Execution
Version




ONCOVISTA
INNOVATIVE THERAPIES, INC.


14785
Omicron Drive, Suite 104


San
Antonio, Texas  78245





January
15, 2009





To
      the holders (including any successors and permitted transferees and
      assignees of such holders, the “Holders”) of warrants
      (the “Warrants”)
      to purchase up to an amount or number of the securities offered in the
      first Qualified Financing (as defined in the Warrant) (the “Offering”) consummated
      by the Company following the date hereof equal to principal amount of the
      Secured Promissory Notes due 2010 (the “Notes”)  (determined
      based on the offering price in such Qualified Financing) at a price per
      security equal to the product of (A) and (B), where (A) equals the
      offering price per security in the next Qualified Financing consummated by
      the Company and where (B) equals 0.90, or, under certain circumstances,
      shares of common stock, par value $0.001 per share (the “Common Stock”), in each
      case of OncoVista Innovative Therapies, Inc., a Delaware corporation (the
      “Company”)





Ladies
and Gentlemen:





Reference is made to the Subscription
Letter Agreement submitted by each of the Holders to the Company (the “Subscription
Agreements”).  This letter agreement sets forth the
registration rights referenced in the Subscription Agreement.





As further inducement for Holders to
undertake the transactions contemplated by the Subscription Agreement, the
Company hereby agrees with the Holders as follows:







(a)          
Registration
Rights.





(i)           
 (A)           On or
prior to each Filing Date (as hereinafter defined), the Company shall prepare
and file with the Securities and Exchange Commission (the “SEC”) a registration
statement (the “Registration
Statement”) covering the resale of all or such portion of the shares of
Common Stock issuable upon the exercise of the Warrants (the “Registrable Securities”) as
shall be permitted by any publicly-available written or oral guidance, comments,
requirements or requests of the SEC staff and the Securities Act of 1933, as
amended (the “Securities
Act”).  The Company agrees to use commercially reasonable
efforts to advocate with the SEC for the registration of all of the Registrable
Securities the resale of which on such Filing Date is not then registered on an
effective registration statement for an offering to be made on a continuous
basis pursuant to Rule 415 under the Securities Act.  The Registration
Statement shall be on Form S-1, or another appropriate form.  The
Company shall use its best efforts to cause a registration statement to be
declared effective under the Securities Act as promptly as practicable after the
filing thereof, and shall use its best efforts to keep such registration
statement continuously effective under the Securities Act until all Registrable
Securities covered by such Registration Statement have been sold, or may be sold
without volume restrictions pursuant to Rule 144(e).  If any SEC
guidance sets forth a limitation of the number of Registrable Securities to be
registered on a particular registration statement (and notwithstanding that the
Company used best efforts to advocate with the SEC for the registration of all
or a greater number of Registrable Securities), unless otherwise directed in
writing by a holder as to its Registrable Securities, the number of Registrable
Securities to be registered on such registration statement will be reduced on a
pro rata basis based on the total number of Registrable Securities held by such
Holders).  At least fifteen (15) days prior to the first anticipated
filing date of the Registration Statement, the Company shall notify each Holder
of any information of such Holder that is reasonably required to be included in
the Registration Statement under the Securities Act.  Any such Holder
shall provide such information to the Company at least five (5) days prior to
the first anticipated filing date of such Registration
Statement.  Notwithstanding the foregoing, the Company shall not be
required to register the resale of Registrable Securities held by any such
Holder that does not, prior to such five (5) days prior to the anticipated
filing date of such Registration Statement, provide to the Company such
information.





(B)           In
the event that the Company shall not file the registration statement with the
SEC on or prior to the 45th day
following its respective Filing Date, or cause such registration statement to be
declared effective under the Securities Act on or prior to its respective
Effective Date (as hereinafter defined), the Company shall pay to each investor
in the Offering liquidated damages in the amount of 0.5% of the Offering price
of the Notes and the Warrants purchased thereby for each thirty (30) days
thereafter until such registration statement shall be filed or effective under
the Securities Act, as applicable, provided, however, that no penalty shall be
applicable with respect to (i) the Registrable Securities of any investor herein
which does not provide to the Company promptly upon request information
reasonably required to be set forth in such registration statement pursuant to
the rules and regulations of the SEC or (ii) any delay resulting from compliance
by the Company with SEC Guidance.  Further, in no event shall such
cumulative liquidated damages exceed 10% of the purchase price of the investors
in the Offering.





