Exhibit 10.34

                               SUBLEASE AGREEMENT

     THIS  SUBLEASE  AGREEMENT  ("Sublease")  is made  and  entered  into by and
between ZERO STAGE CAPITAL,  INC., a California  corporation  ("Sublessor")  and
KERYX BIOPHARMACEUTICALS, INC., a Delaware corporation ("Sublessee").

                                    RECITALS

     A. Reference is made to that certain Lease Agreement,  dated as of June 28,
1991,  as amended by Amendment No. 1 to Agreement to Lease dated March 31, 1994,
Amendment  No. 2 to Agreement to Lease dated April 7, 1994,  Amendment  No. 3 to
Agreement  to Lease dated July 31, 1996,  Amendment  No. 4 to Agreement to Lease
dated  January 12, 1998 and Fifth  Amendment  to Lease dated as of November  21,
2000 (as amended, the "Lease"),  whereby Sublessor leases from Riverfront Office
Park Joint Venture,  predecessor in interest to NOP Riverfront LLC ("Landlord"),
a  portion  of the  seventeenth  (17th)  floor  comprising  approximately  8,605
rentable square feet contained in the building  ("Building")  known and numbered
as  101  Main  Street,   Cambridge,   Massachusetts   ("Leased  Premises")  more
particularly described in Exhibit "A" attached hereto and incorporated herein by
reference. The Lease is incorporated herein by this reference in accordance with
Section 9 hereof.  Terms  capitalized in this Sublease and not otherwise defined
herein shall have the meanings ascribed to them in the Lease.

     B.  Sublessee  desires to  sublease a portion of the Leased  Premises  from
Sublessor.

     C. The Lease provides that Sublessor shall not sublet the whole or any part
of the Leased Premises without first obtaining the consent of Landlord.

                                    AGREEMENT

     Subject  to the terms and  conditions  and in  consideration  of the mutual
covenants contained in this Sublease, the parties mutually agree as follows:

     1. Leased Premises.  Sublessor hereby subleases to Sublessee, and Sublessee
hereby  subleases from Sublessor a portion of the Leased Premises located on the
seventeenth  (17th) floor comprising  approximately  2,915 rentable square feet,
more  particularly  described  in Exhibit "B" attached  hereto and  incorporated
herein by reference  ("Subleased  Premises")  together  with the right to use in
common, those roadways, walkways,  elevators,  hallways, stairways necessary for
access to that  portion of the  Building  occupied  by the  Subleased  Premises.
Sublessee  shall  not make any  alteration  to the  Subleased  Premises  without
Sublessor's prior written consent, not to be unreasonably withheld,  conditioned
or delayed,  and the Landlord's  consent to the extent required under the Lease;
except  that  Sublessee  may  make  non-structural  decorative  changes  to  the
Subleased Premises without Sublessor's  consent,  provided however,  that in the
event Landlord objects to such changes,  Sublessee will immediately  remove such
changes and restore the Subleased Premises to their original condition.


                                      -1-
<PAGE>

     The Subleased Premises shall be taken "As Is" by Sublessee provided however
that Sublessor shall be responsible for demising the Subleased Premises from the
remainder of the Leased Premises  ("Sublessor's Work") prior to the Commencement
Date as hereinafter defined.

     2. Term. The term of this Sublease  ("Sublease Term") shall commence on the
date of July 1, 2001  ("Commencement  Date"),  and shall  continue  through  and
terminate  on April 30, 2003 unless  otherwise  terminated  as provided  herein.
Sublessor  shall use  commercially  reasonable  efforts to deliver the Subleased
Premises to Sublessee on or before the Commencement Date; provided,  however, if
for any reason  Sublessor  does not deliver  full  possession  of the  Subleased
Premises  to  Sublessee  on the  Commencement  Date,  or if  Sublessor  has  not
completed  demising  the  Subleased  Premises  from the  remainder of the Leased
Premises as certified by Sublessor's  architect,  Sublessor shall not be subject
to any liability for such failure, and the validity of the Sublease shall not be
impaired,  but rent shall abate until delivery of full possession.  In the event
Sublessor  has not received  Landlord's  Consent  pursuant to Section 12 of this
Sublease on or before July 15, 2001, Sublessee shall have the right to terminate
the  Sublease  upon  prior  written  notice  to  Sublessor.  In the  event  full
possession of the Subleased Premises with the Sublessor's Work completed, is not
delivered to Sublessee on or before  August 15, 2001,  Sublessee  shall have the
right to terminate the Sublease upon prior written notice to Sublessor.

