Exhibit 4.3


 


PLACEMENT AGENT COMMON STOCK PURCHASE
WARRANT


 


ONCONOVA THERAPEUTICS, INC.


 


	Warrant Shares:	 	Issue Date: November 25, 2019


 


	 	 	Initial Exercise Date: November 25, 2019


 


THIS PLACEMENT AGENT COMMON STOCK PURCHASE
WARRANT (the “Warrant”) certifies that, for value received,                       
or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the
conditions hereinafter set forth, at any time on or after the date set forth above (the “Initial Exercise Date”)
and on or prior to 5:00 p.m. (New York City time) on November 21, 2024 (the “Termination Date”) but
not thereafter, to subscribe for and purchase from Onconova Therapeutics, Inc., a Delaware corporation (the “Company”),
up to                       
shares (as subject to adjustment hereunder, the “Warrant Shares”) of the Company’s Common Stock. The purchase
price of one share of Common Stock under this Warrant shall be equal to the Exercise Price, as defined in Section 2(b). 
This Warrant is issued pursuant to that certain engagement letter, dated as of September 20, 2019, by and between the Company and
H.C. Wainwright & Co., LLC (the “Engagement Letter”).


 


Section 1.             
Definitions.  In addition to the terms defined elsewhere in this Warrant, the following terms have the meanings indicated
in this Section 1:


 


“Affiliate” means any
Person that, directly or indirectly through one or more intermediaries, controls or is controlled by or is under common control
with a Person, as such terms are used in and construed under Rule 405 under the Securities Act.


 


“Bid Price” means, for
any date, the price determined by the first of the following clauses that applies: (a) if the Common Stock is then listed
or quoted on a Trading Market, the bid price of the Common Stock for the time in question (or the nearest preceding date) on the
Trading Market on which the Common Stock is then listed or quoted as reported by Bloomberg L.P. (based on a Trading Day from 9:30
a.m. (New York City time) to 4:02 p.m. (New York City time)), (b)  if OTCQB or OTCQX is not a Trading Market, the
volume weighted average price of the Common Stock for such date (or the nearest preceding date) on OTCQB or OTCQX as applicable,
(c) if the Common Stock is not then listed or quoted for trading on OTCQB or OTCQX and if prices for the Common Stock are
then reported on The Pink Open Market (or a similar organization or agency succeeding to its functions of reporting prices), the
most recent bid price per share of the Common Stock so reported, or (d) in all other cases, the fair market value of a share
of Common Stock as determined by an independent appraiser selected in good faith by the Holders of a majority in interest of the
Warrants then outstanding and reasonably acceptable to the Company, the fees and expenses of which shall be paid by the Company.


 


“Board of Directors” means
the board of directors of the Company.


 


“Commission” means the
United States Securities and Exchange Commission.


 


“Common Stock” means the
common stock of the Company, par value $0.01 per share, and any other class of securities into which such securities may hereafter
be reclassified or changed.


 


“Common Stock Equivalents”
means any securities of the Company or its subsidiaries which would entitle the holder thereof to acquire at any time shares of
Common Stock, including, without limitation, any debt, preferred stock, right, option, warrant or other instrument that is at any
time convertible into or exercisable or exchangeable for, or otherwise entitles the holder thereof to receive, Common Stock.


 


“Exchange Act” means the
Securities Exchange Act of 1934, as amended, and the rules and regulations promulgated thereunder.


 






    


     


    

 


“Person” means an individual
or corporation, partnership, trust, incorporated or unincorporated association, joint venture, limited liability company, joint
stock company, government (or an agency or subdivision thereof) or other entity of any kind.


 


“Purchase Agreement” means
that certain Securities Purchase Agreement, dated as of November 21, 2019, by and among the Company and the purchasers signatory
thereto.


 


“Registration Statement”
means the Company’s registration statement on Form S-1 (File No. 333-234360), including the final prospectus filed
in connection with the transaction contemplated by the Purchase Agreement.


 


“Securities Act” means
the Securities Act of 1933, as amended, and the rules and regulations promulgated thereunder.


 


“Trading Day” means a day
on which the Common Stock is traded on a Trading Market.


 


“Trading Market” means
any of the following markets or exchanges on which the Common Stock is listed or quoted for trading on the date in question: the
NYSE American, the Nasdaq Capital Market, the Nasdaq Global Market, the Nasdaq Global Select Market or the New York Stock Exchange
(or any successors to any of the foregoing).


 


“Transfer Agent” means
EQ Shareowner Services, the current transfer agent of the Company, with a mailing address of P.O. Box 64945, St. Paul, MN
55164-0945 and any successor transfer agent of the Company.


 


“VWAP” means, for any date,
the price determined by the first of the following clauses that applies: (a) if the Common Stock is then listed or quoted
on a Trading Market, the daily volume weighted average price of the Common Stock for such date (or the nearest preceding date)
on the Trading Market on which the Common Stock is then listed or quoted as reported by Bloomberg L.P. (based on a Trading Day
from 9:30 a.m. (New York City time) to 4:02 p.m. (New York City time)), (b)  if OTCQB or OTCQX is not a Trading
Market, the volume weighted average price of the Common Stock for such date (or the nearest preceding date) on OTCQB or OTCQX as
applicable, (c) if the Common Stock is not then listed or quoted for trading on OTCQB or OTCQX and if prices for the Common
Stock are then reported on The Pink Open Market (or a similar organization or agency succeeding to its functions of reporting prices),
the most recent bid price per share of the Common Stock so reported, or (d) in all other cases, the fair market value of a
share of Common Stock as determined by an independent appraiser selected in good faith by the Holders of a majority in interest
of the Warrants then outstanding and reasonably acceptable to the Company, the fees and expenses of which shall be paid by the
Company.


 


“Warrants” means this Warrant
and other Placement Agent Common Stock purchase warrants issued by the Company pursuant to the Engagement Letter.


 


Section 2.             
Exercise.