For
purposes of this Memorandum, “Effective Date” shall mean
the 120th day
following the Filing Date.





(ii)           For
purposes of this Memorandum, “Filing Date” shall mean, with
respect to the initial registration statement required hereunder, the 45th
calendar day following (1) the date of the final closing of the Offering, and,
(2) with respect to any additional Registration Statements which may be
required, the earliest practical date on which we are permitted by SEC Guidance
to file such additional registration statement related to the Registrable
Securities.


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(iii)           The
Company shall use best efforts to (A) (1) prevent the issuance of any stop order
or other suspension of effectiveness and, (2) if such order is issued, obtain
the withdrawal of any such order at the earliest possible moment and (B) cause
all Registrable Securities covered by a Registration Statement to be listed on
each securities exchange, interdealer quotation system or other market on which
similar securities issued by the Company are then listed;




(iv)          Notwithstanding
the foregoing, the Company shall not be obligated to prepare and to file a
post-effective amendment or supplement to the Registration Statement or the
prospectus constituting a part thereof, and no Holder may offer or sell
Registrable Securities pursuant to the Registration Statement, during the
continuance of a Blackout Event (as defined below);provided, however, that (A) the Company shall use best efforts to ensure
that no Blackout Event may be deemed to exist for more than thirty (30)
consecutive days, nor more than forty five (45) days during any 12-month period
(the period during which such Blackout Event shall continue, a “Blackout Period”), (B) the Company shall promptly (1) notify the
Holders in writing of the existence of (but in no event, without the prior
written consent of the Holder, shall the Company disclose to the Holders any of
the facts or circumstances regarding) the event giving rise to an Blackout
Event, provided that the Company shall not be required to disclose material
nonpublic information to the Holder; (2) advise the Holders in writing to cease
all sales under the Registration Statement until the end of the Blackout Period;
and (c) use commercially reasonable efforts to terminate an Blackout Period as
promptly as practicable.  A “Blackout Event” means any of
the following: (a) the reasonable belief that there is or may be in existence
material nonpublic information or events involving the Company, the failure of
which to be disclosed in the prospectus included in the Registration Statement
could result in a Violation (as defined below); or (b) any material engagement
or activity by the Company which would, in the reasonable andgood faith determination of the
Chief Executive Officer (“CEO”) or the Board of
Directors of the Company (the “Board”) (as set forth in a
certificate signed by the CEO or the Chairman of the Board and delivered to the
Holders), be materially adversely affected by disclosure in a registration
statement or prospectus at such time.  A Blackout Event will be deemed
to commence when such Registration Statement ceases, for either of the reasons
set forth in clauses (a) or (b) above, to be effective and available to the
Holders as to some or all of the Registrable Securities at any time prior to the
expiration of the effectiveness period with respect to such Registration
Statement set forth herein.  Without the
express written consent of the Holders, if required topermit the continued sale of Shares or Warrant Shares
by the Holders, a post-effective amendment or supplement to Registration
Statement or the prospectus constituting a part thereof must be filed as soon as
reasonably practicable following any Blackout Event.A “Violation” by the Company includes: (x) any untrue statement or
alleged untrue statement of a material fact contained in such Registration
Statement, including any preliminary prospectus or final prospectus contained
therein or any amendments or supplements thereto, (y) the omission or alleged
omission to state therein a material fact required to be stated therein, or
necessary to make the statements therein not misleading, or (z) any violation or
alleged violation by the Company of the Securities Act, the Securities Exchange
Act of 1934 or any state securities law in connection with the offering covered
by such registration statement.