     Sublessee  shall  be  allowed  reasonable  early  access  to the  Subleased
Premises prior to the  Commencement  Date in order to assess the capabilities of
the voice,  data and furniture  systems  located within the Subleased  Premises.
Sublessee and its agents,  contractors  or  representatives  shall not interfere
with the completion of Sublessor's  construction  of the demising  walls. In the
event that any of Sublessee's  activities in the Subleased Premises prior to the
Commencement Date interfere with Sublessor's construction of the demising walls,
Sublessee  shall  immediately  cease such  activity  after  verbal  notice  from
Sublessor or its agents.

     Sublessee  agrees  to assume  all risk of loss or damage to any  machinery,
equipment,  fixtures,  and other personal property installed or brought onto the
Subleased  Premises  by  Sublessee  and agrees to  indemnify,  defend,  and hold
Sublessor harmless from any loss or damage to such property,  and all liability,
loss, or damage arising from any injury to the Subleased  Premises and any death
or  personal  injury  to any  person  or  persons  arising  out  of  Sublessee's
activities  on the  Subleased  Premises,  unless any of the  foregoing,  damage,
liability,  death,  or personal  injury was caused by the  negligence or willful
misconduct of Sublessor and/or Sublessor's agents, employees and contractors.

     3. Rent.  Sublessee shall pay to Sublessor as rent, without deduction,  set
off, notice,  or demand, at the notice address herein, or at such other place as
Sublessor shall  designate from time to time by notice to Sublessee,  the sum of
$12,024.38 per month based upon a rental rate of $49.50 per rentable square foot
per annum, in advance of the first day of each month of the Sublease Term ("Base
Rent").  If the  Sublease  Term  begins or ends on a day other than the first or
last day of a month, the rent for such month shall be prorated on a daily basis.

     Additional  Tax Rent.  The  proportionate  share of all real  estate  taxes
imposed  against the Building and the Land,  to be paid by Sublessor to Landlord
under Paragraph 6.2 and


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<PAGE>

6.4 of the Lease, for the fiscal year 2001, shall  hereinafter be referred to as
the "Tax  Expense  Base Year".  If,  with  respect to any fiscal year during the
Sublease  Term  after  the Tax  Expense  Base  Year,  the  aggregate  amount  of
Sublessor's  proportionate  share of real  estate  taxes  paid by  Sublessor  to
Landlord exceeds the Tax Expense Base Year,  Sublessee shall pay to Sublessor as
"Additional  Tax Rent"  thirty-four  percent  (34%) of such excess.  Sublessee's
obligation  under this  Additional  Tax Rent  provision  shall be pro-rated  for
partial fiscal years at the end of the Sublease Term.

     Additional  Operating  Rent.  The  proportionate  share  of all  costs  and
expenses  incurred by Landlord in the operation and  maintenance of the Building
and the Land, to be paid by Sublessor to Landlord under Paragraph 6.3 and 6.4 of
the Lease, for the calendar year 2001,  shall  hereinafter be referred to as the
"Operating  Expense Base Year". If, with respect to any calendar year during the
Sublease Term after the  Operating  Expense Base Year,  the aggregate  amount of
Sublessor's  proportionate  share of real  estate  taxes  paid by  Sublessor  to
Landlord  exceeds  the  Operating  Expense  Base  Year,  Sublessee  shall pay to
Sublessor as  "Additional  Operating  Rent"  thirty-four  percent  (34%) of such
excess.  Sublessee's  obligation under this Additional  Operating Rent provision
shall be pro-rated for partial calendar years at the end of the Sublease Term.

