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                                                                   Exhibit 10.58

                                    AGREEMENT

         This Agreement, dated as of December 3, 2003 is entered into by and
among University of Massachusetts, a public institution of higher education of
the Commonwealth of Massachusetts having an address at 365 Plantation Street,
Suite 130, Worcester, MA 01605 ("UMass"), Advanced BioScience Laboratories,
Inc., a Delaware corporation having its principal place of business at 5510
Nicholson Lane, Kensington, MD 20895 ("ABL") and CytRx Corporation, a Delaware
corporation having an address at 11726 San Vicente Boulevard, Suite 650, Los
Angeles, California 90049 ("CytRx") with reference to the following facts:

         A.       In December 2002, UMass filed a provisional patent
application, U.S. Patent Application Serial Number 60/430,732 (the "03-24 Patent
Filing") with the United States Patent and Trademark Office covering a
foundational HIV vaccine technology invention referred to by UMass as UMMC 03-24
(the "03-24 Technology").

         B.       In May 2003, UMass granted an exclusive worldwide license to
the 03-24 Patent Filing and 03-24 Technology to CytRx pursuant to an Exclusive
License Agreement, dated as of April 15, 2003 by and between UMass and CytRx and
which UMass and CytRx have agreed to clarify Section 4.8 of the Exclusive
License Agreement pursuant to an amendment that will be substantially in the
form as provided to ABL (such Agreement, as so amended, being referred to herein
as the "03-24 License Agreement").

         C.       In June, 2000, ABL was awarded a $15 million NIH grant (NIAID
Prime Contract N01-05394) (the "NIH Grant") in connection with the development
of a DNA-based HIV vaccine that incorporates the 03-24 Technology (the "HIV
Vaccine") and on June 26, 2000, ABL entered into a subcontract with UMass
(Subcontract No. 00454B-UMM-NAID-N01-A1-05395) (the "UMass Subcontract") in
connection with the development of the HIV Vaccine.

         D.       ABL anticipates filing in December 2003 or January 2004 an IND
with the United States Food and Drug Administration ("FDA") for a Phase I
clinical trial of the HIV Vaccine (the "IND") and to commence this Phase I trial
(the "Phase I Trial") within 30 to 60 days following the IND being cleared by
the FDA.

         E.       In September, 2003, ABL filed a provisional patent application
U. S. Patent Application Serial Number 60/503,907 (the "03-111 Patent Filing")
covering an HIV protein boost technology invention referred to by UMass and ABL
as UMMC 03-111 (the "03-111 Technology").

         F.       ABL, UMass and CytRx are willing to make the filing with the
United States Patent and Trademark Office of a combined patent application (the
"Joint Patent Filing") for the 03-24 Technology and the 03-111 Technology that
will include all of the claims of the 03-24 Patent Filing and 03-111 Patent
Filing, with the Joint Patent Filing to be conditioned on the terms set forth in
this Agreement. Both a U.S. non-provisional patent application and a PCT
application designating all countries will be filed simultaneously. Both the
non-provisional and the PCT applications will claim priority to the 03-24 Patent
Filing.

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         G.       ABL, CytRx and UMass have had discussions concerning the
development and commercialization of the HIV Vaccine, as described in this
Agreement, and wish to provide for the framework for negotiation of a definitive
agreement covering such development and commercialization (the "Definitive
Collaborative Agreement"), as well for the rights and obligations of each of the
parties in the event they are unable to conclude the Definitive Collaborative
Agreement within the time period specified in this Agreement.

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

         1.       Joint Patent Filing. The parties hereby agree that the Joint
Patent Filing will be made with the United States Patent and Trademark Office by
no later than December 3, 2003. The Joint Patent Filing shall be prepared by
Fish & Richardson, as counsel for UMass, in consultation with patent counsel for
ABL and CytRx. The Joint Patent Filing shall be submitted and prosecuted by Fish
& Richardson (or another patent firm retained by UMass and reasonably acceptable
to ABL and CytRx). The Joint Patent Filing shall also be filed in such foreign
jurisdictions as shall be requested by either ABL or CytRx. The costs of
preparing, submitting and prosecuting the Joint Patent Filing (limited to the
actual fees of the appropriate patent offices and expenses of patent counsel for
UMass) shall be borne by CytRx, except that ABL shall bear all of the legal fees
and other expenses of preparing, submitting and prosecuting the Joint Patent
Filing in any foreign jurisdiction that it requests be made. The Joint Patent
Filing will be submitted in a form so as to avoid or minimize any prejudice to
the rights of the parties in the event the Joint Patent Filing is divided into
divisional patent applications pursuant to Section 6 hereof.

