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                                                                    Exhibit 4.12

                                     WARRANT

Warrant No. W-6

THIS WARRANT (AND THE SECURITIES ISSUABLE UPON EXERCISE OF THIS WARRANT) HAVE
NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933 OR ANY STATE SECURITIES
LAWS. THE SECURITIES HAVE BEEN ACQUIRED FOR INVESTMENT AND NOT WITH A VIEW TO
DISTRIBUTION OR RESALE, AND MAY NOT BE SOLD, MORTGAGED, PLEDGED, HYPOTHECATED OR
OTHERWISE TRANSFERRED WITHOUT AN EFFECTIVE REGISTRATION STATEMENT FOR SUCH
SECURITIES UNDER THE SECURITIES ACT OF 1933 AND ANY APPLICABLE STATE SECURITIES
STATUTE, OR UNLESS AN EXEMPTION FROM REGISTRATION IS AVAILABLE THEREUNDER AS
EVIDENCED BY AN OPINION OF COUNSEL OR NO-ACTION LETTER FROM THE SECURITIES AND
EXCHANGE COMMISSION, IN EITHER CASE IN FORM AND SUBSTANCE SATISFACTORY TO THE
COMPANY.

                               WARRANT TO PURCHASE
                             SHARES OF COMMON STOCK

                             Expires AUGUST 10, 2005

        THIS CERTIFIES THAT, for value received, Dr. Robert E. Pennington (the
"Holder"), is entitled to subscribe for and purchase up to Four Hundred
Sixty-six and 11/100 (466.11) shares (the "Shares") of the fully paid and
nonassessable Common Stock of Point Therapeutics, Inc., a Delaware corporation
(the "Company"), for an exercise price per share determined pursuant to the
terms of Section 4.1 hereof (the "Warrant Price"), subject to the provisions and
upon the terms and conditions hereinafter set forth.

        As used herein, the term "Shares" shall mean the Company's presently
authorized Common Stock and the term "Grant Date" shall mean August 10, 1998.

        1.      Term. Subject to the provisions of this Warrant, the purchase
right represented by this Warrant is exercisable, in whole or in part, at any
time and from time to time after the date hereof and prior to the seventh
anniversary of the Grant Date.

        2.      Method of Exercise.

                2.1.    Standard Method. The purchase right represented by this
Warrant may be exercised by the holder hereof, in whole or in part and from time
to time, by the surrender of this Warrant (with the notice of exercise form
attached hereto as Exhibit A duly executed) at the Principal office of the
Company and by the payment to the Company, by certified or bank check or by wire
transfer, of an amount equal to the then applicable Warrant Price per share
multiplied by the number of Shares then being purchased, The person or persons
in whose name(s) any certificate(s) representing Shares shall be issuable upon
exercise of this Warrant shall be deemed

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to have become the holder(s) of record of, and shall be treated for all purposes
as the record holder(s) of, the shares represented thereby (and such shares
shall be deemed to have been issued) immediately prior to the close of business
on the date or dates upon which this Warrant is exercised and the then
applicable Warrant Price paid. In the event of any exercise of the rights
represented by this Warrant, certificates for the shares of stock so purchased
shall be delivered to the holder hereof as soon as possible and in any event
within thirty days of receipt of such notice and payment of the then applicable
Warrant Price and, unless this Warrant has been fully exercised or expired, a
new Warrant representing the portion of the Shares, if any, with respect to
which this Warrant shall not then have been exercised shall also be issued to
the holder hereof as soon as possible and in any event within such thirty-day
period.

                2.2.    Net Issue Exercise.

                        (a)     In lieu of exercising this Warrant, holder may
elect to receive shares equal to the value of this Warrant (or the portion
thereof being canceled) by surrender of this Warrant at the principal office of
the Company together with notice of such election in which event the Company
shall issue to Holder a number of shares of the Company's Common Stock computed
using the following formula:

                                    X=Y(A-B)
                                      ------
                                        A

Where

        X =     the number of Shares to be issued to Holder.

        Y =     the number of Shares purchasable under this Warrant.

        A =     the fair market value of one Share.