     Electricity.  Sublessee  shall  also pay to  Sublessor  all  costs  for the
furnishing of  electricity  to the Subleased  Premises  ("Additional  Electrical
Rent" and together  with  Additional  Operating  Rent and  Additional  Tax Rent,
"Additional  Rent").  Additional Rent shall be paid by Sublessee to Sublessor in
the same manner as Base Rent.

     4.  Furniture.  Sublessor  shall  lease to  Sublessee  at no charge for the
duration of the  Sublease  Term any  furniture  contained  within the  Subleased
Premises as of the date of execution of this Sublease which is listed on Exhibit
C attached  hereto  ("Furniture").  The Furniture will be delivered in its as-is
condition and Sublessee will,  promptly,  upon termination of the Sublease Term,
deliver  possession  of the  Furniture  to  Sublessor  in the same  condition as
received, ordinary wear and tear excepted.

     5. Use.  Sublessee  shall  occupy and use the  Subleased  Premises  only as
delineated in paragraph 5 of the Lease and for no other purpose. Sublessee shall
fully comply with all provisions of the Lease including, without limitation, the
rules  and  regulations  under  the  Lease,  and  any and  all  laws,  statutes,
ordinances, orders, regulations and requirements of all federal, state and local
governmental,  public  or  quasi-public  authorities,  whether  now or  later in
effect,  which may be applicable to or in any way affect the Subleased  Premises
or any part thereof.

     6. Condition of Leased  Premises.  Sublessee agrees to accept the Subleased
Premises in an "AS IS", broom clean, condition,  subject to Sublessor completing
the Sublessor's Work.

     7.  Parking  Spaces.  Sublessee  shall be  entitled to the use of three (3)
parking  spaces and shall pay to  Sublessor  the  current  market  rate for such
spaces, which rate is currently $200.00 per month.


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<PAGE>

     8.  Security  Deposit.  Concurrently  with  Sublessee's  execution  of this
Sublease, Sublessee shall deposit with Sublessor the sum of $12,024.38, which is
an amount  equal to one month's  rent of the monthly  rental  payable  under the
Sublease,  to be held by  Sublessor  as security for the payment by Sublessee of
the rent and for the  faithful  performance  of all the  terms,  conditions  and
covenants of this  Sublease.  If Sublessee  defaults in the  performance  of any
provision of this Sublease,  following the  expiration of any applicable  notice
and cure period,  Sublessor may, but shall not be required to, use such deposit,
or so much  thereof  as is  necessary,  in payment of any rent in default or any
expense,   damage,  loss  or  liability  suffered  by  Sublessor  by  reason  of
Sublessee's  default. In such event,  Sublessee shall within five (5) days after
written demand from  Sublessor,  deposit with  Sublessor a sufficient  amount in
cash to restore such deposit to its original amount.  Sublessee's  failure to do
so shall be a material  breach of this Sublease.  Sublessor's  rights  hereunder
shall be in addition to all its other rights and remedies.  The security deposit
shall not be considered an advanced  payment of rent or a measure of Sublessor's
damages in case of default by Sublessee  and if claims of  Sublessor  exceed the
deposit,  Sublessee  shall  remain  liable for the  balance of such  claims.  If
Sublessee  is not in  default  hereunder  at the  expiration  of the  Term,  the
security  deposit or any balance  thereof shall be returned to Sublessee (or, at
Sublessor's  option,  to the  last  assignee  of  Sublessee's  interest)  at the
expiration  of the Sublease  Term and after  Sublessee has vacated the Subleased
Premises.  Sublessor shall not be required to keep the security deposit separate
from its general funds and  Sublessee  shall not be entitled to interest on such
deposit. Sublessee shall not assign or encumber or attempt to assign or encumber
the deposit  except  that  Sublessee  may assign such  deposit in the event of a
permitted assignment of this Sublease.