 


a)            Exercise
of Warrant.  Exercise of the purchase rights represented by this Warrant may be made, in whole or in part, at any
time or times on or after the Initial Exercise Date and on or before the Termination Date by delivery to the Company of a
duly executed facsimile copy or PDF copy submitted by e-mail (or e-mail attachment) of the Notice of Exercise in the form
annexed hereto (the “Notice of Exercise”).  Within the earlier of (i) two (2) Trading Days
and (ii) the number of Trading Days comprising the Standard Settlement Period (as defined in
Section 2(d)(i) herein) following the date of exercise as aforesaid, the Holder shall deliver the aggregate
Exercise Price for the Warrant Shares specified in the applicable Notice of Exercise by wire transfer or cashier’s
check drawn on a United States bank unless the cashless exercise procedure specified in Section 2(c) below is
specified in the applicable Notice of Exercise.  No ink-original Notice of Exercise shall be required, nor shall any
medallion guarantee (or other type of guarantee or notarization) of any Notice of Exercise be required.  Notwithstanding
anything herein to the contrary, the Holder shall not be required to physically surrender this Warrant to the Company until
the Holder has purchased all of the Warrant Shares available hereunder and the Warrant has been exercised in full, in which
case, the Holder shall surrender this Warrant to the Company for cancellation within three (3) Trading Days of the date
on which the final Notice of Exercise is delivered to the Company. Partial exercises of this Warrant resulting in purchases
of a portion of the total number of Warrant Shares available hereunder shall have the effect of lowering the
outstanding number of Warrant Shares purchasable hereunder in an amount equal to the applicable number of Warrant Shares
purchased.  The Holder and the Company shall maintain records showing the number of Warrant Shares purchased and the
date of such purchases. The Company shall deliver any objection to any Notice of Exercise within one (1) Trading Day of
receipt of such notice.  The Holder and any assignee, by acceptance of this Warrant, acknowledge and agree that, by
reason of the provisions of this paragraph, following the purchase of a portion of the Warrant Shares hereunder, the number
of Warrant Shares available for purchase hereunder at any given time may be less than the amount stated on the face
hereof.


 






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b)           
Exercise Price.  The exercise price per share of Common Stock under this Warrant shall be $0.25, subject to
adjustment hereunder (the “Exercise Price”).


  


c)            
Cashless Exercise. If at the time of exercise hereof there is no effective registration statement registering, or the prospectus
contained therein is not available for the issuance or resale of the Warrant Shares to or by the Holder, then this Warrant may
also be exercised, in whole or in part, at such time by means of a “cashless exercise” in which the Holder shall be
entitled to receive a number of Warrant Shares equal to the quotient obtained by dividing [(A-B) (X)] by (A), where:


 


(A) = as applicable: (i) the
VWAP on the Trading Day immediately preceding the date of the applicable Notice of Exercise if such Notice of Exercise is (1) both
executed and delivered pursuant to Section 2(a) hereof on a day that is not a Trading Day or (2) both executed and
delivered pursuant to Section 2(a) hereof on a Trading Day prior to the opening of “regular trading hours”
(as defined in Rule 600(b)(68) of Regulation NMS promulgated under the federal securities laws) on such Trading Day, (ii) at
the option of the Holder, either (y) the VWAP on the Trading Day immediately preceding the date of the applicable Notice of
Exercise or (z) the Bid Price of the Common Stock on the principal Trading Market as reported by Bloomberg L.P. as of the
time of the Holder’s execution of the applicable Notice of Exercise if such Notice of Exercise is executed during “regular
trading hours” on a Trading Day and is delivered within two (2) hours thereafter (including until two (2) hours
after the close of “regular trading hours” on a Trading Day) pursuant to Section 2(a) hereof or (iii) the
VWAP on the date of the applicable Notice of Exercise if the date of such Notice of Exercise is a Trading Day and such Notice of
Exercise is both executed and delivered pursuant to Section 2(a) hereof after the close of “regular trading hours”
on such Trading Day;


 


(B) = the Exercise Price
of this Warrant, as adjusted hereunder; and


 


(X) = the number of Warrant
Shares that would be issuable upon exercise of this Warrant in accordance with the terms of this Warrant if such exercise were
by means of a cash exercise rather than a cashless exercise.


 


If Warrant Shares are issued in
such a cashless exercise, the parties acknowledge and agree that in accordance with Section 3(a)(9) of the Securities
Act, the Warrant Shares shall take on the registered characteristics of the Warrants being exercised.  The Company agrees
not to take any position contrary to this Section 2(c).


 


Notwithstanding anything herein
to the contrary, on the Termination Date, this Warrant shall be automatically exercised via cashless exercise pursuant to this
Section 2(c).


 






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d)           
Mechanics of Exercise.


 


i.                  Delivery
of Warrant Shares Upon Exercise.  The Company shall cause the Warrant Shares purchased hereunder to be
transmitted by the Transfer Agent to the Holder by crediting the account of the Holder’s or its designee’s
balance account with The Depository Trust Company through its Deposit or Withdrawal at Custodian system
(“DWAC”) if the Company is then a participant in such system and either (A) there is an effective
registration statement permitting the issuance of the Warrant Shares to or resale of the Warrant Shares by the Holder or
(B) this Warrant is being exercised via cashless exercise, and otherwise by physical delivery of a certificate,
registered in the Company’s share register in the name of the Holder or its designee, for the number of Warrant Shares
to which the Holder is entitled pursuant to such exercise to the address specified by the Holder in the Notice of Exercise by
the date that is the earlier of (A) the earlier of (i) two (2) Trading Days and (ii) the number of days
comprising the Standard Settlement Period, in each case after the delivery to the Company of the Notice of Exercise and
(B) one (1) Trading Day after delivery of the aggregate Exercise Price to the Company (such date, the
 “Warrant Share Delivery Date”). Upon delivery of the Notice of Exercise, the Holder shall be deemed for
all corporate purposes to have become the holder of record of the Warrant Shares with respect to which this Warrant has been
exercised, irrespective of the date of delivery of the Warrant Shares, provided that payment of the aggregate Exercise Price
(other than in the case of a cashless exercise) is received by the Warrant Share Delivery Date.  If the Company fails
for any reason to deliver to the Holder the Warrant Shares subject to a Notice of Exercise by the Warrant Share
Delivery Date, the Company shall pay to the Holder, in cash, as liquidated damages and not as a penalty, for each $1,000 of
Warrant Shares subject to such exercise (based on the VWAP of the Common Stock on the date of the applicable Notice of
Exercise), $10 per Trading Day (increasing to $20 per Trading Day on the fifth Trading Day after such liquidated damages
begin to accrue) for each Trading Day after such Warrant Share Delivery Date until such Warrant Shares are delivered or
Holder rescinds such exercise. The Company agrees to maintain a transfer agent that is a participant in the FAST program so
long as this Warrant remains outstanding and exercisable. As used herein, “Standard Settlement Period”
means the standard settlement period, expressed in a number of Trading Days, on the Company’s primary Trading Market
with respect to the Common Stock as in effect on the date of delivery of the Notice of Exercise.


