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                                                                   EXHIBIT 10.12

                                  OFFICE LEASE

THIS LEASE is made this 30th day of October, 1995, by and between Denver Jack
Limited Partnership, (hereinafter referred to as "Lessor") and Allos
Therapeutics, Inc., a Virginia corporation, (hereinafter referred to as
"Lessee").

     Lessor hereby leases to Lessee and Lessee hereby leases from Lessor, Suite
No. 310, as designated on the plan attached hereto as Exhibit "A" (hereinafter
referred to as "The Premises") in 7000 North Broadway for the term and upon the
conditions and agreements hereinafter set forth.

                                    1. TERM

     The term of this lease is for four (4) years and shall commence on
December 22, 1995 or on such earlier date as Lessee may take possession of the
Premises, and shall and on December 21, 1999.

                                 2. POSSESSION

     If Lessor is unable to deliver possession of the Premises to Lessee on the
date of commencement of the term hereof, Lessor shall not be subject to any
liability for the failure to deliver possession on said date, and such failure
shall not affect the validity of this lease or the obligations of Lessee
hereunder or extend the term hereof, but the rent reserved shall not commence
to accrue until possession of the Premises is tendered to Lessee. If Permission
is given to Lessee to occupy the Premises prior to the date specified for
commencement of the term hereof, such occupancy shall be subject to all of the
provisions of this lease.

                                    3. RENT

     Lessee shall pay lessor a monthly rent of See Rider Number One, Section 35
dollars ($          ), plus applicable taxes (see Article 9), in lawful money
of the United States which shall be legal tender at the time of payment, in
advance on the first day of each calendar month during said term, at the office
of Lessor or at such other place as Lessor may from time to time so designate
in writing, except that the first month's rent shall be paid upon the execution
hereof. Said rental shall be paid without deduction or setoff. The installment
of rent payable for any portion, less than all, of a calendar month shall be a
pro rata portion of the installment payable for a full calendar month.

                               4. RENT ADJUSTMENT

     (a) Real Estate Taxes.

     The Lessor agrees to pay real estate taxes assessed to Lessor upon the
demised Premises except that, in the event at the any time during the term of
this lease, the real estate taxes assessed on the real property (the term "real
property" includes the building thereon) of which the demised Premises are a
part are increased above $  **    per square foot, then Lessee shall within
fifteen (15) days upon receipt from Lessor of a notice and bill for such
increase, pay to Lessor as additional rent the amount of said increase. ** the
Base Year 1995 actual expenses.

     In all events, any taxes assessed on Lessee's personal property, or any
improvements, alterations or installations made by Lessee, and any other tax
or assessments arising out of the existence of this Lease except income,
estate, or inheritance taxes shall be paid by Lessee.

     The term "real estate taxes" described above shall include all taxes
hereafter in substitution for or in lieu of present real estate taxes.

     (b) Operating Expenses.

     If, in any calendar year (the comparison year) during the term of this
lease, the Operating Expenses (as hereinafter defined) paid or incurred by
Lessor, for the building of which the demised Premises are a part, shall be
higher than $ ***   per square foot, the rent payable by Lessee for the
comparison year shall be increased by the amount of said Operating Expenses
increase. *** the Base Year 1995 actual expenses.

     Operating Expenses shall include:

          (i) All Utility charges paid or incurred by Lessor for lights, heat,
     air conditioning, power, water, sewer, drainage and waste disposal.

          (ii) All other costs paid or incurred by Lessor for operation,
     maintenance replacement and repair including, without limiting the
     generality of the foregoing, the following: security, landscape
     maintenance, pest control, management fees, supplies, insurance, cost of
     service of independent contractors, wages (including employment taxes and
     fringe benefits of all employees performing services uniformly available to
     or performed for substantially all building tenants) licenses and permits,
     equipment and tools, and professional fees which reduce or attempt to
     reduce Operating Expenses.

     Operating Expenses shall not include tenant alterations, depreciation,
interest, leasing fees or capital expenditures required to be capitalized for
federal income tax purposes. However, capital expenditures made to reduce the
Operating Expenses may be included if allocated over the life of the component
or extended life of the building.

     As soon as possible after the end of each comparison year, Lessor shall
furnish to Lessee a written statement showing in reasonable detail Lessor's
Operating Expenses for the applicable comparison year and showing the amount, if
any, due from Lessee for said comparison year.

     On the monthly rent payment date next following Lessee's receipt of such
statement, Lessee shall pay to Lessor (in the case of a rent increase),
one-twelfth (1/12th) of the rent adjustment for the comparison year multiplied
by the number of rent payment dates then elapsed in the current year.
Subsequent rent payments shall be increased by one-twelfth (1/12th) of the rent
adjustment for such comparison year.

     The annual determination and statement of said Operating Expenses shall be
prepared in accordance with generally recognized accounting practices and each
such annual determination and statement, certified by Lessor, shall be final
and conclusive on both parties.

                              5. SECURITY DEPOSIT

     Lessee has deposited with Lessor the sum of Twelve Thousand One Hundred
Sixty Six and 56/100 dollars ($12,166.56) as security for the full and faithful
performance of every provision of this Lease to be performed by Lessee. If
Lessee defaults with respect to any provision of this Lease, including but not
limited to the provisions relating to the payment of any rent or any other sum
in default, or for the payment of any other amount which Lessor may spend by
reason of Lessee's default or to compensate Lessor for any other loss or damage
which Lessor may suffer by reason of Lessee's default. If any portion of said
deposit is so used or applied, Lessee shall within five (5) days after written
demand therefore deposit cash with Lessor in an amount sufficient to restore the
security deposit to its original amount and Lessee's failure to do so shall be a
material breach of this Lease. Lessor shall not be required to keep this
security deposit separate from its general funds and Lessee shall not be
entitled to interest on such deposit. If Lessee shall fully and faithfully
perform every provision of this Lease to be performed by it, the security
deposit or any balance thereof shall be returned to Lessee (or, at Lessor's
option, to the last assignee of Lessee's interests hereunder) at the expiration
of the lease term.

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                                6. CONSTRUCTION

     Lessor agrees to cause the leased Premises to be completed in accordance
with the plans, specifications and agreements approved by both parties, which
are attached to and made a part of this lease. Lessor will not be obliged to
construct or install at its expense any improvements or facilities of any kind
other than those called for on the attached specifications and agreements.
Lessor agrees to commence and complete the construction of the building and/or
improvements with reasonable diligence.

                                7. HOLDING OVER

     Lessee shall have no right to hold over after the expiration of the term
of this lease without Lessor's consent. If, with Lessor's consent, Lessee holds
over after the termination of this lease, Lessee shall become a tenant from
month-to-month only, upon each and all of the terms herein provided as may be
applicable to such month-to-month tenancy and any such holding over shall not
constitute extension of this lease. During such holding over, Lessee shall pay
rent at 150% of the monthly rate then prevailing at the expiration of the term
of this lease, payable in advance on or before the first day of each month. In
such event Lessee shall continue in possession or until Lessee or Lessor shall
have given to the other party a written notice of its intention to terminate
such tenancy. Such written notice must be given no less than thirty (30) days
prior to said termination date.

