THIS NOTE IS NOT  TRANSFERABLE  WITHOUT  THE  EXPRESS  WRITTEN  CONSENT OF GENTA
INCORPORATED,  (THE "COMPANY"). THE SECURITIES REPRESENTED BY THIS NOTE HAVE NOT
BEEN  REGISTERED  UNDER  THE  SECURITIES  ACT OF  1933 OR ANY  APPLICABLE  STATE
SECURITIES LAWS, AND MAY NOT BE SOLD,  OFFERED FOR SALE, PLEDGED OR HYPOTHECATED
OR OTHERWISE  TRANSFERRED IN THE ABSENCE OF A  REGISTRATION  STATEMENT IN EFFECT
WITH RESPECT TO THE  SECURITIES  UNDER SUCH ACT OR AN EXEMPTION  THEREFROM.  ANY
SUCH TRANSFER MAY ALSO BE SUBJECT TO APPLICABLE STATE SECURITIES LAWS.


                               GENTA INCORPORATED

                                                                         No. B-1
           AMENDED AND RESTATED SENIOR SECURED CONVERTIBLE BRIDGE NOTE

$1,050,000                                                 New York, New York
                                                           January 28, 1997, as
                                                           amended and restated
                                                           on June 23, 1997

                  Genta Incorporated,  a Delaware corporation,  (the "Company"),
for value  received,  hereby promises to pay to THE ARIES DOMESTIC FUND, LP (the
"Holder"),  or  registered  assigns,  the  principal  sum of ONE  MILLION  FIFTY
THOUSAND DOLLARS ($1,050,000),  with interest from the date of original issuance
of this Senior Secured  Convertible  Bridge Note on the unpaid principal balance
at a rate  equal to  twelve  percent  (12%) per  annum,  on the  earlier  of (a)
December  31,  1997,  (b)  September  30,  1997 if on or prior to such  date the
Company has not received gross proceeds of at least $2,000,000 in respect of its
offering of Premium Preferred Units which was commenced in May, 1997 and (c) the
date of any decision, order or other determination adverse to the Company or any
of its  directors  by any  court  or  other  tribunal  in any  lawsuit  or other
proceeding  against  the  Company  and/or  any  of its  directors  by any of the
Company's preferred  stockholders,  including,  without limitation,  any adverse
result or other  determination  in  connection  with an  appeal of the  decision
rendered by the Delaware  Court of Chancery in May,  1997 in respect of the suit
described in Item 3 of the Company's  Form 10-K for the year ended  December 31,
1996 (such earliest date,  the "Maturity  Date").  Payment shall be made at such
place  as  designated  by the  Holder  upon  surrender  of this  Senior  Secured
Convertible  Bridge  Note,  and shall be in such coin or  currency of the United
States  of  America  as at the time of  payment  shall be legal  tender  for the
payment of public and private debts.  Interest shall be computed on the basis of
a 360-day year of twelve 30-day months.  This Senior Secured  Convertible Bridge
Note  is one  of a duly  authorized  issue  of  Genta  Incorporated  12%  Senior
Convertible  Bridge  Notes  in  an  aggregate  principal  amount  of  $3,000,000
(individually a "Note"




<PAGE>



and  collectively  the "Notes") issued  pursuant to a Note and Warrant  Purchase
Agreement  dated  January  28,  1997  between  the  Company  and the Holder (the
"Purchase  Agreement").  The Senior  Secured  Convertible  Bridge Notes shall be
senior to all other  indebtedness of the Company ("Other  Indebtedness") and all
Other Indebtedness shall be subordinated to the Senior Bridge Notes. These Notes
are secured  pursuant to the Security  Agreement dated as of January 28, 1997 by
and between the Company, Paramount Capital, Inc. and the Purchasers.

SECTION 1.          PREPAYMENT.

                  This Note (including interest accrued on the principal hereof)
may be prepaid by the Company,  at any time without penalty or premium  provided
that the  Company  shall  provide the holders of the Notes with at least 30 days
prior written notice of prepayment, and prior to such prepayment, the holders of
the Notes shall have the  opportunity  to  exercise  their  optional  conversion
rights pursuant to Section 2 hereof.

SECTION 2.          OPTIONAL CONVERSION

                  (a) Right of  Conversion.  (i)  Immediately,  or,  (ii) if the
rules of the Nasdaq National Market or any other law or regulation,  require the
approval  of the  shareholders  of the Company to permit  convertibility  of the
Notes, then upon the receipt of such approvals,  the Notes shall be convertible,
in whole or in part, at the option of the holder  thereof and upon notice to the
Corporation as set forth in paragraph  2(b) below,  into the number of shares of
Series D Preferred  Stock of the Company (the  "Preferred  Stock")  equal to the
Conversion  Amount  divided by the then  current  Conversion  Price (as  defined
below). The Conversion Amount shall be the Liquidation Amount, or in the case of
a partial conversion, such lesser amount as designated by the converting holder.
The Liquidation Amount shall be the aggregate  principal value of the Notes held
by such Holder plus any accrued and unpaid interest.  The Conversion Price shall
initially be $50.00,  subject to adjustment as provided  below,  representing an
initial conversion rate (subject to adjustment) of 200 shares of Preferred Stock
per $10,000 of  Conversion  Amount.  Notwithstanding  anything  to the  contrary
contained in this Note,  no right of  conversion  shall exist if and only to the
extent that such  conversion  would result in the  occurrence of a  "Fundamental
Change"  under  Article  IV  of  the  Corporation's   Restated   Certificate  of
Incorporation.