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(v)           At
least ten (10) business days prior to the filing with the SEC of the
Registration Statement (or any amendment thereto) or the prospectus forming a
part thereof (or any supplement thereto), the Company shall provide draft copies
thereof to the Holders and shall (A) incorporate into such documents such
material furnished to the Company in writing, which in the reasonable judgment
of the Holders (and its counsel) and counsel for the Company should be
incorporated therein and (B) not file any document to which such Holder’s
counsel may reasonably object based upon such counsel’s belief that such
Registration Statement is not in compliance with applicable laws, rules or
regulations or contains a material misstatement or
omission.  Notwithstanding the foregoing, no prospectus supplement,
the form of which has previously been provided to the Holders, need be delivered
in draft form to the Holders.





(vi)          The
Company shall (A) promptly notify the Holders upon the occurrence of any of the
following events in respect of the Registration Statement or the prospectus
forming a part thereof: (i) receipt of any request for additional information
from the SEC or any other federal or state governmental authority during the
Registration Period, the response to which would require any amendments or
supplements to the Registration Statement or related prospectus; (ii) the
issuance by the SEC or any other federal or state governmental authority of any
stop order suspending the effectiveness of the Registration Statement or the
initiation of any proceedings for that purpose;  (iii) receipt of any
notification with respect to the suspension of the qualification or exemption
from qualification of any of the Registrable Securities for sale in any
jurisdiction or the initiation or threatening of any proceeding for such
purpose; or (iv) the effectiveness of the Registration Statement within 48 hours
following such Registration Statement being declared effective and (B)
immediately notify the Holders, at any time when a prospectus relating to
Registrable Securities is required to be delivered under the Securities Act,
upon discovery that, or upon the happening of any event or the passage of time
as a result of which, the prospectus included in a Registration Statement, as
then in effect, includes an untrue statement of a material fact or omits to
state any material fact required to be stated therein or necessary to make the
statements therein not misleading in light of the circumstances then existing,
and at the request of any such Holder, promptly prepare and furnish to such
Holder a reasonable number of copies of a supplement to or an amendment of such
prospectus or the Registration Statement as may be necessary so that, as
thereafter delivered to the purchasers of such Registrable Securities, such
prospectus shall not include an untrue statement of a material fact or omit to
state a material fact required to be stated therein or necessary to make the
statements therein not misleading in light of the circumstances then
existing.


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(vii)         The
Company shall, as soon as reasonably practicable after the effectiveness of the
Registration Statement, at the request of any Holder, furnish such Holder with
respect to the Registrable Securities registered under the Registration
Statement such number of copies of any Registration Statement and any amendment
thereto, each preliminary prospectus and Prospectus and each amendment or
supplement thereto, and each letter written by or on behalf of the Company to
the SEC or the staff of the SEC as such Holder may reasonably request, and each
item of correspondence from the SEC or the staff of the SEC, in each case
relating to such Registration Statement (other than any portion of any thereof
which contains information for which the Company has sought confidential
treatment), and such number of copies of prospectuses and such other documents
as such Holder may reasonably request, in order to facilitate the public sale or
other disposition of all or any of the Registrable Securities by such Holder
pursuant to the Registration Statement.





(viii)        The
Company shall file or cause to be filed such documents to register and qualify
the securities covered by the Registration Statement under such other securities
or “blue sky” laws of such jurisdictions as shall be in effect for so long as
such Registration Statement remains in effect; provided, however, that the
Company shall not be required to qualify to do business or consent to service of
process in any jurisdiction in which it is not now so qualified or has not so
consented.





