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                                                                     EXHIBIT 4.3

                          REGISTRATION RIGHTS AGREEMENT

         This Agreement for Provision of Registration Rights (the "Agreement")
is executed as of this 8th day of August, 1994 by BioNumerik Pharmaceuticals,
Inc., a Delaware corporation (the "Company").

                                   WITNESSETH:

         WHEREAS, the persons identified on Schedule A hereto (the "Purchasers")
have agreed to purchase shares of the Company's Preferred Stock (as defined
herein) with the understanding that the Company would grant certain registration
rights to the Purchasers.

         NOW, THEREFORE, the Company grants the registration rights contained
herein to the Purchasers, subject to the terms and conditions contained herein:

         1.       CERTAIN DEFINITIONS. As used in this Agreement, the following
terms shall have the following respective meanings:

         "Commission" means the Securities and Exchange Commission or any other
federal agency at the time administering the Securities Act.

         "Common Stock" means the Common Stock, par value $.01 per share, of the
Company.

         "Conversion Shares" means the shares of Common Stock issued and
issuable upon conversion of the Preferred Stock.

         "Exchange Act" means the Securities Exchange Act of 1934, as amended,
or any similar federal statute and the rules and regulations of the Commission
thereunder, all as the same shall be in effect at the time.

         "Holders" means the Purchasers and any holder of Registrable Securities
to whom the registration rights conferred by this Agreement have been
transferred in compliance with Section 2.10 hereof.

         "Initiating Holders" means any Holder or Holders who in the aggregate
hold more than fifty percent (50%) of the then-outstanding Registrable
Securities, but no less than the number of Registrable Securities issued or
issuable upon conversion of twenty percent (20%) of the total number of shares
of Preferred Stock issued by the Company to all Purchasers.

         "Preferred Stock" means the Series B Convertible Preferred Stock, par
value $.01 per share, of the Company.

         "Registrable Securities" means (i) the Conversion Shares and (ii) any
Common Stock issued as a dividend or other distribution with respect to or in
exchange for or in replacement of the Conversion Shares or Preferred Stock,
provided, however, that Registrable Securities shall not include any shares of
Common Stock which have previously been registered or which have been sold
pursuant to Rule 144.

         The terms "register," "registered" and "registration" refer to a
registration effected by preparing and filing a registration statement in
compliance with the Securities Act, and the declaration or ordering of the
effectiveness of such registration statement.

         "Rule 144" means Rule 144 as promulgated by the Commission under the
Securities Act, as such Rule may be amended from time to time, or any similar
successor rule that may be promulgated by the Commission.

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         "Series A Persons" means those persons entitled to registration rights
pursuant to Section 10 of the Preferred Stock Purchase Agreement dated February
19, 1993 between the Company and certain purchasers of its securities, as
amended.

         "Securities Act" means the Securities Act of 1933, as amended, or any
similar federal statute and the rules and regulations of the Commission
thereunder, all as the same shall be in effect at the time.

         "Warrants" means the warrants to purchase Preferred Stock issued by the
Company to certain Purchasers.

         For purposes of the definitions of "Holder" and "Initiating Holders"
above, holders of Preferred Stock and Warrants shall be deemed to be the holders
of Registrable Securities issuable upon conversion or exercise thereof; and for
the purpose of calculating any percentage of Registrable Securities, the
calculation shall be made as if the Preferred Stock and the Warrants (and the
Preferred Stock issued upon exercise thereof) had been fully converted or
exercised.

         2.       Registration of Registrable Securities.

         2.1      Registration on Request.

         (a)      Request. Subject to the limitations provided herein,
commencing on January 31, 1998, or on the first anniversary of the effective
date of the Company's first registration statement under the Securities Act,
whichever shall first occur, until the fifth anniversary of the effective date
of the Company's first registration statement under the Securities Act, upon the
written request (specifying that it is being made pursuant to this Section 2.1)
of the Initiating Holders, requesting that the Company effect the registration
under the Securities Act of at least fifty percent (50%) of the then-outstanding
Registrable Securities, but no less than the number of Registrable Securities
issued or issuable upon conversion of twenty percent 20%) of the total number of
shares of Preferred Stock issued by the Company to all Purchasers, and
specifying (x) the intended method of disposition thereof, (y) whether or not
such requested registration is to be an underwritten offering, and (z) the price
range (net of underwriting discounts and commissions) acceptable to such Holder
or Holders to be received for such Registrable Securities, the Company will
within 10 business days after the Company receives such written request give
written notice of such requested registration to all other Holders of
Registrable Securities and thereupon the Company will use reasonable efforts to
effect the registration under the Securities Act of:

         (i)      the Registrable Securities which the Company has been so
requested to register by such Initiating Holders, and

         (ii)     all other Registrable Securities which the Company has been
requested to register by the other Holders thereof by written request given to
the Company within 15 days after the giving of such written notice by the
Company (which request shall specify the same information called for by the
original request to effect registration described above), all to the extent
requisite to permit the disposition (in accordance with Section 2.1(b) hereof)
of the Registrable Securities so to be registered.

         (b)      Method of Distribution. The Holders of 51% of the Registrable
Securities to be included in such registration statement shall determine the
method of distribution of the Registrable Securities so included; provided,
however, that if no agreement of Holders of 51% or more of the Registrable
Securities to be included in such registration statement is obtained, then if

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Holders of more than 30% of the Registrable Securities to be included in such
registration statement request an underwritten public offering, an underwritten
public offering shall be the method of distribution with other methods permitted
to the extent the managing underwriter for such offering, in its sole
discretion, agrees to other methods of distribution being covered by such
registration statement.

         (c)      Registration of Other Securities. Whenever the Company shall
effect a registration pursuant to this Section 2.1 in connection with an
underwritten offering, no securities other than Registrable Securities shall be
included among the securities covered by such registration unless (a) the
managing underwriter of such offering shall have advised each Holder of
Registrable Securities to be covered by such registration in writing that the
inclusion of such other securities would not adversely affect such offering or
(b) the Holders of more than 51% or more of all Registrable Securities to be
covered by such registration shall have consented in writing to the inclusion of
such other securities; provided, however, that the rights of Holders hereunder
shall be subject to the prior right of Series A Persons requesting registration
(whether pursuant to "demand" or "piggyback" registration rights) to include all
of the securities requested to be registered by such Series A Persons in such
registration.

