<PAGE>   1
           CONFIDENTIAL TREATMENT REQUESTED: Certain portions of this
               document have been omitted and are marked with the
           notation, "*Confidential Treatment Requested." A complete
        copy has been filed with the Securities and Exchange Commission.


                                                                   EXHIBIT 10.05

                    ASSIGNMENT AND ASSUMPTION AGREEMENT WITH
                                    AMENDMENT

         THIS ASSIGNMENT AND ASSUMPTION AGREEMENT ("Agreement"), is entered into
this 28th day of July, 1997 ("Effective Date"), by and among The Center for
Innovative Technology, and Virginia Corporation located in Herndon Virginia
(hereinafter referred to as "C.I.T."), and Virginia Commonwealth University
Intellectual Property Foundation located in Richmond, Virginia (hereinafter
referred to as "VCUIPF"), and Allos Therapeutics, Inc., a Delaware Corporation
located in Denver, Colorado (hereinafter "Allos").

         WHEREAS, C.I.T. is the owner of several patents and patent applications
related to the allosteric modification of hemoglobin which were developed at
Virginia Commonwealth University, and which are the subject of a license
agreement between C.I.T. and Allos, formerly Hemotech Sciences, Inc. identified
as "HEMOTECH AND C.I.T. AMENDED AND RESTATED ALLOSTERIC MODIFIERS OF HEMOGLOBIN
AGREEMENT" (hereinafter the "Allos License Agreement"),

         WHEREAS, C.I.T. wishes to assign the entire right, title and interest
in the Allos License Agreement to VCUIPF, except for the stock provisions of
Article 2.6 of the Allos License Agreement, and VCUIPF wishes to assume all
rights and responsibilities of C.I.T. under the License Agreement;

         NOW THEREFORE, for and in consideration of good and valuable
consideration, the receipt and sufficiency of which is hereby acknowledged, the
parties hereto agree as follows:

1. Incorporation of Existing Agreement and Amendments

         1.1 Attached to this Agreement is a copy of the Allos License Agreement
executed by C.I.T. on January 12, 1994, and by Hemotech on January 10, 1994; a
copy of first amendment to the License Agreement entitled "AMENDMENT TO ALLOS
THERAPEUTICS, INC. AND C.I.T. AMENDED AND RESTATED ALLOSTERIC MODIFIERS OF
HEMOGLOBIN AGREEMENT" (hereinafter "First Amendment") which was made effective
January 17, 1995; and a copy of the second amendment to the License Agreement
also entitled "AMENDMENT TO ALLOS THERAPEUTICS, INC. AND C.I.T. AMENDED AND
RESTATED ALLOSTERIC MODIFIERS OF HEMOGLOBIN AGREEMENT" (hereinafter "Second
Amendment") which was executed by both Allos and C.I.T. on March 12, 1996.

         1.2 The Allos License Agreement, the first Amendment, and the Second
Amendment constitute the entire licensing arrangement between C.I.T. and Allos,
and are herein incorporated by reference.



                                       1
<PAGE>   2


2. Assignment and Assumption

         2.1 From the Effective Date of this Agreement, C.I.T. hereby assigns,
transfers, and sets over to VCUIPF, its successors and assigns, except for any
monetary obligation of Allos to C.I.T. accruing prior to the Effective Date of
this Agreement and except for the stock provided under Article 2.6 of the Allos
License Agreement, all of its right, title and interest in and to, and all of
C.I.T.'s obligations arising under the Allos License Agreement and its
amendments, and VCUIPF accepts the assignment from C.I.T. and agrees to be bound
by all of the terms and assumes any and all obligations of C.I.T. under the
Allos License Agreement and its amendments.

         2.2 In consideration for the assignment, [*].

         2.3 C.I.T. agrees to execute assignment documents assigning the patents
and patent applications to VCUIPF and to record the assignments, and C.I.T.'s
expense, in the U.S. Patent and Trademark Office.

3. Mutual Releases and Warranties and Indemnification

         3.1 C.I.T. hereby releases VCUIPF from any and all claims and
liabilities, known or unknown, whether now existing or hereafter arising, that
C.I.T. may have against VCUIPF with respect to the Allos License Agreement and
its amendments, and VCUIPF hereby releases C.I.T. from any and all claims and
liabilities, known or unknown, whether now existing or hereafter arising that
VCUIPF may have against C.I.T. with respect to the Allos License Agreement and
its amendments.

         3.2 C.I.T. makes no representations or warranties to VCUIPF concerning
the validity, originality, infringement, fitness for the particular purpose, or
any other aspect of the patents and patent applications.