                                     8. USE

     (a)  Lessee shall use and occupy the Premises for general office use for
the purpose of administrative offices for a pharmaceutical research and
development company, and for no other purpose.

     (b)  Lessee shall:

          (i) Not use or permit upon the Premises anything that would invalidate
     any policies or insurance now or hereafter carried on the building or that
     will increase the rate of insurance on the Premises or on the building.

         (ii) Pay all extra insurance premiums which may be caused by the use
     which Lessee shall make of the Premises;

        (iii) Not use or permit upon the Premises anything that may be
     dangerous to life or limb;

         (iv) Not in any manner deface or injure the building or any part
     thereof or overload any floor of the premises;

          (v) Not do anything or permit anything to be done upon the Premises in
     any way tending to create a nuisance, or tending to disturb any other
     lessee in the building or the occupants of neighboring property, or tending
     to injure the reputation of the building;

         (vi) Comply with all governmental, health and police requirements and
     regulations respecting the Premises;

        (vii) Not use the Premises for lodging or sleeping purposes or for any
     immoral or illegal purpose, nor conduct or permit to be conducted upon the
     Premises any activity contrary to any of the laws of the United States of
     America or of the State of Colorado or which is contrary to the ordinances
     of the unincorporated Adams County nor commit or suffer to be committed any
     waste upon the Premises.

                                    9. TAXES

     (a)  Lessee shall pay, prior to delinquency, all taxes assessed against or
levied upon Lessee's fixtures, furnishings, equipment and other personal
property located in or upon the Premises. Lessee shall cause said fixtures,
furnishings, equipment and other personal property to be assessed and billed
separately from the real property. In the event any or all of Lessee's
fixtures, furnishings or equipment and other personal property shall be
assessed and taxed with said real property, Lessee shall pay to Lessor its
share of such taxes within fifteen (15) days after delivery to Lessee by Lessor
of a statement in writing setting forth the amount of such taxes applicable to
Lessee's personal property.

     (b)  Lessee shall, simultaneously with the payment of any sums required
hereunder, reimburse Lessor for any excise, sales or transaction privilege tax
imposed or levied by any government or governmental agency upon Lessor as a
result of Lessor's receipt of any such payment.

                           10. CONDITION OF PREMISES

     Lessee's taking possession shall be conclusive evidence as against the
Lessee that the Premises were in good order and satisfactory condition when
Lessee took possession. No promise of Lessor to alter, remodel or improve the
Premises or the building and no representation respecting the condition of the
Premises or the building have been made by Lessor to Lessee, other than as may
be contained herein or in a separate rider or work letter attached hereto and
made a part hereof.

                             11. BUILDING SERVICES

     (a)  Lessor agrees to furnish to the premises during reasonable hours of
generally recognized business days, to be determined by Lessor, and subject to
the rules and regulations of the building of which the premises are a part,
water, electricity, heat and air conditioning and janitorial services required
in the Lessor's judgment for the comfortable use and occupation of the
Premises. Lessor shall not be liable for, and Lessee shall not be entitled to,
any abatement or reduction of rental by reason of Lessor's failure to furnish
any of the foregoing when such failure is due to any cause beyond the
reasonable control of Lessor. Lessor shall not be liable under any
circumstances for loss, however occurring, through or in connection with or
incidental to failure to furnish any of the foregoing.

     (b)  Lessee will not, without the written consent of Lessor, use any
apparatus or device in the Premises, including but without limitation thereto,
electronic data processing machines, punch card machines and machines using
current in excess of 110 volts, which will in any way increase the amount of
electricity, water or other utilities, which would otherwise be furnished or
supplied for use of the Premises as a general office space; nor connect with
electric current except through existing electrical outlets in the Premises, or
water pipes, or any apparatus or device for the purposes of using electric
current, water or other utilities. Whenever heat generating machines or
equipment are used in the Premises which affect the temperature otherwise
maintained by the air conditioning system, lessor reserves the right to install
supplementary air conditioning units in the Premises and the cost thereof,
including the cost of installation and the cost of operation and maintenance
thereof, shall be paid by Lessee to Lessor upon demand by Lessor.

                         12. ASSIGNMENT AND SUBLETTING

     Lessee shall not, either voluntarily or by operation of law, sell, assign,
hypothecate or transfer this lease, or sublet the premises or any part thereof,
or permit the Premises or any part thereof to be occupied by anyone other than
Lessee or Lessee's employees, without the prior written consent of Lessor in
each instance. Lessor's consent shall not be reasonably withheld provided the
proposed assignee or sublessee is reasonably satisfactory to Lessor as to
credit and character and will occupy the Premises for office purposes
consistent with Article 8 of this Lease and Lessor's commitments to other
tenants. Any sale, assignment, mortgage, transfer or subletting of this lease
which is not in compliance with the provisions of this Article 12 shall be
voidable and shall, at the option of Lessor, terminate this lease. The consent
by Lessor to any assignment of subletting shall not be construed as relieving
Lessee from obtaining the express written consent of Lessor to any further
assignment or subletting or as releasing Lessee from any liability of
obligation hereunder, whether or not then accrued. The

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Lessor reserves the right, should the Lessee request such assignment or
subletting, to release the Lessee from the terms and provision of this lease and
the Lessor shall have thirty (30) days to make such determination. Should the
Lessor exercise this right, then the lease shall terminate as set forth in
Article 27 as of the date notice is given to Lessee.

                              13. CARE OF PREMISES

     (a)  Lessee, at Lessee's own expense, shall take good care of the Premises
and shall promptly repair all damages to the Premises and the building and
replace or repair all damaged or broken fixtures and appurtenances which are
made necessary as a result of any use, misuse, neglect or negligence of Lessee,
its employees or invitees. If Lessee does not do so, Lessor may, but need not,
make such repairs and replacements, and Lessee shall pay Lessor the cost
thereof upon being billed for same, or Lessor shall have the right to deduct
the same from the security deposit held by Lessor. Lessor may, but shall not be
required to do so, enter the Premises at all reasonable times to make any
repairs as Lessor shall desire or deem necessary to the Premises or to the
building of which the premises form a part or to any equipment located in the
building or as Lessor may be required to do by the unincorporated Adams
County or by the order or decree of any court or by any other governmental
authority.

     (b)  Except as otherwise provided herein, Lessor shall repair and maintain
the building (including the plumbing, heating, air conditioning and electrical
systems), grounds and common areas and facilities. Lessor shall not be liable
for any failure to make any repairs or to perform any maintenance unless
written notice of the need for such repairs or maintenance is given to Lessor by
Lessee, and unless Lessor then fails to commence within a reasonable period of
time, to make such repairs or perform such maintenance and thereafter fails to
use due diligence in so doing. Except as provided in Article 17 hereof, there
shall be no abatement of rent and no liability of Lessor by reason of any entry
to or interference with Lessee's business arising from the making of any repairs
in or to any portion of the building or the premises or in or to fixtures,
appurtenances and equipment therein. Lessee waives the right to make repairs at
Lessor's expense under any provision of statutory or common law now or hereafter
in effect.