         (d)      Registration Statement Form. Registrations under this Section
2.1 shall be on such appropriate registration form of the Commission (i) as
shall be selected by the Company, and (ii) as shall permit the disposition of
such Registrable Securities in accordance with the method or methods of
disposition selected pursuant to Section 2.1(b) hereof.

         (e)      Expenses. Except as otherwise provided in this Section 2.1(e)
or in Section 2.1(i), the Company shall bear all expenses incurred in connection
with two effective registrations pursuant to Section 2 hereof and each
registration pursuant to Section 2.2 hereof (excluding in each case underwriting
discounts and commissions applicable to Registrable Securities), including,
without limitation, in each case: (i) all registration, filing and National
Association of Securities Dealers fees; (ii) all fees and expenses of complying
with securities or blue sky laws; (iii) all word processing, duplicating and
printing expenses, messenger, delivery and shipping expenses; (iv) the fees and
disbursements of the accountants and counsel for the Company including the
expenses of any special audits or "cold comfort" letters or opinions required by
or incident to such registrations; (v) the fees and disbursements of the
accountants and counsel for the Company for services rendered in connection with
inclusion of Registrable Securities in the registration; provided, however, that
if the accountants or the counsel for the Company refuse or decline to undertake
such representation because of an actual or perceived conflict of interest or
otherwise, then the Company shall bear the reasonable fees and disbursements of
one firm of counsel and one firm of accountants (as appropriate) retained by the
Holders of such Registrable Securities; (vi) premiums and other costs of
policies of insurance maintained for the benefit of the Company against
liabilities arising out of the public offering of the Registrable Securities;
(vii) any fees and disbursements of underwriters customarily paid by issuers or
sellers of securities, but excluding underwriting discounts and commissions, if
any. In all cases, each Holder of Registrable Securities shall pay the
underwriting discounts and commissions applicable to the securities sold by such
Holder.

         (f)      Effective Registration Statement. A registration requested
pursuant to this Section 2.1 shall not be deemed to have been effected (i)
unless a registration statement with respect thereto has become effective
(unless a substantial cause of the failure of such registration statement to
become effective shall be attributable to one or more Holders of Registrable
Securities whose securities were to have been included in such registration
statement), (ii) if after it has become

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effective, such registration is interfered with by any stop order, injunction or
other order or requirement of the Commission or other governmental agency or
court for any reason, resulting in a failure to consummate the offering of
Registrable Securities offered thereby, (iii) if after a registration statement
with respect thereto has become effective, the offering of Registrable
Securities offered thereby is not consummated due to factors beyond the control
of the Holders of such Registrable Securities, including without limitation in
the context of a proposed firm commitment underwriting, the fact that the
underwriters have advised the Holders of such Registrable Securities that such
Registrable Securities cannot be sold at a net price equal to or above the net
price specified in the notice to the Company at the time of the request, or (iv)
if the conditions to closing specified in the purchase agreement or underwriting
agreement entered into in connection with such registration are not satisfied
(unless a substantial cause of such conditions to closing not being satisfied
shall be attributable to one or more Holders of Registrable Securities whose
Registrable Securities were included in such registration statement).

         (g)      Selection of Underwriters. If a requested registration
pursuant to this Section 2.1 involves an underwritten offering, the underwriter
or underwriters thereof shall be selected by the Company with the approval of
the Holders of at least 50% of the Registrable Securities to be so registered,
which approval will not be unreasonably withheld.

         (h)      Priority in Requested Registrations. If a requested
registration pursuant to this Section 2.1 involves an underwritten offering, and
the managing underwriter shall advise the Company in writing (with a copy to
each Holder requesting registration) that, in its opinion, the number of
securities requested to be included in such registration exceeds the number
which can be sold in such offering within a price range acceptable to the
Holders of more than 50% of the Registrable Securities requested to be included
in such registration, then the Registrable Securities requested to be registered
pursuant to this Section 2.1 shall be reduced to the number of Registrable
Securities which the Company is so advised can be sold in (or during the time
of) such offering by decreasing the Registrable Securities requested to be
registered (pro rata among the Holders requesting such registration on the basis
of the percentage of the Registrable Securities held by such Holder immediately
prior to the filing of the registration statement with respect to such
registration). Nothing in this Section 2.1(h) shall affect the rights of Series
A Persons requesting registration to include all of the securities requested to
be registered by such Series A Persons in such registration without reduction
prior to the inclusion of any Registrable Securities requested to be registered
hereunder.

         (i)      Form S-3. Notwithstanding the other provisions of this Section
2.1, until the fifth anniversary of the effective date of the Company's first
registration statement under the Securities Act, the Company shall be required
by this Section 2.1 to effect, and bear all expenses (as determined pursuant to
Section 2.1(e) hereof) incurred in connection with, up to four registrations on
Form S-3 (or any successor similar form) during such period, provided that the
Registrable Securities to be registered thereon are expected to have an
aggregate disposition price (before deductions for underwriting discounts and
commissions) of at least $500,000.

         (j)      Notwithstanding anything to the contrary contained herein, the
Company shall not be obligated to prepare and file any other Registration
Statement pursuant to this Section 2.1 within 180 days of the consummation of an
underwritten public offering of Common Stock pursuant to a registration
statement filed under the Securities Act.