 


ii.              
Delivery of New Warrants Upon Exercise.  If this Warrant shall have been exercised in part, the Company shall, at the
request of a Holder and upon surrender of this Warrant certificate, at the time of delivery of the Warrant Shares, deliver to the
Holder a new Warrant evidencing the rights of the Holder to purchase the unpurchased Warrant Shares called for by this Warrant,
which new Warrant shall in all other respects be identical with this Warrant.


 


iii.           
Rescission Rights.  If the Company fails to cause the Transfer Agent to transmit to the Holder the Warrant Shares pursuant
to Section 2(d)(i) by the Warrant Share Delivery Date, then the Holder will have the right to rescind such exercise.


 


iv.           Compensation
for Buy-In on Failure to Timely Deliver Warrant Shares Upon Exercise.  In addition to any other rights available to
the Holder, if the Company fails to cause the Transfer Agent to transmit to the Holder the Warrant Shares in accordance with
the provisions of Section 2(d)(i) above pursuant to an exercise on or before the Warrant Share Delivery Date,
and if after such date the Holder is required by its broker to purchase (in an open market transaction or otherwise) or the
Holder’s brokerage firm otherwise purchases, shares of Common Stock to deliver in satisfaction of a sale by the Holder
of the Warrant Shares which the Holder anticipated receiving upon such exercise (a “Buy-In”), then the
Company shall (A) pay in cash to the Holder the amount, if any, by which (x) the Holder’s total purchase
price (including brokerage commissions, if any) for the shares of Common Stock so purchased exceeds (y) the amount
obtained by multiplying (1) the number of Warrant Shares that the Company was required to deliver to the Holder in
connection with the exercise at issue times (2) the price at which the sell order giving rise to such purchase
obligation was executed, and (B) at the option of the Holder, either reinstate the portion of the Warrant and equivalent
number of Warrant Shares for which such exercise was not honored (in which case such exercise shall be deemed rescinded) or
deliver to the Holder the number of shares of Common Stock that would have been issued had the Company timely complied with
its exercise and delivery obligations hereunder.  For example, if the Holder purchases Common Stock having a total
purchase price of $11,000 to cover a Buy-In with respect to an attempted exercise of shares of Common Stock with an aggregate
sale price giving rise to such purchase obligation of $10,000, under clause (A) of the immediately preceding sentence
the Company shall be required to pay the Holder $1,000. The Holder shall provide the Company written notice indicating the
amounts payable to the Holder in respect of the Buy-In and, upon request of the Company, evidence of the amount of such
loss.  Nothing herein shall limit a Holder’s right to pursue any other remedies available to it hereunder, at law
or in equity including, without limitation, a decree of specific performance and/or injunctive relief with respect to
the Company’s failure to timely deliver shares of Common Stock upon exercise of the Warrant as required pursuant to the
terms hereof.


 






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v.           No
Fractional Shares or Scrip.  No fractional shares or scrip representing fractional shares shall be issued upon the exercise
of this Warrant.  As to any fraction of a share which the Holder would otherwise be entitled to purchase upon such exercise,
the Company shall round up to the next whole share.


 


vi          Charges,
Taxes and Expenses.  Issuance of Warrant Shares shall be made without charge to the Holder for any issue or transfer tax
or other incidental expense in respect of the issuance of such Warrant Shares, all of which taxes and expenses shall be paid by
the Company, and such Warrant Shares shall be issued in the name of the Holder or in such name or names as may be directed by the
Holder; provided, however, that in the event that Warrant Shares are to be issued in a name other than the name of
the Holder, this Warrant when surrendered for exercise shall be accompanied by the Assignment Form attached hereto duly executed
by the Holder and the Company may require, as a condition thereto, the payment of a sum sufficient to reimburse it for any transfer
tax incidental thereto.  The Company shall pay all Transfer Agent fees required for same-day processing of any Notice of Exercise
and all fees to the Depository Trust Company (or another established clearing corporation performing similar functions) required
for same-day electronic delivery of the Warrant Shares.


 


vii.           Closing of
Books.  The Company will not close its stockholder books or records in any manner which prevents the timely exercise of
this Warrant, pursuant to the terms hereof.


 


