<PAGE>
                                                                EXHIBIT 10.2(A)
 
                              SEVERANCE AGREEMENT
                              -------------------

          THIS AGREEMENT, dated May  , 1999, is made by and between Centocor,
Inc. a Pennsylvania corporation (the "Company"), and _________ (the
"Executive").

          WHEREAS, the Company considers it essential to the best interests of
its shareholders to foster the continued employment of key management personnel;
and

          WHEREAS, the Board recognizes that, as is the case with many publicly
held corporations, the possibility of a Change in Control exists and that such
possibility, and the uncertainty and questions which it may raise among
management, may result in the departure or distraction of management personnel
to the detriment of the Company and its stockholders; and

          WHEREAS, the Board has determined that appropriate steps should be
taken to reinforce and encourage the continued attention and dedication of
members of the Company's management, including the Executive, to their assigned
duties without distraction in the face of poten-
<PAGE>
 
tially disturbing circumstances arising from the possibility of a Change in
Control;

          NOW, THEREFORE, in consideration of the premises and the mutual
covenants herein contained, the Company and the Executive hereby agree as
follows:
 
          1.  Defined Terms.  The definitions of capitalized terms used in this
              -------------                                                    
Agreement are provided in the last Section hereof.

          2.  Term of Agreement.  Subject to the provisions of Section 12.2
              -----------------                                            
hereof, the Term of this Agreement shall commence on the date hereof and shall
continue in effect through December 31, 2000; provided, however, that commencing
                                              --------  -------                 
on January 1, 2000 and each January 1 thereafter, the Term shall automatically
be extended for one additional year unless, not later than September 30 of the
preceding year, the Company or the Executive shall have given notice not to
extend the Term; and further provided, however, that if a Change in Control
                     ------- --------  -------                             
shall have occurred during the Term, the Term shall expire no ear-

                                       2
<PAGE>
 
lier than twenty-four (24) months beyond the month in which such Change in
Control occurred.

          3.  Company's Covenants Summarized.  In order to induce the Executive
              ------------------------------                                   
to remain in the employ of the Company and in consideration of the Executive's
covenants set forth in Section 4 hereof, the Company agrees, under the
conditions described herein, to pay the Executive the Severance Payments and the
other payments and benefits described herein.  Except as provided in Section 9.1
hereof, no Severance Payments shall be payable under this Agreement unless there
shall have been (or, under the terms of the second sentence of Section 6.1
hereof, there shall be deemed to have been) a termination of the Executive's
employment with the Company following a Change in Control and during the Term.
This Agreement shall not be construed as creating an express or implied contract
of employment and, except as otherwise agreed in writing between the Executive
and the Company, the Executive shall not have any right to be retained in the
employ of the Company.

                                       3
<PAGE>
 
          4.  The Executive's Covenants.  The Executive agrees that, subject to
              -------------------------                                        
the terms and conditions of this Agreement, in the event of a Potential Change
in Control during the Term, the Executive will remain in the employ of the
Company until the earliest of (i) a date which is twelve (12) months from the
date of such Potential Change in Control, (ii) the date of a Change in Control,
(iii) the date of termination by the Executive of the Executive's employment for
Good Reason or by reason of death, Disability or Retirement, or (iv) the
termination by the Company of the Executive's employment for any reason.  The
Executive further agrees that if the Executive's employment is terminated
following a Change in Control and during the Term, other than (A) by the Company
for Cause, (B) by reason of death or Disability, or (C) by the Executive without
Good Reason, then for a period of 12 months following the Date of Termination
the Executive will make himself available to the Company for consultation with
senior executive officers of the Company or the Board; provided, however, that
(i) the Executive shall 

                                       4
<PAGE>
 
not be required to perform such consulting services (x) for more than four (4)
days in any month and (y) for more than twenty (20) hours in any calendar month,
(ii) such consulting services will be required at such time and such places as
will result in the least inconvenience to the Executive, taking into
consideration Executive's other business commitments during such period which
may obligate Executive to honor such other commitments prior to his rendering
services hereunder, (iii) such consulting services shall be rendered by personal
consultation at Executive's principal residence or office, wherever maintained,
or by correspondence through mail, telephone or facsimile or other similar modes
of communication at times, including weekends and evenings, most convenient to
Executive and (iv) if during such period the Executive should engage in full-
time employment, the Executive shall not be required to consult at times that
will conflict with his responsibilities with respect to such employment. The
Company will pay or promptly reimburse the Executive for reasonable expenses
actually incurred 

                                       5
<PAGE>
 
by the Executive in connection with such consulting services.

          5.  Compensation Other Than Severance Payments.
              ------------------------------------------ 

          5.1  Following a Change in Control and during the Term, during any
period that the Executive fails to perform the Executive's full-time duties with
the Company as a result of incapacity due to physical or mental illness, the
Company shall pay the Executive's full salary to the Executive at the rate in
effect at the commencement of any such period, together with all compensation
and benefits payable to the Executive under the terms of any compensation or
benefit plan, program or arrangement (other than the Company's short- or long-
term disability plan, as applicable) maintained by the Company during such
period, until the Executive's employment is terminated by the Company for
Disability.

          5.2  If the Executive's employment shall be terminated for any reason
following a Change in Control and during the Term, the Company shall pay the
Executive's full salary to the Executive through the Date of 

                                       6
<PAGE>
 
Termination at the rate in effect immediately prior to the Date of Termination
or, if higher, the rate in effect immediately prior to the first occurrence of
an event or circumstance constituting Good Reason, together with all
compensation and benefits payable to the Executive through the Date of
Termination under the terms of the Company's compensation and benefit plans,
programs or arrangements as in effect immediately prior to the Date of
Termination or, if more favorable to the Executive, as in effect immediately
prior to the first occurrence of an event or circumstance constituting Good
Reason.