                                14.  ALTERATIONS

Lessee shall make no alterations, additions or improvements (including initial
tenant improvements) to the Premises without the prior written consent of
Lessor, which consent shall not be unreasonably withheld, and Lessor may
impose, as a condition of such consent, such requirements as Lessor in its sole
discretion may deem reasonable or desirable, including without limiting the
generality of the foregoing requirements as to the manner in which, the time or
times at which, and the contractor by whom such work shall be done. All such
alterations, additions, or improvements shall become the property of Lessor and
shall be surrendered with the Premises, as a part thereof, at the end of the
term hereof, except that the Lessor may, by written notice to Lessee given at
least thirty (30) days prior to the end of the term, require Lessee to remove
all partitions, counters, railings and the like installed by Lessee, and to
repair any damages to the Premises from such removal.

                     15.  CERTAIN RIGHTS RESERVED BY LESSOR

     (a)  Lessor shall have the following rights, exercisable without notice
and without liability to Lessee for damage or injury to property, person or
business and without effecting an eviction, construction or actual, or
disturbance of Lessee's use or possession or giving rise to any claim for set
off or abatement of rents:

           (i)   To change the building's name or street address.

           (ii)  To install, affix and maintain any and all signs on the
      exterior, interior and/or roof of the building.

           (iii) To designate and/or approve, prior to installation, all types
      of window shades, blinds, drapes, awnings, window ventilators and other
      similar equipment and to control all internal lighting, that may be
      visible from the exterior lobbies, hallways or other common areas.

           (iv)  To show the Premises to prospective tenants at reasonable
      hours and if vacated by Lessee, to prepare the Premises for reoccupancy.

           (v)   To retain at all times and to use in appropriate instances,
      keys to all doors within and into the Premises. No lock shall be changed
      and no new lock shall be installed without the prior written consent of
      Lessor.

           (vi)  To decorate and to make repairs, alterations, additions or
      improvements, whether structural or otherwise, in and about the building
      or in any part thereof and for such purposes to enter upon the Premises
      and, during the continuance of any such work, to temporarily close doors,
      entryways, public space and corridors in the building and to interrupt or
      temporarily suspend building services and facilities, all without
      abatement of rent or affecting any of Lessee's obligations hereunder so
      long as the Premises are reasonably accessible.

           (vii) To have and retain a paramount title to the premises, free
      and clear of any act of Lessee purporting to burden or encumber it.

           (viii)To grant or deny to anyone the right to conduct any business
      or render any service in or to the building, provided such exclusive right
      shall not operate to exclude Lessee from the use expressly permitted
      herein.

           (ix)  To require all furniture and similar items to be moved into
      and/or out of the building and Premises only at such times and in such
      manner as Lessor shall direct in writing. Movements of Lessee's property
      into or out of the building and within the building are entirely at the
      risk and responsibility of Lessee and Lessor reserves the right to require
      permits before allowing any such property to be moved into or out of the
      building.

           (x)   To approve or disapprove in writing the placing of vending or
      dispensing machines of any kind in or about the Premises.

           (xi)  To have access for Lessor and other tenants of the building
      to any mail chutes located on the Premises according to the rules of the
      United States Post Office.

           (xii) To close the building after regular working hours and on
      Saturday, Sunday and legal holidays, subject, however, to Lessee's right
      to admittance under such regulations as Lessor may prescribe from time to
      time.

     (b)  Lessor may enter upon the Premises and may exercise any or all of the
foregoing rights hereby reserved without being deemed guilty of an eviction or
of a disturbance of Lessee's use or possession, and without being deemed guilty
of an eviction or of a disturbance of Lessee's use or possession, and without
being liable in any manner to Lessee.

             16.  DAMAGE TO PROPERTY; INJURY TO PERSONS; INSURANCE

     (a)  Lessee shall indemnify and hold Lessor harmless from any and all
claims arising from Lessee's use of the Premises or of the conduct of its
business or from any activity, work, or thing done, permitted or suffered by
Lessee in or about the Premises and shall further indemnify and hold Lessor
harmless from any and all claims arising from any breach or default in the
performance of any obligation on Lessee's part to be performed under the terms
of this lease, or arising from any act or negligence of Lessee, or of its
agents or employees, and from all costs, attorneys' fees, expenses and
liabilities incurred as a result of any such claim or any action or proceeding
brought thereon; and in case any action or proceeding be brought against Lessor
by reason of any such claim. Lessee, upon notice from Lessor, shall defend the
same at Lessee's expense by counsel satisfactory to Lessor. Lessee, as a
material part of the consideration to Lessor, hereby assumes all risk of damage
to property or injury to persons, in, upon, or about the end liabilities
incurred as a result of any such claim or any action or Premises from any cause
which does not result from the negligence of Lessor and Lessee hereby waives
all claims in respect thereof against Lessor.

     (b)  Lessor or anyone authorized to act for Lessor shall not be liable for
any damage to property entrusted to employees of the building, nor for loss of
or damage to any property by theft or otherwise, nor for any injury or damage
to persons or property resulting from fire, explosion, falling plaster, steam,
gas, electricity, water or rain which may leak from any part of the building or
from the pipes, appliances or plumbing works therein, or from the roof, street
or subsurface, or from any other place resulting from damages or any other
cause whatsoever which does not result from the negligence of Lessor, Lessor or
its agents shall not be liable for interference with the natural light, nor
shall Lessor be liable for any latent defect in the Premises or in the
building. Lessee shall give prompt notice to Lessor of any fire, accident or
defect discovered within the Premises or the building.

     (c)  Lessee agrees to carry at its own expense throughout the term of the
lease, comprehensive public liability insurance insuring both Lessor and Lessee
against all claims, demands or actions arising out of or in connection with
Lessee's use or occupancy, of the Premises, or by the conditions of Premises
with a combined single limit of liability of $500,000 per

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person and $500,000 per occurrence for property damage. Lessee shall deliver a
Certificate of Insurance to Lessor prior to the date of occupancy of the
Premises and said insurance policy shall list and protect Lessor and Lessee as
their interests may appear and shall contain an endorsement stating that the
Insurer agrees to give no less than thirty (30) days prior written notice to
Lessor in the event of any material reduction in coverage with respect to this
lease document or cancellation thereof.

