Director and was re-elected at that meeting shall be granted an Option
to purchase 10,000 shares of Common Stock. In addition,  a Chairman of the Board
of  Directors,  unless  the  Compensation  Committee  of  the  Board  determines
otherwise, shall receive an additional grant of fifteen thousand (15,000) shares
of Common Stock.

(e) Each Option  provided for in this  Section 6 shall be granted  automatically
and  without  further  action  by the  Company,  the Board of  Directors  or the
Company's stockholders. Promptly after the Date of Grant of each Option provided
for in this  Section  6, the  Company  shall  cause an  Option  Agreement  to be
executed  and  delivered  to the holder of the Option.  No other  Options may be
granted at any time under this Plan.

7.       Option Provisions.

(a) Exercise Price. The Exercise Price of the Initial Option will be 200% of the
Fair Market  Value of the Common  Stock on the Date of Grant of the Option.  The
Exercise  Price of each Option other than the Initial Option will be 100% of the
Fair Market Value of the Common Stock on the Date of Grant of the Option.

(b)      Term; Vesting.

(i) No Option  granted under this Plan may be exercised more than 10 years after
the Date of Grant of the option.

(ii) Except as provided in Sections 7(b)(iii),  7(f), 7(g) and 7(h), the Initial
Option shall become exercisable in one-third  increments  annually on the first,
second, and third anniversaries of the Date of Grant, and Options other than the
Initial Option shall become  exercisable in full on the first anniversary of the
Date of Grant.

(iii) Upon the occurrence of a Major Event,  all of the Option Shares covered by
an Option shall become  immediately  available for purchase upon exercise of the
option, without regard to the vesting provisions of Section 7(b)(ii).

(c)  Exercise of Options.  An Option may be exercised in whole or in part at any
time, or from time to time,  during its term. To exercise an Option,  the person
exercising the Option must deliver to the Company, at its principal office:

(i) a notice of  exercise of the  Option,  which  states the extent to which the
option is being exercised; and

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(ii) payment in full in cash,  which may be  satisfied by a check,  in an amount
equal to the Exercise Price of the option times the number of shares as to which
it is being exercised.

(d) Delivery of Stock  Certificates.  As promptly as practicable after an option
is  exercised,  the Company will deliver to the person who exercises the Option,
certificates  registered in that person's name representing the number of shares
of Common  Stock  which were  purchased  by the  exercise  of the  option.  Each
certificate may bear a legend to indicate, if applicable,  that the Common Stock
represented  by the  certificate  was  issued  in a  transaction  which  was not
registered under the Securities Act of 1933, as amended, and may only be sold or
transferred  in a transaction  which is  registered  under that Act or is exempt
from the registration requirements of that Act.

(e)  Nontransferability  of Options.  During the lifetime of a person to whom an
option is issued,  the Option may be exercised only by that person or his or her
guardian  or legal  representative.  An Option may not be  assigned,  pledged or
hypothecated  in any way,  will not be  subject  to  execution,  and will not be
transferable otherwise than by will or the laws of descent and distribution. The
Company will not recognize any attempt to assign, transfer,  pledge, hypothecate
or otherwise  dispose of an option  contrary to the  provisions of this Plan, or
any levy of any attachment or similar  process upon any Option,  and,  except as
expressly  stated in this Plan,  the Company  will not be required  to, and will
not,  issue  Common  Stock on exercise of an option to anyone who claims to have
acquired that option from the person to whom it was granted.

(f)  Termination of Service of Director  Holding an Option Other Than Because of
Death or  Disability.  Subject to the  provisions  of Sections 7(b) and 7(h), if
there is a  Termination  of  Service  of a  director  to whom an Option has been
granted,  other  than by  reason  of the  director's  death  or  disability,  or
retirement,  each Option held by the director may be exercised until the earlier
of (x) the end of the  three-month  period  immediately  following  the  date of
Termination of service, or (y) the expiration of the term of the option.

(g) Death or  Disability  of  Director  Holding an Option.  Notwithstanding  the
provisions of Section  7(b), if there is a Termination  of Service of a director
to whom an  option  has  been  granted  by  reason  of the  director's  death or
disability,  or a former director dies within three months following the date of
his or her Termination of Service,  each option held by the Director on the date
of the  Director's  Termination  of Service may be exercised  in full (i.e.,  in
respect of up to 100% of the Option shares, regardless of the time elapsed since
the Date of  Grant)  until the  earlier  of (x) the end of the  one-year  period
immediately  following the date of  Termination of service or (y) the expiration
of the term of the option. In the event of an Eligible  Director's death, all of
such person's  outstanding Options will transfer to the maximum extent permitted
by law to such person's designated Beneficiary. Each Eligible Director may name,
from  time to  time,  any  beneficiary  or  beneficiaries  (which  may be  named
contingently  or  successively)  as his or her  Beneficiary for purposes of this
Plan. Each  designation  shall be on a form  prescribed by the Company,  will be
effective  only when delivered to the Company and when effective will revoke all
prior designations by the Eligible  Director.  If an Eligible Director dies with

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no such  beneficiary  designation  in  effect,  such  person's  Options  will be
transferable  by will  or  pursuant  to the  laws of  descent  and  distribution
applicable to such person.