                  (b)  Conversion  Procedures.  Any holder of Notes  desiring to
convert such Notes into Preferred Stock shall surrender the Notes at the offices
of the Company,  which Notes shall be accompanied by irrevocable  written notice
to the  Corporation  that  the  holder  elects  so to  convert  such  Notes  and
specifying  the  name  or  names  (with  address)  in  which  a  certificate  or
certificates  evidencing  shares  of  Preferred  Stock  are  to be  issued.  The
Corporation  will make a  notation  of the date that a notice of  conversion  is
received,  which  date shall be deemed to be the date of  receipt  for  purposes
hereof.

                  The  Corporation  shall deliver to the holder  converting  the
Notes, or to the nominee or nominees of such person, certificates evidencing the
number of full shares of



                                        2

<PAGE>



Preferred  Stock to which such person shall be entitled as  aforesaid,  together
with a cash  adjustment  of any  fraction  of a share as  hereinafter  provided.
Subject to the following provisions of this paragraph,  such conversion shall be
deemed to have been made as of the date of such  surrender  of the Notes and the
person or persons  entitled  to receive the  Preferred  Stock  deliverable  upon
conversion  of such Notes shall be treated for all purposes as the record holder
or holders of such Preferred  Stock on such date;  provided,  however,  that the
Corporation  shall not be required to convert any Notes while the stock transfer
books of the Corporation are closed for any purpose,  but the surrender of Notes
for  conversion  during any period  while such books are so closed  shall become
effective for conversion  immediately upon the reopening of such books as if the
surrender had been made on the date of such reopening,  and the conversion shall
be at the conversion rate in effect on such date.

                  All  notices of  conversion  shall be  irrevocable;  provided,
however,  that if the  Corporation  has  sent  notice  of an event  pursuant  to
paragraph  2(e) hereof,  a holder of Notes may, at its election,  provide in its
notice of conversion  that the conversion of its Notes shall be contingent  upon
the occurrence of the record date or  effectiveness  of such event (as specified
by such  holder),  provided  that such notice of  conversion  is received by the
Corporation prior to such record date or effective date, as the case may be.

                  (c) Protection From Dilution. (i) If, at any time or from time
to time after the date of this Note,  the Company  shall issue or  distribute to
the holders of shares of Preferred Stock evidence of its indebtedness, any other
securities  of the Company or any cash,  property or other  assets  (excluding a
subdivision,  combination  or  reclassification,  or  dividend  or  distribution
payable  solely to  holders of  Preferred  Stock in shares of  Preferred  Stock,
referred to in Subsection  (c)(ii),  and also  excluding  cash dividends or cash
distributions  paid out of net profits  legally  available  therefor in the full
amount  thereof  (any such  non-excluded  event being  herein  called a "SPECIAL
DIVIDEND"), the Conversion Price shall be adjusted by multiplying the Conversion
Price then in effect by a  fraction,  the  numerator  of which shall be the then
Current  Market Price Per Share of Preferred  Stock in effect on the record date
of such issuance or  distribution  less the fair market value (as  determined in
good faith by the Company's Board of Directors) of the evidence of indebtedness,
cash,  securities  or property,  or other assets issued or  distributed  in such
Special Dividend  applicable to one share of Preferred Stock and the denominator
of which shall be the then Current Market Price Per Share of Preferred  Stock in
effect on the record date of such issuance or  distribution.  An adjustment made
pursuant to this Subsection 2(a) shall become  effective  immediately  after the
record date of any such Special  Dividend.  The then  "CURRENT  MARKET PRICE PER
SHARE OF PREFERRED  STOCK" shall equal the then Current Market Price  multiplied
by the then effective  "Conversion Rate" (as defined and used in the Certificate
of Designation for the Preferred Stock).

The then Current  Market Price per share (the "CURRENT  MARKET  PRICE") shall be
deemed to be the last sale price of the Common Stock on the trading day prior to
such date or, in case no such reported sales take place on such day, the average
of the last  reported  bid and asked  prices of the Common Stock on such day, in
either case on the principal  national  securities  exchange on which the Common
Stock is admitted to trading or listed, or if not listed or admitted to trading


                                        3

<PAGE>

on any such exchange,  the representative  closing bid price of the Common Stock
as reported by the National  Association of Securities  Dealers,  Inc. Automated
Quotations  System  ("NASDAQ"),  or other similar  organization  if NASDAQ is no
longer  reporting such  information,  or, if the Common Stock is not reported on
NASDAQ,   the  high  per  share  bid   price  for  the   Common   Stock  in  the
over-the-counter  market as reported by the National Quotation Bureau or similar
organization,  or if not so available, the fair market value of the Common Stock
as determined in good faith by the Board of Directors.

