EXHIBIT 10.11

         STOCKHOLDERS   AGREEMENT  (this  "Agreement")  made  and  entered  into
effective  as of  September  17,  2003 by and among  Araios,  Inc.,  a  Delaware
corporation (the "Corporation"),  and the Stockholders (as hereinafter defined),
with reference to the following facts:

         A. Each  Stockholder  owns or has the right to acquire  that  number of
shares of Stock (as herein defined) set forth opposite such  Stockholder's  name
on Schedule 1 hereto.

         B. It is deemed to be in the best interests of the  Corporation and the
Stockholders  that  provision be made for the  continuity  and  stability of the
business and policies of the  Corporation  and, to this end, the Corporation and
the  Stockholders  hereby set forth their  agreement  with  respect to the Stock
owned by the Stockholders.

         NOW,  THEREFORE,  in  consideration  of the  premises and of the mutual
covenants and obligations hereinafter set forth, the parties hereto hereby agree
as follows:

SECTION 1.  Definitions.  As used  herein,  the  following  terms shall have the
meanings indicated:

         (a) "AAA" has the meaning set forth in Section 21(a).

         (b) "Affiliate" means, with respect to any Stockholder, any Person that
directly or indirectly  controls,  is  controlled by or is under common  control
with such  Stockholder.  For purposes of the  definition,  "control" of a Person
means the power to direct or cause the direction of the  management and policies
of such Person,  whether  directly or  indirectly,  through  ownership of voting
securities, by contract or otherwise.

         (c) "Board" shall mean the Board of Directors of the Corporation.

         (d) "Call Option" has the meaning set forth in Section 4(a).

         (e) "Certificate of Incorporation"  shall mean the Amended and Restated
Certificate  of  Incorporation  of the  Corporation,  as in  effect  on the date
hereof.

         (f) "Common  Stock"  shall mean the common  stock,  $0.01 par value per
share, of the Corporation.

         (g) "Control" or "Controlled"  shall have the meaning  ascribed to such
term under Section 368(c) of the Internal Revenue Code of 1986, as amended,  and
applicable Treasury Regulations.

         (h)  "CytRx"  means  CytRx  Corporation,  a Delaware  corporation,  its
successors  and  assigns,  and any  Affiliate  thereof to which  Stock  shall be
transferred as permitted in this Agreement.

         (i) "CytRx Common  Stock" means the common stock,  $0.001 par value per
share, of CytRx.


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         (j) "Czech" means Dr. Michael P. Czech.

         (k) "Field"  means the  treatment,  prevention  and diagnosis of type 2
diabetes and/or obesity.

         (l)  "Non-Affiliated  Person" means any Person that is not an Affiliate
of  the  Corporation,  any  Stockholder  or  any  member  of  the  Group  of any
Stockholder.

         (m) "Person" means any  individual,  partnership,  corporation,  group,
trust, joint venture or other legal entity.

         (n) "Preferred Stock" means (i) the Series A Preferred Stock, $0.01 par
value per share, of the  Corporation,  and (ii) any other class or series of the
capital  stock of the  Corporation  that is  entitled to at least a fixed sum or
percentage  of par or stated  value in  respect  of the  rights  of the  holders
thereof to  participate in dividends or in the  distribution  of assets upon any
liquidation, dissolution or winding up of the Corporation.

         (o) "Purchase  Agreement" means the Preferred Stock Purchase Agreement,
of even date herewith, between the Corporation and CytRx.

         (p) "Put Option" has the meaning set forth in Section 4(b).

         (q)  "Qualified   Merger"  means  a  merger  or  consolidation  of  the
Corporation  into  or  with  any  Non-Affiliated   Person  in  which  merger  or
consolidation the holders of capital stock of the Corporation  receive less than
a majority  of the  voting  power of the  resulting  or  surviving  corporation;
provided,  however,  that in the event that the holders of capital  stock of the
Corporation  are to receive  voting common stock in any such  transaction,  such
voting common stock must be (A) validly  registered  under the Securities Act of
1933,  as amended (the  "Securities  Act"),  and the  Exchange  Act of 1934,  as
amended (the "Exchange Act"), or any successor provisions thereto, (B) traded on
a national  securities exchange or included on the automated quotation system of
the National  Association of Securities Dealers,  Inc., and (C) immediately upon
issuance  to the  Stockholders  in  connection  with  such  transaction,  freely
tradeable  without any restriction  under the Exchange Act or the Securities Act
or  any  of  the  rules  and  regulations  promulgated  pursuant  to  such  Acts
(including, without limitation, Rule 144 promulgated under the Securities Act or
any successor  provision  thereto),  other than pursuant to Rule 145 promulgated
under the Securities Act or any successor provision thereto.

         (r)  "Qualified  Non-Affiliated  Transaction"  means  any bona fide (i)
Qualified  Merger,  (ii)  Qualified  Sale of  Assets  or (iii)  Qualified  Stock
Transaction.

         (s) "Qualified  Public  Offering" means the consummation of a bona fide
underwritten  public offering of Common Stock of the Corporation at an aggregate
public offering price of not less than $10,000,000.

         (t) "Qualified Sale of Assets" means the sale, lease, license, transfer
or  other  disposition  of  all  or  substantially  all  of  the  assets  of the
Corporation as an entirety to any Non- Affiliated  Person,  in which transaction
the Corporation  would (i) receive solely cash in consideration for such assets,
(ii) dissolve and wind up following the  consummation of such  transaction,  and
(iii) distribute the cash proceeds thereof to its stockholders.