        B =     the Warrant Price

                        (b)     For purposes of this Section, fair market value
of one share of the Company's Common Stock shall be the average of the closing
per share bid and asked prices of the Company's Common Stock quoted in the
Over-The-Counter Market Summary or the closing price quoted on Nasdaq or any
exchange on which the Common Stock is listed, whichever is applicable, as
published in the Eastern Edition of The Wall Street Journal for the ten trading
days prior to the date of determination of fair market value. If the Common
Stock is not traded Over-The-Counter or on Nasdaq or an exchange, the fair
market value of the Company's Common Stock shall be the price per share which
the Company could obtain from a willing buyer for shares sold by the Company
from authorized but unissued shares, as such price shall be agreed by the
Company and the Holder, and if they fail to agree within 15 days after the
exercise of this Warrant, as determined by arbitration. Such arbitration shall
be conducted in Boston. Massachusetts in accordance with the commercial
arbitration rules of the American Arbitration Association and the costs of
arbitration shall be shared equally by the parties. The arbitrator shall be a
person selected by the Company and the holder who shall have experience in
valuing companies similar to the Company. If the Company and the holder are
unable to agree on a single arbitrator, each shall select an arbitrator and the
two arbitrators so selected shall select a

                                       -2-

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third arbitrator. The determination of the arbitrator(s) shall be binding on the
Company and the holder.

                2.3.    Automatic Exercise.

                        (a)     If the Company has publicly traded stock as of
the expiration date of this Warrant, if the fair market value of one share of
the Company's Common Stock (determined in the same manner as is set forth in
Section 2.2(b)) is as of the expiration date greater than the Warrant Price, as
adjusted, this Warrant shall be deemed automatically exercised pursuant to
Section 2.2 above (even if not surrendered) immediately prior to its expiration.

                        (b)     If as of April 24, 2005, the Company has no
publicly traded stock, the Company shall notify the holder in writing that this
Warrant will expire on July 24, 2005 and shall endeavor to determine what is the
fair market value of one share of the Company's Common Stock in the manner
described in Section 2.2(b), and if the fair market value of one share of the
Company's Common Stock, as so determined is as of the expiration date greater
than the Warrant Price, as adjusted, this Warrant shall be deemed automatically
exercised pursuant to Section 2.2 above (even if not surrendered) immediately
prior to its expiration. If the Company shall fail to give the notice set forth
in this Section 2.3(b), the expiration date of the Warrant shall be postponed
for one day for each day that the Company shall have failed to give such notice,
and shall be extended until ten days after the determination of the fair market
value of one share of Common Stock if such determination shall be made after the
date on which this Warrant otherwise shall have expired, whether pursuant to
Section 1 above or this Section 2.2(b) as a result of the Company's failure to
give notice.

                        (c)     To the extent this Warrant or any portion
thereof is deemed automatically exercised pursuant to this Section 2.3, the
Company agrees to promptly notify the holder hereof of the number of shares of
the Company's Common Stock, if any, the holder is entitled to receive by reason
of such automatic exercise.

        3.      Stock Fully Paid Reservation of Shares. The Shares have been
duly authorized and reserved for issuance by the Company. All Shares that may be
issued upon the exercise of the rights represented by this Warrant, will, upon
issuance, be fully paid and nonassessable, and free from all taxes, liens and
charges with respect to the issue thereof. During the period within which the
rights represented by the Warrant may be exercised, the Company will at all
times have authorized and reserved for the purpose of issuance upon exercise of
the purchase rights evidenced by this Warrant, a sufficient number of Shares to
provide for the exercise of the unexercised rights represented by this Warrant.
The Company covenants that it will from time to time take all such action as may
be requisite to assure that in the event the Common Stock shall have a par
value, such par value per share of the Common Stock shall at all times be equal
to or less than the Warrant Price in effect at the time.

        4.      Initial Warrant Price; Adjustment of Warrant Price and Number of
Shares. The number and kind of securities purchasable upon the exercise of the
Warrant and the Warrant

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Price shall be subject to adjustment from time to time upon the occurrence of
certain events, as follows:

                        (a)     Initial Warrant Price. The initial Warrant Price
shall be $2.90.

                4.2.    Reclassification or Merger. Subject to Section 1, in
case of any reclassification, change or, conversion of securities of the class
issuable upon exercise of this Warrant (other than a change in par value, or
from par value to no par value, or from no par value to par value, or as a
result of a subdivision or combination), or in case of any merger of the Company
with or into another corporation (other than a merger with another corporation
in which the Company is a continuing corporation and which does not result in
any reclassification or change of outstanding securities issuable upon exercise
of this Warrant), or in case of any sale of all or substantially all of the
assets of the Company, the Company, or such successor or purchasing corporation,
as the case may be, shall execute a new Warrant (in form and substance,
satisfactory to the holder of this Warrant) providing that the holder of this
Warrant shall have the right to exercise such new Warrant and upon such exercise
to receive, in lieu of each share of Common Stock theretofore issuable upon
exercise of this Warrant, the kind and amount of shares of stock, other
securities, money and property receivable upon such reclassification, change or
merger by a holder of one share of Common Stock. Such new Warrant shall provide
for adjustments that shall be as nearly equivalent as may be practicable to the
adjustments provided for in this Paragraph 4. The provisions of this Section 4.2
shall similarly apply to successive reclassifications, changes, mergers and
transfers.