(ix)         With
a view to making available to the Holders the benefits of Rule 144, the Company
agrees, from the date of the closing of the Offering and so long as the Holders
own Registrable Securities, to use best efforts to:




(A)           comply
with the provisions of paragraph (c)(1) of Rule 144;




(B)           file
with the SEC in a timely manner all reports and other documents required to be
filed by the Company pursuant to Section 13, 14 or 15(d) under the Exchange Act;
and, if at any time it is not required to file such reports but in the past had
been required to or did file such reports, it will, upon the request of the
Holders, make available other information as required by, and so long as
necessary to permit sales of its Registrable Securities pursuant to, Rule 144;
and




(C)           so
long as a Holder owns any Registrable Securities, furnish to such Holder
forthwith upon request:  (1) a written statement by the Company as to
its compliance with the reporting requirements of  Rule 144 and of the
Exchange Act, (2) a copy of the most recent annual or quarterly report of the
Company, and (3) such other reports and documents as a Holder may reasonably
request in availing itself of any rule or regulation of the SEC allowing it to
sell any such securities without registration.


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(x)          
 The Company shall make available, during normal business hours, upon
reasonable request, for inspection and review by one counsel and accounting firm
to the Holders, all financial and other records, all filings with the SEC, and
all other documents respecting the Company, its assets, its properties or its
business (including without limitation minute books, corporate records,
financial statements, contracts, permits, licenses, approvals, technical or
engineering reports, and any title opinions or valuations which the Company has
obtained) as may be reasonably necessary for the purpose of such review, and
cause the Company’s officers, directors and employees, within a reasonable time
period, to supply all such information reasonably requested by the counsel and
accounting firm to the Holders in connection with the Registration Statement
(including, without limitation, in response to all questions and other inquiries
reasonably made or submitted by any of them) to the extent not publicly
available on EDGAR or the Company’s website, prior to and from time to time
after the filing and effectiveness of the Registration Statement for the sole
purpose of enabling the counsel and the accounting firm to the Holders to
conduct initial and ongoing due diligence with respect to the Company and the
accuracy of such Registration Statement and a reasonable investigation within
the meaning of the Securities Act.  Notwithstanding any of the
foregoing, nothing herein shall obligate the Company to provide to the Holder,
or any advisors, any material nonpublic information.    The
Company shall not disclose material nonpublic information to any Holders or such
counsel and accounting firm, unless prior to disclosure of such information the
Company identifies such information as being material nonpublic information and
provides the Holders and such advisors and representatives with the opportunity
to accept or refuse to accept such material nonpublic information for review and
receives therefrom a confidentiality agreement in form and substance reasonably
satisfactory to the Company.




(xi)           The
Company shall cooperate with the Holders to facilitate the timely preparation
and delivery of certificates representing Registrable Securities to be sold
pursuant to a Registration Statement, which certificates shall, if required
under the terms of this letter agreement and upon the receipt by the Company of
representations of the Holders as to the intent to sell such securities, be free
of all restrictive legends, and to enable such Registrable Securities to be in
such denominations and registered in such names as the Holders may reasonably
request.





(b)           Fees and
Expenses.  All expenses incurred in connection with
registrations pursuant to this letter, including, without limitation, all
registration, qualification and filing fees, fees relating to the filings with
the NASD’s CobraDesk (if required), printing expenses, escrow fees, fees and
disbursements of counsel for the Company, blue sky fees and expenses and the
expense of any special audits incident to or required by any such registration
(but excluding the fees and expenses of any counsel for any Holder or Holders)
shall be borne by the Company.  All underwriting discounts and selling
commissions applicable to the Registrable Securities, shall be borne by the
Holders.





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(c)           Indemnification.





