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                                                                    Exhibit 10.1

                              EMPLOYMENT AGREEMENT


       THIS EMPLOYMENT AGREEMENT (this "Agreement"), dated as of March 14, 2000,
by and between Alteon Inc., a Delaware corporation (the "Company"), and Robert
deGroof, Ph.D. (the "Employee").

       WHEREAS, the Company wishes to employ the Employee as Senior Vice
President for Scientific Affairs; and

       WHEREAS, the Employee wishes to enter into the employ of the Company as
its Senior Vice President for Scientific Affairs;

       NOW, THEREFORE, in consideration of the premises and the mutual covenants
contained herein, the parties hereby agree as follows;

       1.     Term of Employment. Subject to the terms and conditions hereof,
              the Company will employ the Employee, and the Employee will serve
              the Company, as Senior Vice President for Scientific Affairs for a
              period beginning on the date hereof and terminating three (3)
              years from such date, subject to extension by mutual agreement of
              the Company and the Employee (such term, as it may be extended, is
              hereinafter referred to as the "Term of Employment").

       2.     Duties. During the Term of Employment, the Employee will serve as
              Senior Vice President for Scientific Affairs, subject to the terms
              of this Agreement and the direction and control of the Board of
              Directors and/or the Chief Executive Officer of the Company. The
              Employee will, during the Term of Employment, serve the Company
              faithfully, diligently and competently and to the best of his
              ability, and will, consistent with the dignity of Senior Vice
              President for Scientific Affairs of the Company, hold, in addition
              to the offices of Senior Vice President of Scientific Affairs of
              the Company, such other offices in the Company to which he may be
              appointed or assigned from time to time by the Board of Directors
              and/or the Chief Executive Officer of the Company and will
              discharge such duties in connection therewith. The Employee shall
              devote all of his business time to the performance of his duties
              hereunder.

       3.     Compensation. The Company will, during the Term of Employment, pay
              to the Employee as compensation for the performance of his duties
              and obligations hereunder an initial base salary at the rate of
              $200,000 per annum ("Salary"), payable in equal semi-monthly
              installments. Such Salary shall be reviewed annually by the Board
              of Directors of the Company in
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Employment Agreement                                                      Page 2


              accordance with the Company's compensation program. In each of the
              Company's fiscal years during the Term of Employment, the Employee
              shall be eligible to receive a bonus, to be awarded at the sole
              discretion of the Board of Directors of the Company, in an amount
              of up to $25,000 per year for the term of the employment
              agreement. The Board shall use as a basis for determining the
              extent of such bonus awards the attainment of stated goals and
              objectives for the Employee to be set by the Compensation
              Committee of the Board after consultation with the Chief Executive
              Officer.

       4.     Other Benefits. During the Term of Employment:

              A.     The Company shall grant to the Employee an incentive stock
                     option, pursuant to the Company's 1995 Stock Option Plan,
                     to purchase 250,000 shares of Common Stock of the Company
                     ("Common Stock") with an exercise price equal to the
                     closing price of the Company's Common Stock on March 14,
                     2000. Such option shall be in the form of and on such terms
                     and conditions as provided in, the Company's standard form
                     of Stock Option Grant Agreement in effect as of the date of
                     this Agreement. Such option grant shall provide, on
                     condition that the Employee is employed by the Company on
                     the relevant vesting dates, that such options shall vest as
                     follows:

                     (1)    10,000 shares shall vest on hire; and

                     (2)    25,000 shares shall vest on the first anniversary of
                            the date of this Agreement and 75,000 shares shall
                            vest over a thirty-six month period at the rate of
                            2,083 shares on the first day of each calendar month
                            commencing on March 14; and

                     (3)    140,000 shares shall vest upon the accomplishment by
                            the Employee of specified milestones, as determined
                            by the Compensation Committee of the Board after
                            consultation with the Chief Executive Officer; and

              B.     The Employee shall be entitled during the Term of
                     Employment to participate in employee benefit plans and
                     programs of the Company to the extent that his position,
                     tenure, salary, age, health and other qualifications make
                     him eligible to participate. The Company does not guarantee
                     the adoption or continuance of any particular employee
                     benefit plan or program during the Term of Employment, and
                     the Employee's participation in any such plan or program
                     shall be subject to the provisions, rules, regulations and
                     laws applicable thereto; provided, however, that during the
                     Term of Employment the Employee shall be entitled to health
                     and hospital insurance benefits consistent with the past
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Employment Agreement                                                      Page 3


                     practices of the Company in effect with respect to Company
                     personnel generally; and, further provided, the Employee is
                     eligible for protection under the Alteon Inc. Change in
                     Control Severance Benefits Plan, as in effect from time to
                     time.