         UMass shall decide all patent prosecution matters in consultation with
ABL and CytRx. ABL and CytRx shall receive copies of all material correspondence
from any patent office within a reasonable amount of time and shall be provided
with copies of all proposed material filings or other submissions to any patent
office so as to afford ABL and CytRx with a reasonable opportunity to comment
upon such proposed filing or submission.

         2.       Filing of IND; Commencement of Phase I Trial. ABL shall use
its commercially reasonable best efforts to file the IND by no later than
January 31, 2004, to obtain clearance of the IND by the FDA and to commence the
Phase I Trial by no later than February 2004. ABL shall notify UMass and CytRx
in writing within one business day following the IND filing and the commencement
of the Phase I Trial and shall promptly provide UMass and CytRx with all
material correspondence received from or delivered to the FDA or the institution
at which the Phase I Trial will be conducted relating to the IND or Phase I
Trial.

         3.       Disclosure. Upon the signing of the Definitive Collaborative
Agreement, the parties shall jointly issue a press release announcing such
signing, with the text of such press release to contain a summary description of
the material terms of the Definitive Collaborative Agreement (but not the
specific royalty rates or other similar financial terms) and to be reasonably
acceptable to all of the parties (the "Collaborative Press Release"). In the
event ABL determines to file and does file the IND prior to the signing of the
Definitive Collaborative Agreement or the issuance of the Collaborative Press
Release, CytRx shall be entitled immediately following such filing to issue a
press release in substantially the form attached

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hereto as Exhibit A (the "IND Press Release"). If the IND is filed after the
issuance of the Collaborative Press Release, the parties shall jointly issue a
press release announcing such filing, with the text of such press release to be
reasonably acceptable to all of the parties.

         4.       Definitive Collaborative Agreement. The parties shall
negotiate in good faith to enter into the Definitive Collaborative Agreement by
no later than January 31, 2004. The parties agree that, apart from the
obligation to negotiate in good faith upon the terms stated herein, this Section
4 represents only the intent of the parties and shall not be binding upon the
parties. The Definitive Collaborative Agreement shall contain the following
provisions, together with such other terms and conditions as would customarily
be included in an agreement of that type:

                  4.1      Phase I Trial. UMass, in consultation with CytRx,
will be responsible as provided in the UMass Subcontract for carrying out the
Phase I Trial. CytRx will have no financial responsibility for carrying out the
Phase I Trial.

                  4.2      Assignment of HIV Vaccine. Following completion of
the Phase I Trial, ABL will assign to CytRx ownership of the HIV Vaccine
(subject to its economic interest in the vaccine as described below), with CytRx
to thereafter be the sponsor for FDA purposes of the HIV Vaccine. ABL and UMass
will cooperate with CytRx in making all necessary FDA and foreign healthcare
regulatory agency filings to reflect this assignment and will provide CytRx with
copies of all filings and correspondence with the FDA and any foreign healthcare
regulatory agencies in connection with the HIV Vaccine.

                  4.3      Subsequent Clinical Development of HIV Vaccine. CytRx
will be responsible at its own expense for carrying out and completing all
clinical trials after the Phase I Trial that are required to obtain FDA
marketing approval for the HIV Vaccine and marketing approval for any other
countries that shall be agreed to by ABL and CytRx. The parties acknowledge that
CytRx may seek to obtain additional NIH or other government or private grants to
support the foregoing clinical development of the HIV Vaccine, and UMass agrees
to reasonably assist CytRx in filing for and obtaining such grants. CytRx shall
consult with ABL and UMass in connection with all material matters relating to
the development of the HIV Vaccine.

                  4.4      Manufacture of HIV Vaccine. Provided that ABL or its
affiliate has the required regulatory approvals and manufacturing capacity at
the time, ABL or its affiliate shall have an option (which must be exercised
within 30 days of being notified by CytRx that CytRx has received an "approvable
NDA" letter from the FDA for the HIV Vaccine or equivalent notification from any
foreign healthcare regulatory agency) to acquire the commercial manufacturing
rights for the HIV Vaccine for the United States or any other applicable
territory. The terms of the commercial manufacturing agreement shall be
negotiated in good faith by ABL and CytRx and shall include such economic and
other terms as are customarily contained in an agreement of that type.