                  (ii) In case the Company shall hereafter (i) pay a dividend or
make a  distribution  on its capital  stock in shares of Preferred  Stock,  (ii)
subdivide its  outstanding  shares of Preferred  Stock into a greater  number of
shares,  (iii) combine its outstanding  shares of Preferred Stock into a smaller
number of shares or (iv) issue by  reclassification  of its Preferred  Stock any
shares of capital stock of the Company (other than the Conversion  Shares),  the
Conversion  Price shall be  proportionately  adjusted so that the Notes shall be
convertible  into a number and kind of  securities  which the holders would have
been  entitled  to  receive  after any such event had they  converted  the Notes
immediately  prior  thereto.  An  adjustment  made  pursuant to this  Subsection
2(c)(ii) shall become effective immediately after the record date in the case of
a dividend or  distribution  and shall become  effective  immediately  after the
effective date in the case of a subdivision, combination or reclassification.

                  (iii) Except as provided in Subsections (c)(i) and (c)(iv), in
case  the  Company  shall  hereafter  issue  or sell any  Preferred  Stock,  any
securities  convertible into Preferred Stock, any rights, options or warrants to
purchase Preferred Stock or any securities  convertible into Preferred Stock, in
each case for a price per share or  entitling  the  holders  thereof to purchase
Preferred  Stock at a price  per share  (determined  by  dividing  (i) the total
amount,  if any,  received or receivable by the Company in  consideration of the
issuance  or sale of such  securities  plus  the  total  consideration,  if any,
payable  to  the  Company  upon  exercise  or  conversion  thereof  (the  "TOTAL
CONSIDERATION")  by (ii) the  number of  additional  shares of  Preferred  Stock
issuable  upon exercise or  conversion  of such  securities)  which is less than
either the then Current  Market Price Per Share of Preferred  Stock in effect on
the date of such issuance or sale or the Conversion  Price, the Conversion Price
shall be adjusted as of the date of such  issuance  or sale by  multiplying  the
Conversion  Price then in effect by a fraction,  the numerator of which shall be
(x) the sum of (A) the number of shares of Preferred  Stock  outstanding  on the
record date of such issuance or sale plus (B) the Total Consideration divided by
the Current Market Price Per Share of Preferred Stock or the current  Conversion
Price,  whichever  is  greater,  and the  denominator  of which shall be (y) the
number of shares of  Preferred  Stock  outstanding  on the  record  date of such
issuance or sale plus the maximum number of additional shares of Preferred Stock
issued, sold or issuable upon exercise or conversion of such securities.

                  (iv)   In   case   of   any    capital    reorganization    or
reclassification, or any consolidation or merger to which the Company is a party
other than a merger or  consolidation  in which the  Company  is the  continuing
corporation,  or in case of any sale or  conveyance  to  another  entity  of the
property of the Company as an entirety or substantially as a entirety, or in the
case of any statutory exchange of securities with another corporation (including
any exchange effected in


                                        4

<PAGE>

connection with a merger of a third corporation into the Company), the Holder of
this Note shall have the right  thereafter to receive on the  conversion of this
Note the kind and amount of securities,  cash or other property which the Holder
would  have  owned or have been  entitled  to  receive  immediately  after  such
reorganization,  reclassification,  consolidation,  merger,  statutory exchange,
sale or  conveyance  had  this  Note  been  converted  immediately  prior to the
effective date of such reorganization, reclassification,  consolidation, merger,
statutory  exchange,  sale or  conveyance  and in any such case,  if  necessary,
appropriate  adjustment  shall be made in the  application of the provisions set
forth in this Section 2 with respect to the rights and  interests  thereafter of
the Holder of this Note to the end that the provisions set forth in this Section
2  shall  thereafter  correspondingly  be  made  applicable,  as  nearly  as may
reasonably  be,  in  relation  to any  shares  of stock or other  securities  or
property  thereafter  deliverable  on the  Note.  The above  provisions  of this
Subsection   (c)(iv)  shall  similarly  apply  to  successive   reorganizations,
reclassifications,   consolidations,  mergers,  statutory  exchanges,  sales  or
conveyances.  The  Company  shall  require  the issuer of any shares of stock or
other securities or property thereafter deliverable on the exercise of this Note
to be  responsible  for all of the  agreements  and  obligations  of the Company
hereunder. Notice of any such reorganization,  reclassification,  consolidation,
merger,  statutory  exchange,  sale  or  conveyance  and of said  provisions  so
proposed  to be made,  shall be mailed to the Holders of the Notes not less than
30 days prior to such event. A sale of all or substantially all of the assets of
the Company for a  consideration  consisting  primarily of  securities  shall be
deemed a consolidation or merger for the foregoing purposes.

                  (v) In case  any  event  shall  occur as to  which  the  other
provisions  of this  Section 2 are not strictly  applicable  but as to which the
failure to make any adjustment  would not fairly  protect the conversion  rights
represented by this Note in accordance with the essential  intent and principles
hereof  then,  in each such case,  the  Holders  of Notes may  appoint a firm of
independent  public  accountants  of  recognized  national  standing  reasonably
acceptable to the Company,  which shall give their opinion as to the adjustment,
if  any,  on a  basis  consistent  with  the  essential  intent  and  principles
established herein, necessary to preserve the conversion rights. Upon receipt of
such  opinion,  the Company will  promptly  mail a copy thereof to the Holder of
this  Note  and  shall  make the  adjustments  described  therein.  The fees and
expenses of such independent public accountants shall be borne by the Company.