(i)          
 Subject to the conditions set forth below, the Company agrees to indemnify
and hold harmless the Holders, their respective officers, directors, partners,
employees, agents, and counsel, and each person, if any, who controls any such
person within the meaning of Section 15 of the Act or Section 20(a) of the
Securities Exchange Act of 1934, as amended (the “Exchange Act”), from and
against any and all loss, liability, charge, claim, damage, and expense
whatsoever (which shall include, for all purposes of this paragraph (c), without
limitation, reasonable attorneys' fees and reasonable expenses incurred in
investigating, preparing, or defending against any litigation, commenced or
threatened, or any claim whatsoever, and any and all amounts paid in settlement
of any claim or litigation), as and when incurred, arising out of, based upon,
or in connection with, (A) any untrue statement or alleged untrue statement of a
material fact contained in (1) any registration statement, preliminary
prospectus, or final prospectus (as from time to time amended and supplemented),
or any amendment or supplement thereto, relating to the offer and sale of any of
the Registrable Securities, or (2) any application or other document or
communication (in this paragraph (c), referred to collectively as an “application”) executed by, or
on behalf of, the Company or based upon written information furnished by, or on
behalf of, the Company filed in any jurisdiction in order to register or qualify
any of the Registrable Securities under the securities or “blue sky” laws thereof or
filed with any securities exchange; or any omission or alleged omission to state
a material fact required to be stated therein or necessary to make the
statements therein not misleading, unless such statement or omission was made in
reliance upon, and in conformity with, written information furnished to the
Company with respect to such Holder by, or on behalf of, such person expressly
for inclusion in any registration statement, preliminary prospectus or final
prospectus, or any amendment or supplement thereto, or in any application, as
the case may be, or (B) any breach of any representation, warranty, covenant, or
agreement of the Company contained in this letter agreement.  The
foregoing agreement to indemnify shall be in addition to any liability the
Company may otherwise have, including liabilities arising under this letter, the
aforementioned warrant, and the related documentation.





If any action is brought against the
Holders or any of its officers, directors, partners, employees, agents, or
counsel, or any controlling persons of such person (an “indemnified party”) in
respect of which indemnity may be sought against the Company pursuant to the
foregoing paragraph, such indemnified party or parties shall promptly notify the
Company in writing of the institution of such action (but the failure so to
notify shall not relieve the Company from any liability it may have other than
pursuant to this paragraph (c)(i)) and the Company shall promptly assume the
defense of such action, including, without limitation, the employment of counsel
reasonably satisfactory to such indemnified party or parties and payment of
reasonable expenses.  Such indemnified party or parties shall have the
right to employ its or their own counsel in any such case, but the fees and
expenses of such counsel shall be at the expense of such indemnified party or
parties unless the employment of such counsel shall have been authorized in
writing by the Company in connection with the defense of such action or the
Company shall not have promptly employed counsel reasonably satisfactory to such
indemnified party or parties to have charge of the defense of such action or
such indemnified party or the Holders shall have reasonably concluded, with the
advice of counsel, that there may be one or more legal defenses available to it
or them or to other indemnified parties which are different from, or in addition
to, those available to the Company, in any of which events such reasonable fees
and expenses shall be borne by the Company, and the Company shall not have the
right to direct the defense of such action on behalf of the indemnified party or
parties.  Anything in this paragraph to the contrary notwithstanding,
(i) the Company shall not be liable for the fees and expenses of more than one
counsel to represent the Holders, and (B) the Company shall not be liable for
any settlement of any such claim or action effected without its written consent,
which consent shall not be unreasonably withheld.  The Company shall
not, without the prior written consent of each indemnified party that is not
released as described in this sentence, settle or compromise any action, or
permit a default or consent to the entry of judgment or otherwise seek to
terminate any pending or threatened action, in respect of which indemnity may be
sought hereunder (whether or not any indemnified party is a party thereto),
unless such settlement, compromise, consent, or termination includes an
unconditional release of each indemnified party from all liability in respect of
such action.  The Company agrees promptly to notify the Holders of the
commencement of any litigation or proceedings against the Company or any of its
officers or directors in connection with the sale of any Registrable Securities
or any preliminary prospectus, prospectus, registration statement, or amendment
or supplement thereto, or any application relating to any sale of any
Registrable Securities.