                  4.5      Marketing of HIV Vaccine. CytRx will be responsible
at its own expense for the marketing of the HIV Vaccine.

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                  4.6      CytRx Licensee or Strategic Partner. CytRx shall have
the right to enter into sublicense or strategic alliance or other agreements
with one or more third parties pursuant to which the sublicensee or strategic
partner may be responsible (either jointly with CytRx or alone) for the
development, commercial manufacture (unless ABL or its affiliate is the
commercial manufacturer) or marketing of the HIV Vaccine. Any such agreement
shall be subject to the terms of the 03-24 License Agreement, as such license
agreement shall be modified pursuant to Section 4.8 hereof.

                  4.7      Compensation Payable to ABL. UMass, CytRx and ABL
agree that as payment in full for ABL's assignment of the HIV Vaccine to CytRx
and its other agreements under this Agreement, ABL shall be entitled to receive
from CytRx (i) {***} of the payments that are due to UMass under Sections 4.3,
4.5, 4.6, 4.7 and 4.8 of the 03-24 License Agreement; (ii) {***} of the
following milestone payments listed under Section 4.4 of said agreement: for
entry into Phase II clinical trial; for entry into Phase III clinical trial;
upon filing for market approval outside the US; for commencement of product
marketing in the US; and for market approval for the first three European
countries; and (iii) {***} of the milestone payment so listed for the filing of
IND; provided, that amounts payable by CytRx to UMass under the terms of said
Sections 4.3 thru 4.8 shall be reduced by {***} of the amounts so paid by CytRx
to ABL pursuant to the terms of this Section.

                  4.8      03-24 License Agreement. The parties agree that upon
the Joint Patent Filing, the 03-111 Technology shall become part of the Patent
Rights as defined in the 03-24 License Agreement. ABL agrees that the inclusion
of the 03-111 Technology into the 03-24 License Agreement shall occur without
further compensation to UMass or ABL, except as specified in this Agreement, and
at no additional cost to CytRx. ABL shall also grant CytRx a non-exclusive,
royalty-bearing license to any additional technologies outside of the 03-24
Technology and the 03-111 Technology that are owned or licensed to ABL
(including those acquired by ABL pursuant to its right of first refusal under
the UMass Subcontract) and that result from work done by UMass under the UMass
Subcontract for a DNA-based HIV vaccine with protein boost and that are
necessary or advantageous to CytRx for the development or commercialization of
the HIV Vaccine, with the amount of the royalty to be established in the
Definitive Collaborative Agreement and to be negotiated in good faith by the
parties. UMass shall grant CytRx a right of first negotiation to obtain a
royalty-bearing license to UMass' exclusive or non-exclusive rights to any
additional technology outside of the 03-24 Technology and 03-111 Technology that
are owned by UMass and have not been acquired or licensed to ABL pursuant to its
right of first refusal under the UMass Subcontract and that result from work
done under the UMass Subcontract and that are necessary or advantageous to CytRx
for the development or commercialization of the HIV Vaccine. ABL shall represent
that it does not currently own or have any other rights to any other technology
that would be infringed by the development or commercialization of the HIV
Vaccine.

                  4.9      Competing Vaccines. ABL and CytRx each shall be
permitted to develop and commercialize other HIV vaccines that may compete with
the HIV Vaccine; provided, however, that if such other vaccine would infringe
any of the claims set forth in the Joint Patent Filing but for the existing
ownership rights of that party in the Joint Patent Filing, the party seeking to
commercialize such other vaccine (the "New Vaccine Party") shall pay to the
other

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party {***} of the net sales by the New Vaccine Party of the other HIV vaccine
(or {***} of the milestone payments and other income received if the New Vaccine
Party sublicenses the vaccine). However, the percentage of the net sales to be
paid by the New Vaccine Party to the other party shall be increased to {***} (or
{***} of the milestone payments and other income received if the New Vaccine
Party sublicenses the vaccine) in the event the HIV Vaccine has been
commercialized and will compete with the other HIV vaccine. The exact percentage
of net sales to be paid by the New Vaccine Party shall be agreed to by ABL and
CytRx in the Definitive Collaborative Agreement. Any payments received by CytRx
from ABL pursuant to the foregoing provisions shall be treated as Sublicense
Income pursuant to the 03-24 License Agreement.

         Subject to the other provisions of this Section 4.9, ABL shall have the
right to use the 03-24 Technology and 03-111 Technology, provided that such use
is solely for the purpose of developing and commercializing other HIV vaccines.
CytRx agrees to grant ABL a non-exclusive sublicense under the 03-24 License
Agreement and as amended to include the 03-111 Technology pursuant to the
preceding sentence.