    (d) Lessee shall be responsible for its own personal property insurance

                             17.  FIRE OR CASUALTY

    (a) Except as provided in paragraph 13 relating to repair of the Premises,
if the Premises or the building (including machinery and equipment used in its
operation) are wholly or partially destroyed or damaged by fire or other
casualty which is covered by the usual form of fire and extended coverage
insurance, and if such destruction or damage is not caused by the act or neglect
of Lessee, its agents or servants, then Lessor shall be obligated to repair and
restore the same with reasonable promptness, unless Lessor elects to terminate
this lease as hereinafter set forth. In the event the Premises or the building
are wholly or partially destroyed or damaged as a result of any cause, other
than the perils covered by the usual form of fire and extended coverage
insurance, or in the event the Premises or the building are destroyed or damaged
by any fire or casualty to the extent of not less than twenty-five percent (25%)
of the replacement cost thereof, then Lessor shall have the option to terminate
this lease by giving notice to Lessee within sixty (60) days after the
occurrence of such damage or destruction. If Lessor does not terminate this
lease as provided above, it shall proceed to complete the necessary restoration
or repairs with reasonable promptness and this lease shall continue in full
force and effect; provided, however, that if any destruction or damage not
caused by the act or neglect of Lessee, its agents or servants, renders the
Premises untenantable, and if this lease is not terminated as provided herein by
reason of such damage or destruction, then rent shall abate during the period
beginning with the date of such destruction or damage and end with the date when
the Premises are again rendered tenantable by an amount bearing the same ratio
to the total amount of rent due for such period that the untenantable portion of
the Premises bears to the entire Premises.

    (b) Lessor shall in no event be obligated to repair any injury or damage by
fire or other cause or to make any repairs or replacements of any items
originally installed by Lessee at its expense.

                                  18.  ACCESS

    Lessor and anyone authorized by Lessor shall have the right to enter the
Premises at all reasonable times for the purpose of examining or inspecting the
same, showing the same to prospective purchasers or lessees of the building,
and making such alterations, repairs, improvements or additions to the Premises
or the building of which they are a part as Lessor may deem necessary or
desirable. If Lessee shall not personally be present to open and permit an
entry into the Premises at any time when such entry by Lessor is necessary or
permitted hereunder, Lessor may enter by means of a master key or may enter
forcibly, without liability to Lessee except for any failure to exercise due
care of Lessee's property, and without breaching the terms of this lease.

                               19.  CONDEMNATION

    If the whole or any part of the Premises or of the building shall be taken
or condemned by any governmental authority for any public use or purpose or if
any adjacent property or street shall be condemned or improved in such manner
as to require the use of the whole or any part of the premises or of the
building, the term of this lease, at the option of Lessor, shall end on the
date when the possession of the part so taken shall be required for such use or
purpose and Lessor shall be entitled to receive the entire award without any
payment to Lessee. Current rent shall be apportioned as of the date of such
termination. In the event of a taking which does not result in the termination
of this lease, the rent shall be apportioned according to the part of the
Premises remaining usable by Lessee.

                                20.  ABANDONMENT

    Lessee shall not vacate or abandon the Premises at any time during the
term, and if Lessee shall abandon, vacate or surrender said Premises or be
dispossessed by process of law or otherwise, any personal property belonging to
Lessee and left in the Premises shall be conclusively presumed to be abandoned
and may be kept or disposed of by Lessor as provided in Article 27 hereof.

                              21.  SALE BY LESSOR

    In the event of a sale or conveyance by Lessor of the building containing
the Premises, the same shall operate to release Lessor from any future liability
upon any of the covenants or conditions, express or implied, herein contained
in favor of Lessee, and in such event Lessee agrees to look solely to the
responsibility of the successor in interest of Lessor in and to this lease.
This lease shall not be affected by any such sale, and Lessee agrees to attorn
to such successor in interest. If any security deposit has been made by Lessee
hereunder, Lessor may transfer such security deposit to such successor in
interest and thereupon Lessor shall be discharged from any further liability in
reference thereto.

                   22.  MUTUAL RELEASE/WAIVER OF SUBROGATION

    Lessor and Lessee each hereby release the other from any and all liability
or responsibility for any director or consequential loss, injury or damage to
the Premises, or its contents, caused by fire or any other casualty, during the
term of this lease, even if such fire or other casualty may have been caused
by the negligence of the other party or one for whom such party may be
responsible. Inasmuch as the above mutual waivers will preclude the assignment
of any aforesaid claim by way of subrogation (or otherwise) to an insurance
company (or any other person), each party hereto agrees if required by said
policies to give to each insurance company which has issued to it fire and
other property insurance, written notice of the terms of said mutual waivers,
and to have said insurance policies properly endorsed, if necessary to prevent
the invalidation of said insurance coverage by reason of said waivers.

                                  23.  WAIVER

    (a) No waiver by Lessor of any provision of this lease or any breach by
Lessee hereunder shall be deemed to be a waiver of any other provision hereof,
or of any subsequent breach by Lessee of the same or any other provision.
Lessor's consent to or approval of any act by Lessee requiring Lessor's consent
or approval shall not be deemed to render unnecessary the obtaining of Lessor's
consent to or approval of any subsequent act of Lessee whether or not similar
to the act so consented to or approved. No act done by Lessor or anyone
authorized by Lessor during the term of this lease shall be deemed an
acceptance of a surrender of Premises, and no agreement to accept such
surrender shall be valid unless in writing and signed by Lessor. No employee of
Lessor or of anyone authorized by Lessor shall have any power to accept the keys
to the Premises prior to the termination of this lease, and the delivery of the
keys to any such employee shall not operate as a termination of the lease or a
surrender of the Premises.

    (b) Except as provided in Article 26 relating to Lessor's remedies, Lessee
hereby expressly waives the service of any notice of intention to terminate
this lease or to re-enter the Premises and waives the service of any demand for
payment of rent or for possession and waives the service of any other notice or
demand prescribed by any statute or other law.

                           24.  ESTOPPEL CERTIFICATE

    (a) Lessee shall at any time and from time to time upon not less than ten
(10) days' prior written notice from Lessor execute, acknowledge and deliver to
Lessor a statement in writing (i) certifying that this lease, is unmodified and
in full force and effect (or if modified, stating the nature of such
modification and certifying that this lease, as so modified, is in full force
and effect) and the dates to which the rental and other charges are paid in
advance, if any, and (ii) acknowledging that there are not, to Lessee's
knowledge, any uncured defaults on the part of Lessor hereunder, or specifying
such defaults if they are claimed. Any such statement may be relied upon by any
prospective purchaser or encumbrancer of all or any portion of the real property
of which the Premises are a part.

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     (b) Lessee's failure to deliver such statement within such time shall be
conclusive upon Lessee (i) that this lease is in full force and effect, without
modification except as may be represented by Lessor, (ii) that there are no
uncured defaults in Lessor's performance, and (iii) that not more than one
month's rental had been paid in advance.

                      25. INTEREST ON PAST DUE OBLIGATIONS

     Any amount due from Lessee to Lessor hereunder which is not paid when due
shall bear interest at the rate of one and one half percent (1 1/2%) per month
from the due date until paid, unless otherwise specifically provided herein,
but payment of such interest shall not excuse or cure any default by Lessee
under this lease.

                   26. DEFAULTS; REMEDIES; EARLY TERMINATION

     (a) Defaults. The occurrence of any one or more of the following events
shall constitute a material default ("Default") and breach of this lease by
Lessee:

            (i) The vacating or abandonment of the Premises by Lessee.