                4.3.    Subdivisions or Combination of Shares. If the Company at
any time while this Warrant remains outstanding and unexpired shall subdivide or
combine its Common Stock, the Warrant Price shall be proportionately adjusted.

                4.4.    Stock Dividends. If the Company at any time while this
warrant is outstanding and unexpired shall pay a dividend payable in shares of
Common Stock (except any distribution specifically provided for in the foregoing
Sections 4.2 and 4.3), then the Warrant Price shall be adjusted, from and after
the date of determination of shareholders entitled to receive such dividend or
distribution, to that price determined by multiplying the Warrant Price in
effect immediately prior to such date of determination by a fraction (a) the
numerator of which shall be the total number of shares of Common Stock
outstanding immediately prior to such dividend or distribution (assuming the
conversion, exchange or exercise of all securities convertible into,
exchangeable for or exercisable for Common Stock), and (b) the denominator of
which shall be the total number of shares of Common Stock outstanding
immediately after such dividend or distribution (assuming the conversion,
exchange or exercise of all securities convertible into, exchangeable for or
exercisable for Common Stock).

                4.5.    Dilutive Issuances. If and whenever the Company shall
issue or sell, or is, in accordance with subparagraphs (a) through (r) below,
deemed to have issued or sold, any shares of Common Stock for a consideration
per share less than the Warrant Price in effect immediately prior to the time of
such issue or sale, then, forthwith upon such issue or sale, the Warrant Price
shall be reduced to the price determined by dividing (i) an amount equal to the
sum of (x) the number of shares of Common Stock outstanding immediately prior to
such issue or sale multiplied by the then existing Warrant Price and (y) the
consideration, if any, received

                                       -4-

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by the Company upon such issue or sale, by (ii) the total number of shares of
Common Stock outstanding immediately after such issue or sale. For purposes of
this Section 4.5, the following subparagraphs (a) through (h) shall also be
applicable:

                        (a)     Issuance of Rights or Options. In case at any
time the Company shall in any manner grant (whether directly or by assumption in
a merger or otherwise) any warrants or other rights to subscribe for or to
purchase, or any options for the purchase of, Common Stock or any stock or
security directly or indirectly convertible into or exchangeable for Common
Stock (such warrants, rights or options being called "Options" and such
convertible or exchangeable stock or securities being called "Convertible
Securities") whether or not such Options or the right to convert or exchange any
such Convertible Securities are immediately exercisable, and the price per share
for which Common Stock is issuable upon the exercise of such Options or upon the
conversion or exchange of such Convertible Securities (determined by dividing
(x) the total amount, if any, received or receivable by the Company as
consideration for the granting of such Options, plus the minimum aggregate
amount of additional consideration payable to the Company upon the exercise of
all such Options, plus, in the case of such Options which relate to Convertible
Securities, the minimum aggregate amount of additional consideration, if any,
payable upon the issue or sale of such Convertible Securities and upon the
conversion or exchange thereof, by (y) the total maximum number of shares of
Common Stock issuable upon the exercise of such Options or upon the conversion
or exchange of all such Convertible Securities issuable upon the exercise of
such Options) shall be less than the Warrant Price in effect immediately prior
to the time of the granting of such options, then, in calculating the
adjustments to the Warrant Price, the total maximum number of shares of Common
Stock issuable upon the exercise of such Options or upon conversion or exchange
of the total maximum amount of such Convertible Securities issuable upon the
exercise of such Options shall be deemed to have been issued for such price per
share as of the date of granting of such Options or the issuance of such
Convertible Securities and thereafter shall be deemed to be outstanding. Except
as otherwise provided in subparagraph (c) below, no adjustment of the Warrant
Price shall be made upon the actual issue of such Common Stock or of such
Convertible Securities upon exercise of such options or upon the actual issue of
such Common Stock upon conversion or exchange of such Convertible Securities.