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         (u) "Qualified Shares" means (i) with respect to Czech,  650,000 shares
of CytRx  Common  Stock  (appropriately  adjusted  for any  stock  split,  stock
dividend, reverse stock split, reclassification and the like occurring after the
date hereof),  of which 300,000 shares (the "Vested Qualified  Shares") shall be
immediately  vested upon issuance  thereof,  and 350,000 shares (the "Restricted
Qualified  Shares") shall be subject to the vesting and  forfeiture  provisions,
all as set forth in the Restricted Stock Agreement, and (ii) with respect to all
other  stockholders  of the Corporation  (other than CytRx and its  Affiliates),
shares  of  CytRx  Common  Stock   commensurate  with  each  such  stockholder's
stockholdings in the Corporation.

         (v) "Qualified Stock  Transaction"  means the Sale of all, but not less
than  all,  of  the  outstanding   capital  stock  of  the  Corporation  to  any
Non-Affiliated Person solely in exchange for cash.

         (w) "Qualified CytRx  Transaction"  means any acquisition of all of the
capital stock, or all or substantially  all of the assets, of the Corporation by
CytRx or any Affiliate  Controlled by CytRx in a transaction  (i) in which Czech
and  all  other  stockholders  of the  Corporation  (other  than  CytRx  and its
Affiliates)  receive Qualified Shares only and (ii) which is structured so as to
qualify as a tax-free  reorganization  for federal income tax purposes unless it
is not  possible  to do so due to a  subsequent  change in the tax laws or other
regulatory requirements.

         (x) "Restricted Period" means the period commencing on the date of this
Agreement and ending on March 12, 2006.

         (y) "Restricted Stock Agreement" means a restricted stock agreement, in
substantially  the form  attached as Exhibit A, to be entered into between CytRx
and Czech in  connection  with the exercise of the Call Option or the Put Option
or a Qualified CytRx Transaction.

         (z) "SAB" means the Scientific  Advisory Board of the Corporation or of
CytRx, as the context requires.

         (aa)  "Sell" (or  "Sale"),  as to any Stock,  means to sell,  or in any
other way  directly or  indirectly  to  transfer,  assign,  pledge,  distribute,
encumber or otherwise  dispose of, either  voluntarily or involuntarily and with
or without consideration,  including,  but not limited to, any event pursuant to
which an Affiliate which holds Stock ceases to be an Affiliate.

         (bb)  "Series  A  Preferred  Stock"  has the  meaning  set forth in the
recitals to this Agreement.

         (cc) "Stockholders"  means Czech and CytRx, and shall include any other
Person  who  agrees in  writing  with the  parties  hereto to be bound by and to
comply with all applicable provisions of this Agreement.

         (dd)  "Stock"  means (i) the  outstanding  shares  of Common  Stock and
Preferred Stock and any other issued and outstanding  shares of capital stock of
the  Corporation,  and any options or stock  subscription  warrants  exercisable
therefor  (which  options and warrants  shall be deemed to be equivalent to that


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<PAGE>

number  of  outstanding  shares of Common  Stock or other  capital  stock of the
Corporation for which they are convertible or exercisable),  (ii) any additional
shares of capital stock of the Corporation  hereafter issued and outstanding and
(iii) any shares of capital stock of the Corporation  into which such shares may
be converted or for which they may be exchanged or exercised.

         (ee)  "Termination  Date"  means the  earliest  to occur of the date of
consummation of (i) a Qualified  Non-Affiliated  Transaction or (ii) a Qualified
Public Offering.

         (ff) "UMass" means the University of Massachusetts.

SECTION 2. Election of Directors; Voting.

         (a) During the term of this Agreement,  each Stockholder shall vote all
of his or its Stock and shall  take all other  necessary  or  desirable  actions
within  his  or  its  control  (whether  in  such  Stockholder's  capacity  as a
stockholder of the Corporation or otherwise, and including,  without limitation,
attending  meetings in person or by proxy for purposes of obtaining a quorum and
executing written consents in lieu of meetings),  and the Corporation shall take
all necessary  and  desirable  actions  within its control  (including,  without
limitation, calling special Board and stockholder meetings), so that:

                  (i) the  authorized  number of  directors  on the Board  shall
         consist of five directors;

                  (ii) the following  individuals  shall be elected to the Board
         and each committee of the Board:

                           (A) three individuals designated by CytRx;

                           (B) the Chief  Executive  Officer (or  President,  if
                  there is no Chief Executive Officer) of the Company; and

                           (C)  one  individual  who  shall  be  designated  and
                  approved  by a  majority  of  the  executive  officers  of the
                  Corporation  in a  writing  delivered  to the  Board  and  the
                  Stockholders.

                  (iii) In the event that a party  elects not to  designate as a
         director  one or more  individuals  which  such  party is  entitled  to
         designate in accordance with Section 2(a)(ii),  the Stockholders  agree
         not to fill such  vacancy,  or suffer such vacancy to be filled,  other
         than with an individual designated by such party as provided in Section
         2(a)(ii).