         2.2      Incidental Registration.

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         (a)      Right to Include Registrable Securities. If the Company at any
time prior to the fifth anniversary of the effective date of the Company's first
registration statement under the Securities Act proposes to register any of its
securities under the Securities Act (other than by a registration on Form S-8,
S-4 or any successor similar forms or any other form not available for
registering the Registrable Securities for sale to the public and other than
pursuant to Section 2.1 hereof), whether or not for sale for its own account, it
will each such time, at least 15 days prior to filing the registration
statement, give written notice to all Holders of Registrable Securities of its
intention to do so. Upon the written request of Holders of an aggregate of at
least 100,000 shares (appropriately adjusted for subdivisions and combinations
of shares of Common Stock and dividends on Common Stock payable in shares of
Common Stock hereafter) of Registrable Securities, made within 15 days after the
receipt of any such notice (which request shall specify the Registrable
Securities intended to be disposed of by each such Holder and the intended
method of disposition thereof), the Company will use reasonable efforts to
effect the registration under the Securities Act of all Registrable Securities
which the Company has been so requested to register by the Holders of such
Registrable Securities, to the extent requisite to permit the disposition
(determined pursuant to the provisions of Section 2.1(b) hereof) of the
Registrable Securities so to be registered, provided that if, at any time after
giving written notice of its intention to register any securities and prior to
the effective date of the registration statement filed in connection with such
registration, the Company shall determine for any reason not to register or to
delay registration of such securities, the Company may, at its election, give
written notice of such determination to each Holder of Registrable Securities
and, thereupon, (i) in the case of a determination not to register, shall be
relieved of its obligation to register any Registrable Securities in connection
with such registration (but not from its obligation to pay expenses in
accordance with Section 2.1(e) hereof), without prejudice, however, to the
rights of any Holder or Holders of Registrable Securities entitled to do so to
request that such registration be effected as a registration under Section 2.1
hereof, and (ii) in the case of a determination to delay registering, shall be
permitted to delay registering any Registrable Securities being registered
pursuant to this Section 2.2(a), for the same period as the delay in registering
such other securities. No registration effected under this Section 2.2 shall
relieve the Company of its obligation to effect any registration upon request
under Section 2.1 hereof.

         (b)      Priority in Incidental Registrations. If (i) a registration
pursuant to this Section 2.2 involves an underwritten offering of the securities
so being registered, whether or not for sale for the account of the Company, to
be distributed (on a firm, commitment basis) by or through one or more
underwriters of recognized standing, whether or not the Registrable Securities
so requested to be registered for sale for the account of Holders of Registrable
Securities are also to be included in such underwritten offering, and (ii) the
managing underwriter of such underwritten offering shall inform the Company and
the Holders of the Registrable Securities requesting such registration by letter
of its belief that the number of securities requested to be included in such
registration exceeds the number which can be sold in (or during the time of)
such offering, then the Company may include in such offering all securities
proposed by the Company to be sold for its own account and may decrease the
number of Registrable Securities and other securities of the Company that
persons have requested to be included in such registration by (a) first
decreasing the securities requested to be included in such registration other
than Registrable Securities (pro rata among the persons requesting such
registration on the basis of the number of shares of such securities held by
such person immediately prior to the filing of the registration statement with
respect to such registration) and (b) then, to the extent necessary, decreasing
the Registrable Securities requested to be registered (pro rata among the
Holder's requesting such registration on the basis of the percentage of the
Registrable Securities held by such Holder's immediately prior to the filing of
the registration statement with respect to such registration); provided,
however, that the rights of Holders hereunder shall be subject to the right of
the Series A Persons requesting inclusion of

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securities in such registration to include all of the securities requested to be
registered by such Series A Persons in such registration without reduction prior
to the inclusion of any Registrable Securities requested to be included in such
registration pursuant to this Section 2.2.

         2.3      Registration Procedures. If and whenever the Company is
required to use reasonable efforts to effect the registration of any Registrable
Securities under the Securities Act as provided in Sections 2.1 and 2.2 hereof,
the Company will, subject to the limitations provided herein, as expeditiously
as possible:

         (a)      prepare and (as soon thereafter as possible or in any event no
later than 60 days after the end of the period within which requests for
registration may be given to the Company or such longer period as the Company
shall in good faith require to produce the financial statements required in
connection with such registration) file with the Commission the requisite
registration statement to effect such registration and thereafter use reasonable
efforts to cause such registration statement to become effective, provided that
the Company may discontinue any registration of its securities which are not
Registrable Securities (and, under the circumstances specified in Section 2.2(a)
hereof, its securities which are Registrable Securities) at any time prior to
the effective date of the registration statement relating thereto;

         (b)      prepare and file with the Commission such amendments and
supplements to such registration statement and the prospectus used in connection
therewith as may be necessary to keep such registration statement effective and
to comply with the provisions of the Securities Act with respect to the
disposition of all securities covered by such registration statement until such
time as all of such securities have been disposed of in accordance with the
intended methods of disposition by the seller or sellers thereof set forth in
such registration statement; provided, however, that the Company shall not in
any event be required to keep the registration statement effective for a period
of more than three months after such registration statement becomes effective;

         (c)      furnish to each seller of Registrable Securities covered by
such registration statement such number of conformed copies of such registration
statement and of each such amendment and supplement thereto (in each case
including all exhibits), such number of copies of the prospectus contained in
such registration statement (including each preliminary prospectus and any
summary prospectus) and any other prospectus filed under Rule 424 under the
Securities Act, and such other documents, as such seller may reasonably request;

         (d)      use reasonable efforts to register or qualify all Registrable
Securities and other securities covered by such registration statement under
such other securities or blue sky laws of such jurisdictions as each seller
thereof shall reasonably request, to keep such registration or qualification in
effect for so long as such registration statement remains in effect (provided,
however, that the Company shall not in any event be required to keep such
registration or qualification in effect for a period of more than three months
after such registration or qualification becomes effective), and take any other
action which may be reasonably necessary or advisable to enable such seller to
consummate the disposition in such jurisdictions of the securities owned by such
seller, except that the Company shall not for any such purpose be required to
qualify generally to do business as a foreign corporation in any jurisdiction
wherein it would not but for the requirements of this subdivision (d) be
obligated to be so qualified or to consent to general service of process in any
such jurisdiction;

         (e)      use reasonable efforts to cause all Registrable Securities
covered by such registration statement to be registered with or approved by such
other United States federal or state

<PAGE>

governmental agencies or authorities as may be necessary to enable the seller or
sellers thereof to consummate the disposition of such Registrable Securities;

         (f)      furnish to each seller of Registrable Securities a copy, or,
upon request, a signed counterpart, addressed to such seller (and the
underwriters, if any) of