                        (b)     Issuance of Convertible Securities. In case the
Company shall in any manner issue (whether directly or by assumption in a merger
or otherwise) or sell any Convertible Securities, whether or not the rights to
exchange or convert any such Convertible Securities are immediately exercisable,
and the price per share for which Common Stock is issuable upon such conversion
or exchange (determined by dividing (x) the total amount received or receivable
by the Company as consideration for the issue or sale of such Convertible
Securities, plus the minimum aggregate amount of additional consideration, if
any, payable to the Company upon the conversion or exchange thereof, by (y) the
total maximum number of shares of Common Stock issuable upon the conversion or
exchange of all such Convertible Securities) shall be less than the Warrant
Price in effect immediately prior to the time of such issue or sale, then, in
calculating the adjustment(s) to the Warrant Price, the total maximum number of
shares of Common Stock issuable upon conversion or exchange of all such
Convertible Securities shall be deemed to have been issued for such price per
share as of the date of the issue or sale of such Convertible Securities and
thereafter shall be deemed to be outstanding, provided that (i) except as
otherwise provided in subparagraph (c), no adjustment of the Warrant Price shall
be made

                                       -5-

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upon the actual issue of such Common Stock upon conversion or exchange of such
Convertible Securities and (ii) if any such issue or sale of such Convertible
Securities is made upon exercise of any Options to purchase any such Convertible
Securities for which adjustments of the Warrant Price have been or are to be
made pursuant to other provisions of this paragraph 4, no further adjustment of
the Warrant Price shall be made by reason of such issue or sale.

                        (c)     Change in Option Price or Conversion Rate. Upon
the happening of any of the following events, namely, if the purchase price
provided for in any Option referred to in subparagraph (a), the additional
consideration, if any, payable upon the conversion or exchange of any
Convertible Securities referred to in subparagraphs (a) or (b), or the rate at
which convertible Securities referred to in subparagraphs (a) or (b) are
convertible into or exchangeable for Common Stock shall change at any time
(including, but not limited to, changes under or by reason of provisions
designed to protect against dilution), the Warrant Price in effect at the time
of such event shall forthwith be readjusted to the Warrant Price which would
have been in effect at such time had such Options or Convertible Securities
still outstanding provided for such changed purchase price, additional
consideration or conversion rate, as the case may be, at the time initially
granted, issued or sold; and on the termination of any such Option or any such
right to convert or exchange such Convertible Securities, the Warrant Price then
in effect hereunder shall forthwith be increased to the Warrant Price which
would have been in effect at the time of such termination had such Option or
Convertible Securities, to the extent outstanding immediately prior to such
termination, never been issued.

                        (d)     Stock Dividends. In case the Company shall
declare a dividend or make any other distribution upon any stock of the Company
payable in Common Stock (except for dividends or distributions upon the Common
Stock), Options or Convertible Securities, any Common Stock, Options or
Convertible Securities, as the case may be, issuable in payment of such dividend
or distribution shall be deemed to have been issued or sold without
consideration.

                        (e)     Consideration for Stock. In case any shares of
Common Stock, Options or Convertible Securities shall be issued or sold for
cash, the consideration received therefor shall be deemed to be the amount
received by the Company therefor, after deduction therefrom of any reasonable
expenses incurred or reasonable underwriting commissions or concessions paid or
allowed by the Company in connection therewith. In case any shares of Common
Stock, Options or Convertible Securities shall be issued or sold for a
consideration other than cash, the amount of the consideration other than cash
received by the Company shall be deemed to be the fair value of such
consideration as determined in good faith by the Board of Directors of the
Company, without deduction of any expenses incurred or any underwriting
commissions or concessions paid or allowed by the Company in connection
therewith. In case any Options shall be issued in connection with the issue and
sale of other securities of the Company, together comprising one integral
transaction in which no specific consideration is allocated to such Options by
the parties thereto, such Options shall be deemed to have been issued for such
consideration as determined in good faith by the Board of Directors of the
Company.

                        (f)     Record Date. In case the Company shall take a
record of the holders of its Common Stock for the purpose of entitling them (i)
to receive a dividend or other distribution payable in Common Stock, Options or
Convertible Securities or (ii) to subscribe for

                                       -6-

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or purchase Common Stock; Options or Convertible Securities, then such record
date shall be deemed to be the date of the issue or sale of the shares of Common
Stock deemed to have been issued or sold upon the declaration of such dividend
or the making of such other distribution or the date of the granting of such
right of subscription or purchase, as the case may be.