                  (vi) For purposes of the anti-dilution protection contained in
this  Section  (c),  at all times  following  the  conversion  of all  shares of
Preferred  Stock into shares of Common Stock,  the term Preferred Stock shall be
read  to  be  Common  Stock,  context  permitting,  so  that  the  anti-dilution
provisions  will continue to protect the conversion  rights  represented by this
Note after the  conversion of all the  Preferred  Stock into the Common Stock in
accordance with the essential  intent and principles of this Section 3 (it being
understood that prior to such conversion,  the  anti-dilution  provisions of the
Preferred Stock  underlying this Note shall be applicable to any dilutive events
with  respect to the Common  Stock and protect  the Holder from  dilution of the
Common Stock).


                                        5

<PAGE>


                  (d)   Reservation  of  Shares;   Transfer   Taxes;   Etc.  The
Corporation shall at all times reserve and keep available, out of its authorized
and unissued shares of Preferred Stock,  solely for the purpose of effecting the
conversion of the Notes,  such number of shares of its  Preferred  Stock free of
preemptive  rights as shall be sufficient to effect the  conversion of all Notes
from time to time  outstanding.  The Corporation shall use its best efforts from
time to time, in accordance with the laws of the State of Delaware,  to increase
the authorized  number of shares of Preferred Stock if at any time the number of
shares of Preferred Stock not outstanding  shall not be sufficient to permit the
conversion of all the then-outstanding Notes.

                  The  Corporation  shall pay any and all  issue or other  taxes
that may be payable in respect of any issue or delivery  of shares of  Preferred
Stock on  conversion  of the  Notes.  The  Corporation  shall not,  however,  be
required to pay any tax which may be payable in respect of any transfer involved
in the issue or delivery of Preferred Stock (or other securities or assets) in a
name other than that in which the Notes so  converted  were  registered,  and no
such issue or delivery shall be made unless and until the person requesting such
issue has paid to the Corporation the amount of such tax or has established,  to
the satisfaction of the Corporation, that such tax has been paid.

                  (e)      Prior Notice of Certain Events.  In case:

                    (i)    the Corporation shall declare any dividend (or any 
         other distribution); or

                    (ii) the  Corporation  shall  authorize  the granting to the
         holders of Preferred  Stock of rights or warrants to  subscribe  for or
         purchase  any  shares of stock of any  class or of any other  rights or
         warrants; or

                    (iii) of any reclassification of Preferred Stock (other than
         a subdivision or combination of the outstanding  Preferred  Stock, or a
         change in par value,  or from par value to no par value, or from no par
         value to par value); or

                    (iv) of any consolidation or merger to which the Corporation
         is  a  party  and  for  which  approval  of  any  stockholders  of  the
         Corporation  shall be  required,  or of the sale or  transfer of all or
         substantially all of the assets of the Corporation or of any compulsory
         share  exchange  whereby the  Preferred  Stock is converted  into other
         securities, cash or other property; or

                    (v)    of the voluntary or involuntary dissolution, 
         liquidation or winding up of the Corporation;

then the Corporation  shall cause to be mailed to the holders of Notes, at their
last addresses as they shall appear upon the books of the Corporation,  at least
20 days prior to the  applicable  record date  hereinafter  specified,  a notice
stating  (x) the date on which a record (if any) is to be taken for the  purpose
of such dividend, distribution or granting of rights or warrants or, if a record
is not to be  taken,  the date as of which the  holders  of  Preferred  Stock of
record to be



                                        6

<PAGE>



entitled to such dividend, distribution, rights or warrants are to be determined
and a description  of the cash,  securities or other  property to be received by
such holders upon such dividend,  distribution or granting of rights or warrants
or (y) the date on which such  reclassification,  consolidation,  merger,  sale,
transfer,  share  exchange,  dissolution,  liquidation  or  winding  up or other
liquidation  event is expected to become  effective,  the date as of which it is
expected that holders of Preferred Stock of record shall be entitled to exchange
their shares of Preferred  Stock for  securities or other  property  deliverable
upon such exchange, dissolution,  liquidation or winding up or other liquidation
event and the  consideration,  including  securities  or other  property,  to be
received by such holders upon such exchange;  provided, however, that no failure
to mail such notice or any defect therein or in the mailing thereof shall affect
the validity of the corporate action required to be specified in such notice.

                  (f) Other Changes in Conversion  Rate.  The  Corporation  from
time to time may  increase the  Conversion  Rate by any amount for any period of
time if the period is at least 20 days and if the increase is irrevocable during
the period. Whenever the Conversion Rate is so increased,  the Corporation shall
mail to  holders  of record of Notes a notice of the  increase  at least 15 days
before the date the  increased  Conversion  Rate takes  effect,  and such notice
shall state the increased Conversion Rate and the period it will be in effect.

                  The  Corporation  may make such  increases  in the  Conversion
Rate, in addition to those  required or allowed by this paragraph 4, as shall be
determined by it, as evidenced by a resolution of the Board of Directors,  to be
advisable  in order to avoid or  diminish  any  income  tax to holders of Common
Stock resulting from any dividend or distribution of stock or issuance of rights
or warrants to purchase or subscribe for stock or from any event treated as such
for income tax purposes.