              C.     The Employee shall be entitled to three (3) weeks' vacation
                     per year while employed hereunder. Such vacation may be
                     taken by the Employee at such times as do not unreasonably
                     interfere with the business of the Company. The
                     accumulation of annual vacation time earned but not taken
                     will be in accordance with the Company policy guidelines.
                     Additional vacation will be earned in accordance with
                     Company policy.

       5.     Expenses. During the Term of Employment, the Company will
              reimburse the Employee for commuting and housing expenses in an
              amount of $2,500 per month up to a maximum of $30,000 per year. In
              addition, during the Term of Employment, all travel and other
              reasonable business expenses incident to the rendering of services
              by the Employee under this Agreement will be paid or reimbursed by
              the Company subject to the submission of appropriate vouchers and
              receipts in accordance with the Company's policy from time to time
              in effect.

       6.     Death or Disability.

              A.     This Agreement shall be terminated by the death of the
                     Employee. In addition, this Agreement may be terminated by
                     the Board of Directors of the Company if the Employee shall
                     be rendered incapable by illness or any other disability
                     from complying with the terms, conditions and provisions on
                     his part to be kept, observed and performed for a period in
                     excess of 180 days (whether or not consecutive) or 90 days
                     consecutively, as the case may be, during a 12-month period
                     during the Term of Employment ("Disability"). If this
                     Agreement is terminated by reason of Disability of the
                     Employee, the Company shall give written notice to that
                     effect to the Employee in the manner provided herein. In
                     the event that the Employee receives disability insurance
                     benefits paid for by the Company during any period prior to
                     termination of this Agreement pursuant to this Section
                     6(a), the Employee's Salary shall be reduced by an amount
                     equal to such disability insurance benefits during such
                     period.

              B.     In addition to and not in substitution for any other
                     benefits which may be payable by the Company in respect of
                     the death or Disability of the Employee, in the event of
                     such death or Disability, the Salary payable hereunder
                     shall continue to be paid at the then current rate for
                     three (3) months after the termination of employment, and
                     any bonus to which the Employee would have been entitled
                     for the year in which his death occurs
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Employment Agreement                                                      Page 4


                     shall be pro rated to the date of his death and paid not
                     later than three (3) months after the termination of
                     employment. In the event of the death of the Employee
                     during the Term of this Agreement, the sums payable
                     hereunder shall be paid to his personal representative.

       7.     Disclosure of Information, Inventions and Discoveries. The
              Employee shall promptly disclose to the Company all processes,
              trademarks, inventions, improvements discoveries and other
              information related to the business of the Company (collectively,
              "Developments") conceived, developed or acquired by him alone or
              with others during the Term of Employment or during any earlier
              period of employment by the Company or any predecessor of the
              Company, whether or not during regular working hours or through
              the use of materials or facilities of the Company. All such
              Developments shall be the sole and exclusive property of the
              Company, and, upon request, the Employee shall promptly deliver to
              the Company all drawings, sketches, models and other data and
              records relating to such Developments. In the event any such
              Development shall be deemed by the Company to be patentable, the
              Employee shall, at the expense of the Company, assist the Company
              in obtaining a patent or patents thereon and execute all documents
              and do all such other acts and things necessary or proper to
              obtain letters of patents and to invest in the Company full right,
              title and interest in and to such Developments.

       8.     Non-Disclosure. The Employee shall not, at any time during or
              after the Term of Employment, divulge, furnish or make accessible
              to anyone (otherwise than in the regular course of business of the
              Company) or use for his own account or for the account of any
              person any knowledge or information with respect to confidential
              or secret processes, inventions, discoveries, improvements,
              formulae, plans, materials, devices or ideas or other know-how,
              whether patentable or not, with respect to any confidential or
              secret development or research work or with respect to any other
              confidential or secret aspects of the Company's business
              (including, without limitation, customer lists, supplier lists and
              pricing arrangements with customers or suppliers).