          5.3  If the Executive's employment shall be terminated for any reason
following a Change in Control and during the Term, the Company shall pay to the
Executive the Executive's normal post-termination compensation and benefits as
such payments become due. Such post-termination compensation and benefits shall
be determined under, and paid in accordance with, the Company's retirement,
insurance and other compensation or benefit plans, programs and arrangements as
in effect 

                                       7
<PAGE>
 
immediately prior to the Date of Termination or, if more favorable to the
Executive, as in effect immediately prior to the occurrence of the first event
or circumstance constituting Good Reason.

          6.  Severance Payments.
              ------------------ 

          6.1  Subject to Section 6.2 hereof, if the Executive's employment is
terminated following a Change in Control and during the Term, other than (A) by
the Company for Cause, (B) by reason of death or Disability, or (C) by the
Executive without Good Reason, then the Company shall pay the Executive the
amounts, and provide the Executive the benefits, described in this Section 6.1
("Severance Payments") and Section 6.2, in addition to any payments and benefits
to which the Executive is entitled under Section 5 hereof.  For purposes of this
Agreement, the Executive's employment shall be deemed to have been terminated
following a Change in Control by the Company without Cause or by the Executive
with Good Reason, if (i) the Executive's employment is terminated by the Company
without Cause prior to a Change in Control 

                                       8
<PAGE>
 
(whether or not a Change in Control ever occurs) and such termination was at the
request or direction of a Person who has entered into an agreement with the
Company the consummation of which would constitute a Change in Control, (ii) the
Executive terminates his employment for Good Reason prior to a Change in Control
(whether or not a Change in Control ever occurs) and the circumstance or event
which constitutes Good Reason occurs at the request or direction of such Person,
or (iii) the Executive's employment is terminated by the Company without Cause
or by the Executive for Good Reason and such termination or the circumstance or
event which constitutes Good Reason is otherwise in connection with or in
anticipation of a Change in Control (whether or not a Change in Control ever
occurs). For purposes of any determination regarding the applicability of the
immediately preceding sentence, any position taken by the Executive shall be
presumed to be correct unless the Company establishes to the Board by clear and
convincing evidence that such position is not correct.

                                       9
<PAGE>
 
               (A)  In lieu of any further salary payments to the Executive for
     periods subsequent to the Date of Termination and in lieu of any severance
     benefit otherwise payable to the Executive, the Company shall pay to the
     Executive a lump sum severance payment, in cash, equal to three times the
     sum of (i) the Executive's base salary as in effect immediately prior to
     the Date of Termination or, if higher, in effect immediately prior to the
     first occurrence of an event or circumstance constituting Good Reason, and
     (ii) the greatest of (w) the Executive's target bonus under any annual
     bonus or incentive plan maintained by the Company as in effect immediately
     prior to the Change in Control in respect of the fiscal year in which the
     Change in Control occurs (x) the Executive's target bonus under such plan
     in respect of the fiscal year ending immediately prior to the fiscal year
     in which occurs the Date of Termination, (y) the Executive's target bonus
     under such plan in respect of the fiscal year 

                                       10
<PAGE>
 
     immediately prior to the fiscal year in which occurs the first event or
     circumstance constituting Good Reason and (z) the average annual bonus
     earned by the Executive pursuant to such plan in respect of the three
     fiscal years (or such shorter period during which the Executive was
     employed by the Company) ending immediately prior to the fiscal year in
     which occurs the Date of Termination or, if higher, immediately prior to
     the fiscal year in which occurs the first event or circumstance
     constituting Good Reason.

               (B)  For the thirty-six (36) month period immediately following
     the Date of Termination, the Company shall arrange to provide the Executive
     and his dependents life, disability, accident and health insurance benefits
     substantially similar to those provided to the Executive and his dependents
     immediately prior to the Date of Termination or, if more favorable to the
     Executive, those provided to the Executive and his dependents immedi-

                                       11
<PAGE>
 
     ately prior to the first occurrence of an event or circumstance
     constituting Good Reason, at no greater cost to the Executive than the cost
     to the Executive immediately prior to such date or occurrence; provided,
                                                                    --------
     however, that, unless the Executive consents to a different method (after
     -------
     taking into account the effect of such method on the calculation of
     "parachute payments" pursuant to Section 6.2 hereof), such health insurance
     benefits shall be provided through a third-party insurer. Benefits
     otherwise receivable by the Executive pursuant to this Section 6.1(B) shall
     be reduced to the extent benefits of the same type are received by or made
     available to the Executive during the thirty-six (36) month period
     following the Executive's termination of employment (and any such benefits
     received by or made available to the Executive shall be reported to the
     Company by the Executive); provided, however, that the Company shall
                                --------  -------                        
     reimburse the Executive for the excess, if any, of the cost of such
     benefits to 

                                       12
<PAGE>
 
     the Executive over such cost immediately prior to the Date of Termination
     or, if more favorable to the Executive, the first occurrence of an event or
     circumstance constituting Good Reason. If the Severance Payments shall be
     decreased pursuant to Section 6.2 hereof, and the Section 6.1(B) benefits
     which remain payable after the application of Section 6.2 hereof are
     thereafter reduced pursuant to the immediately preceding sentence, the
     Company shall, no later than five (5) business days following such
     reduction, pay to the Executive the least of (a) the amount of the decrease
     made in the Severance Payments pursuant to Section 6.2 hereof, (b) the
     amount of the subsequent reduction in these Section 6.1(B) benefits, or (c)
     the maximum amount which can be paid to the Executive without being, or
     causing any other payment to be, nondeductible by reason of section 280G of
     the Code.