SECTION 3.          DEFAULT CONVERSION.

                  (a) If this Note and all accrued  interest shall not have been
paid in full on or before the Maturity  Date or upon the  occurrence of an Event
of Default  (as  defined in Section 7 hereof),  the Holder  shall have the right
(the "Default  Conversion  Right"),  in addition to any other available remedies
set forth in  Section  8 hereof or at law or in  equity,  to  convert  up to the
lesser of (i) the then outstanding  principal amount of this Note or (ii) 10% of
the original  principal amount of this Note, into the number of shares of Common
Stock of the Company  ("Common  Stock"),  equal to the amount  converted  by the
Noteholder upon such Event of Default (the "Default  Conversion Amount") divided
by $.001 (the "Default  Conversion Price").  Upon conversion,  the Company shall
pay all accrued and unpaid interest on the Default Conversion Amount.

                  (b) To exercise the Default  Conversion  Right, the Holder, on
or before the 60th day after the Maturity  Date,  but before  payment in full of
the then  outstanding  principal and interest under this Note,  shall deliver to
the Company, at its office at as set forth in section 11, or at such other place
as is designated in writing by the Company,  a notice (the "Conversion  Notice")
stating that the Holder is exercising the Default Conversion Right, the Default


                                        7

<PAGE>

Conversion  Amount  and the  name or  names  in  which  the  Holder  wishes  the
certificates for shares of Common Stock to be issued.

                  (c) To the extent  permitted by applicable  law, upon exercise
of the Default  Conversion Right, the Holder shall be deemed to be the holder of
record  of  the  shares  of  Common  Stock  issuable  upon  such  exercise  (the
"Conversion  Shares"),  notwithstanding  that the transfer  books of the Company
shall then be closed or certificates  representing  such Conversion Shares shall
not then have been actually  delivered to the Holder. As soon as practicable and
in any event  within  five (5) days after  exercise  of the  Default  Conversion
Right,  the  Company  shall  issue and  deliver to the Holder a  certificate  or
certificates  evidencing  the  Conversion  Shares  registered in the name of the
Holder or its  designee,  provided  that the Company may require the holder,  by
notice given to the Holder promptly after receipt of the Conversion Notice, as a
condition to the delivery of such certificate or  certificates,  to present this
Note to the Company for the  placement  hereon of a legend  indicating  that the
Default  Conversion  Right  has been  exercised  to the  extent  of the  Default
Conversion  Amount,  and  this  Note  (unless  thereby  paid in  full)  shall be
immediately returned to the Holder.

                  (d) The  issuance of any shares or other  securities  upon the
exercise of the Default  Conversion  Right,  and the delivery of certificates or
other instruments  representing  such shares or other securities,  shall be made
without  charge to the  Holder  for any tax or other  charge in  respect of such
issuance.  The Company shall not, however,  be required to pay any tax which may
be payable in respect of any transfer  involved in the issue and delivery of any
certificate in a name other than that of the Holder and the Company shall not be
required to issue or deliver any such certificate unless and until the person or
persons  requesting  the issue thereof shall have paid to the Company the amount
of such tax or shall have  established to the  satisfaction  of the Company that
such tax has been paid.

                  (e) The  Holder  shall not have,  solely  on  account  of such
status as a Holder of this Note,  any rights of a  stockholder  of the  Company,
either at law or in equity,  or any notice of meetings of stockholders or of any
other proceedings of the Company except as provided in this Note.

                  (f) The  Company  shall at all times  following  the  Issuance
Date,  reserve and keep available out of its  authorized and unissued  shares of
Common  Stock,  solely for the  purpose of  providing  for the  exercise  of the
Default  Conversion  Right, such number of shares of Common Stock as shall, from
time to time, be sufficient for the exercise of the Default  Conversion Right in
full.  The  Company  covenants  that all shares of Common  Stock  issuable  upon
exercise of the Default Conversion Right shall be validly issued, fully paid and
nonassessable.

                  (g) The  anti-dilution  protections  set forth in Section 2(c)
hereof shall apply as well to the Default Conversion Right and the adjustment of
the Default Conversion Price hereunder,  provided, however, that for purposes of
such application all appropriate  references to Preferred Stock shall be read as
references to Common Stock and all references to the  Conversion  Price shall be
read as references to the Default Conversion Price, so as to give the Default


                                        8

<PAGE>

Conversion  Rights,  as  nearly  as  practicable,  the  anti-dilution  and other
protections provided for in section 2(c) with respect to the Optional Conversion
Right.

SECTION 4.          FRACTIONAL SHARES.

                  (a) The Company  shall not be required to issue  fractions  of
shares of Common Stock or other  capital  stock of the Company upon the exercise
of the Optional and Default  Conversion  Right. If any fraction of a share would
be issuable  on any  exercise of the  Optional or Default  Conversion  Right (or
specified  portions  thereof),  the Company shall  purchase such fraction for an
amount in cash equal to the same  fraction of the  closing  price for the Common
Stock on the  trading  date  immediately  preceding  the date of exercise of the
Optional or Default Conversion Right.