       9.     Non-Competition. The Company and the Employee agree that the
              services rendered by the Employee hereunder are unique and
              irreplaceable. The Employee hereby agrees that, during the Term of
              Employment and for a period of one (1) year thereafter, the
              Employee shall not (i) in any geographical area in the United
              States or in those foreign countries where the Company, during the
              Term of Employment, conducts or proposes to conduct business or
              initiates activities, engage or participate in, directly or
              indirectly (whether as an officer, director, employee, partner,
              consultant, holder of an equity or debt investment, lender or in
              any other manner or capacity), or lend
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Employment Agreement                                                      Page 5


              his name (or any part or variant thereof) to any business which
              is, or as a result of the Employee's engagement or participation
              would become, competitive with any aspect of the business of the
              Company, such business being the commercialization of the
              measurement, prevention therapy or reversal of glucose-mediated
              non-enzymatic cross-linking of macro-molecules, and such other
              specific technologies in which the Company has, during the Term of
              Employment, initiated significant plans to develop products, (ii)
              deal, directly or indirectly, in a competitive manner with any
              customers doing business with the Company during the Term of
              Employment (except in connection with the performance of the
              duties and obligations of the Employee during the Term of
              Employment), (iii) solicit any officer, director, employee,
              consultant or agent of the Company to become an officer, director,
              employee, consultant or agent of the Employee, his respective
              affiliates or anyone else, and (iv) engage in or participate in,
              directly or indirectly, any business conducted under any name that
              shall be the same as or similar to the name of the Company or any
              trade name used by it. Ownership, in the aggregate, of less than
              1% of the outstanding shares of capital stock of any corporation
              with one or more classes of its capital stock listed on a national
              securities exchange or publicly traded in the over-the-counter
              market shall not constitute a violation of the foregoing
              provision.

       10.    Remedies. The Employee acknowledges that irreparable damage would
              result to the Company if the provisions of Section 7, 8, 9 or 14
              were not specifically enforced, and agrees that the Company shall
              be entitled to any appropriate legal, equitable or other remedy,
              including injunctive relief, in respect to any failure to comply
              with the provisions of Section 7, 8, 9 or 14.

       11.    Termination for Cause. In addition to any other remedy available
              to the Company, either at law or in equity, the Employee's
              employment with the Company may be terminated by the Board of
              Directors for cause, which shall include (i) the Employee's
              conviction for, or plea of nolo contendere to, a felony or a crime
              involving moral turpitude, (ii) the Employee's commission of an
              act of personal dishonesty or a breach of fiduciary duty involving
              personal profit in connection with the Employee's employment by
              the Company, (iii) the Employee's commission of an act which the
              Board of Directors shall reasonably have found to have involved
              willful misconduct or gross negligence on the part of the
              Employee, in the conduct of his duties under this Agreement, (iv)
              habitual absenteeism, (v) the Employee's material breach of any
              material provision of this Agreement, or (vii) the willful and
              continued failure by the Employee to perform substantially his
              duties with the Company (other than any such failure resulting
              from his incapacity due to physical or mental illness). In the
              event of termination under this Section 11, the Company's
              obligations under this Agreement shall cease and the Employee
              shall forfeit all rights to receive any future compensation under
              this
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Employment Agreement                                                      Page 6


              Agreement. Notwithstanding any termination of this Agreement
              pursuant to this Section 11, the Employee, in consideration of his
              employment hereunder to the date of such termination, shall remain
              bound by the provisions of Section 7, 8, 9 and 14 hereof.

       12.    Termination Without Cause. Each of the Company and Employee may
              terminate this Agreement at any time for any reasons whatsoever,
              without any further liability or obligation of the Company to the
              Employee or of the Employee to the Company from and after the date
              of such termination (other than liabilities or obligations accrued
              but unsatisfied on, or surviving, the date of such termination),
              by sending thirty (30) days prior written notice to the other
              party. In the event (a) the Company elects to terminate this
              Agreement prior to the end of the Term of Employment or (b) the
              Company gives Employee notice of its election not to extend the
              Term of Employment beyond the expiration of the then current Term
              of Employment, or (c) by the date which is four (4) months prior
              to the end of the then current Term of Employment, the Company has
              not offered to extend the then current Term of Employment, the
              Company shall continue to pay the Employee the full Salary
              (exclusive of bonuses, if any) as such Salary would have otherwise
              accrued for a period of three (3) months if the effective date of
              such termination occurs prior to the first anniversary of this
              Agreement and for a period of six (6) months if the effective date
              of such termination occurs thereafter. In the event the Employee
              elects to terminate prior to the end of the Term of Employment,
              the Company's obligation to pay Salary shall cease as of the
              effective date of termination. Notwithstanding any termination of
              this Agreement pursuant to this Section 12, the Employee, in
              consideration of his employment hereunder to the date of such
              termination, shall remain bound by the provisions of Section 7, 8,
              9 and 14 hereof. Any termination of this Agreement by the Company
              as provided in this Section 12 shall be in addition to, and not in
              substitution for, any rights with respect to termination of the
              Employee which the Company may have pursuant to Section 11.