e)             Holder’s
Exercise Limitations.    The Company shall not effect any exercise of this Warrant, and a Holder shall not
have the right to exercise any portion of this Warrant, pursuant to Section 2 or otherwise, to the extent that after
giving effect to such issuance after exercise as set forth on the applicable Notice of Exercise, the Holder (together with
the Holder’s Affiliates, and any other Persons acting as a group together with the Holder or any of the
Holder’s Affiliates (such Persons, “Attribution Parties”)), would beneficially own in excess of the
Beneficial Ownership Limitation (as defined below).  For purposes of the foregoing sentence, the number of shares of
Common Stock beneficially owned by the Holder and its Affiliates and Attribution Parties shall include the number of shares
of Common Stock issuable upon exercise of this Warrant with respect to which such determination is being made, but shall
exclude the number of shares of Common Stock which would be issuable upon (i) exercise of the remaining, nonexercised
portion of this Warrant beneficially owned by the Holder or any of its Affiliates or Attribution Parties and
(ii) exercise or conversion of the unexercised or nonconverted portion of any other securities of the Company
(including, without limitation, any other Common Stock Equivalents) subject to a limitation on conversion or exercise
analogous to the limitation contained herein beneficially owned by the Holder or any of its Affiliates or Attribution
Parties.  Except as set forth in the preceding sentence, for purposes of this Section 2(e), beneficial ownership
shall be calculated in accordance with Section 13(d) of the Exchange Act and the rules and regulations
promulgated thereunder, it being acknowledged by the Holder that the Company is not representing to the Holder that such
calculation is in compliance with Section 13(d) of the Exchange Act and the Holder is solely responsible for
any schedules required to be filed in accordance therewith.   To the extent that the limitation contained in this
Section 2(e) applies, the determination of whether this Warrant is exercisable (in relation to other securities
owned by the Holder together with any Affiliates and Attribution Parties) and of which portion of this Warrant is exercisable
shall be in the sole discretion of the Holder, and the submission of a Notice of Exercise shall be deemed to be the
Holder’s determination of whether this Warrant is exercisable (in relation to other securities owned by the Holder
together with any Affiliates and Attribution Parties) and of which portion of this Warrant is exercisable, in each case
subject to the Beneficial Ownership Limitation, and the Company shall have no obligation to verify or confirm the accuracy of
such determination.   In addition, a determination as to any group status as contemplated above shall be determined
in accordance with Section 13(d) of the Exchange Act and the rules and regulations promulgated
thereunder.  For purposes of this Section 2(e), in determining the number of outstanding shares of Common Stock, a
Holder may rely on the number of outstanding shares of Common Stock as reflected in (A) the Company’s most recent
periodic or annual report filed with the Commission, as the case may be, (B) a more recent public announcement by the
Company or (C) a more recent written notice by the Company or the Transfer Agent setting forth the number of shares of
Common Stock outstanding.  Upon the written or oral request of a Holder, the Company shall within one
(1) Trading Day confirm orally and in writing to the Holder the number of shares of Common Stock then outstanding. 
In any case, the number of outstanding shares of Common Stock shall be determined after giving effect to the conversion or
exercise of securities of the Company, including this Warrant, by the Holder or its Affiliates or Attribution Parties since
the date as of which such number of outstanding shares of Common Stock was reported.  The “Beneficial Ownership
Limitation” shall be 4.99% of the number of shares of the Common Stock outstanding immediately after giving effect
to the issuance of shares of Common Stock issuable upon exercise of this Warrant.  The Holder, upon notice to the
Company, may increase or decrease the Beneficial Ownership Limitation provisions of this Section 2(e), provided that the
Beneficial Ownership Limitation in no event exceeds 9.99% of the number of shares of the Common Stock outstanding immediately
after giving effect to the issuance of shares of Common Stock upon exercise of this Warrant held by the Holder and the
provisions of this Section 2(e) shall continue to apply.  Any increase in the Beneficial Ownership Limitation
will not be effective until the 61st day after such notice is delivered to the
Company.  The provisions of this paragraph shall be construed and implemented in a manner otherwise than in strict
conformity with the terms of this Section 2(e) to correct this paragraph (or any portion hereof) which may be
defective or inconsistent with the intended Beneficial Ownership Limitation herein contained or to make changes or
supplements necessary or desirable to properly give effect to such limitation. The limitations contained in this
paragraph shall apply to a successor holder of this Warrant.


 






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Section 3.             
Certain Adjustments.


 


a)           
Stock Dividends and Splits. If the Company, at any time while this Warrant is outstanding: (i) pays a stock dividend
or otherwise makes a distribution or distributions on shares of its Common Stock or any other equity or equity equivalent securities
payable in shares of Common Stock (which, for avoidance of doubt, shall not include any shares of Common Stock issued by the Company
upon exercise of this Warrant), (ii) subdivides outstanding shares of Common Stock into a larger number of shares, (iii) combines
(including by way of reverse stock split) outstanding shares of Common Stock into a smaller number of shares, or (iv) issues
by reclassification of shares of the Common Stock any shares of capital stock of the Company, then in each case the Exercise Price
shall be multiplied by a fraction of which the numerator shall be the number of shares of Common Stock (excluding treasury
shares, if any) outstanding immediately before such event and of which the denominator shall be the number of shares of Common
Stock outstanding immediately after such event, and the number of shares issuable upon exercise of this Warrant shall be proportionately
adjusted such that the aggregate Exercise Price of this Warrant shall remain unchanged.  Any adjustment made pursuant to this
Section 3(a) shall become effective immediately after the record date for the determination of stockholders entitled
to receive such dividend or distribution and shall become effective immediately after the effective date in the case of a subdivision,
combination or re-classification.


 


b)           
Subsequent Rights Offerings.  In addition to any adjustments pursuant to Section 3(a) above, if at any time
the Company grants, issues or sells any Common Stock Equivalents or rights to purchase stock, warrants, securities or other property
pro rata to the record holders of any class of shares of Common Stock (the “Purchase Rights”), then the Holder
will be entitled to acquire, upon the terms applicable to such Purchase Rights, the aggregate Purchase Rights which the Holder
could have acquired if the Holder had held the number of shares of Common Stock acquirable upon complete exercise of this Warrant
(without regard to any limitations on exercise hereof, including without limitation, the Beneficial Ownership Limitation) immediately
before the date on which a record is taken for the grant, issuance or sale of such Purchase Rights, or, if no such record is taken,
the date as of which the record holders of shares of Common Stock are to be determined for the grant, issue or sale of such Purchase
Rights (provided, however, that to the extent that the Holder’s right to participate in any such Purchase Right
would result in the Holder exceeding the Beneficial Ownership Limitation, then the Holder shall not be entitled to participate
in such Purchase Right to such extent (or beneficial ownership of such shares of Common Stock as a result of such Purchase Right
to such extent) and such Purchase Right to such extent shall be held in abeyance for the Holder until such time, if ever, as its
right thereto would not result in the Holder exceeding the Beneficial Ownership Limitation).