     9.  Lease.  Except  to the  extent  not  otherwise  inconsistent  with  the
agreements and  understandings  expressed in this Sublease or applicable only to
the  original  parties  to the  Lease,  the  terms,  provisions,  covenants  and
conditions  of the Lease  (excluding  Sections 4.1 through 4.6,  inclusive,  19,
second  paragraph of Section 24, 27.3,  Exhibit C and D of the Lease) are hereby
incorporated herein by reference on the following understandings:

     (a) The term "Landlord" as used therein shall refer to Sublessor hereunder,
its successors and assigns, and the term "Tenant" as used therein shall refer to
Sublessee hereunder, its successors and permitted assigns.

     (b) In any case  where  the  Landlord  reserves  the  right  to  enter  the
Premises,  said right shall  inure to the benefit of the  Landlord as well as to
the Sublessor.

     (c) Each party hereto  represents and warrants that it will (i) perform and
comply with the terms,  provisions,  covenants and conditions of the Lease;  and
(ii) not do or suffer or permit  anything  to be done  which  would  result in a
default under or cause the Lease to be terminated or forfeited.

     (d) Sublessee by this Sublease assumes  Sublessor's  obligations to observe
and  perform  all of the  terms,  covenants,  conditions  and  agreements  to be
performed or observed  during the Sublease  Term on the part of Sublessor  under
the  Lease  with  respect  to  the  Subleased   Premises   except  as  otherwise
specifically provided in this Sublease.


                                      -4-
<PAGE>

     (e) Sublessee shall not have the right to (i) assign,  pledge,  hypothecate
or otherwise  transfer,  by operation of law or otherwise,  this Sublease or any
interest  herein;  or (ii) sublease the  Subleased  Premises or any part thereof
without  Sublessor's  consent,  such consent not to be unreasonably  withheld or
delayed,  subject to the  provisions  of Article 14 of the Lease.  Any attempted
assignment, transfer or sublease shall be void and of no effect. Notwithstanding
the foregoing,  subject to the  provisions of Article 14 of the Lease  Sublessee
shall have the right to assign the Sublease or sublease the Subleased  Premises,
without  the consent of  Sublessor,  if such  assignment  or sublease is made in
accordance with Section 14.3 of the Lease.

     (f) Sublessor shall not take any action to amend the Lease in any way which
would have the material adverse effect on Sublessee  without first obtaining the
consent of Sublessee.

     (g)  Sublessor   shall   exercise  due  diligence  in  seeking   Landlord's
performance of its obligations under the Lease for the benefit of Sublessee.

     10. Default and Remedies.  If Sublessee  shall default in fulfilling any of
the terms,  covenants or agreements  hereof or of the Lease, and (i) in the case
of a monetary default,  such default continues for a period of five (5) business
days after Sublessee's  receipt of written notice thereof,  and (ii) in the case
of a non-monetary  default,  such default continues for a period of fifteen (15)
days after Sublessee's  receipt of written notice thereof, or such longer period
as may be necessary if such default  cannot  reasonably be cured within  fifteen
(15) days, provided that Sublessee commences to cure such default within fifteen
(15) days and thereafter proceeds to diligently complete the same, Sublessor may
give  Sublessee  three (3) days' written  notice of intention to end the term of
this  Sublease,  and at the end of said period,  the Sublease  Term shall expire
with the same effect as if that day were the date hereinbefore set forth for the
expiration of the Sublease Term without a necessity of re-entry or any other act
on Sublessor's  part, any  requirement  for any other act or notice by Sublessor
being hereby waived by Sublessee. If the Sublease is terminated, Sublessee shall
be and remain  liable to  Sublessor  for  damages as  hereinafter  provided  and
Sublessor  shall be entitled to recover  forthwith  from Sublessee as damages an
amount  equal to the  total  of;  (i) all sums  remaining  unpaid at the time of
termination  of the  Sublease,  and (ii) the amount of all other sums that would
have been payable  hereunder if the Sublease had not been  terminated,  less the
net proceeds,  if any, of any reletting of the Leased Premises,  after deducting
all of Sublessor's  reasonable  expenses in connection with such  reletting.  No
provisions  of the Sublease  shall limit or prejudice  the right of Sublessor to
prove or obtain as  liquidated  damages  by  reason  of any  termination  of the
Sublease,  an amount equal to the maximum  allowed by any statute or rule of law
in effect at the time,  when,  and  governing  the  proceedings  in which,  such
damages are to be proved,  whether or not such  amount be greater,  equal to, or
less than the amount referred to above.