           (ii) The failure of Lessee to make any payment of rent or any other
payment required to be made by Lessee hereunder, as when due, where such
failure shall continue for a period of five (5) days after written notice
thereof from Lessor to Lessee.

          (iii) The failure by Lessee to observe or perform any of the
covenants, conditions or provisions of this lease to be observed or performed
by Lessee, other than described above, where such failure shall continue for a
period of fifteen (15) days after written notice thereof from Lessor to Lessee.

           (iv) The making by Lessee of any general assignment, or general
arrangement for the benefit of creditors; the filing by or against Lessee of a
petition to have Lessee adjudged as bankrupt or a petition for reorganization or
arrangement under any law relating to bankruptcy (unless, in the case of a
petition filed against Lessee, the same is dismissed within sixty (60) days);
the appointment of a trustee or receiver to take possession of substantially
all of Lessee's assets located at the Premises or of Lessee's interest in this
lease, where possession is not restored to Lessee within thirty (30) days; or
the attachment, execution or other judicial seizure of substantially all of
Lessee's assets located at the Premises or of Lessee's interest in this lease
where such seizure is not discharged within thirty (30) days.

     (b) Remedies. In the event of any Default by Lessee, at any time
thereafter, and without limiting Lessor in the exercise of any other right or
remedy which Lessor may have by reason of such default or breach, Lessor may:
(a) choose not to reenter but to hold Lessee responsible for all terms of this
lease, (b) reenter the Premises and terminate this lease and hold Lessee
responsible for all damages resulting from the breach; or (c) reenter the
Premises, keep this lease intact, and attempt to relet the Premises on behalf
of Lessee as Lessee's agent. Lessor shall have no obligation to attempt to
relet. Upon reentering the Premises, Lessor may relet the Premises or any part
thereof for such term, on such conditions and at such rental as Lessor may deem
advisable with the right to make alterations and repairs to the premises.
Lessor may remove therefrom all automobiles, signs and other property and such
property may be removed and stored in any place for the account and the
expense and risk of Lessee. Lessee hereby waives all claims for damages which
may be caused by the reentry of Lessor add taking possession of the Premises,
or the removing or storage of the property as herein provided, and will save
Lessor harmless from any loss, cost or damages occasioned thereby, and no such
reentry shall be considered or construed to be forcible entry or detainer.

     Should Lessor elect to reenter as herein provided, rentals received by
Lessor from reletting shall be applied in this order: first, to any Indebtedness
other than rent due under this lease; second, to the payment of any costs of
such reletting; third, to the payment of the cost of any alteration and repairs
to the Premises; and fourth, to the payment of rent due and unpaid under this
lease; and the remainder, if any, shall be held by Lessor and applied in payment
of future rent as the same becomes due and payable under this lease. Should
rentals received from such reletting during any month be less than that agreed
to be paid during that month by Lessee under this lease, then Lessee immediately
shall pay and be liable for such deficiency to Lessor. No such reentry or taking
possession by Lessor shall be construed as an election on its part to terminate
this lease unless a written notice of such intention is given to Lessee.
Notwithstanding any such reletting without termination, at any time thereafter,
Lessor may elect to terminate this lease for such previous default. Should
Lessor at any time terminate this lease for any default, in addition to any
other remedy it may have, Lessor may recover from Lessee all damages Lessor may
incur by reason of such breach, including, without limitation, the cost of
recovering the Premises and the present worth at the time of such termination of
the rent and charges equivalent to rent as reserved in this lease for the
remainder of the stated term.

                          27. SURRENDER OF POSSESSION

Upon the termination of this lease and the term hereby created or upon the
termination of Lessee's right of possession, whether by lapse of time or at the
option of Lessor as aforesaid, Lessee will at once surrender possession of the
premises to Lessor in good order, repair and condition, ordinary wear excepted,
and remove all effects therefrom. Without limiting the generality of the
foregoing, Lessee agrees to remove, at the termination of this lease, the items
of personal property to which Lessee is entitled under article 14 hereof,
together with any alterations, improvements or additions as Lessor shall
designate to be removed. All damage to the premises or the building arising out
of Lessee's moving of property in or out of the building, including damage to
floors due to overloading, shall be fully repaired at Lessee's sole cost and
expense. If Lessee shall fail or refuse to remove all such property from the
Premises Lessee shall be conclusively presumed to have abandoned the same, and
the title thereto shall thereupon pass to Lessor without cost either by setoff,
credit allowance or otherwise, and Lessor may, at its option, accept the title
to such property, or, at Lessee's expense, (a) remove the same or any part
thereof in any manner that Lessor shall choose and (b) store the same without
incurring liability to Lessee or any other person.

                                  28. NOTICES

     All notices to be given by one party to the other under this lease shall
be in writing, mailed or delivered to each as follows:

     (a) To Lessor:

          c/o CB Commercial Management, a Property Manager for Denver
          Jack Limited Partnership
          Independence Plaza
          1050 17th Street, Suite 800
          Denver, Colorado 80265

     (b) To Lessee:

          Mr. John Greff
          Allos Therapeutics Inc.
          7000 Broadway, Suite 310
          Denver, Colorado 80221

     Mailed notices shall be sent by United States certified or registered
mail, postage prepaid. Such notices shall be deemed to have been given upon
posting in the United States mail.

                                       5
<PAGE>   6
                            29. INABILITY TO PERFORM

     This lease and the obligations of Lessee hereunder shall not be affected or
impaired because Lessor is unable to fulfill any of its obligations hereunder or
it delayed in doing so, if such inability of delay is caused by reason of any
strike, other labor dispute or other cause beyond the reasonable control of
Lessor.

                               30. SUBORDINATION

     Lessor expressly reserves the right at any time to place liens and
encumbrances on and against the Premises and the building, superior in lien and
effect to this lease and the estate created hereby, provided however, that any
such lien or encumbrance shall provide that the holder thereof will recognize
Lessee's rights hereunder, notwithstanding any foreclosure of such lien or
encumbrance.

                          31. SUBSTITUTION OF PREMISES

     Lessor may, at its election; upon thirty (30) days' written notice to
Lessee of its desire to do so, exclude the specified leased Premises from the
lease and substitute other Premises within the building therefore, upon the
following terms and conditions:

     (a)  The substituted Premises shall contain approximately the same square
footage as the specified leased Premises, without increase of rental and shall
be usable for Lessee's purpose.

     (b)  Any and all costs necessary or incidental to Lessee's move to the
substituted Premises shall be at the sole cost and expense of Lessor and free of
all cost and expense to Lessee.

     (c)  Upon the expiration of thirty (30) days after such written notice to
Lessee, the substituted Premises shall be considered the leased Premises
described in the lease, for all uses and purposes, as though originally leased
unto Lessee at the time of the execution and delivery of this lease, and the
specified leased Premises shall be considered excluded from the lease.

                               32. MISCELLANEOUS

     (a)  All rights and remedies of Lessor under this lease shall be cumulative
and none shall exclude any other rights and remedies allowed by law.