 


c)            
Pro Rata Distributions.  During such time as this Warrant is outstanding, if the Company shall declare or make any
dividend or other distribution (other than cash) of its assets (or rights to acquire its assets) to holders of shares of Common
Stock, by way of return of capital or otherwise (including, without limitation, any distribution of stock or other securities,
property or options by way of a dividend, spin off, reclassification, corporate rearrangement, scheme of arrangement or other similar
transaction) (a “Distribution”), at any time after the issuance of this Warrant, then, in each such case, the
Holder shall be entitled to participate in such Distribution to the same extent that the Holder would have participated therein
if the Holder had held the number of shares of Common Stock acquirable upon complete exercise of this Warrant (without regard to
any limitations on exercise hereof, including without limitation, the Beneficial Ownership Limitation) immediately before the date
of which a record is taken for such Distribution, or, if no such record is taken, the date as of which the record holders of shares
of Common Stock are to be determined for the participation in such Distribution (provided, however, that to the extent
that the Holder’s right to participate in any such Distribution would result in the Holder exceeding the Beneficial Ownership
Limitation, then the Holder shall not be entitled to participate in such Distribution to such extent (or in the beneficial ownership
of any shares of Common Stock as a result of such Distribution to such extent) and the portion of such Distribution shall be held
in abeyance for the benefit of the Holder until such time, if ever, as its right thereto would not result in the Holder exceeding
the Beneficial Ownership Limitation).


 






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d)            Fundamental
Transaction. If, at any time while this Warrant is outstanding, (i) the Company, directly or indirectly, in one or
more related transactions effects any merger or consolidation of the Company with or into another Person,
(ii) the Company, directly or indirectly, effects any sale, lease, license, assignment, transfer, conveyance or other
disposition of all or substantially all of its assets in one or a series of related transactions, (iii) any, direct or
indirect, purchase offer, tender offer or exchange offer (whether by the Company or another Person) is completed pursuant to
which holders of Common Stock are permitted to sell, tender or exchange their shares for other securities, cash or property
and has been accepted by the holders of 50% or more of the outstanding Common Stock, (iv) the Company, directly or
indirectly, in one or more related transactions effects any reclassification, reorganization or recapitalization of the
Common Stock or any compulsory share exchange pursuant to which the Common Stock is effectively converted into or exchanged
for other securities, cash or property, or (v) the Company, directly or indirectly, in one or more related transactions
consummates a stock or share purchase agreement or other business combination (including, without limitation, a
reorganization, recapitalization, spin-off, merger or scheme of arrangement) with another Person or group of Persons whereby
such other Person or group acquires more than 50% of the outstanding shares of Common Stock (not including any shares of
Common Stock held by the other Person or other Persons making or party to, or associated or affiliated with the other Persons
making or party to, such stock or share purchase agreement or other business combination) (each a “Fundamental
Transaction”), then, upon any subsequent exercise of this Warrant, the Holder shall have the right to receive, for
each Warrant Share that would have been issuable upon such exercise immediately prior to the occurrence of such Fundamental
Transaction, at the option of the Holder (without regard to any limitation in Section 2(e) on the exercise of this
Warrant), the number of shares of Common Stock of the successor or acquiring corporation or of the Company, if it is the
surviving corporation, and any additional consideration (the “Alternate Consideration”) receivable as a
result of such Fundamental Transaction by a holder of the number of shares of Common Stock for which this Warrant is
exercisable immediately prior to such Fundamental Transaction (without regard to any limitation in Section 2(e) on
the exercise of this Warrant).  For purposes of any such exercise, the determination of the Exercise Price shall be
appropriately adjusted to apply to such Alternate Consideration based on the amount of Alternate Consideration issuable in
respect of one share of Common Stock in such Fundamental Transaction, and the Company shall apportion the Exercise Price
among the Alternate Consideration in a reasonable manner reflecting the relative value of any different components of the
Alternate Consideration.  If holders of Common Stock are given any choice as to the securities, cash or property to be
received in a Fundamental Transaction, then the Holder shall be given the same choice as to the Alternate Consideration it
receives upon any exercise of this Warrant following such Fundamental Transaction.


 


Notwithstanding anything to the contrary, in
the event of a Fundamental Transaction, the Company or any Successor Entity (as defined below) shall, at the Holder’s
option, exercisable at any time concurrently with, or within 30 days after, the consummation of the Fundamental Transaction
(or, if later, the date of the public announcement of the applicable Fundamental Transaction), purchase this Warrant from the
Holder by paying to the Holder an amount of cash equal to the Black Scholes Value (as defined below) of the remaining
unexercised portion of this Warrant on the date of the consummation of such Fundamental Transaction; provided, however,
if the Fundamental Transaction is not within the Company’s control, including not approved by the Company’s Board
of Directors, Holder shall only be entitled to receive from the Company or any Successor Entity, as of the date of
consummation of such Fundamental Transaction, the same type or form of consideration (and in the same proportion), at the
Black Scholes Value (as defined below) of the unexercised portion of this Warrant, that is being offered and paid to the
holders of Common Stock of the Company in connection with the Fundamental Transaction, whether that consideration be in the
form of cash, stock or any combination thereof, or whether the holders of Common Stock are given the choice to receive from
among alternative forms of consideration in connection with the Fundamental Transaction. “Black Scholes
Value” means the value of this Warrant based on the Black Scholes Option Pricing Model obtained from the
 “OV” function on Bloomberg, L.P. (“Bloomberg”) determined as of the day of consummation of the
applicable Fundamental Transaction for pricing purposes and reflecting (A) a risk-free interest rate corresponding to
the U.S. Treasury rate for a period equal to the time between the date of the public announcement of the applicable
Fundamental Transaction and the Termination Date, (B) an expected volatility equal to the remaining term of this Warrant
obtained from the HVT function on Bloomberg as of the Trading Day immediately prior to the public announcement of the
applicable Fundamental Transaction or, if the Fundamental Transaction is not publicly announced, the date the Fundamental
Transaction is consummated, (C) the underlying price per share used in such calculation shall be the greater of (i) the sum
of the price per share being offered in cash, if any, plus the value of any non-cash consideration, if any, being offered in
such Fundamental Transaction and (ii) the greater of (x) the last VWAP immediately prior to the public announcement of such
Fundamental Transaction and (y) the last VWAP immediately prior to the consummation of such Fundamental Transaction and (D) a
remaining option time equal to the time between the date of the public announcement of the applicable Fundamental Transaction
and the Termination Date. The payment of the Black Scholes Value will be made by wire transfer of immediately available funds
within five (5) Trading Days of the Holder’s election (or, if later, on the effective date of the Fundamental
Transaction). The Company shall cause any successor entity in a Fundamental Transaction in which the Company is not the
survivor (the “Successor Entity”) to assume in writing all of the obligations of the Company under this
Warrant in accordance with the provisions of this Section 3(e) pursuant to written agreements in form and substance
reasonably satisfactory to the Holder and approved by the Holder (without unreasonable delay) prior to such Fundamental
Transaction and shall, at the option of the Holder, deliver to the Holder in exchange for this Warrant a security of the
Successor Entity evidenced by a written instrument substantially similar in form and substance to this Warrant which is
exercisable for a corresponding number of shares of capital stock of such Successor Entity (or its parent entity)
equivalent to the shares of Common Stock acquirable and receivable upon exercise of this Warrant (without regard to any
limitations on the exercise of this Warrant) prior to such Fundamental Transaction, and with an exercise price which applies
the exercise price hereunder to such shares of capital stock (but taking into account the relative value of the shares of
Common Stock pursuant to such Fundamental Transaction and the value of such shares of capital stock, such number of shares of
capital stock and such exercise price being for the purpose of protecting the economic value of this Warrant immediately
prior to the consummation of such Fundamental Transaction), and which is reasonably satisfactory in form and substance to the
Holder. Upon the occurrence of any such Fundamental Transaction, the Successor Entity shall succeed to, and be substituted
for (so that from and after the date of such Fundamental Transaction, the provisions of this Warrant referring to the
 “Company” shall refer instead to the Successor Entity), and may exercise every right and power of the Company and
shall assume all of the obligations of the Company under this Warrant with the same effect as if such Successor Entity had
been named as the Company herein.