                  (iv) The  designation  of an  individual  pursuant  to Section
         2(a)(ii)  at any time  shall be  effective  only  upon  written  notice
         thereof  to the  Corporation  by  the  party  or  parties  making  such
         designation.   Such  written  notice  shall  be  recorded  as  soon  as
         reasonably  practical  in the  minutes  of the  Corporation  and may be
         relied upon by the  Corporation  as  conclusive  until such time as the
         Corporation  is in receipt of a subsequent  written notice making a new
         designation.


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<PAGE>

SECTION 3. Limitations on Sales of Stock.

         (a) Czech agrees that, during the Restricted  Period, he shall not Sell
any Stock except:

                  (i)  pursuant  to the  exercise  of the Call Option or the Put
         Option in accordance with Section 4 hereof; or

                  (ii) pursuant to a Qualified Non-Affiliated Transaction;

                  (iii) as part of a Qualified Public Offering;

                  (iv) pursuant to a Qualified CytRx Transaction; or

                  (v) to a  member  of  Czech's  immediate  family,  or a trust,
         partnership  or limited  liability  company for the benefit of Czech or
         for the benefit of a member of his immediate family,  provided, in each
         case, that such transferee  agrees in writing in connection with and as
         a condition to such Sale to be bound by all of the  provisions  of this
         Agreement.

         (b) CytRx agrees that, during the Restricted  Period, it shall not Sell
any Stock except:

                  (i) pursuant to a Qualified Non-Affiliated Transaction; or

                  (ii) as part of a Qualified Public Offering; or

                  (iii) to an Affiliate Controlled by CytRx,  provided that such
         Affiliate  agrees in writing in  connection  with and as a condition to
         such Sale to remain an Affiliate  Controlled  by CytRx  throughout  the
         Restricted  Period  and to be  bound by all of the  provisions  of this
         Agreement.

SECTION 4. Call and Put Options.

         (a) Czech hereby  agrees that at any time during the period  commencing
March 12, 2005 and ending  September  12,  2005,  CytRx shall have the right and
option (the "Call  Option")  to purchase  all (but not less than all) of Czech's
Stock in exchange for the  issuance to Czech of Qualified  Shares in a Qualified
CytRx Transaction.  The Call Option may be exercised by CytRx by notice ("Notice
of Call Exercise") given to Czech as provided in this Agreement.

         (b) CytRx hereby agrees that,  unless the Call Option shall  previously
have been exercised, at any time during the period commencing September 13, 2005
and ending  March 12,  2006,  Czech  shall  have the right and option  (the "Put
Option") to cause CytRx to purchase all (but not less than all) of Czech's Stock
in exchange  for the  issuance to Czech of the  Qualified  Shares in a Qualified
CytRx Transaction.  The Put Option may be exercised by Czech by notice (the "Put
Exercise Notice") given to CytRx as provided in this Agreement.

         (c) The closing of the sale and purchase of Czech's  Stock  pursuant to
the  exercise  of the Call  Option  or the Put  Option  shall be held as soon as
practicable  following the Notice of Call Exercise or Notice of Put Exercise, as
the case may be, but in no event more than 30 days following such Notice. At the

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<PAGE>

closing,  Czech shall sell and  exchange,  and CytRx or any  Affiliate  of CytRx
shall  acquire,  all of  Czech's  Stock,  free  and  clear of any  lien,  claim,
encumbrance or restriction,  other than those imposed by this Agreement.  In the
event that any of Czech's  Stock is  subject to any lien or  encumbrance  at the
closing other than those imposed by this Agreement  (whether or not in breach of
this Agreement),  the number of Vested Qualified Shares and Restricted Qualified
Shares to be issued to Czech shall be reduced ratably by the number of Qualified
Shares  having a market  value equal to the sum of (i) the amount of the lien or
encumbrance and by (ii) the reasonable  costs and expenses  incurred by CytRx in
connection with removing or satisfying such lien or encumbrance. At the closing:

                  (i) Czech shall (1) deliver to CytRx or its Affiliate,  as the
         case may be, one or more stock certificates or other instruments,  duly
         endorsed  or  accompanied  by stock  powers  duly  endorsed  in  blank,
         evidencing  all of Czech's  Stock and (2) shall  execute and deliver to
         CytRx the Restricted Stock Agreement; and

                  (ii)  CytRx or its  Affiliate,  as the case may be,  shall (1)
         issue,  or cause  to be  issued,  in  Czech's  name  one or more  stock
         certificates  evidencing the Qualified Shares, (2) deliver, or cause to
         be  delivered  one or more  stock  certificates  evidencing  the Vested
         Qualified  Shares and (3) deliver,  or cause to be delivered,  to Czech
         the Restricted Stock Agreement as executed by CytRx.

         (d)  Notwithstanding  any  provision  of this  Agreement,  neither  the
Corporation  nor CytRx or its Affiliates  shall have any liability or obligation
to Czech, including without limitation any liability for taxes payable by Czech,
in the event that the exchange and  acquisition of Czech's Stock pursuant to the
exercise  of the  Call  Option  or  the  Put  Option,  or  any  Qualified  CytRx
Transaction,  cannot be  accomplished  as a  tax-free  transaction  to Czech for
federal income tax purposes due to a subsequent  change in the tax laws or other
regulatory  requirements or a final  determination  by the IRS, and the sale and
exchange of Czech's Stock pursuant to the exercise of the Call Option or the Put
Option, or pursuant to a Qualified CytRx  Transaction,  shall not be conditioned
upon such tax treatment.