               (C)  Notwithstanding any provision of any annual or long-term
     incentive plan to the con-

                                       13
<PAGE>
 
     trary, the Company shall pay to the Executive a lump sum amount, in cash,
     equal to the sum of (i) any unpaid incentive compensation which has been
     allocated or awarded to the Executive for a completed fiscal year or other
     measuring period preceding the Date of Termination under any such plan and
     which, as of the Date of Termination, is contingent only upon the continued
     employment of the Executive to a subsequent date, and (ii) a pro rata
     portion to the Date of Termination of the aggregate value of all contingent
     incentive compensation awards to the Executive for all then uncompleted
     periods under any such plan, calculated as to each such award by
     multiplying the award that the Executive would have earned on the last day
     of the performance award period, assuming the achievement, at the target
     level, of the individual and corporate performance goals established with
     respect to such award, by the fraction obtained by dividing the number of
     full months and any fractional portion of a month during 

                                       14
<PAGE>
 
     such performance award period through the Date of Termination by the
     total number of months contained in such performance award period.

               (D)  In addition to the benefits to which the Executive is
     entitled under the Pension Plan, the Company shall pay the Executive a lump
     sum amount, in cash, equal to the sum of (i) the amount that would have
     been contributed thereto by the Company on the Executive's behalf during
     the three years immediately following the Date of Termination, determined
     (x) as if the Executive made the maximum permissible contributions thereto
     during such period, (y) as if the Executive earned compensation during such
     period at a rate equal to the Executive's compensation (as defined in the
     Pension Plan) during the twelve (12) months immediately preceding the Date
     of Termination or, if higher, during the twelve months immediately prior to
     the first occurrence of an event or circumstance constituting Good Reason,
     and (z) without regard to any amendment to 

                                       15
<PAGE>
 
     the Pension Plan made subsequent to a Change in Control and on or prior to
     the Date of Termination, which amendment adversely affects in any manner
     the computation of benefits thereunder, and (ii) the excess, if any, of (x)
     the Executive's account balance under the Pension Plan as of the Date of
     Termination over (y) the portion of such account balance that is
     nonforfeitable under the terms of the Pension Plan.

               6.2  (A)  Whether or not the Executive becomes entitled to the
     Severance Payments, if any payment or benefit received or to be received by
     the Executive in connection with a Change in Control or the termination of
     the Executive's employment (whether pursuant to the terms of this Agreement
     or any other plan, arrangement or agreement with the Company, any Person
     whose actions result in a Change in Control or any Person affiliated with
     the Company or such Person) (all such payments and benefits, excluding the
     Gross-Up Payment, being hereinafter 

                                       16
<PAGE>
 
     called "Total Payments") will be subject (in whole or part) to the Excise
     Tax, then, subject to the provisions of subsection (B) of this Section 6.2,
     the Company shall pay to the Executive an additional amount (the "Gross-Up
     Payment") such that the net amount retained by the Executive, after
     deduction of any Excise Tax on the Total Payments and any federal, state
     and local income and employment taxes and Excise Tax upon the Gross-Up
     Payment, shall be equal to the Total Payments. For purposes of determining
     the amount of the Gross-Up Payment, the Executive shall be deemed to pay
     federal income taxes at the highest marginal rate of federal income
     taxation in the calendar year in which the Gross-Up Payment is to be made
     and state and local income taxes at the highest marginal rate of taxation
     in the state and locality of the Executive's residence on the Date of
     Termination (or if there is no Date of Termination, then the date on which
     the Gross-up Payment is calculated for purposes of this Section 

                                       17
<PAGE>
 
     6.2), net of the maximum reduction in federal income tax which could be
     obtained from deduction of such state and local taxes.
     
          (B) In the event that, after giving effect to any redeterminations
described in subsection (D) of this Section 6.2, a reduction in the Severance
Payments to the largest amount that would result in no portion of the Total
Payments being subject to the Excise Tax (after taking into account any
reduction in the Total Payments provided by reason of section 280G of the Code
in such other plan, arrangement or agreement) would produce a net amount (after
subtracting the net amount of federal, state and local income and employment
taxes on such reduced Total Payments) that would be greater than or equal to the
net amount of unreduced Total Payments (after deduction of the net amount of
federal, state and local income and employment taxes and the amount of Excise
Tax to which the Executive would be subject in respect of such unreduced Total
Payments), then subsection (A) of this Section 6.2 shall not apply and the cash

                                       18
<PAGE>
 
Severance Payments shall first be reduced (if necessary, to zero), and the
noncash Severance Benefits shall thereafter be reduced (if necessary, to zero);
provided, however, that the Executive may elect to have the noncash Severance
--------  -------                                                            
Payments reduced (or eliminated) prior to any reduction of the cash Severance
Payments.