 






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e)            
Calculations. All calculations under this Section 3 shall be made to the nearest cent or the nearest 1/100th of a share,
as the case may be. For purposes of this Section 3, the number of shares of Common Stock deemed to be issued and outstanding
as of a given date shall be the sum of the number of shares of Common Stock (excluding treasury shares, if any) issued and outstanding.


 


f)            
Notice to Holder.


 


i.                 
Adjustment to Exercise Price. Whenever the Exercise Price is adjusted pursuant to any provision of this Section 3,
the Company shall promptly deliver to the Holder by facsimile or email a notice setting forth the Exercise Price after such adjustment
and any resulting adjustment to the number of Warrant Shares and setting forth a brief statement of the facts requiring such adjustment.


 


ii.              
Notice to Allow Exercise by Holder. If (A) the Company shall declare a dividend (or any other distribution in whatever
form) on the Common Stock, (B) the Company shall declare a special nonrecurring cash dividend on or a redemption of the Common
Stock, (C) the Company shall authorize the granting to all holders of the Common Stock rights or warrants to subscribe for
or purchase any shares of capital stock of any class or of any rights, (D) the approval of any stockholders of the Company
shall be required in connection with any reclassification of the Common Stock, any consolidation or merger to which the Company
is a party, any sale or transfer of all or substantially all of the assets of the Company, or any compulsory share exchange whereby
the Common Stock is converted into other securities, cash or property, or (E) the Company shall authorize the voluntary or
involuntary dissolution, liquidation or winding up of the affairs of the Company, then, in each case, the Company shall cause to
be delivered by facsimile or email to the Holder at its last facsimile number or email address as it shall appear upon the Warrant
Register of the Company, at least 20 calendar days prior to the applicable record or effective date hereinafter specified, a notice
stating (x) the date on which a record is to be taken for the purpose of such dividend, distribution, redemption, rights or
warrants, or if a record is not to be taken, the date as of which the holders of the Common Stock of record to be entitled to such
dividend, distributions, redemption, rights or warrants are to be determined or (y) the date on which such reclassification,
consolidation, merger, sale, transfer or share exchange is expected to become effective or close, and the date as of which it is
expected that holders of the Common Stock of record shall be entitled to exchange their shares of the Common Stock for securities,
cash or other property deliverable upon such reclassification, consolidation, merger, sale, transfer or share exchange; provided
that the failure to deliver such notice or any defect therein or in the delivery thereof shall not affect the validity of the corporate
action required to be specified in such notice.  To the extent that any notice provided in this Warrant constitutes, or contains,
material, non-public information regarding the Company or any of its subsidiaries, the Company shall simultaneously file such notice
with the Commission pursuant to a Current Report on Form 8-K.  The Holder shall remain entitled to exercise this Warrant
during the period commencing on the date of such notice to the effective date of the event triggering such notice except as may
otherwise be expressly set forth herein.


 






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Section 4.             

Transfer of Warrant.


 


a)            
Transferability.  Pursuant to FINRA Rule 5110(g)(1), neither this Warrant nor any Warrant Shares issued upon exercise
of this Warrant shall be sold, transferred, assigned, pledged or hypothecated, or be the subject of any hedging, short sale, derivative,
put or call transaction that would result in the effective economic disposition of the securities by any person for a period of
180 days immediately following the date of effectiveness or commencement of sales of the offering pursuant to which this Warrant
is being issued, except the transfer of any security:


 


i.             by operation of law or by reason of reorganization of the Company;


 


ii.             to any FINRA member firm participating in the offering and the officers and partners thereof, if all securities so transferred
remain subject to the lock-up restriction in this Section 4(a) for the remainder of the time period;


 


iii.             if the aggregate amount of securities of the Company held by the Holder or related person do not exceed 1% of the securities being
offered;


 


iv.             that is beneficially owned on a pro-rata basis by all equity owners of an investment fund, provided that no participating member
manages or otherwise directs investments by the fund, and participating members in the aggregate do not own more than 10% of the
equity in the fund; or


 


v.             the exercise or conversion of any security, if all securities received remain subject to the lock-up restriction in this Section 4(a) for
the remainder of the time period.


 


Subject to the foregoing restriction,
this Warrant and all rights hereunder (including, without limitation, any registration rights) are transferable, in whole or in
part, upon surrender of this Warrant at the principal office of the Company or its designated agent, together with a written assignment
of this Warrant substantially in the form attached hereto duly executed by the Holder or its agent or attorney and funds sufficient
to pay any transfer taxes payable upon the making of such transfer.  Upon such surrender and, if required, such payment, the
Company shall execute and deliver a new Warrant or Warrants in the name of the assignee or assignees, as applicable, and in the
denomination or denominations specified in such instrument of assignment, and shall issue to the assignor a new Warrant evidencing
the portion of this Warrant not so assigned, and this Warrant shall promptly be cancelled.  Notwithstanding anything herein
to the contrary, the Holder shall not be required to physically surrender this Warrant to the Company unless the Holder has assigned
this Warrant in full, in which case, the Holder shall surrender this Warrant to the Company within three (3) Trading Days
of the date on which the Holder delivers an assignment form to the Company assigning this Warrant in full.  The Warrant, if
properly assigned in accordance herewith, may be exercised by a new holder for the purchase of Warrant Shares without having a
new Warrant issued.