SECTION  5.  Certain  Covenants  and  Representations  of Czech.  As a  material
inducement  to the  Corporation  and CytRx to enter into this  Agreement,  Czech
hereby represents,  warrants and agrees as follows,  with such  representations,
warranties  and covenants to survive the  termination  of this Agreement and any
transfer by Czech of his Stock except as set forth in Sections 5(d) and (e):

         (a) Czech  shall use  commercially  reasonable  efforts  to  acquire by
assignment  or,  if an  assignment  is  not  possible  due to  applicable  UMass
policies,  an  exclusive  license  for the  Corporation  or  CytRx to all of the
existing inventions,  technologies and other intellectual  property in the Field
that have been developed or identified  through the date hereof by Czech and his
laboratory;

         (b) That, to the best of his knowledge and without independent inquiry,
apart from the inventions, technologies and other intellectual property referred
to in (a) above,  UMass holds no inventions,  technologies or other intellectual
property  (including  without  limitation  any  technologies  that  it may  have
licensed to any third  parties) that are necessary for the  Corporation to carry
out its  scientific  development  plans in  accordance  with the budget and time
frames contained in the Corporation's  Business Plan delivered by Czech to CytRx
in connection with the Purchase Agreement;

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<PAGE>

         (c) Czech shall use his commercially  reasonable best efforts to secure
from UMass exclusive  licenses for the Corporation or its Affiliates to genomics
and proteomics databases (inventions disclosures 01-31, 00-37, 02-38 and 03-134)
and a receptor activated  reporter system (invention  disclosure 93-09) on terms
no less favorable to the  Corporation  than those set forth in Exhibit B to this
Agreement;

         (d) During the term of any SAB  Agreement  between Czech and either the
Corporation or CytRx,  Czech shall use his commercially  reasonable best efforts
to obtain from UMass on behalf of the  Corporation  a right of first refusal for
the  Corporation to license from UMass for the exclusive use by the  Corporation
in the  Field  any  inventions,  technologies  or  other  intellectual  property
developed  or acquired by UMass after the date of this  Agreement of which Czech
becomes aware;

         (e) During the term of any SAB  Agreement  between Czech and either the
Corporation  or  CytRx,  Czech  shall  assist  CytRx in  developing  a  proposed
long-term strategic plan, business plan and annual budget for the Corporation;

         (f) Czech shall  serve,  without  compensation,  as the Chairman of the
Corporation's  SAB and shall serve,  for the  compensation  described in Section
6(b) below, as a member of CytRx's SAB, subject to the standard-form  Scientific
Advisory Board  Agreements of the Corporation and CytRx in  substantially in the
forms attached hereto as Exhibits A and B, respectively (the "SAB  Agreements");
and

         (g) Except as set forth on  Schedule  A, Czech is not party to or bound
by any agreement or obligation for personal services,  and there exists no other
impediment,  contractual or otherwise,  restricting  him from entering into this
Agreement, the Purchase Agreement or the SAB Agreements,  or from performing any
of his obligations  hereunder and thereunder in accordance with the terms hereof
and thereof.

SECTION 6. Certain  Covenants  of CytRx.  As a material  inducement  to Czech to
enter into this  Agreement,  CytRx  hereby  represents,  warrants  and agrees as
follows  with such  representations,  warranties  and  covenants  to survive the
termination of this Agreement and any transfer by Czech of his Stock:

         (a) CytRx shall cause the  Corporation  to engage Czech as Chair of the
SAB pursuant to its standard-form Scientific Advisory Board Agreement;

         (b) Czech shall be entitled to receive  from CytRx $5,000 per month for
his service on the CytRx SAB,  which will be  increased to $7,500 per month upon
the  Corporation's  signing of a  strategic  alliance  that  includes a research
agreement   satisfactory   to  CytRx  between  the   Corporation   and  a  major
pharmaceutical company and funding for research and development positions within
the  Corporation,  a licensing  agreement for the  Corporation's  technology and
other payments to the Corporation;


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<PAGE>

         (c) Czech shall not receive any compensation for serving as Chair or as
a member of the Corporation's SAB in addition to the cash compensation described
in (b) above,  and other of the  Corporation's  SAB members shall be entitled to
additional  equity  compensation  based  on  performance,   the  achievement  of
milestones and other relevant criteria;

         (d) Czech shall have the right to approve the Board's  appointments  of
the Chief  Executive  Officer,  President and Vice  President of Research of the
Corporation,  and to review  press  releases  relating to  announcement  of this
Agreement and developments in the Field prior to release,  with such approval of
appointments and press releases not to be unreasonably  delayed or withheld (and
the  Corporation  agrees that any press releases shall be approved in writing by
CytRx prior to their release);

         (e)  Czech  shall  be  authorized  by  the  Board  to  appoint  to  the
Corporation's  SAB up to three  high-profile  scientists  (who shall not include
Mark A. Tepper) who enjoy international renown (with additional  Corporation SAB
members to be approved by CytRx's Board of Directors),  and, subject to approval
by the Board,  these scientists will be offered consulting  contracts  entitling
them up to $7,500 per quarter  plus  options to purchase up to 20,000  shares of
CytRx common stock at the then trading price;

         (f) If the  Corporation's  SAB members identify  technologies  that are
attractive to the Corporation and are licensed to the Corporation,  such members
will be afforded the opportunity to obtain additional equity in CytRx;

         (g)  Czech  shall  approve  the  recruitment  of 12  scientists  to the
Corporation, including the President, Vice President of Research and the head of
the Chemistry  Section,  which approvals  shall not be unreasonably  withheld or
delayed;

         (h) The principal  officers of the Corporation shall be established and
maintained in close proximity of Czech's lab at UMass Medical School; and

         (i)  Czech  may  serve  on the  Scientific  Advisory  Boards  of  other
companies not in competition with the Corporation or CytRx.