          (C) For purposes of determining whether any of the Total Payments will
be subject to the Excise Tax and the amount of such Excise Tax, (i) all of the
Total Payments shall be treated as "parachute payments" within the meaning of
section 280G(b)(2) of the Code, unless in the opinion of tax counsel ("Tax
Counsel") reasonably acceptable to the Executive and selected by the accounting
firm which was, immediately prior to the Change in Control, the Company's
independent auditor (the "Auditor"), such other payments or benefits (in whole
or in part) do not constitute parachute payments, including by reason of section
280G(b)(4)(A) of the Code, (ii) all "excess parachute payments" within the
meaning of section 280G(b)(l) of the Code shall be treated as subject to the

                                       19
<PAGE>
 
Excise Tax unless, in the opinion of Tax Counsel, such excess parachute payments
(in whole or in part) represent reasonable compensation for services actually
rendered, within the meaning of section 280G(b)(4)(B) of the Code, in excess of
the Base Amount allocable to such reasonable compensation, or are otherwise not
subject to the Excise Tax, and (iii) the value of any noncash benefits or any
deferred payment or benefit shall be determined by the Auditor in accordance
with the principles of sections 280G(d)(3) and (4) of the Code.  Prior to the
payment date set forth in Section 6.3 hereof, the Company shall provide the
Executive with its calculation of the amounts referred to in this Section 6.2(C)
and such supporting materials as are reasonably necessary for the Executive to
evaluate the Company's calculations.  If the Executive disputes the Company's
calculations (in whole or in part), the reasonable opinion of Tax Counsel with
respect to the matter in dispute shall prevail.

          (D) In the event that (i) amounts are paid to the Executive pursuant
to subsection (A) of this Section 

                                       20
<PAGE>
 
6.2, (ii) the Excise Tax is finally determined to be less than the amount taken
into account hereunder in calculating the Gross-Up Payment, and (iii) after
giving effect to such redetermination, the Severance Payments are to be reduced
pursuant to subsection (B) of this Section 6.2, the Executive shall repay to the
Company, within five (5) business days following the time that the amount of
such reduction in Excise Tax is finally determined, the portion of the Gross-Up
Payment attributable to such reduction (plus that portion of the Gross-Up
Payment attributable to the Excise Tax and federal, state and local income and
employment taxes imposed on the Gross-Up Payment being repaid by the Executive),
to the extent that such repayment results in (i) no portion of the Total
Payments being subject to the Excise Tax and (ii) a dollar-for-dollar reduction
in the Executive's taxable income and wages for purposes of federal, state and
local income and employment taxes) plus interest on the amount of such repayment
at 120% of the rate provided in section 1274(b)(2)(B) of the Code. In the event
that (x) the 

                                       21
<PAGE>
 
          Excise Tax is determined to exceed the amount taken into account
hereunder at the time of the termination of the Executive's employment
(including by reason of any payment the existence or amount of which cannot be
determined at the time of the Gross-Up Payment) and (y) after giving effect to
such redetermination, the Severance Payments should not have been reduced
pursuant to subsection (B) of this Section 6.2, the Company shall make an
additional Gross-Up Payment in respect of such excess and in respect of any
portion of the Excise Tax with respect to which the Company had not previously
made a Gross-Up Payment (plus any interest, penalties or additions payable by
the Executive with respect to such excess and such portion) within five (5)
business days following the time that the amount of such excess is finally
determined.

          6.3  The payments provided in subsections (A), (C) and (D) of Section
6.1 hereof and in Section 6.2 hereof shall be made not later than the fifth day
following the Date of Termination (or if there is no Date of 

                                       22
<PAGE>
 
Termination, then the date on which the Gross-up Payment is calculated for
purposes of Section 6.2 hereof); provided, however, that if the amounts of such
                                 --------  -------
payments, and the limitation on such payments set forth in Section 6.2 hereof,
cannot be finally determined on or before such day, the Company shall pay to the
Executive on such day an estimate, as determined in good faith by the Executive
or, in the case of payments under Section 6.2 hereof, in accordance with Section
6.2 hereof, of the minimum amount of such payments to which the Executive is
clearly entitled and shall pay the remainder of such payments (together with
interest on the unpaid remainder (or on all such payments to the extent the
Company fails to make such payments when due) at 120% of the rate provided in
section 1274(b)(2)(B) of the Code) as soon as the amount thereof can be
determined but in no event later than the thirtieth (30th) day after the Date of
Termination. In the event that the amount of the estimated payments exceeds the
amount subsequently determined to have been due, such excess shall constitute a
loan by the Company 

                                       23
<PAGE>
 
to the Executive, payable on the fifth (5th) business day after demand by the
Company (together with interest at 120% of the rate provided in section
1274(b)(2)(B) of the Code). At the time that payments are made under this
Agreement, the Company shall provide the Executive with a written statement
setting forth the manner in which such payments were calculated and the basis
for such calculations including, without limitation, any opinions or other
advice the Company has received from Tax Counsel, the Auditor or other advisors
or consultants (and any such opinions or advice which are in writing shall be
attached to the statement).

          6.4  The Company also shall pay to the Executive all legal fees and
expenses incurred by the Executive in disputing in good faith any issue
hereunder relating to the termination of the Executive's employment, in seeking
in good faith to obtain or enforce any benefit or right provided by this
Agreement or in connection with any tax audit or proceeding to the extent
attributable to the application of section 4999 of the 

                                       24
<PAGE>
 
Code to any payment or benefit provided hereunder. Such payments shall be made
within five (5) business days after delivery of the Executive's written requests
for payment accompanied with such evidence of fees and expenses incurred as the
Company reasonably may require.

          7.  Termination Procedures and Compensation During Dispute.
              ------------------------------------------------------ 

          7.1  Notice of Termination.  After a Change in Control and during the
               ---------------------                                           
Term, any purported termination of the Executive's employment (other than by
reason of death) shall be communicated by written Notice of Termination from one
party hereto to the other party hereto in accordance with Section 10 hereof.
For purposes of this Agreement, a "Notice of Termination" shall mean a notice
which shall indicate the specific termination provision in this Agreement relied
upon and shall set forth in reasonable detail the facts and circumstances
claimed to provide a basis for termination of the Executive's employment under
the provision so indicated.  Further, a Notice of Termination for Cause is
required to include a 

                                       25
<PAGE>
 
copy of a resolution duly adopted by the affirmative vote of not less than 
three-quarters (3/4) of the entire membership of the Board at a meeting of the
Board which was called and held for the purpose of considering such termination
(after reasonable notice to the Executive and an opportunity for the Executive,
together with the Executive's counsel, to be heard before the Board) finding
that, in the good faith opinion of the Board, the Executive was guilty of
conduct set forth in clause (i) or (ii) of the definition of Cause herein, and
specifying the particulars thereof in detail.