                        (g)     Treasury Shares. The number of shares of Common
Stock outstanding at any given time shall not include shares owned or held by or
for the account of the Company, and the disposition of any such shares shall be
considered an issue or sale of Common Stock for the purpose of this Section 4.5.

                        (h)     Minimum Adjustment. If any adjustment of the
Warrant Price pursuant to this Section 4.5 shall result in an adjustment of less
than ten percent (10%) of the Warrant Price in effect immediately prior to such
adjustment, no such adjustment shall be made, but any such lesser adjustment
shall be carried forward and shall be made at the time and together with the
next subsequent adjustment which, together with any adjustments so carried
forward, shall amount to ten percent (10%) or more of the Warrant Price in
effect immediately prior to such adjustment.

                        (i)     Exceptions. No adjustments of the Warrant Price
shall be made by reason of or in connection with the issuance of up to an
aggregate of 1,248,504 shares of Common Stock (including options to purchase
such shares) pursuant to warrants, stock option agreements, stock option plans,
stock purchase plans or management incentive plans approved by the Board of
Directors or the Compensation Committee to employees, directors, customers,
suppliers or consultants (whether issued on or after July 24, 1998).

                        (j)     Notice of Adjustment. Upon any adjustment of the
Warrant Price, then and in each such case the Company shall give written notice
thereof, by delivery in person, certified or registered mail, return receipt
requested, telecopier or telex, addressed to the Holder at the address or
telecopier number of such holder as shown on the books of the Company, which
notice shall state the Warrant Price resulting from such adjustment, setting
forth in reasonable detail the method upon which such calculation is based.

                        (k)     Other Notices. In case at any time:

                                (i)     the Company shall declare any dividend
upon its Common Stock payable in cash or stock or make any other distribution to
the holders of its Common Stock;

                                (ii)    the Company shall offer for subscription
pro rata to the holders of its Common Stock any additional shares of stock of
any class or other rights;

                                (iii)   there shall be any capital
reorganization or reclassification of the capital stock of the Company, or a
consolidation or merger of the Company with or into another entity or entities,
or a sale, lease, abandonment, transfer or other disposition of all or
substantially all of the assets of the Company; or

                                (iv)    there shall be a voluntary or
involuntary dissolution, liquidation or winding up of the Company; then, in any
one or more of said cases, the Company

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shall give, by delivery in person, certified or registered mail, return receipt
requested, telecopier or telex, addressed to the Holder at the address or
telecopier number of such holder as shown on the books of the Company, (a) at
least 20 days' prior written notice of the date on which the books of the
Company shall close or a record shall be taken for such dividend, distribution
or subscription rights or for determining rights to vote in respect of any such
reorganization, reclassification, consolidation, merger, disposition,
dissolution, liquidation or winding up and (b) in the case of any such
reorganization, reclassification, consolidation, merger, disposition,
dissolution, liquidation or winding up, at least 20 days' prior written notice
of the date when the same shall take place. Such notice in accordance with the
foregoing clause (a) shall also specify, in the case of any such dividend,
distribution or subscription rights, the date on which the holders of Common
Stock shall be entitled thereto and such notice in accordance with the foregoing
clause (b) shall also specify the date on which the holders of Common Stock
shall be entitled to exchange their Common Stock for securities or other
property deliverable upon such reorganization, reclassification, consolidation,
merger, disposition, dissolution, liquidation or winding up, as the case may be.

                        (l)     Issue Tax. The issuance of certificates for
shares of Common Stock upon exercise of this Warrant shall be made without
charge to the holders thereof for any issuance tax in respect thereof, provided
that the Company shall not be required to pay any tax which may be payable in
respect of any transfer involved in the issuance and delivery of any certificate
in a name other than that of the Holder.

                        (m)     Closing of Books. The Company will at no time
close its transfer books against the transfer of any shares of Common Stock
issued or issuable upon the exercise of this Warrant in any manner which
interferes with the timely exercise of this Warrant, except as may otherwise be
required to comply with applicable securities laws.

                        (n)     Definition of Common Stock. As used in this
Section 4.5, the term "Common Stock" shall mean and include the Company's
authorized Common Stock, without par value, as constituted on the date of this
Warrant, and shall also include any capital stock of any class of the Company
thereafter authorized which shall neither be limited to a fixed sum or
percentage in respect of the rights of the holders thereof to participate in
dividends nor entitled to a preference in the distribution of assets upon the
voluntary or involuntary liquidation, dissolution or winding up of the Company;
provided that the shares of Common Stock receivable upon exercise of this
Warrant shall include only shares designated as Common Stock of the Company on
the date of this Warrant or in case of any reorganization or reclassification of
the outstanding shares thereof, the stock, securities or assets provided for in
Section 4.2.