SECTION 7. Czech Approval Rights.  During the Restricted Period, the Corporation
shall not, and CytRx shall not suffer or permit the  Corporation to, directly or
indirectly,  without the  affirmative  vote or prior written  approval of Czech,
adopt or undertake any of the following actions:

         (a) sell, abandon, transfer, lease, license or otherwise dispose of all
or  substantially  all of the  Corporation's  properties  or  assets,  or all or
substantially  all  of the  capital  stock  of  the  Corporation,  or  merge  or
consolidate  with or into, or permit any subsidiary of the  Corporation to merge
with or into,  any  other  Person  other  than  pursuant  to a  Qualified  CytRx
Transaction or a Qualified Non-Affiliated Transaction;

         (b) take any action to voluntarily  liquidate,  dissolve or wind up, or
carry out any partial liquidation or dissolution or transaction in the nature of
a partial liquidation or dissolution,  of the Corporation other than pursuant to
a Qualified CytRx Transaction;


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<PAGE>

         (c)  repurchase,  retire or redeem any shares of capital  stock  except
pursuant  to  a  Qualified  CytRx  Transaction  or  a  Qualified  Non-Affiliated
Transaction; or

         (d) sell or issue any shares of capital  stock of the  Corporation,  or
any stock options,  warrants or other rights or securities  exercisable  for, or
convertible  into,  shares of capital  stock of the  Corporation,  unless,  as a
condition to such sale or issuance,  the  recipient  agrees that all such shares
shall be subject to purchase by CytRx in a Qualified CytRx Transaction  pursuant
to the exercise of the Call Option or of the Put Option.

SECTION 8. Legend on Stock Certificates. Each certificate representing shares of
Stock held by the  Stockholders  shall bear a legend  containing  the  following
words:

         "THE  SALE,  TRANSFER,   ASSIGNMENT,  PLEDGE,  OR  ENCUMBRANCE  OF  THE
         SECURITIES  REPRESENTED  BY THIS  CERTIFICATE  AND/OR THE RIGHTS OF THE
         HOLDER OF THE SECURITIES  REPRESENTED BY THIS CERTIFICATE IN RESPECT OF
         THE ELECTION OF DIRECTORS ARE SUBJECT TO THE TERMS AND  CONDITIONS OF A
         STOCKHOLDERS  AGREEMENT  DATED AS OF SEPTEMBER __, 2003,  AMONG ARAIOS,
         INC.  AND  CERTAIN  HOLDERS  OF  THE  OUTSTANDING  SECURITIES  OF  SUCH
         CORPORATION.  COPIES OF SUCH  AGREEMENT  MAY BE  OBTAINED AT NO COST BY
         WRITTEN REQUEST MADE BY THE HOLDER OF RECORD OF THIS CERTIFICATE TO THE
         SECRETARY OF ARAIOS, INC."

SECTION 9. Additional  Shares of Stock. In the event additional  shares of Stock
are issued by the  Corporation  to a Stockholder  at any time during the term of
this  Agreement,  either directly or upon the exercise or exchange of securities
of the Corporation  exercisable for or exchangeable  into shares of Stock,  such
additional  shares of Stock  shall,  as a  condition  to such  issuance,  become
subject to the terms and provisions of this Agreement.

SECTION 10. Duration of Agreement.

         (a) The term of this  Agreement  shall expire,  and except as otherwise
expressly  provided  herein,  all of the  provisions  of  this  Agreement  shall
terminate  and,  shall be of no further force or effect and shall not be binding
upon any party hereto,  upon the first to occur of (i) the Termination  Date and
(ii) the approval of such termination by the Corporation and the Stockholders.

         (b) As to any  particular  Stockholder,  except  for the  provision  of
Sections 5 and 6, which shall survive until the termination of this Agreement as
provided in paragraph (a) above, this Agreement shall no longer be binding or of
further force or effect as to such  Stockholder as of the date such  Stockholder
has transferred all such Stockholder's interest in Stock in accordance with this
Agreement.

SECTION 11.  Noncircumvention.  The parties  hereto  shall act in good faith and
shall refrain from taking any actions, or failing to take actions, to circumvent
or frustrate  the  provisions  of this  Agreement.  Each of the parties  further
agrees to execute and deliver any such documents or instruments  and to take any
such  actions as shall be  reasonably  necessary  to carry out the terms of this
Agreement.

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<PAGE>

SECTION 12.  Severability;  Governing  Law. If any  provisions of this Agreement
shall be  determined  to be illegal and  unenforceable  by any court of law, the
remaining provisions shall be severable and enforceable in accordance with their
terms.  This Agreement  shall be governed by, and construed in accordance  with,
the  laws of the  State  of  Delaware  applicable  to  contracts  made and to be
performed wholly therein.

SECTION 13. Assignment, Successors and Assigns. Except as otherwise specifically
provided  in this  Agreement,  this  Agreement  may not be assigned by any party
without the prior written consent of the other parties,  which may be granted or
withheld in their sole and absolute  discretion.  This Agreement  shall bind and
inure to the benefit of the parties and their  respective  permitted  successors
and assigns, legal representatives and heirs.