                  (i)      an opinion of counsel for the Company, dated the
         effective date of such registration statement (or, if such registration
         includes an underwritten public offering, dated the date of the closing
         under the underwriting agreement), and

                  (ii)     a "comfort" letter addressed to the underwriters,
dated the effective date of such registration statement (or, if such
registration includes an underwritten public offering, dated the date of the
closing under the underwriting agreement), signed by the independent public
accountants who have audited the Company's financial statements included in such
registration statement, covering substantially the same matters with respect to
such registration statement (and the prospectus included therein) and, in the
case of the accountants' letter, with respect to events. subsequent to the date
of such financial statements, as are customarily covered in opinions of issuer's
counsel and in accountants' letters delivered to the underwriters in
underwritten public offerings of securities and, in the case of the accountants'
letter, such other financial matters, and, in the case of the legal opinion such
other legal matters, as such seller or such Holder (or the underwriters, if any)
may reasonably request;

         (g)      notify each seller of Registrable Securities covered by such
registration statement, at any time when a prospectus relating thereto is
required to be delivered under the Securities Act, upon discovery that, or upon
the happening of any event as a result of which, the prospectus included in such
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 the light of the
circumstances under which they were made, and at the request of any such seller,
prepare and furnish to such seller a reasonable number of copies of a supplement
to or an amendment of such prospectus as may be necessary so that, as thereafter
delivered to the purchasers of such 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 the light of the circumstances under which they were made;

         (h)      otherwise use reasonable efforts to comply with all applicable
rules and regulations of the Commission, and make available to its
securityholders, as soon as reasonably practicable, an earnings statement
covering the period of at least twelve months beginning with the first full
calendar month after the effective date of such registration statement, which
earnings statement shall satisfy the provisions of Section 11(a) of the
Securities Act, and will furnish to each such seller, upon request of such
seller, prior to the filing thereof a copy of any amendment or supplement to
such registration statement or prospectus and shall not file any such supplement
or amendment if such seller shall have delivered to the Company an opinion of
counsel that such amendment or supplement does not comply in all material
respects with the requirements of the Securities Act or of the rules or
regulations thereunder;

         (i)      provide and cause to be maintained a transfer agent for all
Registrable Securities covered by such registration statement from and after a
date not later than the effective date of such registration statement;

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         (j)      use reasonable efforts to list all Registrable Securities
covered by such registration statement on any securities exchange on which the
Common Stock is then listed; and

         (k)      refrain from making any sale or distribution of its equity
securities, except pursuant to any employee stock option plan or other employee
benefit plan and any preexisting agreement for the sale of such securities, for
at least 90 days after the closing of the public offering pursuant to such
registration.

         It shall be a condition precedent to the obligations of the Company to
take any action with respect to registering a Holder's Registrable Securities
pursuant to this Section 2.3 that such seller of Registrable Securities as to
which any registration is being effected furnish the Company in writing such
information regarding such seller, the Registrable Securities and other
securities of the Company held by such seller, and the distribution of such
securities as the Company may from time to time reasonably request in writing.
If a Holder refuses to provide the Company with any of such information on the
grounds that it is not necessary to include such information in the registration
statement, the Company may exclude such Holder's Registrable Securities from the
registration statement if the Company provides such Holder with an opinion of
counsel to the effect that such information must be included in the registration
statement and such Holder thereafter continues to withhold such information. The
deletion of such Holder's Registrable Securities from a registration statement
shall not affect the registration of the other Registrable Securities to be
included in such registration statement.

         Each Holder of Registrable Securities agrees by acquisition of such
Registrable Securities that upon receipt of any notice from the Company of the
happening of any event of the kind described in Section 2.3(g), such Holder will
forthwith discontinue such Holder's disposition of Registrable Securities
pursuant to the registration statement relating to such Registrable Securities
until such Holder's receipt of the copies of the supplemented or amended
prospectus contemplated by Section 2.3(g) and, if so directed by the Company,
will deliver to the Company (at the Company's expense) all copies, other than
permanent file copies then in such Holder's possession, of the prospectus
relating to such Registrable Securities current at the time of receipt of such
notice.

         2.4      Underwritten Offerings.

         (a)      Requested Underwritten Offerings. If requested by the
underwriters for any underwritten offering of Registrable Securities pursuant to
a registration requested under Section 2.1 hereof, the Company will enter into
an underwriting agreement with such underwriters for such offering, the portions
of such agreement that relate to Holders of Registrable Securities being
registered to be reasonably satisfactory in substance and form to each Holder of
Registrable Securities being registered and to contain such representations and
warranties by the Company and such other terms as are generally prevailing in
agreements of this type, including, without limitation, indemnities
substantially to the effect and to the extent provided in Section 2.6 hereof.
Each such Holder of Registrable Securities will cooperate with the Company in
the negotiation of the underwriting agreement and will give consideration to the
reasonable requests of the Company regarding the form thereof, provided that
nothing herein contained shall diminish the foregoing obligations of the
Company. If requested by the underwriters of any underwritten offering pursuant
to a registration under Section 2.1 hereof, each Holder of Registrable
Securities agrees to enter into an agreement with such underwriters not to sell
his or its shares of stock in the Company for a period of time (not to exceed
180 days) after the effectiveness of a registration statement equal to the
period of time which the sellers of securities in such registration have agreed
not to sell their shares after the effectiveness of such registration statement.
The Holders of Registrable Securities

<PAGE>

to be distributed by such underwriters shall be parties to such underwriting
agreement. Any such Holder shall not be required to make any representations or
warranties to or agreements with the Company or the underwriters other than
representations, warranties or agreements regarding such Holder, such Holder's
Registrable Securities and other securities of the Company, such Holder's
intended method of distribution, and any representations, warranties or
agreements required by law.

         (b)      Incidental Underwritten Offerings. If the Company at any time
proposes to register any of its securities under the Securities Act as
contemplated by Section 2.2 hereof and such securities are to be distributed by
or through one or more underwriters, the Company will, if requested by any
Holder of Registrable Securities as provided in Section 2.2 hereof and subject
to the provisions of Section 2.2(b) hereof, arrange for such underwriters to
include all the Registrable Securities to be offered and sold by such Holder
owning the securities to be distributed by such underwriters. In such event, the
Holders of Registrable Securities to be distributed by such underwriters shall
be parties to the underwriting agreement between the Company and such
underwriters. Any such Holder shall not be required to make any representations
or warranties to or agreements with the Company or the underwriters other than
representations, warranties or agreements regarding such Holder, such Holder's
Registrable Securities or other securities of the Company, such Holder's
intended method of distribution and any representations, warranties or
agreements required by law.