                        (o)     "Person" Defined. For the purposes of this
Section 4.5, the term "Person" shall mean an individual, a Company, an
association, a limited liability company, a joint-stock company, a business
trust or other similar organization, a partnership, a joint venture, a trust, an
unincorporated organization or a government or any agency, instrumentality or
political subdivision thereof.

                4.6.    No Impairment. The Company will not, by amendment of its
Charter or through any reorganization, recapitalization, transfer of assets,
consolidation, merger, dissolution, issue or sale of securities or any other
voluntary action, avoid or seek to avoid the

                                       -8-

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observance or performance of any of the terms to be observed or performed
hereunder by the Company, but will at all times in good faith assist in the
carrying out of all the provisions of this Paragraph 4 and in the taking of all
such action as may be necessary or appropriate in order to protect the rights of
the holder of this Warrant against impairment.

        5.      Notice of Adjustments. Whenever the Warrant Price or number of
Shares shall be adjusted pursuant to the provisions hereof, the Company shall
within 30 days of such adjustment deliver a certificate signed by its chief
financial officer to the registered holder(s) hereof setting forth, in
reasonable detail, the event requiring the adjustment, the amount of the
adjustment, the method by which such adjustment was calculated, and the Warrant
Price after giving effect to such adjustment.

        6.      Fractional Shares. No fractional Shares will be issued in
connection with any exercise hereunder, but in lieu of such fractional shares
the Company shall make a cash payment therefor upon the basis of the Warrant
Price then in effect.

        7.      Compliance with Securities Act; Disposition of Warrant or Shares
of Common Stock.

                7.1.    Compliance with Securities Act. The holder of this
Warrant, by acceptance hereof, agrees that this Warrant and the Shares to be
issued upon exercise hereof are being acquired for investment and that such
holder will not offer, sell or otherwise dispose of this Warrant or any Shares
to be issued upon exercise hereof except under circumstances which will not
result in a violation of the Securities Act of 1933, as amended (the "Act").
This Warrant and all Shares issued upon exercise of this Warrant (unless
registered under the Act) shall be stamped or imprinted with a legend in
substantially the following form:

THIS WARRANT (AND THE SECURITIES ISSUABLE UPON EXERCISE OF THIS WARRANT) HAVE
NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933 OR ANY STATE SECURITIES
LAWS. THE SECURITIES HAVE BEEN ACQUIRED FOR INVESTMENT AND NOT WITH A VIEW TO
DISTRIBUTION OR RESALE, AND MAY NOT BE SOLD, MORTGAGED, PLEDGED, HYPOTHECATED OR
OTHERWISE TRANSFERRED WITHOUT AN EFFECTIVE REGISTRATION STATEMENT FOR SUCH
SECURITIES UNDER THE SECURITIES ACT OF 1933 AND ANY APPLICABLE STATE SECURITIES
STATUTE, OR UNLESS AN EXEMPTION FROM REGISTRATION IS AVAILABLE THEREUNDER AS
EVIDENCED BY AN OPINION OF COUNSEL OR NO-ACTION LETTER FROM THE SECURITIES AND
EXCHANGE COMMISSION, IN EITHER CASE IN FORM AND SUBSTANCE SATISFACTORY TO THE
COMPANY.

                7.2.    Disposition of Warrant and Shares. With respect to any
offer, sale or other disposition of this Warrant, any of the Shares or any of
the shares issuable upon conversion of the Shares and until registration of this
Warrant or such Shares or shares, the holder hereof and each subsequent holder
of the Warrant agrees to give written notice to the Company prior thereto,
describing briefly the manner thereof together with a written opinion of
counsel, if requested by the Company, reasonably acceptable to the Company, to
the effect that such offer, sale or other disposition may be effected without
registration or qualification (under the Act as then in effect or any federal or
state law then in effect) of this Warrant or such Shares or shares

                                       -9-

<PAGE>

and indicating whether or not under the Act certificates for this Warrant or
such Shares or shares to be sold or otherwise disposed of require any
restrictive legend as to applicable restrictions on transferability in order to
insure compliance with the Act. Each certificate representing this Warrant or
the Shares or such shares thus transferred shall bear a legend as to the
applicable restrictions on transferability in order to insure compliance with
the Act, unless in the aforesaid opinion of counsel for the holder, such legend
is not required in order to insure compliance with the Act. Nothing herein shall
restrict the transfer of this Warrant, the Shares or such shares or any portion
hereof by the initial holder hereof to any entity affiliated with the initial
holder, or to any partner, member or stockholder of any such entity provided
such transfer may be made in compliance with applicable federal and state
securities laws. The Company may issue stop transfer instructions to its
transfer agent in connection with the foregoing restrictions.