          7.2  Date of Termination.  "Date of Termination," with respect to any
               -------------------                                             
purported termination of the Executive's employment after a Change in Control
and during the Term, shall mean (i) if the Executive's employment is terminated
for Disability, thirty (30) days after Notice of Termination is given (provided
that the Executive shall not have returned to the full-time performance of the
Executive's duties during such thirty (30) day period), and (ii) if the
Executive's employment 

                                       26
<PAGE>
 
is terminated for any other reason, the date specified in the Notice of
Termination (which, in the case of a termination by the Company, shall not be
less than thirty (30) days (except in the case of a termination for Cause) and,
in the case of a termination by the Executive, shall not be less than fifteen
(15) days nor more than sixty (60) days, respectively, from the date such Notice
of Termination is given).

          7.3  Dispute Concerning Termination.  If within fifteen (15) days
               ------------------------------                              
after any Notice of Termination is given, or, if later, prior to the Date of
Termination (as determined without regard to this Section 7.3), the party
receiving such Notice of Termination notifies the other party that a dispute
exists concerning the termination, the Date of Termination shall be extended
until the earlier of (i) the date on which the Term ends or (ii) the date on
which the dispute is finally resolved, either by mutual written agreement of the
parties or by a final judgment, order or decree of an arbitrator or a court of
competent jurisdiction (which is not appealable or with 

                                       27
<PAGE>
 
respect to which the time for appeal therefrom has expired and no appeal has
been perfected); provided, however, that the Date of Termination shall be
                 --------  ------- 
extended by a notice of dispute given by the Executive only if such notice is
given in good faith and the Executive pursues the resolution of such dispute
with reasonable diligence.

          7.4  Compensation During Dispute.  If a purported termination occurs
               ---------------------------                                    
following a Change in Control and during the Term and the Date of Termination is
extended in accordance with Section 7.3 hereof, the Company shall continue to
pay the Executive the full compensation in effect when the notice giving rise to
the dispute was given (including, but not limited to, salary) and continue the
Executive as a participant in all compensation, benefit and insurance plans in
which the Executive was participating when the notice giving rise to the dispute
was given, until the Date of Termination, as determined in accordance with
Section 7.3 hereof. Amounts paid under this Section 7.4 are in addition to all
other amounts due under this Agreement (other than those due 

                                       28
<PAGE>
 
under Section 5.2 hereof) and shall not be offset against or reduce any other
amounts due under this Agreement.

          8.  No Mitigation.  The Company agrees that, if the Executive's
              -------------                                              
employment with the Company terminates during the Term, the Executive is not
required to seek other employment or to attempt in any way to reduce any amounts
payable to the Executive by the Company pursuant to Section 6 hereof or Section
7.4 hereof.  Further, the amount of any payment or benefit provided for in this
Agreement (other than Section 6.1(B) hereof) shall not be reduced by any
compensation earned by the Executive as the result of employment by another
employer, by retirement benefits, by offset against any amount claimed to be
owed by the Executive to the Company, or otherwise.

          9.  Successors; Binding Agreement.
              ----------------------------- 

          9.1  In addition to any obligations imposed by law upon any successor
to the Company, the Company will require any successor (whether direct or
indirect, by purchase, merger, consolidation or otherwise) to all or
substantially all of the business and/or assets of the 

                                       29
<PAGE>
 
Company to expressly assume and agree to perform this Agreement in the same
manner and to the same extent that the Company would be required to perform it
if no such succession had taken place. Failure of the Company to obtain such
assumption and agreement prior to the effectiveness of any such succession shall
be a breach of this Agreement and shall entitle the Executive to compensation
from the Company in the same amount and on the same terms as the Executive would
be entitled to hereunder if the Executive were to terminate the Executive's
employment for Good Reason after a Change in Control, except that, for purposes
of implementing the foregoing, the date on which any such succession becomes
effective shall be deemed the Date of Termination.

          9.2  This Agreement shall inure to the benefit of and be enforceable
by the Executive's personal or legal representatives, executors, administrators,
successors, heirs, distributees, devisees and legatees. If the Executive shall
die while any amount would still be payable to the Executive hereunder (other
than amounts 

                                       30
<PAGE>
 
which, by their terms, terminate upon the death of the Executive) if the
Executive had continued to live, all such amounts, unless otherwise provided
herein, shall be paid in accordance with the terms of this Agreement to the
executors, personal representatives or administrators of the Executive's estate.