SECTION 5.          AFFIRMATIVE COVENANTS OF THE COMPANY.

                  The  Company  covenants  and agrees  that until the payment in
full of this Note, the Company shall:

                  (a) Existence; Business.  (i) Preserve, renew and keep in 
full force and effect its legal  existence  and (ii)  obtain,  preserve,  renew,
extend and keep in full force and effect the licenses, permits,  authorizations,
patents, trademarks and trade names material to its business.

                  (b) Use of  Proceeds.  Use the  proceeds  of the Notes of this
issue  solely  as set  forth in  Section  7.7 of the Note and  Warrant  Purchase
Agreement between the Company and various  purchasers dated the date hereof (the
"Purchase Agreement")

                  (c) Reports.  Furnish to the Holder,  at the time furnished to
the  Company's  stockholders,  reports  furnished  generally  to  the  Company's
stockholders, and copies of Current Reports on Form 8-K.

                  (d) Notice of Events of Default.  Furnish to the Holder prompt
written notice of any Event of Default, specifying the nature and extent thereof
and corrective action, if any, proposed to be taken with respect thereto.

                  (e) Authorization of Stock Issuable Upon Conversion.  No later
than the Maturity Date,  authorize and reserve a sufficient number of its shares
for exercise of the Default Conversion Right.

SECTION 6.          NEGATIVE COVENANTS OF THE COMPANY.

                  The  Company  covenants  and agrees with the Holder that until
the payment in full of this Note, the Company shall not:


                                        9

<PAGE>

                  (a) Indebtedness. Incur, create, assume or permit to exist any
indebtedness except (i) indebtedness represented by the Notes, (ii) indebtedness
which by its terms is  subordinated  to the Notes in an amount less than $25,000
in the  aggregate  (iii)  indebtedness  in an amount  less than  fifty  thousand
dollars  ($50,000)  incurred  in the  ordinary  course  of  business,  and  (iv)
indebtedness  for borrowed  money  existing on the date hereof and  disclosed in
writing to the Holder on or prior to the date  hereof,  but not any  extensions,
renewals or replacements of such indebtedness;

                  (b) Liens.  Create,  incur, assume or permit to exist any lien
on any property or assets  (including  stock or other  securities of any person)
now owned or hereafter  acquired by the Company,  except (i) liens for taxes not
yet due or which are being contested by appropriate proceedings; (ii) carriers',
warehousemen's,  mechanic's,  materialmen's,  repairmen's  or other  like  liens
arising in the ordinary course of business and securing obligations that are not
due or which are being  contested;  or (iii) liens of attachments,  judgments or
awards against the Company (X) which could not reasonably be expected to have an
adverse material effect on the Company or (Y) with respect to which an appeal or
proceeding  for review shall be pending or a stay of  execution  shall have been
obtained,  or  which  are  otherwise  being  contested  in  good  faith  and  by
appropriate  proceedings,  or (iv) purchase  money liens,  equipment  leases and
financings incurred in the ordinary course of business.

                  (c)  Sale  and   Lease-Back   Transactions.   Enter  into  any
arrangement,  directly or  indirectly,  with any person whereby it shall sell or
transfer any property, real or personal, used or useful in its business, whether
now owned or hereafter  acquired,  and thereafter rent  (including  intellectual
property),  lease or license such property or other property which it intends to
use for substantially the same purpose or purposes as the property being sold or
transferred.

                  (d) Mergers, Consolidations, Sales of Assets and Acquisitions.
Merge into or consolidate  with any other person,  or permit any other person to
merge into or consolidate with it, or sell, transfer, lease or otherwise dispose
of (in one transaction or in a series of transactions) all or a substantial part
of its assets  (whether now owned or hereafter  acquired) or purchase,  lease or
otherwise  acquire (in one  transaction  or a series of  transactions)  all or a
substantial part of the assets of any other person.

                  (e) Dividends and  Distributions.  Declare or pay, directly or
indirectly, any dividend or make any other distribution (by reduction of capital
or otherwise),  whether in cash, property,  securities or a combination thereof,
with  respect to any  shares of its  capital  stock or  directly  or  indirectly
redeem, purchase,  retire or otherwise acquire for value any shares of any class
of its  capital  stock or set aside any amount for any such  purpose,  except as
permitted by Section 7.15 of the Note and Warrant Agreement.

                  (f) No  Impairment.  By  amendment  of its  charter or through
reorganization,  consolidation, merger, dissolution, sale of assets or any other
voluntary action, avoid or seek to avoid the observance or performance of any of
the  terms of this  Note,  but will at all  times in good  faith  assist  in the
carrying out of all such terms and in the taking of all such action as


                                       10

<PAGE>

may be necessary or  appropriate in order to protect the rights of the Holder of
this Note against impairment.


SECTION 7.          EVENTS OF DEFAULT DEFINED.