         2.5      Preparation: Reasonable Investigation. In connection with the
preparation and filing of each registration statement under the Securities Act
pursuant to this Agreement, the Company will give the Holders of Registrable
Securities registered under such registration statement, their underwriters, if
any, and one counselor firm of counsel and one accountant or firm. of
accountants representing all the Holders of Registrable Securities to be
registered under such registration statement, the opportunity to participate in
the preparation of such registration statement, each prospectus included therein
or filed with the Commission, and each amendment thereof or supplement thereto,
and will give each of them such access to its books and records and such
opportunities to discuss the business of the Company with its officers and the
independent public accountants who have certified its financial statements as
shall be necessary, in the opinion of such Holders' and such underwriters'
respective counsel, to conduct a reasonable investigation within the meaning of
the Securities Act.

         2.6      Indemnification.

         (a)      Indemnification by the Company. In the event any Registrable
Securities are included in a registration statement under this Section 2, to the
extent permitted by law, the Company will, and hereby does, indemnify and hold
harmless the seller of any Registrable Securities covered by such registration
statement, its directors and officers, each other person who participates as an
underwriter in the offering or sale of such securities and each other person, if
any, who controls such seller or any such underwriter within the meaning of the
Securities Act, against any losses, claims, damages or liabilities, joint or
several, to which such seller or any such director or officer or underwriter or
controlling person may become subject under the Securities Act or otherwise,
insofar as such losses, claims, damages or liabilities (or actions or
proceedings, whether commenced or threatened, in respect thereof) arise out of
or are based upon any untrue statement or alleged untrue statement of any
material fact contained in any registration statement under which such
securities were registered under the Securities Act, any preliminary prospectus,
final prospectus or summary prospectus contained therein, or any amendment or
supplement thereto, or any omission or alleged omission to state therein a
material fact required to be stated

<PAGE>

therein or necessary to make the statements therein not misleading, and the
Company will reimburse such seller and each such director, officer, underwriter
and controlling person for any legal or any other expenses reasonably incurred
by them in connection with investigating or defending any such loss, claim,
liability, action or proceeding; provided that the Company shall not be liable
in any such case to the extent that any such loss, claim, damage, liability (or
action or proceeding in respect thereof) or expense arises out of or is based
upon an untrue statement or alleged untrue statement or omission or alleged
omission made in such registration statement, any such preliminary prospectus,
final prospectus, summary prospectus, amendment or supplement in reliance upon
and in conformity with written information furnished to the Company by such
seller expressly for use in the preparation thereof, and provided further that
the Company shall not be liable to any person who participates as an underwriter
in the offering or sale of Registrable Securities or any other Person, if any,
who controls such underwriter within the meaning of the Securities Act, in any
such case to the extent that any such loss, claim, damage, liability (or action
or proceeding in respect thereof) or expense arises out of such person's failure
to send or give a copy of the final prospectus, as the same may be then
supplemented or amended, to the person asserting an untrue statement or alleged
untrue statement or omission or alleged omission at or prior to the written
confirmation of the sale of the Registrable Securities to such person if such
statement or omission was corrected in such final prospectus. Such indemnity
shall remain in full force and effect regardless of any investigation made by or
on behalf of such seller or any such director, officer, underwriter or
controlling person and shall survive the transfer of such securities by such
seller.

         (b)      Indemnification by the Sellers. The Company may require, as a
condition to including any Registrable Securities in any registration statement
filed pursuant to Section 2.3 hereof, that the Company shall have received an
undertaking satisfactory to it from the prospective seller of such securities,
to indemnify and hold harmless (in the same manner and to the same extent as set
forth in subdivision (a) of this Section 2.6) each underwriter, each person who
controls such underwriter within the meaning of the Securities Act, the Company,
each director of the Company, each officer of the Company and each other person,
if any, who controls the Company within the meaning of the Securities Act, with
respect to any statement or alleged statement in or omission or alleged omission
from such registration statement, any preliminary prospectus, final prospectus
or summary prospectus contained therein, or any amendment or supplement thereto,
if such statement or alleged statement or omission or alleged omission was made
in reliance upon and in strict conformity with written information furnished to
the Company by such seller expressly for use in the preparation of such
registration statement, preliminary prospectus, final prospectus, summary
prospectus, amendment or supplement; provided that such prospective seller shall
not be liable to any person who participates as an underwriter in the offering
or sale of Registrable Securities or any other person, if any, who controls such
underwriter within the meaning of the Securities Act, in any such case to the
extent that any such loss, claim, damage, liability (or action or proceeding in
respect thereof) or expense arises out of such person's failure to send or give
a copy of the final prospectus, as the same may be then supplemented or amended,
to the person asserting an untrue statement or alleged untrue statement or
omission or alleged omission at or prior to the written confirmation of the sale
of Registrable Securities to such person if such statement or omission was
corrected in such final prospectus. Such indemnity shall remain in full force
and effect, regardless of any investigation made by or on behalf of any
underwriter, the Company or any such director, officer or controlling person and
shall survive the transfer of such securities by such seller. In no event shall
the liability of any selling holder of Registrable Securities under this Section
2.6(b) be greater in amount than the dollar amount of the proceeds received by
such holder upon the sale of the Registrable Securities giving rise to such
indemnification obligation.