          10.  Notices.  For the purpose of this Agreement, notices and all
               -------                                                     
other communications provided for in the Agreement shall be in writing and shall
be deemed to have been duly given when delivered or mailed by United States
registered mail, return receipt requested, postage prepaid, addressed, if to the
Executive, to the address inserted below the Executive's signature on the final
page hereof and, if to the Company, to the address set forth below, or to such
other address as either party may have furnished to the other in writing in
accordance herewith, except that notice of change of address shall be effective
only upon actual receipt:

                                       31
<PAGE>
 
               To the Company:

               Centocor, Inc.
               200 Great Valley Parkway
               Malvern, PA  19355
               Attention:  Secretary

          11.  Miscellaneous.  No provision of this Agreement may be modified,
               -------------                                                  
waived or discharged unless such waiver, modification or discharge is agreed to
in writing and signed by the Executive and such officer as may be specifically
designated by the Board.  No waiver by either party hereto at any time of any
breach by the other party hereto of, or of any lack of compliance with, any
condition or provision of this Agreement to be performed by such other party
shall be deemed a waiver of similar or dissimilar provisions or conditions at
the same or at any prior or subsequent time.  This Agreement supersedes any
other agreements or representations, oral or otherwise, express or implied, with
respect to the subject matter hereof which have been made by either party;
provided, however, that this Agreement shall supersede any agreement setting
--------  -------                                                           
forth the terms and 

                                       32
<PAGE>
 
conditions of the Executive's employment with the Company only in the event that
the Executive's employment with the Company is terminated on or following a
Change in Control, by the Company other than for Cause or by the Executive other
than for Good Reason. The validity, interpretation, construction and performance
of this Agreement shall be governed by the laws of the Commonwealth of
Pennsylvania. All references to sections of the Exchange Act or the Code shall
be deemed also to refer to any successor provisions to such sections. Any
payments provided for hereunder shall be paid net of any applicable withholding
required under federal, state or local law and any additional withholding to
which the Executive has agreed. The obligations of the Company and the Executive
under this Agreement which by their nature may require either partial or total
performance after the expiration of the Term (including, without limitation,
those under Sections 6 and 7 hereof) shall survive such expiration.

                                       33
<PAGE>
 
          12.  Validity; Pooling.  
               ----------------- 

          12.1 Validity. The invalidity or unenforceability of any provision of 
               --------                   
this Agreement shall not affect the validity or enforceability of any other
provision of this Agreement, which shall remain in full force and effect.

          12.2  Pooling.  In the event that the Company is party to a
                -------                                              
transaction which is otherwise intended to qualify for "pooling of interests"
accounting treatment then (A) this Agreement shall, to the extent practicable,
be interpreted so as to permit such accounting treatment, and (B) to the extent
that the application of clause (A) of this Section 12.2 does not preserve the
availability of such accounting treatment, then, to the extent that any
provision of the Agreement disqualifies the transaction as a "pooling"
transaction (including, if applicable, the entire Agreement), the Board shall be
entitled to cause such provision to be null and void as of the date hereof.  All
determinations under this Section 12.2 shall be made by the accounting firm
whose opinion with 

                                       34
<PAGE>
 
respect to "pooling of interests" is required as a condition to the consummation
of such transaction.

          13.  Counterparts.  This Agreement may be executed in several
               ------------                                            
counterparts, each of which shall be deemed to be an original but all of which
together will constitute one and the same instrument.

          14.  Settlement of Disputes; Arbitration.  
               -----------------------------------   

          14.1 All claims by the Executive for benefits under this Agreement
shall be directed to and determined by the Board and shall be in writing. Any
denial by the Board of a claim for benefits under this Agreement shall be
delivered to the Executive in writing and shall set forth the specific reasons
for the denial and the specific provisions of this Agreement relied upon. The
Board shall afford a reasonable opportunity to the Executive for a review of the
decision denying a claim and shall further allow the Executive to appeal to the
Board a decision of the Board within sixty (60) days after notification by the
Board that the Executive's claim has been denied.

                                       35
<PAGE>
 
          14.2  Any further dispute or controversy arising under or in
connection with this Agreement shall be settled exclusively by arbitration in
Philadelphia, Pennsylvania, in accordance with the rules of the American
Arbitration Association then in effect; provided, however, that the evidentiary
                                        --------  -------                      
standards set forth in this Agreement shall apply.  Judgment may be entered on
the arbitrator's award in any court having jurisdiction.  Notwithstanding any
provision of this Agreement to the contrary, the Executive shall be entitled to
seek specific performance of the Executive's right to be paid until the Date of
Termination during the pendency of any dispute or controversy arising under or
in connection with this Agreement.

          15.  Definitions.  For purposes of this Agreement, the following terms
               -----------                                                      
shall have the meanings indicated below:

          (A)  "Affiliate" shall have the meaning set forth in Rule 12b-2
promulgated under Section 12 of the Exchange Act.

                                       36
<PAGE>
 
          (B)  "Auditor" shall have the meaning set forth in Section 6.2 hereof.

          (C)  "Base Amount" shall have the meaning set forth in section
280G(b)(3) of the Code.

          (D)  "Beneficial Owner" shall have the meaning set forth in Rule 13d-3
under the Exchange Act.

          (E)  "Board" shall mean the Board of Directors of the Company.

          (F)  "Cause" for termination by the Company of the Executive's
employment shall mean (i) the willful and continued failure by the Executive to
substantially perform the Executive's duties with the Company (other than any
such failure resulting from the Executive's incapacity due to physical or mental
illness or any such actual or anticipated failure after the issuance of a Notice
of Termination for Good Reason by the Executive pursuant to Section 7.1 hereof)
that has not been cured within 30 days after a written demand for substantial
performance is delivered to the Executive by the Board, which demand
specifically identifies the manner in which 

                                       37
<PAGE>
 
the Board believes that the Executive has not substantially performed the
Executive's duties, or (ii) the willful engaging by the Executive in conduct
which is demonstrably and materially injurious to the Company or its
subsidiaries, monetarily or otherwise. For purposes of clauses (i) and (ii) of
this definition, (x) no act, or failure to act, on the Executive's part shall be
deemed "willful" unless done, or omitted to be done, by the Executive not in
good faith and without reasonable belief that the Executive's act, or failure to
act, was in the best interest of the Company and (y) in the event of a dispute
concerning the application of this provision, no claim by the Company that Cause
exists shall be given effect unless the Company establishes to the Board by
clear and convincing evidence that Cause exists.