     (b)  The provisions hereof shall apply without regard to the number or
gender of words and expressions unused herein.

     (c)  Each of the provisions of this lease shall extend to and shall, as the
case may require, bind or inure to the benefit, not only of Lessor and of
Lessee, but also their respective heirs, legal representatives, successors and
assigns, provided this clause shall not permit any assignment contrary to the
provisions of Article 12 hereof.

     (d)  Submission of this Instrument for examination shall not bind Lessor in
any manner, and no lease or obligation of Lessor shall arise until this
Instrument is signed and delivered by Lessor and Lessee.

     (e)  No rights to light or air over any property, whether belonging to
Lessor or any other person, are granted to Lessee by this lease.

     (f)  Lessor shall not be responsible to Lessee for the nonperformance by
any other tenant or occupant of the building of any of the rules and regulations
established by the Lessor for the building.

         (g)  Clauses, plats and riders, if any, signed by Lessor and Lessee and
endorsed on or affixed to this lease are a part hereof.

     (h)  Time is of the essence with respect to the performance of every
provision of this lease in which time of performance is a factor.

     (i)  The article captions contained in this lease are for convenience only
and shall not be considered in the construction or interpretation of any
provision hereof.

     (j)  This lease contains all of the agreements of the parties hereto with
respect to any matter covered or mentioned in this lease, and no prior agreement
or understanding pertaining to any such matter shall be effective for any
purpose. No provision of this lease may be amended or added to except by an
agreement in writing signed by the parties hereto or their respective successors
in interest.

     (k)  This lease shall be governed by and controlled pursuant to the laws of
the State of Colorado.

     (l)  In the event of any legal action or proceeding brought by either party
against the other out of this lease in any manner whatsoever, the prevailing
party shall be entitled to recover reasonable attorney's fees incurred in such
action and such amount shall be included in any judgment rendered in such
proceeding.

                             33. SPECIAL PROVISIONS

     A.   Tenant's Responsibility Regarding Hazardous Substances

          1.   Hazardous Substances. The term "Hazardous Substances", as used in
this Lease, shall include, without limitation, flammables, explosives,
radioactive materials, asbestos, polychlorinated byphenyls (PCB's), chemicals
known to cause cancer or reproductive toxicity, pollutants, contaminates,
hazardous wastes, toxic substances or related materials, petroleum and petroleum
products, and substances declared to be hazardous or toxic under any law or
regulation now or hereafter enacted or promulgated by any governmental
authority.

          2.   Tenant's Restrictions. Tenant shall not cause or permit to occur:
(a) Any violation of any federal, state, or local law, ordinance, or regulation
now or hereafter enacted, related to environmental conditions on, under, or
about the Premises, or arising from Tenant's use or occupancy of the Premises,
including, but not limited to, soil and ground water conditions; or (b) The use,
generation, release, manufacture, refining, production, processing, storage, or
disposal of any Hazardous Substance on, under or about the Premises, or the
transportation to or from the Premises of any Hazardous Substance, except as
specifically disclosed on Schedule A to this Lease.

          3.   Environmental clean-up: (a) Tenant shall, at Tenant's own
expense, comply with all laws regulating the use, generation, storage,
transportation, or disposal of Hazardous Substances ("Laws"). (b) Tenant shall,
at Tenant's own expense, make all submissions to, provide all information
required by, and comply with all requirements of all governmental authorities
(the "Authorities") under the Laws. (c) Should any Authority or any third party
demand that a clean-up plan be prepared and that a clean-up be undertaken
because of any deposit, spill, discharge, or other release of Hazardous
Substances that occurs during the term of this Lease, at or from the Premises,
or which arises at any time from Tenant's use or occupancy of the Premises, then
Tenant shall, at Tenant's own expense, prepare and submit the required plans and
all related bonds and other financial assurances; and Tenant shall carry out all
such clean-up plans. (d) Tenant shall promptly provide all information regarding
the use, generation, storage, transportation, or disposal of Hazardous
Substances that is requested by Owner. If Tenant fails to fulfill any duty
imposed under this Paragraph (3) within reasonable time, Owner may do so; and in
such case, Tenant shall cooperate with Owner in order to prepare all documents
Owner deems necessary or appropriate to determine the applicability of the Laws
to the Premises and Tenant's use thereof, and for compliance therewith, the
Tenant shall execute all documents promptly upon Owner's request. No such action
by Owner and no attempt made by Owner to mitigate damages under any Law shall
constitute a waiver of any of Tenant's obligations under this Paragraph (3). (e)
Tenant's obligations and liabilities under this Paragraph (3) shall survive the
expiration of this Lease.

<PAGE>   7
 4. Tenant's Indemnity: (a) Tenant shall Indemnify, defend, and hold harmless
Owner, the manager of the property, and their respective officers, directors,
beneficiaries, shareholders, partners, agents, and employees from all fines,
suits, procedures, claims, and actions of every kind, and all costs associated
therewith (including attorneys' and consultants' fees) arising out of or in any
way connected with any deposit, spill, discharge, or other release of Hazardous
Substances that occurs during the term of this lease, at or from the Premises,
or which arises at any time from Tenant's use or occupancy of the Premises, or
from Tenant's failure to provide all information, make all submissions, and take
all steps required by all Authorities under the Laws and all other environmental
laws. (b) Tenant's obligations and liabilities under this Paragraph (4) shall
survive the expiration of this Lease.

     See Also the Rider Number One attached hereto and made part hereof and
containing Articles 34 through 39.

LESSEE: Allos Therapeutics, Inc.,
        a Virginia Corporation
-------------------------------------------
By:   Stephen J. Hoffman
   ----------------------------------------
Its:  President and Chief Executive Officer
    ---------------------------------------

LESSOR: AmberJack, Ltd., General Partner
        for Denver Jack Limited Partnership

By:     Earle B. Johnson
   ----------------------------------------
Its:    Vice President
    ---------------------------------------
By:     Neil O. Brown
   ----------------------------------------
Its:    President
    ---------------------------------------

<PAGE>   8

                                RIDER NUMBER ONE

THIS RIDER NUMBER ONE is attached to and forms a part of that certain Lease
dated October 30, 1995 between Denver Jack Limited Partnership, Lessor, and
Allos Therapeutics, Inc., a Virginia corporation, Lessee, covering Suite 310,
approximately 4,022 square feet in 7000 Broadway, Denver, Colorado. The parties
agree that should there be any conflict between this Rider Number One and the
Lease, the terms, conditions and covenants of this Rider Number One shall
govern and control.

                                  34. PREMISES

Lessor hereby leases to Lessee and Lessee leases from Lessor those certain
premises, known as Suite 310, consisting of approximately 4,022 rentable square
feet in the building located at 7000 Broadway, Denver, CO 80221, all as
described on Exhibit "A".