                  The  following  shall each  constitute  an "Event of  Default"
hereunder:

                  (a) the failure of the Company to make any payment of 
principal of or interest on this Note when due and payable;

                  (b) the  failure of the  Company  to  observe  or perform  any
covenant in this Note or in the Purchase Agreement,  and such failure shall have
continued unremedied for a period of five (5) days;

                  (c)  if the Company shall:

                           (1)      admit in writing its inability to pay its 
                                    debts generally as they become due,

                           (2)      file a petition in bankruptcy or a petition 
                                    to take advantage of any insolvency act,

                           (3)      make an assignment for the benefit of its 
                                    creditors,

                           (4)      consent to the appointment of a receiver of
                                    itself  or of the whole or any  substantial
                                    part of its property,

                           (5)      on a petition in bankruptcy filed against, 
                                    be adjudicated a bankrupt, or

                           (6)      file   a   petition   or   answer    seeking
                                    reorganization   or  arrangement  under  the
                                    federal   bankruptcy   laws  or  any   other
                                    applicable  law or  statute  of  the  United
                                    States of America or any state thereof;

                  (d) if a court of competent jurisdiction shall enter an order,
judgment or decree appointing, without the consent of the Company, a receiver of
the  Company  or of the  whole  or any  substantial  part  of its  property,  or
approving a petition filed against it seeking  reorganization  or arrangement of
the Company under the federal  bankruptcy  laws or any other  applicable  law or
statute of the United  States of America or any State  thereof,  and such order,
judgment  or decree  shall not be vacated or set aside or stayed  within  thirty
(30) days from the date of entry thereof;


                                       11

<PAGE>

                  (e) if, under the  provisions  of any other law for the relief
or aid of debtors,  any court of competent  jurisdiction shall assume custody or
control of the Company or the whole or any substantial  part of its property and
such custody or control  shall not be  terminated  or stayed  within thirty (30)
days from the date of assumption of such custody or control;

                  (f) the liquidation, dissolution or winding up of the Company;

                  (g) the failure of the  shareholders  to authorize and approve
the  issuance of these Notes or the  issuance of the shares of  Preferred  Stock
underlying  these Notes,  the Bridge Warrants or the New Warrants (as such terms
are defined in the  Purchase  Agreement),  or any Common  Stock  underlying  the
foregoing to the extent such authorization is necessary pursuant to the rules of
the Nasdaq National Market or any other applicable law, rule or regulation.

                  (h) A  default  or  event of  default  which  remains  uncured
following any applicable cure period under the Security Agreement; or

                  (i) A final  judgment or judgments for the payment of money in
excess of $1,000,000  in the aggregate  shall be rendered by one or more courts,
administrative or arbitral tribunals or other bodies having jurisdiction against
the Company and the same shall not be discharged (or provision shall not be made
for such  discharge),  or a stay of  execution  thereof  shall not be  procured,
within 30 days from the date of entry thereof and the Company shall not,  within
such 30-day  period,  or such longer period  during which  execution of the same
shall have been stayed,  appeal therefrom and cause the execution  thereof to be
stayed during such appeal; or

SECTION 8.          REMEDIES UPON EVENT OF DEFAULT.

                  (a) Upon the occurrence of an Event of Default, (i) the entire
principal  amount of, and all  accrued and unpaid  interest  on, this Note shall
automatically  become immediately due and payable without  presentment,  demand,
protest or other  formalities  of any kind,  all of which are  hereby  expressly
waived by the Company and (ii)  additional  interest shall begin to accrue,  and
shall be considered  immediately due and payable, on the unpaid principal amount
of this Note at the rate of eighteen  percent (18%) per annum and shall continue
to accrue  until the  initial  interest  and  additional  interest  is paid.  In
addition,  the  Holder may take any action  available  to it under the  Purchase
Agreement or at law or in equity or by statute or otherwise.

                  (b) No remedy herein conferred upon the Holder of this Note is
intended  to be  exclusive  of any other  remedy and each and every such  remedy
shall be  cumulative  and  shall be in  addition  to every  other  remedy  given
hereunder  or now or  hereafter  existing  at law or in equity or by  statute or
otherwise.





                                       12

<PAGE>



SECTION 9.          NOTE REGISTER.

                  (a) The Company shall keep at its principal executive office a
register  (herein  sometimes  referred  to as the  "Note  Register"),  in which,
subject to such reasonable  regulations as it may prescribe,  but at its expense
(other  than  transfer  taxes,  if  any),  the  Company  shall  provide  for the
registration and transfer of this Note.

                  (b) Whenever this Note shall be  surrendered  at the principal
executive  office of the Company  for  transfer or  exchange,  accompanied  by a
written  instrument of transfer in form  reasonably  satisfactory to the Company
duly executed by the Holder  hereof or his attorney duly  authorized in writing,
the Company shall execute and deliver in exchange  therefor a new Note or Notes,
as may be requested  by such  Holder,  in the same  aggregate  unpaid  principal
amount and payable on the same date as the principal amount of the Note or Notes
so  surrendered;  each  such  new  Note  shall  be dated as of the date to which
interest  has been paid on the unpaid  principal  amount of the Note or Notes so
surrendered and shall be in such principal amount and registered in such name or
names as such Holder may designate in writing.