          (G)  A "Change in Control" shall be deemed to have occurred if the
event set forth in any one of the following paragraphs shall have occurred:

                    (I)  any Person is or becomes the Beneficial Owner, directly
          or indirectly, of 

                                       38
<PAGE>
 
          securities of the Company (not including in the securities
          beneficially owned by such Person any securities acquired directly
          from the Company or its affiliates) representing 50% or more of the
          combined voting power of the Company's then outstanding securities,
          excluding any Person who becomes such a Beneficial Owner in connection
          with a transaction described in clause (i) of paragraph (III) below;
          or

                    (II) the following individuals cease for any reason to
          constitute a majority of the number of directors then serving:
          individuals who, on the date hereof, constitute the Board and any new
          director (other than a director whose initial assumption of office is
          in connection with an actual or threatened election contest, including
          but not limited to a consent solicitation, relating to the election of
          directors of the Company) whose appointment or election by the Board
          or nomination for elec-

                                       39
<PAGE>
 
          tion by the Company's shareholders was approved or recommended by a
          vote of at least two-thirds (2/3) of the directors then still in
          office who either were directors on the date hereof or whose
          appointment, election or nomination for election was previously so
          approved or recommended; or

                    (III)  there is consummated a merger or consolidation of the
          Company or any direct or indirect subsidiary of the Company with any
          other corporation, other than (i) a merger or consolidation which
          would result in the voting securities of the Company outstanding
          immediately prior to such merger or consolidation continuing to
          represent (either by remaining outstanding or by being converted into
          voting securities of the surviving entity or any parent thereof), in
          combination with the ownership of any trustee or other fiduciary
          holding securities under an employee benefit plan of 

                                       40
<PAGE>
 
          the Company or any subsidiary of the Company, at least 55% of the
          combined voting power of the securities of the Company or such
          surviving entity or any parent thereof outstanding immediately after
          such merger or consolidation, or (ii) a merger or consolidation
          effected to implement a recapitalization of the Company (or similar
          transaction) in which no Person is or becomes the Beneficial Owner,
          directly or indirectly, of securities of the Company (not including in
          the securities Beneficially Owned by such Person any securities
          acquired directly from the Company or its Affiliates) representing 50%
          or more of the combined voting power of the Company's then outstanding
          securities; or

               (IV) the shareholders of the Company approve a plan of complete
          liquidation or dissolution of the Company or there is consummated an
          agreement for the sale or disposition 

                                       41
<PAGE>
 
     by the Company of all or substantially all of the Company's assets, other
     than a sale or disposition by the Company of all or substantially all of
     the Company's assets to an entity, at least 55% of the combined voting
     power of the voting securities of which are owned by shareholders of the
     Company in substantially the same proportions as their ownership of the
     Company immediately prior to such sale.

Notwithstanding the foregoing, a "Change in Control" shall not be deemed to have
occurred by virtue of the consummation of any transaction or series of
integrated transactions immediately following which the record holders of the
common stock of the Company immediately prior to such transaction or series of
transactions continue to have substantially the same proportionate ownership in
an entity which owns all or substantially all of the assets of the Company
immediately following such transaction or series of transactions.

                                       42
<PAGE>
 
          (H)  "Code" shall mean the Internal Revenue Code of 1986, as amended
from time to time.

          (I)  "Company" shall mean Centocor, Inc. and, except in determining
under Section 15(G) hereof whether or not any Change in Control of the Company
has occurred, shall include any successor to its business and/or assets which
assumes and agrees to perform this Agreement by operation of law, or otherwise.

          (J)  "Date of Termination" shall have the meaning set forth in Section
7.2 hereof.

          (K)  "Disability" shall be deemed the reason for the termination by
the Company of the Executive's employment, if, as a result of the Executive's
incapacity due to physical or mental illness, the Executive shall have been
absent from the full-time performance of the Executive's duties with the Company
for a period of six (6) consecutive months, the Company shall have given the
Executive a Notice of Termination for Disability, and, within thirty (30) days
after such Notice of Termi-

                                       43
<PAGE>
 
nation is given, the Executive shall not have returned to the full-time
performance of the Executive's duties.

          (L)  "Exchange Act" shall mean the Securities Exchange Act of 1934, as
amended from time to time.

          (M)  "Excise Tax" shall mean any excise tax imposed under section 4999
of the Code.
 
          (N)  "Executive" shall mean the individual named in the first
paragraph of this Agreement.

          (O)  "Good Reason" for termination by the Executive of the Executive's
employment shall mean the occurrence (without the Executive's express written
consent) after any Change in Control, or prior to a Change in Control under the
circumstances described in clauses (ii) and (iii) of the second sentence of
Section 6.1 hereof (treating all references in paragraphs (I) through (VII)
below to a "Change in Control" as references to a "Potential Change in
Control"), of any one of the following acts by the Company, or failures by the
Company to act, unless, in the case of any act or failure to act described in
paragraph (I), (V), (VI) or

                                       44
<PAGE>
 
(VII) below, such act or failure to act is corrected prior to the Date of
Termination specified in the Notice of Termination given in respect thereof:

                    (I)   the assignment to the Executive of any duties
          inconsistent with the Executive's status as a senior executive officer
          of the Company or a substantial adverse alteration in the nature or
          status of the Executive's responsibilities from those in effect
          immediately prior to the Change in Control;

                    (II)  a reduction by the Company in the Executive's annual
          base salary as in effect on the date hereof or as the same may be
          increased from time to time except for across-the-board salary
          reductions similarly affecting all senior executives of the Company
          and all senior executives of any Person in control of the Company;