                                    35. RENT

December 22, 1995 - December 21, 1996   Three Thousand Eight Hundred
                                        Eighty-Seven and 93/100 Dollars
                                        ($3,887.93) per month
December 22, 1996 - December 21, 1998   Four Thousand Fifty-Five and 52/100
                                        dollars ($4,055.52) per month
December 22, 1998 - December 21, 1999   Four Thousand Two Hundred Twenty-Three
                                        and 10/100 Dollars ($4,223.10) per month

                            36. TENANT IMPROVEMENTS

Lessor shall construct the Tenant Improvements for the Premises in accordance
with the plans and specification in Exhibit "A" (Floorplan) prepared by
McDermott Planning and Design dated October 5, 1995. As part of the Tenant
Improvements Lessor will shampoo the carpet and paint the Premises. Lessor
shall pay the cost of the Tenant Improvements and Lessee shall pay the costs
incurred as a result of any changes, modifications or additions to the plans
and specifications in Exhibit "A".

The Tenant Improvements for this Lease specifically do not include the following
items in the scope of the work to be performed by Lessor, and shall be the
responsibility of the Lessee:

     i.   Premises security system
    ii.   Office furniture, supplies, equipment and accessories,
   iii.   Office plantscaping,
    iv.   Modular furniture and partitions,
     v.   Lessee's telephone system and cabling,
    vi.   Computer equipment,
   vii.   Computer cabling.

                                  37. PARKING

Lessee shall have the right to use on an unassigned, unreserved basis twenty
(20) parking spaces in the 7000 Broadway parking area free of charge for the
term of the Lease.

                      38. PERCENTAGE OF OPERATING EXPENSES

Lessee's percentage of Operating Expenses shall consist of 8.86%.
<PAGE>   9
                  LANDLORD'S NOTICE OF LEASE COMMENCEMENT

                     AND VERIFICATION OF LEASE TERMS

RE:  Shopping Center Lease (the "Lease") dated October 30, 1995 between DENVER
     JACK LIMITED PARTNERSHIP ("Landlord") and ALLOS THERAPEUTICS, INC., a
     Virginia corporation ("Tenant") for the premises located at 7000 North
     Broadway, Suite 310, Denver, Colorado ("Premises")

     The undersigned, as Tenant, hereby confirms as of this 22nd day of
February, 1996, the following:

     1. The Substantial Completion of the Premises was completed on January 11,
1996, and Tenant is currently occupying the same.

     2. The Commencement Date, as defined in the Lease, as well as the date on
which the term expires are as follows:

        Commencement Date:      January 11, 1996

        Expiration Date:        January 10, 2000

     3. Initial Minimum Rent:  $3,887.93

     4. As of the date hereof, Landlord has fulfilled all of its obligations
under the Lease.

     5. The Lease is in full force and effect and has not been modified,
altered, or amended.

Please indicate your verification of the above terms by signing below.

                                ACCEPTED AND AGREED:

                                ALLOS THERAPEUTICS, INC., a
                                Virginia corporation

                                By: /s/ [ILLEGIBLE]
                                   -------------------------
                                Title: CFO
                                      ----------------------
                                Date:  2-22-96
                                     -----------------------

<PAGE>   10
              39. RIGHT OF FIRST REFUSAL TO LEASE ADDITIONAL SPACE

If Lessee is not in default under the Lease on the date Lessee desired to
exercise its Right of First Refusal, Lessee shall have a Right of First Refusal
to lease all of Suite 320 consisting of 2,337 rentable square feet (Expansion
Space).

Lessor agrees to notify Lessee pursuant to the requirements of Article 28 of the
Lease of Lessor's intention to offer the Expansion Space for lease. Lessee shall
have three (3) days from its receipt of such notice to notify Lessor in writing
of Lessee's intent to exercise its Right of First Refusal and to execute a
mutually agreed upon Rider to this Lease to include Expansion Space.

If Lessee does not exercise its Right of First Refusal, this Right of First
Refusal shall terminate and Lessor may lease any portion or all of the Expansion
Space to any third party.

If Lessee so elects to exercise its Right of First Refusal to lease the
Expansion Space, the rent, terms, and conditions for leasing the Expansion
Space, shall be based on the then current lease proposal for the Expansion Space
in conjunction with prevailing rental rates for properties of equivalent
quality, size, utility, and location, with the length of the Lease Term and
credit standing of Lessee to be taken into account, but in no event shall the
rent be less than the rent set forth in Section 3 of this Lease and Section 35
of this Rider Number One for the Lease Term, otherwise subject to all the terms,
covenants and conditions of this Lease. Within fifteen (15) business days from
the date of Lessee's election to exercise its Right of First Refusal, Lessee
shall execute plans and specifications and other documents as necessary showing
the construction costs to be paid by Lessee for the Space, if any, otherwise
Lessee's Right of First Refusal shall terminate and Lessor may lease the
Expansion Space to any third party.

<PAGE>   11
                                 7000 BROADWAY
                                    BUILDING

                                  [FLOOR PLAN]

                          McDERMOTT PLANNING & DESIGN

                                  EXHIBIT "A"
                                  Floor Plan

                              ALLOS THERAPEUTICS
                             THIRD FLOOR SPACE PLAN

<PAGE>   12
                                  EXHIBIT "B"
                             RULES AND REGULATIONS

1.   Signs, Directories

     No sign, advertisement or notice shall be inscribed, painted or affixed on
any part of the inside or outside of the building, including windows, doors and
corridors, unless of such color, size and style and in such place upon or in
said building as shall be first designated by Lessor. There shall be no
obligation or duty by Lessor to allow any sign, advertisement or notice to be
inscribed, painted or affixed on any part of the inside or outside of said
building. Lessee shall not mark, paint, drill into, or in any way deface the
walls ceiling, partitions, doors or floors of the building and shall not put
therein any spikes, hooks, screws or nails, except by written consent of
Lessor. Initial nameplate and suite number on doors will be provided by the
Lessor. The cost of additional nameplates for doors shall be borne by Lessee. A
building directory with the names of the tenants will be provided by the Lessor
in the lobby. Any necessary revision in such directory will be made by Lessor
within a reasonable time after written notice from the Lessee of the change
making the revision necessary, but Lessor shall not be responsible for any
inconvenience or damage caused by Lessee as a result of any error in such a
directory. Initial directory listings will be at the cost of Lessor. Changes or
revisions in directory listing will be at the expense of Lessee. No showcase or
any other fixture or objects whatsoever shall be placed in front of the
building or in the court or corridor by Lessee, without written consent of
Lessor.

2.   Building Hours

     The Lessor specifically reserves the right to refuse admittance to the
building after 9:00 p.m. daily, after 6:00 p.m. on Saturday, on Sunday or on
legal holidays to any person or persons who cannot furnish satisfactory
identification or to any person or persons who for any other reason should be
denied access to the Premises. Lessor also reserves the right to designate such
hours as the building shall be open and closed.