     11.  Notices.  All notices  permitted  or required by this  Sublease or the
Lease shall be in writing  and  personally  delivered  or sent by  certified  or
registered mail,  postage prepaid,  to Landlord at the address and in the manner
set  forth  in the  Lease  and  to  Sublessor  and  Sublessee  at the  following
addresses:


                                      -5-
<PAGE>

IF TO SUBLESSOR:
                                            Zero Stage Capital
                                            101 Main Street, 17th Floor
                                            Cambridge, MA  02142
                                            Attn:  Brian Johnson

     With a copy to:                        Brown, Rudnick, Freed & Gesmer, P.C.
                                            One Financial Center
                                            Boston, MA  02111
                                            Attn:  Gregg B. Cosimi, Esq.

IF TO SUBLESSEE PRIOR TO                    KERYX BIOPHARMACEUTICALS
COMMENCEMENT DATE:                          PMB 318
                                            One Kendall Square
                                            Building 600
                                            Cambridge, MA  02139
                                            Attn:  Robert Gallahue

AFTER THE COMMENCEMENT DATE:                KERYX BIOPHARMACEUTICALS, INC.
                                            101 Main Street, 17th Floor
                                            Cambridge, MA  02142
                                            Attn.:  Robert Gallahue

     With a copy to:                        Hale and Dorr LLP
                                            60 State Street
                                            Boston, MA  02109
                                            Attn:  Katharine E. Bachman, Esq.

or at such other address as a party shall designate.

     12. Consent of Landlord. This Sublease is subject to, and conditioned upon,
Sublessor obtaining the prior written consent of Landlord ("Landlord's Consent")
to this  Sublease.  Sublessor  shall use diligent  good faith  efforts to obtain
Landlord's Consent to this Sublease. If Landlord's Consent is not received on or
before July 15, 2001,  Sublessor and Sublessee shall have the right, upon giving
three days' written notice to the other party,  to terminate  this Sublease.  In
such an event,  this Sublease  shall  automatically  terminate,  all parties are
automatically  released from any liability under this Sublease and all payments,
if any,  made by  Sublessee to Sublessor  together  with any security  deposited
pursuant  to this  Sublease  shall be refunded  and  returned  by  Sublessor  to
Sublessee.

     13. Indemnification. Sublessee, its employees, agents or invitees shall not
commit or suffer any act or omission that will violate any of the  provisions of
this  Sublease  or the  Lease.  If the Lease  terminates,  this  Sublease  shall
terminate  and the  parties  shall  be  relieved  of any  further  liability  or
obligation under this Sublease;  provided however,  that if the Lease terminated


                                      -6-
<PAGE>

as a result of a default or breach by Sublessee  under this Sublease  and/or the
Lease,  the  Sublessee  shall  indemnify  and hold  Sublessor  harmless from and
against any and all damage,  cost,  expense or claim  suffered by Sublessor as a
result of such termination.  Sublessor, its employees,  agents or invitees shall
not commit or suffer any act or omission that will violate any of the provisions
of this Sublease or the Lease. If the Lease  terminates as a result of a default
or breach by Sublessor under this Sublease and/or the Lease, the Sublessor shall
indemnify and hold Sublessee harmless from and against any and all damage, cost,
expense or claim suffered by Sublessee as a result of such  termination.  If the
Lease gives Sublessor a right to terminate the Lease in the event of the partial
or total damage,  destruction,  or  condemnation  of the Leased  Premises or the
Building or Project of which the Subleased  Premises are a part, the exercise of
such right by Sublessor shall not constitute a default or breach hereunder.