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(ii)           the
Holders agree, severally, but not jointly, to indemnify and hold harmless the
Company, each director of the Company, each officer of the Company who shall
have signed any registration statement relating to Registrable Securities held
by the Holders, and each other person, if any, who controls the Company within
the meaning of Section 15 of the Act or Section 20(a) of the Exchange Act, to
the same extent as the foregoing indemnity from the Company to the Holders in
paragraph (c)(i)(A), but only with respect to statements or omissions, if any,
made in any registration statement, preliminary prospectus, or final prospectus
(as from time to time amended and supplemented), or any amendment or supplement
thereto, or in any application, in reliance upon, and in conformity with,
written information furnished to the Company with respect to the Holders by, or
on behalf of, the Holders expressly for inclusion in any such registration
statement, preliminary prospectus, or final prospectus, or any amendment or
supplement thereto, or in any application, as the case may be.  If any
action shall be brought against the Company or any other person so indemnified
based on any such registration statement, preliminary prospectus, or final
prospectus, or any amendment or supplement thereto, or any application, and in
respect of which indemnity may be sought against the Holders pursuant to this
paragraph (c)(ii), the Holders shall have the rights and duties given to the
Company, and the Company and each other person so indemnified shall have the
rights and duties given to the indemnified parties, by the provisions of
paragraph (c)(i)(A).  The foregoing agreement to indemnify shall be in
addition to any liability the Holders may otherwise have.


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(iii)           To
provide for just and equitable contribution, if (A) an indemnified party makes a
claim for indemnification pursuant to paragraph (c)(i) or (c)(ii) (subject to
the limitations thereof), but it is found in a final judicial determination, not
subject to further appeal, that such indemnification may not be enforced in such
case, even though this letter agreement expressly provides for indemnification
in such case, or (B) any indemnified or indemnifying party seeks contribution
under the Securities Act, the Exchange Act, or otherwise, then the Company
(including for this purpose any contribution made by, or on behalf of, any
director of the Company, any officer of the Company who signed any such
registration statement, any controlling person of the Company), as one entity,
and the Holders (including for this purpose any contribution by, or on behalf
of, an indemnified party), as a second entity, shall contribute to the losses,
liabilities, claims, damages, and expenses whatsoever to which any of them may
be subject, on the basis of relevant equitable considerations such as the
relative fault of the Company and the Holders in connection with the facts which
resulted in such losses, liabilities, claims, damages, and
expenses.  The relative fault, in the case of an untrue statement,
alleged untrue statement, omission, or alleged omission, shall be determined by,
among other things, whether such statement, alleged statement, omission, or
alleged omission relates to information supplied by the Company or by the
Holders, and the parties' relative intent, knowledge, access to information, and
opportunity to correct or prevent such statement, alleged statement, omission,
or alleged omission.  The Company and the Holders agree that it would
be unjust and inequitable if the respective obligations of the Company and the
Holders for contribution were determined by pro rata or per capita allocation of
the aggregate losses, liabilities, claims, damages, and expenses (even if the
Holders and the other indemnified parties were treated as one entity for such
purpose) or by any other method of allocation that does not reflect the
equitable considerations referred to in this paragraph (c)(iii).  In
no case shall the Holders be responsible for a portion of the contribution
obligation imposed on all holders of Registrable Securities in excess of its pro
rata share based on the number of shares of Common Stock owned (or which would
be owned upon exercise of or conversion of other securities) by it and included
in such registration as compared to the number of shares of Common Stock owned
(or which would be owned upon exercise or conversion of all such other
securities ) by all holders of Registrable Securities and included in such
registration.  No person guilty of a fraudulent misrepresentation
(within the meaning of Section 11(f) of the Securities Act) shall be entitled to
contribution from any person who is not guilty of such fraudulent
misrepresentation.  For purposes of this paragraph (c)(iii), each
person, if any, who controls the Holders within the meaning of Section 15 of the
Act or Section 20(a) of the Exchange Act and each officer, director, partner,
employee, agent, and counsel of the Holders or control person shall have the
same rights to contribution as the Holders or control person and each person, if
any, who controls the Company within the meaning of Section 15 of the Act or
Section 20(a) of the Exchange Act, each officer of the Company who shall have
signed any such registration statement, each director of the Company, and its or
their respective counsel shall have the same rights to contribution as the
Company, subject in each case to the provisions of this paragraph
(c)(iii).  Anything in this paragraph (c)(iii) to the contrary
notwithstanding, no party shall be liable for contribution with respect to the
settlement of any claim or action effected without its written
consent.  This paragraph (c)(iii) is not intended to supersede any
right to contribution under the Securities Act, the Exchange Act, or
otherwise.