       13.    Resignation. In the event that the Employee's services under this
              Agreement are terminated under any of the provisions of this
              Agreement (except by death), the Employee agrees that he will
              deliver his written resignation from all positions held with the
              Company to the Board of Directors, such resignation to become
              effective immediately; provided, however, that nothing herein
              shall be deemed to affect the provisions of Section 7, 8, 9 and 14
              hereof relating to the survival thereof following termination of
              the Employee's services hereunder, and provided, further, that
              except as expressly provided in this Agreement, the Employee shall
              be entitled to no further compensation hereunder.
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Employment Agreement                                                      Page 7


       14.    Data. Upon termination of the Term of Employment or termination
              pursuant to Sections 6, 11 or 12 hereof, the Employee or his
              personal representative shall promptly deliver to the Company all
              books, memoranda, plans, records and written data of every kind
              relating to the business and affairs of the Company which are then
              in his possession.

       15.    Insurance. The Company shall have the right, at its own cost and
              expense to apply for and to secure in its own name, or otherwise,
              life, health or accident insurance or any or all of them covering
              the Employee, and the Employee agrees to submit to usual and
              customary medical examinations and otherwise to cooperate with the
              Company in connection with the procurement of any such insurance,
              and any claims thereunder.

       16.    Waiver of Breach. Any waiver of any breach of this Agreement shall
              not be construed to be a continuing waiver or consent to any
              subsequent breach on the part either of the Employee or of the
              Company.

       17.    Assignment. This Agreement shall inure to the benefit of and be
              binding upon the successors and assigns of the Company upon any
              sale of all or substantially all of the Company's assets, or upon
              any merger or consolidation of the Company with or into any other
              entity, all as though such successors and assigns of the Company
              and their respective successors and assigns were the Company.
              Insofar as the Employee is concerned, this Agreement, being
              personal, may not be assigned.

       18.    Severability. To the extent any provision of this Agreement shall
              be invalid or unenforceable, it shall be considered deleted
              therefrom and the remainder of such provision and of this
              Agreement shall be unaffected and shall continue in full force and
              effect. In furtherance and not in limitation of the foregoing,
              should the duration or geographical extent of, or business
              activities covered by, any provision of this Agreement be in
              excess of that which is valid and enforceable under applicable
              law, then such provision shall be construed to cover only that
              duration, extent or activities which may be validly and
              enforceable covered.

       19.    Notices. All notices, requests and other communications pursuant
              to this Agreement shall be in writing and shall be deemed to have
              been duly given, if delivered in person or by courier,
              telegraphed, telexed or by facsimile transmission or five business
              days after being sent by registered or certified mail, return
              receipt requested, postage paid, addressed as follows:
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Employment Agreement                                                      Page 8



              If to the Employee

                           Robert deGroof, Ph.D.
                           145 Water Crest Drive
                           Doylestown, Pennsylvania 18901

              If to the Company:

                           Alteon Inc.
                           170 Williams Drive
                           Ramsey, NJ 07446

              with a copy to:

                           Richard J. Pinto, Esq.
                           Smith, Stratton, Wise, Heher & Brennan
                           600 College Road East
                           Princeton, NJ 08540

              Any party may, by written notice to the other in accordance with
              this Section 19, change the address to which notices to such party
              are to be delivered or mailed.

       20.    General. Except as otherwise provided herein, the terms and
              provisions of this Agreement and the Stock Option Grant Agreement
              to be entered into between the Employee and the Company shall
              constitute the entire agreement by the Company and the Employee
              with respect to the subject matter hereof, and shall supersede any
              and all prior agreements or understandings between the Employee
              and the Company, whether written or oral. This Agreement may be
              amended or modified only by a written instrument executed by the
              Employee and the Company. This Agreement may be executed in any
              number of counterparts, all of which, when executed, shall be
              deemed to be an original, and all of which together shall
              constitute one and the same instrument.
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Employment Agreement                                                      Page 9



       IN WITNESS WHEREOF, the parties have executed this Employment Agreement
as of the day and year first above written.

                                              ALTEON INC.

                                              By:   /s/ Kenneth I. Moch
                                                 ------------------------------
                                                    Kenneth I. Moch
                                                    Chief Executive Officer

                                                    /s/ Robert deGroof, Ph.D.
                                                 ------------------------------
                                                    Robert deGroof, Ph.D.