SECTION 14. Notices.  All notices,  requests,  consents and other communications
hereunder  to any party  shall be  deemed to be  sufficient  if  contained  in a
written   instrument   delivered   in   person  or  by   telecopy   or  sent  by
nationally-recognized  overnight  courier or first class registered or certified
mail, return receipt requested,  postage prepaid, addressed to such party at the
address set forth below or at such other  address as may hereafter be designated
in writing by such party to the other parties:

                  (i) If to the Corporation, to:

                      Araios, Inc.
                      508 Dudley Road
                      Newton, MA  02459
                      Attention:        President
                      Telephone:        ______________
                      Telecopy:         ______________

                  (ii) If to CytRx, to:

                       CytRx Corporation
                       11726 San Vicente Boulevard, Suite 650
                       Los Angeles, California 90049
                       Attention:        Chief Executive Officer
                       Telephone:        (310) 826-5648
                       Telecopy:         (310) 826-6139

                       with a copy to:

                       Troy & Gould Professional Corporation
                       1801 Century Park East
                       Los Angeles, CA
                       Attention:        Sanford J. Hillsberg, Esq.
                       Telephone:        (310) 553-4441
                       Telecopy:         (310) 201-4746


                                       10
<PAGE>

(iii) If to Czech, to:

                          Dr. Michael P. Czech
                          75 Ruggles Road
                          Westborough,  MA 02093
                          Telephone: ___-___-____
                          Telecopy: ___-___-____

                          with a copy to:



         All such notices, requests,  consents and other communications shall be
deemed to have been  delivered (a) in the case of personal  delivery or delivery
by  telecopy,  on the  date of such  delivery,  (b) in the case of  dispatch  by
nationally-recognized overnight courier, on the next business day following such
dispatch  and (c) in the case of mailing,  on the third  business  day after the
posting thereof.

SECTION 15.  Modification.  Except as otherwise  provided  herein,  neither this
Agreement  nor any  provisions  hereof can be modified,  changed,  discharged or
terminated  except by an instrument in writing signed by the Corporation and the
Stockholders.

SECTION 16.  Headings.  The headings of the sections of this Agreement have been
inserted for  convenience of reference only and shall not be deemed to be a part
of this Agreement.

SECTION 17. Nouns and Pronouns.  Whenever the context may require,  any pronouns
used herein shall include the corresponding masculine, feminine or neuter forms,
and the  singular  form of names and  pronouns  shall  include  the  plural  and
vice-versa.


                                       11
<PAGE>

SECTION 18. Entire Agreement.  This Agreement and the other writings referred to
herein or  delivered  pursuant  hereto  contain the entire  agreement  among the
parties hereto with respect to the subject matter hereof and supersede all prior
and contemporaneous agreements and understandings with respect thereto.

SECTION  19.  Counterparts.  This  Agreement  may be  executed  in any number of
counterparts, and each such counterpart hereof shall be deemed to be an original
instrument,  but  all  such  counterparts  together  shall  constitute  but  one
agreement.

SECTION 20. Attorneys' Fees. In the event that any party hereto brings an action
or  proceeding  for a  declaration  of the  rights  of the  parties  under  this
Agreement,  for injunctive  relief,  for an alleged breach or default of, or any
other action  arising out of, this  Agreement or the  transactions  contemplated
hereby,  or in the event any party is in  default  of its  obligations  pursuant
hereto,  whether  or not suit is  filed or  prosecuted  to final  judgment,  the
prevailing  party  in any  such  action  or  proceeding  shall  be  entitled  to
reasonable  attorneys'  fees,  in addition to any court  costs  incurred  and in
addition to any other damages or relief awarded.


                                       12
<PAGE>

SECTION 21. Dispute Resolution.

         (a) Either for any emergency or preliminary  injunction or relief which
may be  sought  and  obtained  from any  court of  competent  jurisdiction,  any
controversy, claim or dispute arising out of or relating to the rights or duties
of the parties  under this  Agreement  or any  resulting  transaction,  shall be
determined  by binding  arbitration  in  accordance  with this  Section  20. Any
controversy  regarding  whether  a dispute  is an  arbitrable  dispute  shall be
determined by the arbitrator.  The  arbitration  shall be conducted by a retired
superior court judge or appellate  court justice on the panel of  JAMS/ENDISPUTE
in Los Angeles,  California,  or its successor,  in accordance with the rules of
JAMS/ENDISPUTE then prevailing for commercial  disputes,  as modified herein. If
JAMS/ENDISPUTE  is not able to conduct the arbitration,  then unless the parties
shall  otherwise  mutually  agree,  arbitration  shall be conducted by a retired
judge of the  Superior  Court of Los Angeles  County,  California,  or a retired
justice  of the Court of  Appeals  of the  State of  California  for the  Second
District,  in accordance with the rules of the American Arbitration  Association
("AAA"),  as modified herein. In either case, there shall be only one arbitrator
who shall be selected by mutual  agreement  of the  parties,  failing  which the
selection shall be made by the most senior retired judge or justice on the panel
of JAMS/ENDISPUTE  or its replacement.  The parties further agree irrevocably to
submit  themselves,  in any suit to  confirm  the  judgment  of  finding of such
arbitrator,  to the jurisdiction of any court of the State of California located
in Los Angeles County and waive any and all objections to jurisdiction that they
may have under the laws of the State of California or the United States.