                  (c)  Upon  receipt  by  the  Company  of  evidence  reasonably
satisfactory  to it of the loss,  theft,  destruction or mutilation of this Note
and of indemnity  reasonably  satisfactory to it, and upon  reimbursement to the
Company of all reasonable expenses  incidental  thereto,  and upon surrender and
cancellation  of this Note (in case of  mutilation)  the  Company  will make and
deliver  in lieu of this  Note a new Note of like  tenor  and  unpaid  principal
amount  and dated as of the date to which  interest  has been paid on the unpaid
principal  amount  of this  Note in lieu of  which  such  new  Note is made  and
delivered.

SECTION 10.         REGISTRATION UNDER SECURITIES ACT OF 1933.

                  The  Holder of this Note  shall  have  registration  rights as
provided in Section 8 of the Purchase  Agreement,  with respect to the shares of
Common Stock  underlying  the Preferred  Stock  issuable upon  conversion of the
Notes pursuant to the Optional and Default  Conversion  Right.  If the Holder is
not a party to the Purchase  Agreement,  by acceptance of this Note,  the Holder
agrees to comply with  provisions of Section 8 of the Purchase  Agreement to the
same extent as if it were a party thereto.

SECTION 11.       MISCELLANEOUS.

                  (a)  Amendments  and  Waivers.  The holders of  sixty-six  and
two-thirds percent (66 2/3%) or more in principal amount of outstanding Notes of
this  issue  may  waive or  otherwise  consent  to the  amendment  of any of the
provisions  hereof,  provided  that no such waiver or  amendment  may reduce the
principal  amount of or interest on any of the Notes of this issue or change the
stated maturity of the principal or reduce the percentage of holders of Notes of
this issue necessary to waive or amend the provisions of this Note,  without the
consent of each holder of any Note affected thereby.




                                       13

<PAGE>




                  (b)  Restrictions  on  Transferability.  In  addition  to  the
restrictions set forth in Section 9(a) of this Note, the securities  represented
by this Note have been  acquired  for  investment  and have not been  registered
under the  Securities  Act of 1933, as amended,  or the  securities  laws of any
state or other jurisdiction.  Without such registration, such securities may not
be sold,  pledged,  hypothecated  or otherwise  transferred,  except pursuant to
exemptions from the Securities Act of 1933, and the securities laws of any state
or other  jurisdiction.  Notwithstanding  the above, the holder of this Note has
been  provided the  registration  rights  contained in Section 8 of the Purchase
Agreement with respect to the shares of the Company's  Common Stock which may be
acquired upon exercise of the Optional and Default Conversion Right.

                  (c)  Forbearance  from Suit.  No holder of Notes of this issue
shall  institute any suit or proceeding  for the  enforcement  of the payment of
principal or interest unless the holders of at least fifty-one  percent (51%) in
principal amount of all of the outstanding Notes of this issue join in such suit
or proceeding.

                  (d)  Governing  Law.  This  Note  shall  be  governed  by  and
construed in  accordance  with the laws of the State of New York,  excluding the
body of law  relating  to  conflict  of laws.  Notwithstanding  anything  to the
contrary  contained  herein,  in no event  may the  effective  rate of  interest
collected or received by the Holder exceed that which may be charged,  collected
or received by the Holder under applicable law.

                  (e)  Interpretation.  If any term or  provision  of this  Note
shall be held invalid, illegal or unenforceable, the validity of all other terms
and provisions hereof shall in no way be affected thereby.

                  (f) Successors and Assigns.  This Note shall be binding upon 
the Company and its successors and assigns and shall inure to the benefit of the
Holder and its successors and assigns.

                  (g) Notices. All notices, requests, consents and demands shall
be made in writing and shall be mailed postage prepaid, or delivered by hand, to
the Company or to the Holder  thereof at their  respective  addresses  set forth
below or to such other address as may be furnished in writing to the other party
hereto:

                  If to the Holder:  At the address shown on Schedule A attached
hereto.

                  with a copy to:    Paramount Capital, Inc.
                                     787 Seventh Avenue
                                     New York, NY 10019
                                     Attn: David R. Walner

                  If to the Company: Genta Incorporated
                                     3350 General Atomics Court



                                       14

<PAGE>



                               San Diego, CA 92121
                               Attention: Chief Executive Officer

                  (h) Saturdays,  Sundays, Holidays. If any date that may at any
time be  specified  in this  Note as a date for the  making  of any  payment  of
principal or interest under this Note shall fall on Saturday, Sunday or on a day
which in New York shall be a legal holiday, then the date for the making of that
payment  shall be the next  subsequent  day which is not a  Saturday,  Sunday or
legal holiday.

                  (i)  Purchase  Agreement.  This Note is  subject  to the terms
contained in the Purchase  Agreement  dated the date hereof  between the Company
and certain  purchasers of the Senior Secured  Convertible  Bridge Notes and the
holder of this Note is entitled to the benefits of such  Purchase  Agreement and
may, in addition to any rights hereunder,  enforce the agreements of the Company
contained  therein and exercise  the remedies  provided for thereby or otherwise
available in respect thereof.




                                       15

<PAGE>


         IN WITNESS  WHEREOF,  this Note has been  executed  and  delivered as a
sealed  instrument  on the date  first  above  written  by the  duly  authorized
representative of the Company.


ATTEST:                                     GENTA INCORPORATED


_______________________             By:     ________________________________
                                            Name:
                                            Its:



(Corporate Seal)


                                       16