     14.  Insurance.  At all times  during the term of this  Sublease  Sublessee
shall carry and maintain,  at Sublessee's expense,  insurance in the amounts and
with the coverages  required  under the Lease from time to time. All policies of
insurance provided for herein shall name Landlord and Sublessor as an additional
insured.  Certificates  of such  insurance  shall be  delivered  to Sublessor or
Landlord  upon  request.  All such  policies  shall provide that they may not be
terminated or amended  except after thirty (30) days written  notice  thereof to
Landlord and Sublessor. All public liability, property damage and other casualty
policies shall be written as primary policies,  not contributing with and not in
addition to that which Sublessor or Landlord may carry.

     15. Indemnification Generally.  Sublessee shall indemnify and hold harmless
Sublessor,  and  Sublessor's  employees  and agents from and against any and all
claims  arising from  Sublessee's  use of the  Subleased  Premises,  or from the
conduct of  Sublessee's  business  or from any  activity,  work or things  done,
permitted or suffered by Sublessee in or about the Subleased  Premises and shall
further  indemnify and hold harmless  Sublessor  and  Sublessor's  employees and
agents from and against any and all claims arising from any breach or default in
the performance of any obligation on Sublessee's  part to be performed under the
terms of the Sublease, arising from any negligent or wrongful act or omission of
the Sublessee,  or Sublessee's agent,  contractors,  employees, or invitees, and
from and against all cost,  reasonable  attorney fees,  expenses and liabilities
incurred  in the defense of any such claim or any action or  proceeding  brought
thereon.

     16. Surrender of Leased  Premises.  At the end of the Sublease Term or upon
sooner  termination of this Sublease,  Sublessee shall  peaceably  deliver up to
Sublessor  possession  of the  Subleased  Premises  in  the  same  condition  as
received,  reasonable wear and tear excepted.  Sublessee shall, at its sole cost
and expense,  thoroughly  clean the Subleased  Premises to deliver the Subleased
Premises to Sublessor in the same condition as received.  If Sublessee is not in
default,  Sublessee may remove from the Subleased  Premises any trade  fixtures,
movable  equipment and  furniture  placed  therein by Sublessee.  Whether or not
Sublessee is in default, hereunder,  Sublessee shall remove at the expiration of
the Term such alterations,  additions,  improvements,  trade fixtures, equipment
and furniture placed therein by Sublessee as Sublessor shall require at the time
of Sublessor consent to alterations, additions, improvements, or with respect to
alterations,  additions  and  improvements  not  requiring  Sublessor's  consent
hereunder upon, as Sublessor requires by written notice to Sublessee at least 30
days prior to the expiration


                                      -7-
<PAGE>

of the term.  Sublessee shall fully repair any damage  occasioned by the removal
of any such trade fixtures,  equipment,  furniture,  alterations,  additions and
improvements.  Sublessee's obligation to observe and perform this covenant shall
survive the expiration or other termination of this Sublease.

     17. Estoppel  Certificate.  Sublessee shall,  from time to time, within ten
(10) days after Sublessor's  written request  therefore,  deliver to Sublessor a
statement in recordable form,  provided such form is reasonably  satisfactory to
Sublessee,  certifying  that this  Sublease  is in full force and  effect,  this
Sublease is unmodified,  or if modified,  stating any such  modifications,  that
there are no defenses or offsets to the Sublease by, Sublessee,  or stating such
defenses  or  offsets as are  claimed by  Sublessee,  that  Sublessor  is not in
default  hereunder  or  specifying  any  defaults by  Sublessor  that  Sublessee
alleges,  and  specifying  any  further  information  about the  Sublease or the
Subleased  Premises that  Sublessor may reasonably  request.  Failure to deliver
such  certificate  at such  time  shall  be a  material  default  by  Sublessee.
Sublessee agrees such certificates may be relied upon by perspective purchasers,
mortgages or lessors of the Subleased Premises.

     18.  Holding  Over.  If Sublessee  remains in  possession  of the Subleased
Premises or any part  thereof  after the  expiration  of the term  hereof,  such
occupancy  shall be a tenancy from month to month and not a renewal or extension
of this  Sublease,  upon all the  provisions of this Sublease  pertaining to the
obligations of Sublessee, except that the rent payable for such hold over period
shall be payable  monthly and shall be equal to an amount of one  hundred  fifty
(150%)  percent of the amount of monthly rent  payable by Sublessee  immediately
prior to such hold over  period.  Nothing  contained  herein  shall  restrict or
prohibit  Sublessor  from  treating  Sublessee  as  a  trespasser  and  evicting
Sublessee by means of an unlawful detainer or other applicable proceeding.