 


b)             New Warrants. This Warrant may be divided or combined with other Warrants upon presentation hereof at the aforesaid office
of the Company, together with a written notice specifying the names and denominations in which new Warrants are to be issued, signed
by the Holder or its agent or attorney.  Subject to compliance with Section 4(a), as to any transfer which may be involved
in such division or combination, the Company shall execute and deliver a new Warrant or Warrants in exchange for the Warrant or
Warrants to be divided or combined in accordance with such notice. All Warrants issued on transfers or exchanges shall be dated
the Issue Date of this Warrant and shall be identical with this Warrant except as to the number of Warrant Shares issuable pursuant
thereto.


 


c)             Warrant Register. The Company shall register this Warrant, upon records to be maintained by the Company for that purpose
(the “Warrant Register”), in the name of the record Holder hereof from time to time.  The Company may deem
and treat the registered Holder of this Warrant as the absolute owner hereof for the purpose of any exercise hereof or any distribution
to the Holder, and for all other purposes, absent actual notice to the contrary.


 






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Section 5.             

Miscellaneous.


 


a)             No Rights as Stockholder Until Exercise; No Settlement in Cash.  This Warrant does not entitle the Holder to any voting
rights, dividends or other rights as a stockholder of the Company prior to the exercise hereof as set forth in Section 2(d)(i),
except as expressly set forth in Section 3.  Without limiting the rights of a Holder to receive Warrant Shares on
a “cashless exercise,” in no event will the Company be required to net cash settle an exercise of this Warrant.


 


b)             Loss, Theft, Destruction or Mutilation of Warrant. The Company covenants that upon receipt by the Company of evidence reasonably
satisfactory to it of the loss, theft, destruction or mutilation of this Warrant or any stock certificate relating to the Warrant
Shares, and in case of loss, theft or destruction, of indemnity or security reasonably satisfactory to it (which, in the case of
the Warrant, shall not include the posting of any bond), and upon surrender and cancellation of such Warrant or stock certificate,
if mutilated, the Company will make and deliver a new Warrant or stock certificate of like tenor and dated as of such cancellation,
in lieu of such Warrant or stock certificate.


 


c)             Saturdays, Sundays, Holidays, etc.  If the last or appointed day for the taking of any action or the expiration
of any right required or granted herein shall not be a Trading Day, then, such action may be taken or such right may be exercised
on the next succeeding Trading Day.


 


d)            Authorized Shares.


 


The Company covenants that, during
the period the Warrant is outstanding, it will reserve from its authorized and unissued Common Stock a sufficient number of shares
to provide for the issuance of the Warrant Shares upon the exercise of any purchase rights under this Warrant.  The Company
further covenants that its issuance of this Warrant shall constitute full authority to its officers who are charged with the duty
of issuing the necessary Warrant Shares upon the exercise of the purchase rights under this Warrant.  The Company will take
all such reasonable action as may be necessary to assure that such Warrant Shares may be issued as provided herein without violation
of any applicable law or regulation, or of any requirements of the Trading Market upon which the Common Stock may be listed. 
The Company covenants that all Warrant Shares which may be issued upon the exercise of the purchase rights represented by this
Warrant will, upon exercise of the purchase rights represented by this Warrant and payment for such Warrant Shares in accordance
herewith, be duly authorized, validly issued, fully paid and nonassessable and free from all taxes, liens and charges created by
the Company in respect of the issue thereof (other than taxes in respect of any transfer occurring contemporaneously with such
issue).


 


Except and to the extent as waived
or consented to by the Holder, the Company shall not by any action, including, without limitation, amending its certificate of
incorporation or through any reorganization, transfer of assets, consolidation, merger, dissolution, issue or sale of securities
or any other voluntary action, avoid or seek to avoid the observance or performance of any of the terms of this Warrant, but will
at all times in good faith assist in the carrying out of all such terms and in the taking of all such actions as may be necessary
or appropriate to protect the rights of Holder as set forth in this Warrant against impairment.  Without limiting the generality
of the foregoing, the Company will (i) not increase the par value of any Warrant Shares above the amount payable therefor
upon such exercise immediately prior to such increase in par value, (ii) take all such action as may be necessary or appropriate
in order that the Company may validly and legally issue fully paid and nonassessable Warrant Shares upon the exercise of this Warrant
and (iii) use commercially reasonable efforts to obtain all such authorizations, exemptions or consents from any public regulatory
body having jurisdiction thereof, as may be, necessary to enable the Company to perform its obligations under this Warrant.


 


Before taking any action
which would result in an adjustment in the number of Warrant Shares for which this Warrant is exercisable or in the Exercise
Price, the Company shall obtain all such authorizations or exemptions thereof, or consents thereto, as may be necessary from
any public regulatory body or bodies having jurisdiction thereof.


 






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e)             Governing Law. All questions concerning the construction, validity, enforcement and interpretation of this Warrant shall
be governed by and construed and enforced in accordance with the internal laws of the State of New York, without regard to the
principles of conflicts of law thereof. Each party agrees that all legal proceedings concerning the interpretations, enforcement
and defense of the transactions contemplated by this Warrant (whether brought against a party hereto or their respective affiliates,
directors, officers, shareholders, partners, members, employees or agents) shall be commenced exclusively in the state and federal
courts sitting in the City of New York. Each party hereby irrevocably submits to the exclusive jurisdiction of the state and federal
courts sitting in the City of New York, Borough of Manhattan for the adjudication of any dispute hereunder or in connection herewith
or with any transaction contemplated hereby or discussed herein, and hereby irrevocably waives, and agrees not to assert in any
suit, action or proceeding, any claim that it is not personally subject to the jurisdiction of any such court, that such suit,
action or proceeding is improper or is an inconvenient venue for such proceeding. Each party hereby irrevocably waives personal
service of process and consents to process being served in any such suit, action or proceeding by mailing a copy thereof via registered
or certified mail or overnight delivery (with evidence of delivery) to such party at the address in effect for notices to it under
this Warrant and agrees that such service shall constitute good and sufficient service of process and notice thereof. Nothing contained
herein shall be deemed to limit in any way any right to serve process in any other manner permitted by law. If either party shall
commence an action, suit or proceeding to enforce any provisions of this Warrant, the prevailing party in such action, suit or
proceeding shall be reimbursed by the other party for their reasonable attorneys’ fees and other costs and expenses incurred
with the investigation, preparation and prosecution of such action or proceeding.