        8.      Rights as Shareholder; Information.

                8.1.    Shareholder Rights. No holder of the Warrant, as such,
shall be entitled to vote or receive dividends or be deemed the holder of Shares
or any other securities of the Company which may at any time be issuable on the
exercise thereof for any purpose, nor shall anything contained herein be
construed to confer upon the holder of this Warrant, as such, any of the rights
of a shareholder of the Company or any right to vote for the election of
directors or upon any matter submitted to shareholders at any meeting thereof,
or to receive notice of meetings (except as otherwise provided in Section 4.6 of
this Warrant), or to receive dividends or subscription rights or otherwise until
this Warrant shall have been exercised and the Shares purchasable upon the
exercise hereof shall have become deliverable, as provided herein.

                8.2.    Financial Statements and Information. The Company shall
deliver to the registered holder hereof (i) within 120 days after the end of the
fiscal year of the Company, a consolidated balance sheet of the Company as of
the end of such year and a consolidated statement of income, retained earnings
and cash flows for such year, which year-end financial reports shall be in
reasonable detail and certified by independent public accountants of nationally
recognized standing selected by the Company (it being agreed that Ernst & Young
is an acceptable firm of independent public accountants) and (ii) within 30 days
after the end of each month other than the last month of the fiscal year,
unaudited consolidated statements of income, retained earnings and cash flows
for such month and a consolidated balance sheet as of the end of such month. If
the Company has a class of securities registered under the Securities Exchange
Act of 1934, the provisions of this Section 8.2 shall be satisfied by the
delivery to the holder, within 120 days after the end of the Company's fiscal
year, of a report on Form 10-K, or such fiscal year, and with respect to the
first three fiscal quarters in each fiscal year, within 45 days after the end of
each such fiscal quarter, of a report on Form 10-Q for such fiscal quarter. In
addition, the Company shall deliver to the registered holder hereof any other
information or data provided generally to the shareholders of the Company.

        9.      Additional Rights.

                9.1.    Mergers. The Company will provide the holder of this
Warrant with at least the greater of (a) 20 days' notice or (b) such greater
amount of notice as Delaware law requires be given to shareholders with power to
vote at a meeting on any transaction described hereinafter of the terms and
conditions of the proposed transaction, if the Company proposes to

                                      -10-

<PAGE>

(i) sell, lease, exchange, convey or otherwise dispose of all or substantially
all of its property or business, or (ii) merge into or consolidate with any
other corporation (other than a wholly-owned subsidiary of the Company), or
effect any transaction including a merger or other reorganization) or series of
related transactions, in which more than 50% of the voting power of the Company
is disposed of. Subject to the provisions of Section 1 above, in connection with
any transaction described in this Section 9.2 either (a) the sale of this
Warrant shall be arranged in connection with any such transaction on terms
satisfactory to the holder hereof or (b) the holder hereof shall receive in
connection with such transaction either (i) a new Warrant (on the same terms as
set forth herein or otherwise in form and substance satisfactory; to the holder
of this Warrant exercisable for the kind and amount of shares of stock, other
securities, money and property receivable upon such transaction by a holder of
Common Stock or (ii) the remainder of (x) securities, money or other property
receivable upon such transaction by a holder of Common Stock having the same
number of shares of Common Stock as the number issuable on the exercise of this
Warrant, minus (y) the aggregate Warrant Price for such shares.

        10.     Representations and Warranties. This Warrant is issued and
delivered on the basis of the following:

                10.1.   Authorization and Delivery. This Warrant has been duly
authorized and executed by the Company and when delivered will be the valid and
binding obligation of the Company enforceable in accordance with its terms.

                10.2.   Rights and Privileges. The rights, preferences,
privileges and restrictions granted to or imposed upon the Shares and the
holders thereof are as set forth herein and in the Company's Articles of
Organization, true and complete copies of which have been delivered to the
original warrant holder.