         3.3 VCUIPF hereby indemnifies and agrees to hold C.I.T. harmless from
any claim or claims made by any party against VCUIPF and/or C.I.T. arising out
of the Allos License Agreement and its amendments, the patents or patent
applications, or the manufacture, marketing, advertising or sale of any product
related to the allosteric modifier compounds described in the patents and patent
applications by any third party, whether a direct purchaser of such product or
otherwise. VCUIPF shall be responsible for all representations and warranties
made by it to licensees including by not limited to Allos and to purchasers of
products related to the allosteric modifier compounds described in the patents
and patent applications.

* CONFIDENTIAL TREATMENT
        REQUESTED

                                       2
<PAGE>   3


4. Amendment and Consent to Assignment

         4.1 It is agreed to amend the Allos License Agreement to refer to
"Allos Therapeutics" throughout the document wherever "Hemotech" is mentioned.

         4.2 It is agreed to amend the Allos License Agreement at Article 1.1
by deleting the first two sentences and substituting the following language
therefore:

         "C.I.T. possesses several disclosures of technology developed by Dr.
Donald J. Abraham et al. Which are related to allosteric modifiers of
hemoglobin (C.I.T. Case Nos. 116, 169, 214A, 214B, 538, and 569). This
technology being more fully described in the following U.S. Patents, U.S. Patent
Applications, foreign patents, and foreign patent applications:

         U.S. Patents: 5,409,695; 5,122,539; 5,248,785; 5,250,701; 5,290,803;
         5,382,680; 5,432,191; 5,591,892; and 5,648,375

         U.S. Patent Applications: 08/374,206; 08/478,108; 08/478,371;
         08/482,808; 08/741,174; and 08/848,485

         Foreign Patents: UK 0,471,811; Italy 0,471,811; France 0,471,811;
         Germany 691157901-08

         Foreign Patent Applications: Europe 92912561.5; Japan 504932/91; Japan
         05-500,270; Canada 2,051,693; and Canada 2,109,575"

         It being further agreed that this change does not substantively change
the License Agreement as it is amended.

         4.3 Allos consents to the assignment set forth in Article 2.1 of this
Agreement.

         4.4 Allos agrees to make all reports, notices, reimbursements and
payments due under the Allos License Agreement and its amendments to VCUIPF.

         4.5 Allos acknowledges and affirms its obligations to C.I.T. with
respect to any monetary or stock obligation to C.I.T. which accrues prior to the
Effective Date of this Agreement.

5. Miscellaneous

         5.1 Counterparts - This Agreement may be executed in several
counterparts, each of which shall be deemed an original, but such counterparts
shall together constitute but one and the same Agreement.

         5.2 Entire Agreement - This Agreement and all attachments referenced
herein, together constitutes the entire agreement among the parties hereto
pertaining to the subject matter hereof, and supersedes all prior and
contemporaneous agreements, understandings, negotiations, and discussions of the
parties, whether oral or written, and there are no warranties,



                                       3
<PAGE>   4


representations, or other agreements between the parties in connection with the
subject matter hereof.

         5.3 Governing Law and Jurisdiction - This Agreement shall be construed
and interpreted according to the laws of the Commonwealth of Virginia. Each of
the parties hereto hereby irrevocably and unconditionally agrees to submit to
the jurisdiction and venue of the State and Federal Courts which include
Herndon, Virginia in their respective districts for purposes of resolving any
actions, suits or proceedings brought under this Agreement, and not to object to
convenience of the forum.

         5.4 Severability - The provisions of this Agreement are severable, and
in the event that any provisions of this Agreement shall be determined to be
invalid or unenforceable, such invalidity and unenforceability shall not in any
way affect the validity or enforceability of the remaining provisions hereof.

ACCEPTED AND AGREED TO:

THE CENTER FOR INNOVATIVE TECHNOLOGY

By: /s/ ROBERT G. TEMPLIN, JR.               Date:          7-28-97
   ---------------------------------              ------------------------------
   Robert G. Templin, Jr.
   President

VIRGINIA COMMONWEALTH UNIVERSITY INTELLECTUAL PROPERTY
FOUNDATION, INC.


By: /s/ RICHARD C. FRANSON                   Date:          7-30-97
   -------------------------------------          ------------------------------
   Richard C. Franson, Ph.D.
   ------------------------------------
   Title: Director,
          Office of Technology Transfer
          -----------------------------

ALLOS THERAPEUTICS, INC.

By: /s/ STEPHEN J. HOFFMAN                   Date:          8/8/97
   ---------------------------------              ------------------------------
   Stephen J. Hoffman
   President



                                       4