     19. Subordination and Attornment. This sublease shall be subordinate to all
ground  leases,   underlying  leases,   mortgages,   deeds  of  trust  as  other
encumbrances, and any and all conditions,  renewals, extensions,  modifications,
consolidations and replacements of any or all of the foregoing, now or hereafter
affecting such leases or all or any portion of the Subleased Premises (except to
the extent any such  instruments  shall expressly  provide that this Sublease is
superior thereto). This clause shall be self operative and no further instrument
of  subordination  shall be required in order to  effectuate  it.  Nevertheless,
Sublessee shall execute and deliver  promptly any certificate or other assurance
in confirmation of such subordination  requested by any lessor,  mortgagee or by
Sublessor or Landlord provided, however, that Sublessee shall not be required to
deliver any such certificate or other insurance until such time as Sublessee has
received a non-disturbance  agreement from the party requesting such certificate
or other insurance. In the event any proceedings are brought under any ground or
underlying lease or for the foreclosure of any mortgage,  deed of trust or other
encumbrance to which this Sublease is subject and subordinate,  Sublessee shall,
upon request of the party  incurring to the interest of Sublessor or Landlord as
a result of such proceedings,  automatically  attorn to and become the tenant of
such party in interest  without change in the terms of this Sublease.  Sublessee
when  requested  by such  party in  interest  shall,  execute  and  deliver  any
instruments confirming such attornment.


                                      -8-
<PAGE>

     19.  Attorneys'  Fees. If Sublessor or Sublessee  shall  commence an action
against  the other  arising  out of or in  connection  with this  Sublease,  the
prevailing  party shall be entitled to recover its costs of suit and  reasonable
attorney's fees from the non-prevailing party.

     20.  Binding  Effect.  The Sublease  shall be binding upon and inure to the
benefit of the parties  hereto and their  respective  successors  and  permitted
assigns.  In the event of any  conflict  between  the terms of the Lease and the
terms of this Sublease, the terms of this Sublease shall control.

     21.  Broker.  Sublessee and Sublessor  mutually  represent and warrant that
they have dealt with no broker in connection  with this  transaction  except for
Cushman & Wakefield and Trammell  Crow Company  (collectively,  the  "Brokers").
Each agrees to defend,  indemnify  and save the other  harmless from and against
any and all cost,  expense or liability  for any  compensation,  commissions  or
charges  claimed by any broker or agent other than the Brokers,  with respect to
the indemnifying  party's  dealings in connection with this Sublease.  Sublessor
shall pay the commission due to the Brokers.

     22. Signage.  Sublessee shall have the right to install a sign  identifying
Sublessee's name at the main entrance to the Subleased Premises.

                         [SIGNATURES ON FOLLOWING PAGE]



                                      -9-
<PAGE>


IN WITNESS WHEREOF,  the parties hereto have executed this Sublease on this 20th
day of June, 2001.


                                           SUBLESSOR:
                                           ZERO STAGE CAPITAL

                                           By: /s/ Brian M. Johnson
                                               --------------------
                                                   Print Name: Brian M. Johnson
                                                   Title:CFO

                                           SUBLESSEE:
                                           KERYX BIOPHARMACEUTICALS, INC.

                                           By: /s/ Bob Gallahue
                                               ----------------
                                                   Print Name: Bob Gallahue
                                                   Title:CFO & Treasurer

Consented and agreed to by:

LANDLORD:
GERALD D. HINES INTERESTS

By:
   --------------------------
      Print Name:
      Title:



                                      -10-
<PAGE>


                                   EXHIBIT "A"


                         Description of Leased Premises




                                      -A1-
<PAGE>


                                   EXHIBIT "B"


                        Description of Subleased Premises




                                      -B1-
<PAGE>


                                   EXHIBIT "C"

                                List of Furniture



                                      -C1-