<PAGE>

         (c)      Notices of Claims, etc. Promptly after receipt by an
indemnified party of notice of the commencement of any action or proceeding
involving a claim referred to in the preceding subdivisions of this Section 2.6,
as a condition to the obligations of the indemnifying party with respect
thereto, such indemnified party will, if a claim in respect thereof is to be
made against an indemnifying party, give written notice to the latter of the
commencement of such action; provided that the failure of any indemnified party
to give notice as provided herein shall not relieve the indemnifying party of
its obligations under the preceding subdivisions of this Section 2.6, except to
the extent that the indemnifying party is actually prejudiced by such failure to
give notice. In case any such action is brought against an indemnified party,
the indemnifying party shall be entitled to participate in and to assume the
defense thereof, jointly with any other indemnifying party similarly notified to
the extent that it may wish, with counsel reasonably satisfactory to such
indemnified party, and after notice from the indemnifying party to such
indemnified party of its election so to assume the defense thereof, the
indemnifying party shall not be liable to such indemnified party for any legal
or other expenses subsequently incurred by the latter in connection with the
defense thereof other than reasonable costs of investigation. No indemnifying
party shall, without the consent of the indemnified party, consent to entry of
any judgment or enter into any settlement which does not include as an
unconditional term thereof the giving by the claimant or plaintiff to such
indemnified party of a release from all liability in respect to such claim or
litigation.

         (d)      Other Indemnification. Indemnification similar to that
specified in the preceding subdivisions of this Section 2.6 (with appropriate
modifications) shall be given by the Company and each seller or Registrable
Securities with respect to any required registration or other qualification of
securities under any federal or state law or regulation of any governmental
authority other than the Securities Act.

         (e)      Indemnification Payments. The indemnification required by this
Section 2.6 shall be made by periodic payments of the amount thereof during the
course of the investigation or defense, as and when bills are received or
expense, loss, damage or liability is incurred.

         (f)      Contribution. If the indemnification provided for in this
Section 2.6 from the indemnifying party is unavailable to an indemnified party
hereunder in respect of any losses, claims, damages, liabilities or expenses
referred to therein, then the indemnifying party, in lieu of indemnifying such
indemnified party, shall contribute to the amount paid or payable by such
indemnified party as a result of such loss, claims, damages, liabilities or
expenses in such proportion as is appropriate to reflect the relative fault of
the indemnifying party and indemnified parties in connection with the actions
which resulted in such losses, claims, damages, liabilities or expenses, as well
as any other relevant equitable considerations. The relative fault of such
indemnifying party and indemnified parties shall be determined by reference to,
among other things, whether any action in question, including any untrue
statement of material fact or omission or alleged omission to state a material
fact, has been made by, or relates to information supplied by, such indemnifying
party or indemnified parties, and the parties' relative intent, knowledge,
access to information and opportunity to correct or prevent such action. The
amount paid or payable by a party as a result of the losses, claims, damages,
liabilities and expenses referred to above shall be deemed to include, subject
to the limitations set forth in Section 2.6(c) hereof, any legal or other fees
or expenses reasonably incurred by such party in connection with any
investigation or proceeding.

<PAGE>

         The Company and, as a condition to the registration of any of their
Registrable Securities, the Holders agree that it would not be just and
equitable if contribution pursuant to this Section 2.6(f) were determined by pro
rata allocation or by any other method of allocation which does not take account
of the equitable considerations referred to in the immediately preceding
paragraph. Notwithstanding the provisions of this Section 2.6(f), no underwriter
shall be required to contribute any amount in excess of the amount by which the
aggregate total price at which the Registrable Securities underwritten by it and
distributed to the public were offered to the public exceeds the amount of any
damages which such underwriter has otherwise been required to pay by reason of
such untrue or alleged untrue statement or omission or alleged omission, and no
selling Holder shall be required to contribute any amount in excess of the
amount by which the aggregate total price at which the Registrable Securities of
such selling Holder were offered to the public exceeds the amount of any damages
which -such selling Holder has otherwise been required to pay by -reason of such
untrue or alleged untrue statement or omission. No person guilty of fraudulent
misrepresentation (within the meaning of Section 11(f) of the Securities Act)
shall be entitled to contribution from any person who was not guilty of such
fraudulent misrepresentation.

         2.7      Reporting- Requirements Under Exchange Act. When it is first
legally required to do so, the Company shall register its Common Stock under
Section 12 of the Exchange Act (as hereinafter defined) and shall keep effective
such registration and shall timely file such information, documents and reports
as the Commission may require or prescribe under Section 13 of the Exchange Act.
From and after the effective date of the first registration statement flied by
the Company under the Securities Act, the Company shall (whether or not it shall
then be required to do so) timely file such information, documents and reports
which a corporation, partnership or other entity subject to Section 13 or 15(d)
(whichever is applicable) of the Exchange Act is required to file.

         Immediately upon becoming subject to the reporting requirements of
either Section 13 or 15(d) of the Exchange Act, the Company shall forthwith upon
request furnish any Holder of Registrable Securities (i) a written statement by
the Company that it has complied with such reporting requirements, (ii) a copy
of the most recent annual or quarterly report of the Company, and (iii) such
other reports and documents filed by the Company with the Commission as such
Holder may reasonably request in availing itself of an exemption for the sale of
Registrable Securities without registration under the Securities Act. The
Company acknowledges and agrees that the purposes of the requirements contained
in this Section 2.7 are (a) to enable any such Holder to comply with the current
public information requirement contained in Paragraph (c) of Rule 144 should
such Holder ever wish to dispose of any of the securities of the Company
acquired by it without registration under the Securities Act in reliance upon
Rule 144 (or any other similar exemptive provision) and (b) to qualify the
Company for the use of registration statements on Form S-3. In addition, the
Company shall take such other measures and file such other information,
documents and reports, as shall hereafter be required by the Commission as a
condition to the availability of Rule 144 under the Securities Act (or any
similar exemptive provision hereafter in effect) and the use of Form S-3. The
Company also covenants to use reasonable efforts, to the extent that it is
reasonably within its power to do so, to qualify for the use of Form S-3.

         2.8      Stockholder Information. The Company may require each Holder
of Registrable Securities as to which any registration is to be effected
pursuant to this Section 2 to furnish the Company such information in writing
with respect to such Holder and the distribution of such

<PAGE>

Registrable Securities as the Company may from time to time reasonably request
in writing and as shall be required by law or by the Commission in connection
therewith.

         2.9      Forms. All references in this Agreement to particular forms of
registration statements are intended to include, and shall be deemed to include,
references to all successor forms which are intended to replace, or to apply to
similar transactions as, the forms herein referenced.