         (b) The rules to be followed in the arbitration shall be as follows:

                  (i) The  petition  for  arbitration  shall be submitted in the
         form of a complaint,  prepared in conformance  with the California Code
         of Civil  Procedure,  section 420 et seq.,  filed with the  arbitrator,
         with copies personally served on all responding parties.

                  (ii) The  respondent  shall have 30 days to file a response in
         the form of any answer,  prepared in compliance with California Code of
         Civil Procedure section 431.30.

                  (iii) Demurrers, motions to strike, and other pretrial motions
         permitted  under  the  California  Code of  Civil  Procedure  shall  be
         permitted in the arbitration proceeding.

                  (iv) The  matters  at issue  shall be set for  hearing  by the
         arbitrator.

                  (v)  Within  20 days  after  the  filing  of the  answer,  the
         arbitrator  shall  schedule,  upon mutual  agreement of the parties,  a
         pre-hearing conference, discovery and hearing dates. If the parties are
         unable so to agree, the arbitrator shall set the appropriate dates. The
         parties shall be allowed to conduct  discovery  under the provisions of
         the  California  Code of  Civil  Procedure  sections  1282.6,  1283 and
         1283.05,  except  subsection  (e)of  1283.05.  Any disputes  concerning
         discovery  shall be submitted  to the  arbitrator.  At the  arbitration
         hearing,  order of proof shall be governed  by the  California  Code of
         Civil   Procedure   unless  the  parties   mutually  agree   otherwise.
         Admissibility of evidence shall be governed by the California  Evidence
         Code.

         (c)  The  arbitrator  shall  comply  with,  and  the  decision  of  the
arbitrator  shall be  rendered  in  accordance  with,  the laws of the  State of
California.  The parties  agree to be bound by the  decision of the  arbitrator,
which shall be final, shall not be appealable,  and which shall not permit trial

                                       13
<PAGE>

de novo on the same issues.  The arbitrator's  decision shall be rendered within
30 days following  submission of the matters at issue, but the failure to comply
with this  provision  shall in no way invalidate any decision or award as may be
rendered  more  than 30  days  after  submission.  The  fees  and  costs  of the
arbitrator  shall be shared equally by the Members.  The arbitrator  shall award
legal  fees,  disbursements  and  other  expenses  to the  prevailing  party  in
accordance  with the  terms  of this  Agreement.  The  judgment  upon the  award
rendered by the arbitrator may be entered in any court having jurisdiction.

                                      * * *

         IN WITNESS WHEREOF,  the parties hereto have executed this Agreement on
the date first above written.

                                                ARAIOS, INC.


                                                By:  /s/ Mark A. Tepper
                                                    ----------------------------
                                                     Mark A. Tepper, Ph.D.
                                                     President


                                                CYTRX CORPORATION


                                                By:  /s/ Steven A. Kriegsman
                                                    ----------------------------
                                                     Steven A. Kriegsman
                                                     Chief Executive Officer


                                                     /s/ Michael P. Czech
                                                    ----------------------------
                                                     DR. MICHAEL P. CZECH


                                       14
<PAGE>

                                   SCHEDULE 1

                                          # of Shares of         # of Shares of
                                           Common Stock         Preferred Stock
                                          ---------------      -----------------

Dr. Michael P. Czech......................       100                    --

CytRx Corporation.........................        --                 2,000


                                       15
<PAGE>

                                 SPOUSAL CONSENT

         I,  _______________,  the spouse of Dr.  Michael P.  Czech,  one of the
Stockholders  named  in  the  foregoing  Stockholders  Agreement,  dated  as  of
September  17, 2003 (the  "Agreement"),  acknowledge  that I have  reviewed  and
understand the Agreement and hereby agree to be bound by each and every term and
condition of the  Agreement.  I agree to sell any shares of capital stock that I
may have in the Corporation or any interest therein,  including, but not limited
to, my community  property interest in any of the shares of capital stock on the
terms and  conditions  stated in the Agreement and any of the other  Transaction
Documents.  By my signature below, I hereby acknowledge that I have been advised
to, and have had the opportunity to, seek independent legal counsel with respect
to these matters.

         I ACKNOWLEDGE  THAT I HAVE BEEN ADVISED TO HAVE THE AGREEMENT  REVIEWED
BY  INDEPENDENT  LEGAL  COUNSEL AND TO CONSULT WITH SUCH COUNSEL  REGARDING  THE
PROVISIONS AND RESTRICTIONS OF THE AGREEMENT AND ITS IMPACT ON ME. I ACKNOWLEDGE
THAT I HAVE HAD FULL AND ADEQUATE  OPPORTUNITY TO HAVE THE AGREEMENT REVIEWED BY
INDEPENDENT LEGAL COUNSEL AND TO DISCUSS THIS AGREEMENT WITH SUCH COUNSEL.

         Dated this _____ day of September, 2003.


                                                    ----------------------------
                                                              Signature


                                                    ----------------------------
                                                              Print Name


                                       16
<PAGE>

                                   SCHEDULE A

         The  Scientific   Advisory  Board  Consulting   Agreement  and  related
agreements by and between Dr. Michael P. Czech and  Metabolix,  Inc., a Delaware
corporation,  located in Hayward,  CA, a copy of which has been  provided to the
Company and Araios.