                                       45
<PAGE>
 
                    (III) the relocation of the Executive's principal place of
          employment to a location more than 30 miles from the Executive's
          principal place of employment immediately prior to the Change in
          Control or the Company's requiring the Executive to be based anywhere
          other than such principal place of employment (or permitted relocation
          thereof) except for required travel on the Company's business to an
          extent substantially consistent with the Executive's present business
          travel obligations;

                    (IV)   the failure by the Company to pay to the Executive
          any portion of the Executive's current compensation except pursuant to
          an across-the-board compensation deferral similarly affecting all
          senior executives of the Company and all senior executives of any
          Person in control of the Company, or to pay to the Executive any

                                       46
<PAGE>
 
          portion of an installment of deferred compensation under any deferred
          compensation program of the Company, within seven (7) days of the date
          such compensation is due;

                    (V)  the failure by the Company to continue in effect any
          compensation plan in which the Executive participates immediately
          prior to the Change in Control which is material to the Executive's
          total compensation unless an equitable arrangement (embodied in an
          ongoing substitute or alternative plan) has been made with respect to
          such plan, or the failure by the Company to continue the Executive's
          participation therein (or in such substitute or alternative plan) on a
          basis not materially less favorable, both in terms of the amount and
          timing of payment of benefits provided and the level of the
          Executive's participation relative to other participants, 

                                       47
<PAGE>
 
          as existed immediately prior to the Change in Control;

                    (VI)  the failure by the Company to continue to provide the
          Executive with benefits substantially similar to those enjoyed by the
          Executive under any of the Company's pension, savings, life insurance,
          medical, health and accident, or disability plans in which the
          Executive was participating immediately prior to the Change in Control
          (except for across the board changes similarly affecting all senior
          executives of the Company and all senior executives of any Person in
          control of the Company), the taking of any other action by the Company
          which would directly or indirectly materially reduce any of such
          benefits or deprive the Executive of any material fringe benefit
          enjoyed by the Executive at the time of the Change in Control, or the
          failure by the Company to 

                                       48
<PAGE>
 
          provide the Executive with the number of paid vacation days to which
          the Executive is entitled on the basis of years of service with the
          Company in accordance with the Company's normal vacation policy in
          effect at the time of the Change in Control; or

                    (VII)  any purported termination of the Executive's
          employment which is not effected pursuant to a Notice of Termination
          satisfying the requirements of Section 7.1 hereof; for purposes of
          this Agreement, no such purported termination shall be effective.

          The Executive's right to terminate the Executive's employment for Good
Reason shall not be affected by the Executive's incapacity due to physical or
mental illness.  The Executive's continued employment shall not constitute
consent to, or a waiver of rights with respect to, any act or failure to act
constituting Good Reason hereunder.

                                       49
<PAGE>
 
          For purposes of any determination regarding the existence of Good
Reason, any claim by the Executive that Good Reason exists shall be presumed to
be correct unless the Company establishes to the Board by clear and convincing
evidence that Good Reason does not exist.

          (P)  "Gross-Up Payment" shall have the meaning set forth in Section
6.2 hereof.

          (Q)  "Notice of Termination" shall have the meaning set forth in
Section 7.1 hereof.

          (R)  "Pension Plan" shall mean the Centocor Savings and Retirement
Plan or any successor plan thereto.

          (S)  "Person" shall have the meaning given in Section 3(a)(9) of the
Exchange Act, as modified and used in Sections 13(d) and 14(d) thereof, except
that such term shall not include (i) the Company or any of its subsidiaries,
(ii) a trustee or other fiduciary holding securities under an employee benefit
plan of the Company or any of its Affiliates, (iii) an underwriter temporarily
holding securities pursuant to an offering 

                                       50
<PAGE>
 
of such securities, or (iv) a corporation owned, directly or indirectly, by the
shareholders of the Company in substantially the same proportions as their
ownership of stock of the Company.

          (T)  "Potential Change in Control" shall be deemed to have occurred if
the event set forth in any one of the following paragraphs shall have occurred:

                    (I)    the Company enters into an agreement, the
          consummation of which would result in the occurrence of a Change in
          Control;

                    (II)   the Company or any Person publicly announces an
          intention to take or to consider taking actions which, if consummated,
          would constitute a Change in Control;

                    (III)  any Person becomes the Beneficial Owner, directly or
          indirectly, of securities of the Company representing 15% or more of
          either the then outstanding shares of common stock of the Company or
          the combined 

                                       51
<PAGE>
 
          voting power of the Company's then outstanding securities (not
          including in the securities beneficially owned by such Person any
          securities acquired directly from the Company or its affiliates); or

                    (IV)  the Board adopts a resolution to the effect that, for
          purposes of this Agreement, a Potential Change in Control has
          occurred.

          (U)  "Retirement" shall be deemed the reason for the termination by
the Executive of the Executive's employment if such employment is terminated in
accordance with the Company's retirement policy, including early retirement,
generally applicable to its salaried employees.

          (V)  "Severance Payments" shall have the meaning set forth in Section
6.1 hereof.

          (W)  "Tax Counsel" shall have the meaning set forth in Section 6.2
hereof.

                                       52
<PAGE>
 
          (X)  "Term" shall mean the period of time described in Section 2
hereof (including any extension, continuation or termination described therein).

          (Y)  "Total Payments" shall mean those payments so described in
Section 6.2 hereof.

                                       53
<PAGE>
 
          IN WITNESS WHEREOF, the parties have executed this Agreement as of the
date first above written.


                              CENTOCOR, INC.



                              By:____________________________
                                 Name:  David P. Holveck
                                 Title: Chief Executive
                                           Officer



                              _______________________________

                              Address:
 

                                       54