         2.10     Transfer of Registration Rights. The registration rights
granted to the Holders of Registrable Securities under this Section 2 may not be
transferred without the prior written consent of the Company; provided that such
registration rights may be transferred, in whole or in part, without such prior
written consent in connection with the transfer of Registrable Securities to (i)
a partner in or an affiliate (defined as any person which directly or indirectly
controls, is controlled by, or is under common control with such Purchaser) of
one or more of the Purchasers or (ii) to an immediate or remote transferee of a
Purchaser who after such transfer is the Holder of at least 25% of the number of
Registrable Securities purchased by such original Purchaser hereunder as set
forth on Schedule A hereto (appropriately adjusted for subdivisions and
combinations of shares of Common Stock and dividends on Common Stock payable in
shares of Common Stock subsequent to the date of this Agreement).

         3.       MISCELLANEOUS.

         3.1      GOVERNING LAW. THIS AGREEMENT SHALL BE GOVERNED IN ALL
RESPECTS BY THE INTERNAL LAWS OF THE STATE. OF DELA WARE WITHOUT REGARD TO THE
CONFLICT OF LAWS PRINCIPLES THEREOF.

         3.2      Successors and Assigns. Except as otherwise provided herein,
the provisions hereof shall inure to the benefit of, and be binding upon, the
successors, assigns, heirs, executors and administrators of the parties hereto.

         3.3.     Amendment. Except as expressly provided herein, this
Agreement, or any provision hereof, may be amended, waived, discharged or
terminated upon the written consent of the Company and the Holders holding at
least two-thirds (2/3) of the then outstanding Registrable Securities.
Notwithstanding the foregoing, Schedule A to this Agreement may be amended to
add additional Purchasers of Preferred Stock as parties to this Agreement after
the date of this Agreement upon the execution by such Purchasers of a
counterpart hereof, such additional Purchasers shall be "purchasers" for all
purposes of this Agreement as if they had executed this Agreement on the date
hereof.

         3.4      Notices. etc. All notices and other communications required or
permitted hereunder shall be in writing and shall be mailed by registered or
certified mail, postage prepaid, or otherwise delivered by hand or by messenger
including Federal Express or similar courier service, addressed (a) if to a
Holder, at such Holder's address set forth on Schedule A hereto, or at such
other address as such party shall have furnished to the Company in Writing, or
(b) if to the Company at 8122 Datapoint Drive, Suite 1250, San Antonio, Texas
78229, Attn: President, or at such other address as the Company shall have
furnished to the other parties hereto.

         Each such notice or other communication shall for all purposes of this
Agreement be treated as effective upon receipt, if delivered personally or by
courier, or, if sent by mail, at the

<PAGE>

earlier of its receipt or 48 hours after same has been deposited in a regularly
maintained receptacle for the deposit of the United States mail, addressed and
mailed as aforesaid.

         3.5      Delays or Omissions. Except as expressly provided herein, no
delay or omission to exercise any right, power or remedy accruing to any party
to this Agreement shall impair any such right, power or remedy of such party nor
shall it be construed to be a waiver of any such breach or default, or an
acquiescence therein, or of or in any similar breach or default thereafter
occurring; nor shall any waiver or any single breach or default be deemed a
waiver of any other breach or default theretofore or thereafter occurring. Any
waiver, permit, consent or approval of any kind or character on the part of any
party of any breach or default under this Agreement, or any waiver on the part
of any party of any provisions or conditions of this Agreement, must be in
writing and shall be effective only to the extent specifically set forth in such
writing. All remedies, either under this Agreement or by law or otherwise
afforded to any party to this Agreement, shall be cumulative and not
alternative.

         3.6      Counterparts. This Agreement may be executed in any number of
counterparts, each of which may be executed by less than all of the parties
hereto, each of which shall be enforceable against the parties actually
executing such counterparts, and all of which together shall constitute one
instrument.

         3.7      Severability. In the event that any provision of this
Agreement becomes or is declared by a court of competent jurisdiction to be
illegal, unenforceable or void, this Agreement shall continue in full force and
effect without said provision.

         3.8      Titles and Subtitles. The titles and subtitles used in this
Agreement are used for convenience only and are not considered in construing or
interpreting this Agreement.

<PAGE>

         IN WITNESS WHEREOF, this Agreement has been executed by the
undersigned effective upon the date first set forth above.

                                          "COMPANY"

                                          BIONUMERIK PHARMACEUTICALS, INC.
                                          BY: \s\ FREDERICK H. HAUSHEER
                                             -----------------------------------
                                          TITLE: CHAIRMAN OF THE BOARD

<PAGE>

                                   SCHEDULE A

                                     HOLDERS

<TABLE>
<CAPTION>
                                                                                                      NO. OF
PURCHASER                                                            NO. OF SHARES                WARRANT SHARES
---------                                                            -------------                --------------
<S>                                                                  <C>                          <C>
Allyn Sher                                                                4,545                          1,515
JT Ten Wros
2571 Doziers Station Road, Route #6
Columbia, MO 65202-8504

Don M. Delwood, M.D.                                                      7,273                          2,424
1442 Mesa Drive
Columbia, MO 65201

Don M. Delwood Profit Sharing Plan KEOGH                                  6,681                          2,227
Attn.: Nedra Morean
c/o First National Bank & Trust Co.
801 E. Broadway
Columbia, MO 65201

Dennis L. Abernathie & Beth L. Abernathie                                18,182                          6,061
400 Keene Street
Columbia, MO 65201

Richard A. Lange                                                         13,636                          4,545
7 Elmcourt
San Antonio, TX 78209

Carol Loeppky                                                            12,500                          4,167
4000 Maple Bluff Drive
Columbia, MO 65203

WS Investment Company 94A                                                 4,545                          1,515
John B. Goodrich
WS Investment Company 94A
650 Page Mill Road
Palo Alto, CA 94304-1050

D. M. Laurice & M. M. Rosati, TTEES WSGR                                  9,091                          3,030
Retirement Plan for John Goodrich
Wilson, Sonsini, Goodrich & Rosati
Administration Contact: Jayne Brownlee
600 Page Mill Road
Palo Alto, CA 94304-1050