         The conflict of interest and intellectual property transfer policies of
the University of  Massachusetts  ("UMass"),  as outlined in that certain letter
dated July 28, 2003 from Thomas J. Chmura of UMass to Dr. Czech, a copy of which
has  been  provided  to  the  Company  and  Araios,   and  the   "University  of
Massachusetts  Uniform Consulting Agreement  Provisions"  referenced therein and
set forth below:

                           UNIVERSITY OF MASSACHUSETTS
                     UNIFORM CONSULTING AGREEMENT PROVISIONS

         All faculty at the University of Massachusetts  (the  "University") are
subject to the University  Policy on Faculty  Consulting and Outside  Activities
(the  "Policy").  The Policy  recommends  that faculty at the University  attach
these Uniform  Consulting  Agreement  Provisions  ("Uniform  Provisions") to any
agreement or arrangement  ("Consulting  Agreement") under which a faculty member
will  provide  consulting  services  to, or will  engage  in other  non-academic
activities  in his  or  her  area  of  expertise  on  behalf  of any  for-profit
organization  (a "Company").  These Uniform  Provisions are intended to clarify,
among other  things,  the  respective  legal  rights of the  University  and the
Company  in any  intellectual  property  and  other  work  product  that  may be
developed  or  discovered  by the  faculty  member in the  course of  performing
services for the Company.  If any term of the Uniform Provisions is inconsistent
with a term of the  Consulting  Agreement  to which the Uniform  Provisions  are
attached, the terms of the Uniform Provisions govern.

         University  faculty are  permitted to devote the  equivalent of one day
within the academic week to the  performance  of outside  activities,  including
consulting with Companies.  These  activities must he reported to the Department
Chair of the  faculty  member  in order to  ensure  compliance  with  this  time
restriction  and  the  ability  of  the  faculty  member  to  meet  his  or  her
responsibilities to the University. In certain instances,  these activities must
also  be  reviewed  by  the  University's  Conflicts  Committee.  The  Conflicts
Committee may impose restrictions on the consulting relationship.

         University    faculty   are    ordinarily    prohibited    from   using
University-administered  funds, facilities,  and equipment in the performance of
services for a Company pursuant to a Consulting Agreement. In addition,  faculty
must obtain  special  approval to involve  University  students in consulting or
other  services  for  Companies.  Companies  may  obtain  access  to  University
facilities,  equipment,  and personnel under a sponsored research agreement with
the University.

         University  faculty may not use the name of the  University in relation
to any outside activities,  including  consulting work, except to describe their
credentials.

         University faculty are permitted to assign to a Company their rights in
any invention, discovery, or development (collectively, "Intellectual Property")

<PAGE>

that arises while  performing  services under a Consulting  Agreement,  provided
that the faculty member did not use  University-administered  funds, facilities,
or equipment (collectively,  "University Resources") in the course of developing
that  Intellectual  Property.  if a  faculty  member  made  significant  use  of
University Resources, the faculty member is contractually obligated to assign to
the University all of his or her rights in that Intellectual Property.

         The University  presumes that a faculty member did make significant use
of University Resources in the development of Intellectual  Property that is the
same as, directly related to, or substantially  similar to a research project in
which that faculty  member is engaged at the  University.  In order to avoid any
confusion  regarding  ownership of  Intellectual  Property,  the  University has
determined  and Company  agrees that the field of services to be provided  under
this Consulting Agreement is directly related to or substantially similar to the
research projects undertaken by the faculty member at the University. Therefore,
any  Intellectual  Property  developed by the faculty  member during the term of
this Consulting Agreement is owned by the University,  and the Company may enter
into negotiations to obtain license rights to the Intellectual Property.

         No Consulting  Agreement may limit the ability of a University  faculty
member to use or publish  information  that (a) was  developed,  discovered,  or
acquired  by the  faculty  member in the  course of  research  performed  at the
University or otherwise outside the scope of the consulting services, (b) was in
the public domain before the consulting  services were performed (C) entered the
public domain by means other than an unauthorized  disclosure  resulting from an
act or omission by the faculty  member,  (d) was known to the faculty  member or
the University before the consulting services were performed, or (e) is required
to be disclosed in order to comply with applicable law, regulations,  or a court
order.

         A Company  may  require a faculty  member to leave with the Company any
notes,  data, and records  developed in the performance of consulting  services,
provided  that the  faculty  member may retain one copy of those  documents  for
archival purposes.

         Companies  should be aware that, in addition to the Policy,  University
faculty  are  subject to the  University  Intellectual  Property  Policy and the
University Policy on Conflicts of Interest Relating to Intellectual Property and
Commercial Ventures.  The University will make the three policies available upon
request.


                                       2
<PAGE>

         These Uniform Provisions remain in effect during the entire term of the
Consulting Agreement to which they are attached.


AGREED AND ACCEPTED:

Faculty Member                                    Company


By:
   -------------------------------        --------------------------------------
    Printed Name                          Print Legal Name of Company

Date:                                     By:
   -------------------------------            ----------------------------------
                                              Printed Name:
                                                           ---------------------

                                          Title:
                                                --------------------------------

                                          Date:
                                               ---------------------------------

University of Massachusetts


By:
   -------------------------------
    Printed Name

Title:
      ----------------------------

Date:
     -----------------------------


                                       3