3.   Deliveries, Moving of Heavy Equipment

     All safes, furniture, office equipment or other heavy articles shall be
carried up or into the Premises only at such hours and in such manner as shall
be prescribed by Lessor, and Lessor shall in all cases have the right to specify
the proper weight and position of any such safe or other heavy article. All
hand trucks shall be equipped with rubber tires and side guards. Any damage
done to the building by taking in or removing any safe or heavy article or from
overloading any floor in any way shall be paid by Lessee. Defacing or injuring
in any way any part of the building by the Lessee, his agent, employee or
servants shall be paid by the Lessee. Any and all deliveries made to Lessee's
leased Premises shall be made via the back entrance of the building or other
area to be designated by Lessor.

4.   Walk and Passageway Obstruction

     The sidewalks, entries, passages, courts, corridors, stairways and
elevators shall not be obstructed by Lessee, Lessee's employees, or agents or
used by them for other purposes than for ingress or egress to and from their
respective suites.

5.   Unattended Premises

     Lessee, its agents, servants and employees shall, before leaving Premises
unattended, close and lock all doors and turn off all lights.

6.   Lost Items

     Lessor will not be responsible for lost or stolen property, equipment,
money or any article taken from Premises, building or garage facilities
regardless of how loss occurs and whether such loss occurs when such area is
locked against entry.

7.   Locks

     All locks for doors in Lessee's leased areas shall be building standard
and no additional locks shall be placed upon any doors without the written
consent of Lessor nor shall any duplicate keys be made. All necessary keys
shall be furnished by the Lessor and the same shall be surrendered upon the
termination of the Lease. Lessee shall then give to Lessor an explanation of
the combination of all locks upon the doors of vaults. Two keys per every 1,000
square feet of leased area only will be provided as each lockset is installed
or as Lessee's space is occupied. Any requests for additional keys shall be
made to Lessor and shall be at the expense of lessee. Additional locksets
provided by Lessor at request of Lessee will be at the expense of Lessee.

8.   Janitorial Service

     Lessee shall not employ any person or persons other than the janitor of
the Lessor for the purpose of cleaning or taking charge of the Premises leased,
without the consent of Lessor. Lessor shall be in no way responsible to any
Lessee for any loss of property from the leased Premises, however occurring, or
for any damage done to any property by the janitor or any of his employees, or
by any other person or persons whomsoever. If janitorial services are provided
in the Premises, the janitor of the building may at all times keep a pass-key
and shall at all reasonable times by allowed admittance to said leased
Premises. Lessor's janitors shall not be hindered by Lessee after 5:30 p.m.

9.   Excess Trash Disposal

     In the event Lessee must dispose of crates, boxes, and other bulky waste,
it will be the responsibility of Lessee to dispose of same. In no event will
tenant place such items in public hallways or other areas of the building
(excepting Lessee's own Premises) for disposal.

10.  Hazardous Materials

     The Lessee shall not bring into the building, store or permit the use of
any toxic, flammable, or explosive material or any unlawful or controlled
substance. Lessee shall not bring into or allow to be kept in the building any
bicycles, vehicles or animals.

11.  Utilities

     Lessor reserves the right to make such rules and regulations as it may see
fit, concerning the use of electric current, gas, water and other supplies of
the said building.

12.  Extra Utility Usage

     In the event Lessee desires utility or air conditioning service at other
than normal operating hours the request must be made to the project manager's
office at a reasonable length of time prior to need for this service. This
service will be made available at the then prevailing rate established on an
hourly basis.

13.  Elevator Service

     The Lessor shall not be liable for any damages from stoppage of elevators
for necessary or desirable repairs or improvements or delays of any sort of
duration in connection with the elevator service.

14.  Carpet Damage

<PAGE>   13

     Lessee will be responsible for any damage to carpeting and flooring as a
result of rust or corrosion of the file cabinets, potted plant saucers, roller
chairs and metal objects.

15.  Vending, Canvassing and Soliciting

     Canvassing, soliciting and peddling in the building is prohibited. No
vending machines of any type shall be allowed in the Premises without prior
written consent of Lessor.

16.  Contractor Approval

     All contractors and/or technicians performing work for Lessee shall be
referred to Lessor for approval and control. This provision shall apply to all
work performed in the building including, but not limited to, installation of
electrical devices, telephones, telegraphs and other communications equipment.
Lessee will in all areas be responsible for damages to the building caused by
said contractors. If Lessee desires telegraphic, telephonic, annunciator or
other electrical connections or communication services, the Lessor will direct
the electricians as to where and how the wires may be introduced, and without
such directions, no boring or cutting of wires will be permitted.

17.  Additional Rules

     The Lessor reserves the right to rescind and of these rules and
regulations and to make such other and further reasonable rules and regulations
as in its judgment may from time to time be needed for the safety, protection,
care and cleanliness of the Premises, and for the preservation of good order
therein, and the protection and comfort of the Lessee's and their agents,
employees and invitees upon which such rules and regulations shall be binding in
like manner as if originally herein prescribed.<PAGE>   1
                                                                   EXHIBIT 10.13

                                FIRST AMENDMENT
                     TO 7000 BROADWAY BUILDING OFFICE LEASE
                                    between
                        DENVER JACK LIMITED PARTNERSHIP
                                      and
                            ALLOS THERAPEUTICS, INC.
                             Dated October 30, 1995

THIS FIRST AMENDMENT is to that certain lease agreement (the "Lease") dated
October 30, 1995, by and between DENVER JACK LIMITED PARTNERSHIP ("Lessor") and
ALLOS THERAPEUTICS, INC. ("Lessee") with respect to approximately 4,022 square
feet of space on the third floor, known as Suite 310 (the "Premises"), in the
building known as 7000 Broadway, Denver, Colorado (the "Building"). In the event
of any conflict between the terms and provisions of the lease and the terms and
provisions of this First Amendment, the terms and provisions of this First
Amendment shall control.

     1) Amendment to Article 4 of the Lease Document.

     Landlord and Tenant do hereby agree that a portion of Article 4, Rent
     Adjustment, Paragraph (a) Real Estate Taxes and Paragraph (b) Operating
     Expenses shall be amended to read "the Base Year 1996 actual expenses".
     This will effectively change the Base Year for Operating Expense and Real
     Estate Tax adjustments from 1995 to 1996.

Except as herein specifically set forth, all other provisions of the Lease shall
remain in full force and effect and be binding upon the parties in accordance
with their terms.

IN WITNESS WHEREOF, the parties have hereunto set their hands and seals the day
and year fist above written.

                                     LESSOR:

                                     AMBERJACK, LTD., General Partner for
                                     DENVER JACK LIMITED PARTNERSHIP

                                     By:  CB Commercial Real Estate Group, Inc.
                                        ---------------------------------------
                                     Its: As Manager
                                         --------------------------------------
                                     By:  [ILLEGIBLE]
                                        ---------------------------------------

                                     Its: Senior Vice President
                                         --------------------------------------
                                          [ILLEGIBLE]
                                          Asst. V.P.

                                     LESSEE:

                                     ALLOS THERAPEUTICS, INC.
                                     a Virginia corporation

                                     By:  John Greff
                                        ---------------------------------------
                                     Its: V.P. Finance & CFO
                                         --------------------------------------

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00000-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00000-of-00352.parquet"}]]