M. B. Wildermuth                                                          4,545                          1,515
14 Lewis Wharf, #332
Boston, MA 02110
</TABLE>

<PAGE>

<TABLE>
<S>                                                                      <C>                             <C>
William G. Quinn                                                          9,091                          3,030
2450 Purdy Lane
Columbia, MO 65201

Lilian E. McCann                                                          4,545                          1,515
10100 Reunion Place, Suite 260
San Antonio, TX 78216

Zellars C. West                                                           6,000                          2,000
One Monroeville Center, Suite 950
Monroeville, PA 15146

Robert F. McDermott, Jr.                                                 27,273                          9,091
4202 Kimbrelee Court
Alexandria, VA 22309

Brigadier General Robert F. McDermott                                    27,273                          9,091
USAA, C-3-E
9800 Fredericksburg Road
San Antonio, TX 78228

Linda J. Delwood, M.D.                                                    4,545                          1,515
100 Fox Glen Circle
Irving, TX 75062

Kimberly Jamison, M.D.                                                    3,636                          1,212
Kimberley Jamison Stewart, M.D.
110 Edgewood
Columbia, MO 65203

Kris B. Tufto                                                             1,000                            333
9033 Duckwood Trail
Woodbury, MN 55125

Lon J. Lutz, M.D.                                                         2,727                            909
559 Capitol Boulevard
St. Paul, MN 55103

Michael David Kamitsuka                                                   4,545                          1,515
22612 NE, 23rd PL
Redmond, W A 98053

Michael E. Oliver, M.D.                                                   4,545                          1,515
38 Granburg Circle
San Antonio, TX 78218

Richard L. Doane                                                          9,091                          3,030
P.O. Box 97030
Kirkland, W A 98083
</TABLE>

<PAGE>

                                ADDENDUM NO.1 TO

                                   SCHEDULE A

                                     HOLDERS

<TABLE>
<CAPTION>
                                                                                                      NO. OF
PURCHASER                                                            NO. OF SHARES                WARRANT SHARES
---------                                                            -------------                --------------
<S>                                                                  <C>                          <C>
Southwestern Bell Corporation                                            181,820                       8,547
175 E. Houston, Room 7-A-50
San Antonio, Texas 78205

Paraic J. Mulgrew                                                          5,000
28 Aston Glen
San Antonio, Texas 78257

Renal Associates P .A. Pension Sharing                                     5,000
Profit Account for Paraic J. Mulgrew
28 Aston Glen
San Antonio, Texas 78257
</TABLE>

<PAGE>

<TABLE>
<S>                                                                        <C>                       <C>
John C. Kerr                                                               4,545                     1,515
1020 NE Loop 410, Suite 812
San Antonio, TX 78209

Edward D. Moore                                                            5,000                     1,667
8700 Crownhill Boulevard, #601
San Antonio, TX 78209

David H. Kramer                                                            5,000                     1,667
#8 Darby Glen
San Antonio, TX 78257

Haddock Family Limited Partnership                                         4,545                     1,515
Eugene Haddock, M.D.
9749 Tower View
Helotes, TX 78023
</TABLE>

<PAGE>

                                ADDENDUM NO.2 TO
                                   SCHEDULE A
                                     HOLDERS

<TABLE>
<CAPTION>
PURCHASER                                                                          NUMBER OF SHARES
---------                                                                          ----------------
<S>                                                                                <C>
SW Immunodiagnostics, Inc.                                                             18,000
401(k) PSPP, FBO Gordon L. Bilbrey, M.D.
29330 Grand Coteau
Boerne, TX 78006

Gordon L. Bilbrey                                                                      18,000
29330 Grand Goteau
Boerne, TX 78006

Clayton Hudnall                                                                         9,091
837 College Blvd.
San Antonio, TX 78209

Joe R. Colingo and Wife, Johnette W. Colingo,                                          18,182
as joint tenants with rights of survivorship
710 Delmas Avenue
Pascagoula, MS 39567.

Roy C. Williams & Sandra P. Williams                                                    9,091
as joint tenants with rights of survivorship
710 Delmas Avenue
Pascagoula, MS 39567

Lanette G. Duperier                                                                    15,455
535 Elizabeth Rd.
San Antonio, TX 78209

John B. Goodman                                                                        45,500
1501 Seamist
Houston, TX 77008

J.F. Clingman, Jr.                                                                     18,182
6 Morning Downs
San Antonio, TX 78257

B.P. Investment Partners, L.P.                                                        163,637
7640 Poplar Avenue, Suite 207
Germantown, TN 38138

Nell Labatt Family Limited Partnership                                                 72,000
135 W. Elsmere
San Antonio, TX 78212

Harold G. Goodman 1984 Grantor Trust                                                   45,500
5847 San Felipe, Suite 950
Houston, TX 77057
</TABLE>

<PAGE>

                               ADDENDUM NO. 3 TO
                                   SCHEDULE A
                                    HOLDERS

<TABLE>
<CAPTION>
PURCHASER                                                                          NUMBER OF SHARES
---------                                                                          ----------------
<S>                                                                                <C>
Lanette G. Duperier                                                                      2,727
As Sole and Separate Property
535 Elizabeth Road
San Antonio, TX 78209

Felix L. Stehling                                                                       20,000
4040 Broadway, Suite 420
San Antonio, TX 78209

Elizabeth B. Messick                                                                    50,000
    Issue Tr Dtd 5/20/68
c/o Inverness Counsel, Inc.
545 Madison Avenue
New York, NY 10022

Joe B. Kercheville                                                                      10,000
15750 IH 10 West
San Antonio, TX 78249

T. Craig Benson                                                                          9,091
1929 Allen Parkway
Houston, TX 77019

Southwest Venture Partners III, L.P.                                                   181,820
16414 San Pedro, Suite 345
San Antonio, TX 78232

Jerry D. Kennett, M.D. Pension Plan                                                      3,945
2801 Peppertree Lane
Columbia, MO 65201

Jerry D. Kennett, M.D. Profit Sharing Plan                                               5,146
2801 Peppertree Lane
Columbia. MO 65201
</TABLE>