         5.       Option for UMMC 91-03. UMass hereby grants CytRx an option for
a fee of {***} (with such fee creditable to the cost of the exclusive license)
to acquire for its sole use and benefit an exclusive, worldwide license (the
"91-03 License Agreement") to a HIV vaccine related technology referred to by
UMass as UMMC 91-03 (the "91-03 Technology"). The 91-03 License Agreement will
be on such economic terms as shall be agreed to by UMass and CytRx, but shall be
no less attractive to CytRx than those set forth in UMass's licensing term sheet
delivered to CytRx on November 25, 2003. The other terms and conditions of the
91-03 License Agreement shall be substantially similar to those set forth in the
03-24 License Agreement. The foregoing option shall be exercised by CytRx at its
sole discretion at any time prior to April 1, 2004.

         6.       Failure to Conclude Definitive Collaborative Agreement. Each
of the parties acknowledges that the signing and performance of the Definitive
Collaborative Agreement is an essential part of their agreement to make the
Joint Patent Filing. The parties will negotiate in good faith with a goal of
signing the Definitive Collaborative Agreement by no later than December 31,
2003. In the event the parties have been unable to conclude the Definitive
Collaborative Agreement by January 31, 2004 for any reason, the parties hereby
agree that upon such failure (a "Termination Event") the Joint Patent Filing
will immediately be divided (or will be divided as soon as legally permitted
under the PCT rules for the PCT portion of the Joint Patent Filing) into
divisional applications separately covering the 03-24 Technology (with UMass as
the sole owner) and the 03-111 Technology (with UMass and ABL as the co-owners).

         Upon a Termination Event, each of the parties will be entitled to
assert against each other all of their legal rights, if any, with respect to the
HIV Vaccine, the 03-24 Technology and the 03-111 Technology as if the Joint
Patent Filing had not been previously made. In such an event, each of the
parties further agrees to not assert that the Joint Patent Filing by itself (i)
has created any implied licenses to the HIV Vaccine, the 03-24 Technology or the
03-111 Technology in favor of any party who would not otherwise have such a
license or (ii) has constituted a waiver by any party of any of its rights that
it possessed prior to the Joint Patent Filing. The parties

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agree that in the event of any dispute following a Termination Event as to the
ownership or other rights of any party in the HIV Vaccine, the 03-24 Technology
or the 03-111 Technology, such dispute shall be resolved to the maximum extent
possible so that no party to this Agreement shall have gained an advantage over
another party to this Agreement solely as the result of the Joint Patent Filing
having been made (including without limitation the creation of any implied
licenses or waivers or the advancement of any filing priority date).

         Upon a Termination Event, the 03-24 License Agreement between UMass and
CytRx and the Subcontract between UMass and ABL shall continue in full force and
effect, and UMass shall have the right to license its interest in the 03-111
Technology to CytRx or any third party deemed appropriate by UMass on a
non-exclusive basis.

         7.       Parties' Reliance on Counsel. All the parties have each
consulted and relied upon their respective attorneys' legal advice and their own
judgment and choice in deciding to enter into this Agreement. The parties to
this Agreement have read it completely and their attorneys have explained it to
them. The undersigned parties voluntarily accept the terms of this Agreement and
fully understand those terms.

         8.       Entire Agreement; Transaction Costs. This Agreement
constitutes the entire agreement between the parties with regard to the subject
matter of this Agreement. It supersedes all prior understandings, transactions
and communications, whether written or oral, between the parties with respect to
the matters referred to herein. Each party shall bear its own fees and expenses
in connection with negotiating this Agreement and the Definitive Collaborative
Agreement. Subject to Sections 4 hereof, no party shall have any liability to
any other party under this Agreement or be required to enter into and perform
the Definitive Collaboration Agreement based on such party's failure to enter
into the Definitive Collaborative Agreement unless such party has failed to
negotiate in good faith to enter into the Definitive Collaborative Agreement.

         9.       Amendments. No modification of this Agreement, nor any future
representation, promise or agreement in connection with the subject matter of
this Agreement shall be binding on the parties unless made in writing and signed
on their respective behalf by their respective authorized representatives.

         10.      Assignment. The parties shall not assign or transfer this
Agreement or any of its obligations hereunder without the prior written consent
of the other parties, except as otherwise permitted by Section 4.6 hereof.