(iv)           Survival.  The
obligations of the Company and the Holders under this paragraph (c) shall
survive completion of any offering of Registrable Securities in a Registration
Statement and the termination of this letter.





(d)          Further
Assurances.  The parties shall execute and deliver all such
further instruments and documents and take all such other actions as may
reasonably be required to carry out the transactions contemplated hereby and to
evidence the fulfillment of the intent of the agreements herein
contained.


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(e)           Transfer and
Assignment.  The registration rights set forth herein may be
transferred by the Holders together with the transfer thereby of Registrable
Securities.  This letter agreement shall be binding upon and inure to
the benefit of the parties and their successors and permitted assigns and shall
inure to the benefit of each Holder and its successors and permitted
assigns.  The Company may not assign this letter agreement or any of
its rights or obligations hereunder without the prior written consent of the
Holder.  Each Holder may assign its rights hereunder in the manner and
to the Persons as permitted under this letter agreement.




(f)           Remedies.  In
the event of a breach by the Company or by the Holders, of any of their
obligations under this letter agreement, the Holders or the Company, as the case
may be, in addition to being entitled to exercise all rights granted by law and
under this letter agreement, including recovery of damages, will be entitled to
specific performance of its rights under this letter agreement.  The
Company and the Holders agree that monetary damages would not provide adequate
compensation for any losses incurred by reason of a breach by it of any of the
provisions of this letter agreement and hereby further agrees that, in the event
of any action for specific performance in respect of such breach, it shall waive
the defense that a remedy at law would be adequate.




(g)           No Inconsistent
Agreements.  Except as set forth herein, the Company has not,
as of the date hereof entered into and currently in effect, nor shall the
Company, on or after the date of this letter agreement, enter into any agreement
with respect to its securities that is inconsistent with the rights granted to
the Holders in this letter agreement or otherwise conflicts with the provisions
hereof.




(h)           Amendments and
Waivers.  The provisions of this letter agreement, including
the provisions of this sentence, may not be amended, modified or supplemented,
and waivers or consents to departures from the provisions hereof may not be
given, unless the same shall be in writing and signed by the Company and each of
the Holders.  Notwithstanding the foregoing, a waiver or consent to
depart from the provisions hereof with respect to a matter that relates
exclusively to the rights of Holders and that does not directly or indirectly
affect the rights of other Holders may be given by Holders of at least a
majority of the Registrable Securities to which such waiver or consent relates;
provided, however, that the provisions of this sentence may not be amended,
modified, or supplemented except in accordance with the provisions of the
immediately preceding sentence.




(i)           Notices.  Any
and all notices or other communications or deliveries required or permitted to
be provided hereunder shall be in writing and shall be deemed given and
effective on the earlier of (i) the date of transmission, if such notice or
communication is delivered via facsimile at the facsimile telephone number
specified for notice prior to 5:00 p.m., EST, on a business day, (ii) the
business day after the date of transmission, if such notice or communication is
delivered via facsimile at the facsimile telephone number specified for notice
later than 5:00 p.m., EST, on any date and earlier than 11:59 p.m., EST, on such
date, (iii) the business day following the date of mailing, if sent by
nationally recognized overnight courier service or (iv) actual receipt by the
party to whom such notice is required to be given.  The addresses for
such communications shall be with respect to each Holder at its address set
forth under its name on the signature page hereto, or with respect to the
Company, at the address set forth in the letterhead above.


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(j)           Counterparts.  This
letter agreement may be executed in any number of counterparts, each of which
when so executed shall be deemed to be an original and, all of which taken
together shall constitute one and the same agreement.




(k)          Cumulative
Remedies.  The remedies provided herein are cumulative and not
exclusive of any remedies provided by law.