                10.3.   No Inconsistency. The execution and delivery of this
Warrant are not, and the issuance of the Warrant upon exercise of this Warrant
in accordance with the terms hereof will not be, inconsistent with the Company's
Certificate of Incorporation or by-laws, do not and will not contravene any law,
governmental rule or regulation, judgment or order applicable to the Company,
and do not and will not contravene any provision of, or constitute a default
under, any indenture, mortgage, contract or other instrument of which the
Company is a party or by which it is bound or require the consent or approval
of, the giving of notice to, the registration with or the taking of any action
in respect of or by, any Federal, state or local government authority or agency
or other person.

        11.     Modification and Waiver. This Warrant and any provision hereof
may be changed, waived, discharged or terminated only by an instrument in
writing signed by the party against which enforcement of the same is sought.

        12.     Notices. Any notice, request or other document required or
permitted to be given or delivered to the holder hereof or the Company shall be
delivered by facsimile where confirmation of receipt by the receiving party's
receiver can be documented, or delivered by hand, or shall be sent by reputable
overnight courier, certified or registered mail, postage prepaid, to each such
holder at its address as shown on the books of the Company or to the Company at
the address indicated therefore on the signature page of this Warrant.

                                      -11-

<PAGE>

        13.     Binding Effect on Successors. This Warrant shall be binding upon
any corporation succeeding the Company by merger or consolidation, and all of
the obligations of the Company relating to the Shares issuable upon the exercise
of this Warrant shall be as set forth in the Company's Certificate of
Incorporation and the Company's by-laws (each as amended from time to time) and
shall survive the exercise and termination of this Warrant and all of the
covenants and agreements herein and in such other documents and instruments of
the Company shall inure to the benefit of the successors and assigns of the
holder hereof. The Company will, at the time of the exercise of this Warrant, in
whole or in part, upon request of the holder hereof but at the Company's
expense, acknowledge in writing its continuing obligation to the holder hereof
in respect of any rights to which the holder hereof shall continue to be
entitled after such exercise in accordance with this Warrant; provided, that the
failure of the holder hereof to make any such request shall not affect the
continuing obligation of the Company to the holder hereof in respect of such
rights.

        14.     Lost Warrants or Stock Certificates. The Company covenants to
the holder hereof that upon receipt of evidence reasonably satisfactory to the
Company of the loss, theft, destruction, or mutilation of this Warrant or any
stock certificate and, in the case of any such loss, theft or destruction, upon
receipt of an indemnity reasonably satisfactory to the Company, or in the case
of any such mutilation upon surrender and cancellation of such Warrant or stock
certificate, the Company will make and deliver a new Warrant or stock
certificate, or like tenor, in lieu of the lost, stolen, destroyed or mutilated
Warrant or stock certificate.

        15.     Descriptive Headings. The descriptive headings of the several
paragraphs of this warrant are inserted for convenience only and do not
constitute a part of this Warrant.

        16.     Governing Law. THIS WARRANT SHALL BE CONSTRUED AND ENFORCED IN
ACCORDANCE WITH, AND THE RIGHTS OF THE PARTIES SHALL BE GOVERNED BY, THE LAWS OF
THE STATE OF DELAWARE.

                                  POINT THERAPEUTICS, INC.

                                  By:    /s/ Donald R. Kiepert, Jr.
                                         --------------------------
                                    Title: President and Chief Executive Officer

                                    Address:
                                    125 Summer Street
                                    Boston, MA  02110

Date: JULY 31, 2002

                                      -12-

<PAGE>

                                    EXHIBIT A

                               Notice of Exercise

To:

        1.      The undersigned hereby elects to purchase _________ shares of
Common Stock of Point Therapeutics, Inc. pursuant to the terms of the attached
Warrant, and tenders herewith payment of the purchase price of such shares in
full.

        2.      Please issue a certificate or certificates representing said
shares in the name of the undersigned or, subject to compliance with the
restrictions on transfer set forth in Section 7 of the Warrant, in such other
name or names as are specified below:


                                        _________________________________
                                                      (Name)

                                        _________________________________

                                        _________________________________

                                        _________________________________
                                                    (Address)

        3.      The undersigned represents that the aforesaid shares being
acquired for the account of the undersigned for investment and not with a view
to, or for resale in connection with, the distribution thereof and that the
undersigned has no present intention of distributing or reselling such shares.


                                        _________________________________
                                                    Signature

Date:________________

                                      -13-