(h)  Retirement  or  Resignation.  If there is a  Termination  of  Service  of a
Director by reason of the Director's retirement or resignation at any time after
the  Director  has  reached age 55 with a minimum of three  years'  service as a
non-employee  director,  each  Option  held by the  Director  on the date of the
Director's  Termination of Service may be exercised in full (i.e., in respect of
up to 100% of the Option  Shares,  regardless of the time elapsed since the Date
of Grant)  until the earlier of (x) the end of the five year period  immediately
following the date of  Termination  of Service or (y) the expiration of the term
of the option.

8. Recapitalization, reorganizations, stock splits and the like.

(a) The existence of  outstanding  Options shall not affect in any way the right
or power of the  Company or its  stockholders  to make or  authorize  any or all
adjustments,   recapitalizations,   reorganizations  or  other  changes  in  the
Company's capital  structure or its business,  or any merger or consolidation of
the Company,  or any issue of bonds,  debentures,  preferred or prior preference
stock  ahead of or  affecting  the Common  Stock or the rights  thereof,  or the
dissolution or liquidation of the Company, or any sale or transfer of all or any
part of its assets or business or any other corporate act or proceeding, whether
of a similar character or otherwise.  Except as hereinafter  expressly provided,
the  issue  by the  Company  of  shares  of stock of any  class,  or  securities
convertible  into  shares of stock of any class,  for cash or  property,  or for
labor or services  either  upon  direct  sale or upon the  exercise of rights or
warrants to subscribe therefor, or on conversion of shares or obligations of the
Company convertible into such shares or other securities,  shall not affect, and
no adjustment by reason thereof shall be made with respect to, the number, class
or price of shares of Common Stock then subject to outstanding options.

(b) If as a result of any (i)  reorganization  or  liquidation of the Company or
(ii) reclassification of the Company's capital stock, stock splits, stock splits
in the form of dividends,  reverse stock splits, or similar recapitalizations of
the  Company,  or (iii)  consolidation  or  merger of the  Company  with or into
another  corporation,  or sale of all or  substantially  all the  assets  of the
Company (a reorganization or liquidation of the Company or  reclassification  of
the Company's  capital  stock,  or a merger,  consolidation  or sale of the type
described in this subsection being a "Corporate Transaction") while an Option is
outstanding,  the holders of the Common  Stock  become  entitled to receive with
respect to their Common  Stock,  securities or assets other than, or in addition
to, their  Common  Stock,  upon  exercise of that Option the holder will receive
what the  holder  would  have  owned if the  holder  had  exercised  the  Option
immediately  before the first  Corporate  Transaction  which  occurred while the
option was  outstanding  and had not  disposed of anything the holder would have
received as a result of that and all subsequent Corporate Transactions.


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9.       Rights of Option Holder.

The holder of an Option will not have any rights as a  stockholder  by reason of
holding that Option.  Upon  exercise of an Option,  the holder will be deemed to
acquire the rights of a stockholder when, but not before, the issuance of Common
Stock as a result  of the  exercise  is  recorded  in the stock  records  of the
Company.

10.      Laws and Regulations.

The  obligation  of the  Company to sell and deliver  shares of Common  Stock on
exercise of options will be subject to the condition  that legal counsel for the
Company be satisfied  that the sale and delivery will not violate the Securities
Act of 1933, as amended, or any other applicable laws, rules or regulations.

11.      Reservation of Shares.

The Company will at all times keep  reserved for issuance on exercise of options
a number of authorized  but unissued or reacquired  shares of Common Stock equal
to the maximum number of shares the Company may be required to issue on exercise
of outstanding options (assuming no subsequent adjustments under Section 8).

12. Amendment of the Plan.

The Board of  Directors  may at any time and from  time to time  modify or amend
this  Plan  in any  respect  effective  at  any  date  the  Board  of  Directors
determines;  provided,  that  without the  approval of the  stockholders  of the
Company  the Board of  Directors  may not,  (i) except as provided in Section 8,
increase  the  maximum  number of shares of Common  Stock which may be issued on
exercise  of Options  granted  under this Plan;  (ii) change the  provisions  of
Section 6 or Section  7; (iii)  change the  categories  of persons  eligible  to
receive options under this Plan; or (iv) otherwise  materially  increase (within
the meaning of Rule 16b-3 of the Exchange Act) the benefits  accruing under this
Plan. No modification or amendment of this Plan will, without the consent of the
holder of an outstanding Option, adversely affect the holder's rights under that
Option.  Notwithstanding approval by shareholders, the Board may amend this Plan
without further  shareholder  approval to add provisions  required or enabled by
changes to Rule 16b-3.

13. Termination of the Plan.

This Plan will terminate on June 16, 2008, unless sooner  terminated.  The Board
of  Directors  may  suspend or  terminate  this Plan at any time or from time to
time, but no such action may adversely  affect the rights of a person holding an
outstanding  Option.  The  applicable  terms  of the  Plan,  and any  terms  and
conditions as applicable  to Options  granted prior to such date,  shall survive
the termination of the Plan and continue to apply to such Options.

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