(l)           Severability. If any
term, provision, covenant or restriction of this letter agreement is held to be
invalid, illegal, void or unenforceable in any respect, the remainder of the
terms, provisions, covenants and restrictions set forth herein shall remain in
full force and effect and shall in no way be affected, impaired or invalidated,
and the parties hereto shall use their reasonable efforts to find and employ an
alternative means to achieve the same or substantially the same result as that
contemplated by such term, provision, covenant or restriction.  It is
hereby stipulated and declared to be the intention of the parties that they
would have executed the remaining terms, provisions, covenants and restrictions
without including any of such that may be hereafter declared invalid, illegal,
void or unenforceable.





(m)         Governing law;
Jurisdiction.  The aforementioned matters shall be governed by,
and construed in accordance with, the laws of the State of New York, without
giving effect to principles of conflicts of laws.  Each of the parties
hereto irrevocably submits to the exclusive jurisdiction of the courts of the
State of New York and the United States District Court for the Southern District
of New York, in each case sitting in the Borough of Manhattan, City of New York,
for the purpose of any suit, action, proceeding or judgment relating to or
arising out of this letter agreement.  Service of process in
connection with any such suit, action or proceeding may be served on each party
hereto anywhere in the world by the same methods as are specified for the giving
of notices under this letter agreement.  Each of the parties hereto
irrevocably consents to the jurisdiction of any such court in any such suit,
action or proceeding and to the laying of venue in such court.  Each
party hereto irrevocably waives any objection to the laying of venue of any such
suit, action or proceeding brought in such courts and irrevocably waives any
claim that any such suit, action or proceeding brought in any such court has
been brought in an inconvenient forum.




(n)          Notwithstanding
anything contained herein, (i) the Company may include in any Registration
Statement hereunder such number of registrable securities that it is required to
register under that certain Investors’ Rights Agreement dated November 27, 2007
by and among OncoVista, Inc. and OSI Pharmaceuticals, Inc, and (ii) the Holder’s
registration rights set forth in this letter agreement are subordinate to the
registration rights granted to (x) the holders pursuant to that Registration
Rights Letter (the “Registration Rights Letter”)
by and among OncoVista, Inc. and purchasers of units in the OncoVista, Inc.
private placement that closed on August 15, 2007, and (y) the Maxim Group LLC
(“Maxim”) pursuant to
that certain Letter Agreement (the “Maxim Letter”) dated July 11,
2007 by and among OncoVista, Inc. and Maxim, with respect to their registrable
securities. In the event any of the terms of this letter agreement are deemed to
conflict with the terms of the Registration Rights Letter or the Maxim Letter,
the terms of the Registration Rights Letter and the Maxim Letter shall
govern.


11




(o)          Specific
Performance.  The parties acknowledge that the Holders’ damages
at law would be an inadequate remedy for the breach or non-performance of any
provision of this letter by the Company, and agree in the event of such breach
that the aggrieved party obtain temporary and permanent injunctive relief
restraining the Company from such breach or compelling specific performance of
such provision, and, to the extent permissible under applicable statutes and
rules of procedure, a temporary injunction may be granted immediately upon the
commencement of any such suit without proof of any actual
harm.  Nothing contained in this letter shall be construed as
prohibiting any party from pursing other remedies available at law or equity for
such breach or non-performance.





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SIGNATURES
FOLLOW]


12





Please
execute this letter agreement where indicated below to express your agreement
with the terms hereof.





ONCOVISTA
      INNOVATIVE THERAPIES, INC.By:Alex
      L. Weis, Ph.D.Chief
      Executive Officer





ACCEPTED
AND AGREED TO AS OF


THE
DATE FIRST ABOVE-WRITTEN:





WEXFORD
SPECTRUM TRADING LIMITED





By:Name:
      Arthur AmronTitles:
      Vice President and Assistant
Secretary





John
      Wenner





GLOBAL
PHARMACAL, INC.





By:Name:Titles:





BIOMARKERS,
LLC





By:Name:Titles:


Signature
Page – Registration Rights Agreement