         11.      Governing Law. This Agreement shall be governed by and
construed in accordance with the laws of the State of California (United States
of America) without reference to any conflict of law provisions thereof. The
parties hereby submit to the exclusive jurisdiction of, and venue in, the state
and federal courts located in Los Angeles, California.

         12.      Waivers. The waiver by one or several parties of any right
hereunder, or of any failure to perform or breach by one party hereunder, shall
not be deemed a waiver of any other right hereunder or of any other breach or
failure by the other parties hereunder whether of a similar nature or otherwise.

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         In witness whereof, the parties have caused this Agreement to be
signed, in multiple identical originals, by their duly authorized
representatives, with effect as of the date first written above.

                                       UNIVERSITY OF MASSACHUSETTS

                                       By: /s/ CHESTER A. BISBEE
                                         ------------------------------------

                                       Its:      Acting Director, OTM
                                            ---------------------------------

                                       Date: December 3, 2003
                                            ---------------------------------

                                       CYTRX CORPORATION

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

                                       Date: December 3, 2003
                                            ---------------------------------

                                       ADVANCED BIOSCIENCE LABORATORIES, INC.

                                       By: /s/ JOHANNES BURLIN
                                          -----------------------------------
                                                 Johannes Burlin
                                       Its:      President and CEO

                                       Date: December 3, 2003
                                            -------------------------------


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                                    EXHIBIT A

         CYTRX ANNOUNCES FILING OF INVESTIGATIONAL NEW DRUG APPLICATION
                                 FOR HIV VACCINE

         Los Angeles, December ___, 2003 -- CytRx Corporation (Nasdaq: CYTR)
announced today that an Investigational New Drug Application (IND) has been
filed with the Food and Drug Administration (FDA) for a Phase I clinical trial
for a new DNA-based HIV vaccine.

         The new HIV vaccine incorporates proprietary technology exclusively
licensed to CytRx by the University of Massachusetts Medical School (UMMS). The
Phase I trial will be funded out of a portion of a $15 million National
Institutes of Health grant previously provided to Advanced BioScience
Laboratories (ABL) and subcontracted in part to UMMS to develop an enhanced HIV
vaccine that utilizes UMMS' technology licensed to CytRx. ABL and CytRx expect
that the Phase I trial will begin in February 2004 and take approximately twelve
to eighteen months to complete.

         "There is a worldwide urgent need for an effective HIV vaccine," said
Steven A. Kriegsman, Chief Executive Officer of CytRx. "With the anticipated
launch of the Phase I trial for this vaccine utilizing our licensed UMMS
technology, CytRx will take a major step forward in efforts to create such a
vaccine." In addition to the HIV vaccine technology, CytRx also has exclusive
technology licenses from UMMS for RNAi-based therapies for Amyotrophic Lateral
Sclerosis (ALS, also known as Lou Gehrig's Disease) and for obesity and Type II
Diabetes.

         ABL and UMMS have filed a joint patent application covering CytRx's
licensed foundational technology and ABL's and UMMS' protein boost technology
that are incorporated into the HIV vaccine. CytRx believes that this joint
filing should substantially bolster CytRx's patent position for its licensed
technology.

         [STANDARD TRAILERS FOR CYTRX]

         This press release contains forward-looking statements within the
meaning of Section 21E of the Securities Exchange Act of 1934, as amended, that
involve risks and uncertainties that could cause actual events or results to
differ materially from the events or results described in the forward-looking
statements, including risks or uncertainties related to the risk that ABL may
encounter delays in having the IND cleared by the FDA or in starting the Phase I
vaccine trial due to delays in obtaining clinical supplies of the vaccine or for
other reasons, the risk of delays in completing and the uncertainty of the
results of the Phase I trial or future trials, the risk of obtaining adequate or
any patent coverage for the HIV vaccine and the need for CytRx to separately
obtain or develop a new protein boost technology and to separately organize and
fund Phase I and subsequent clinical trials for an HIV vaccine if it is unable
to enter into an agreement with ABL for the development and commercialization of
the HIV vaccine that is described in this press release. Additional
uncertainties and risks are described in CytRx's most recently filed SEC
documents, such as its most recent annual report on Form 10-K, all quarterly
reports on Form 10-Q and any current reports on Form 8-K filed since the date of
the last Form 10-K. All forward-looking statements are based upon information
available to CytRx on the date the statements are first published. CytRx
undertakes no obligation to publicly update or revise any forward-looking
statements, whether as a result of new information, future events or otherwise.