 


f)             Restrictions.  The Holder acknowledges that the Warrant Shares acquired upon the exercise of this Warrant, if not registered,
and the Holder does not utilize cashless exercise, will have restrictions upon resale imposed by state and federal securities laws.


 


g)             Nonwaiver and Expenses.  No course of dealing or any delay or failure to exercise any right hereunder on the part of
Holder shall operate as a waiver of such right or otherwise prejudice the Holder’s rights, powers or remedies, notwithstanding
the fact that the right to exercise this Warrant terminates on the Termination Date.  Without limiting any other provision
of this Warrant, if the Company willfully and knowingly fails to comply with any provision of this Warrant, which results in any
material damages to the Holder, the Company shall pay to the Holder such amounts as shall be sufficient to cover any costs and
expenses including, but not limited to, reasonable attorneys’ fees, including those of appellate proceedings, incurred by
the Holder in collecting any amounts due pursuant hereto or in otherwise enforcing any of its rights, powers or remedies hereunder.


 


h)             Notices. 
Any and all notices or other communications or deliveries to be provided by the holders hereunder including, without limitation,
any Notice of Exercise, shall be in writing and delivered personally, by facsimile or e-mail, or sent by a nationally recognized
overnight courier service, addressed to the Company, at 375 Pheasant Run, Newtown, PA 18940, Attention: Mark Guerin, Chief Financial
Officer, email address: MGuerin@onconova.us, facsimile: (267) 759-3681, or such other facsimile number, email address or address
as the Company may specify for such purposes by notice to the Holders. Any and all notices or other communications or deliveries
to be provided by the Company hereunder shall be in writing and delivered personally, by facsimile or e-mail, or sent by a nationally
recognized overnight courier service addressed to each Holder at the facsimile number, e-mail address or address of such Holder
appearing on the books of the Company. Any notice or other communication or deliveries hereunder shall be deemed given and effective
on the earliest of (i) the time of transmission, if such notice or communication is delivered via facsimile at the facsimile
number or via e-mail at the e-mail address set forth in this Section prior to 5:30 p.m. (New York City time) on any
date, (ii) the next Trading Day after the date of transmission, if such notice or communication is delivered via facsimile
at the facsimile number or via e-mail at the e-mail address set forth in this Section on a day that is not a Trading Day
or later than 5:30 p.m. (New York City time) on any Trading Day, (iii) the second Trading Day following the date of
mailing, if sent by U.S. nationally recognized overnight courier service, or (iv) upon actual receipt by the party to whom
such notice is required to be given.


 






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i)            
Limitation of Liability.  No provision hereof, in the absence of any affirmative action by the Holder to exercise this
Warrant to purchase Warrant Shares, and no enumeration herein of the rights or privileges of the Holder, shall give rise to any
liability of the Holder for the purchase price of any Common Stock or as a stockholder of the Company, whether such liability is
asserted by the Company or by creditors of the Company.


 


j)             Remedies.  The Holder, in addition to being entitled to exercise all rights granted by law, including recovery of damages,
will be entitled to specific performance of its rights under this Warrant.  The Company agrees that monetary damages would
not be adequate compensation for any loss incurred by reason of a breach by it of the provisions of this Warrant and hereby agrees
to waive and not to assert the defense in any action for specific performance that a remedy at law would be adequate.


 


k)             Successors and Assigns.  Subject to applicable securities laws, this Warrant and the rights and obligations evidenced
hereby shall inure to the benefit of and be binding upon the successors and permitted assigns of the Company and the successors
and permitted assigns of Holder.  The provisions of this Warrant are intended to be for the benefit of any Holder from time
to time of this Warrant and shall be enforceable by the Holder or holder of Warrant Shares.


 


l)             Amendment.  This Warrant may be modified or amended or the provisions hereof waived with the written consent of the
Company and the Holder.


 


m)             Severability.  Wherever possible, each provision of this Warrant shall be interpreted in such manner as to be effective
and valid under applicable law, but if any provision of this Warrant shall be prohibited by or invalid under applicable law, such
provision shall be ineffective to the extent of such prohibition or invalidity, without invalidating the remainder of such provisions
or the remaining provisions of this Warrant.


 


n)             Headings.  The headings used in this Warrant are for the convenience of reference only and shall not, for any purpose,
be deemed a part of this Warrant.


 


********************


 


(Signature Page Follows)


 






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IN WITNESS WHEREOF, the Company has caused
this Warrant to be executed by its officer thereunto duly authorized as of the date first above indicated.


 


	 	ONCONOVA THERAPEUTICS, INC.
	 	 	 
	 	By:  	          
                                
	 	 	Name:
	 	 	Title:


 






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NOTICE OF EXERCISE


 


TO:              
ONCONOVA THERAPEUTICS, INC.


 


(1)        
The undersigned hereby elects to purchase          Warrant Shares of the Company pursuant
to the terms of the attached Warrant (only if exercised in full), and tenders herewith payment of the exercise price in full, together
with all applicable transfer taxes, if any.


 


(2)        
Payment shall take the form of (check applicable box):


 


 ̈ in lawful
money of the United States; or


 


 ̈ if permitted
the cancellation of such number of Warrant Shares as is necessary, in accordance with the formula set forth in subsection 2(c),
to exercise this Warrant with respect to the maximum number of Warrant Shares purchasable pursuant to the cashless exercise procedure
set forth in subsection 2(c).


 


(3)        
Please issue said Warrant Shares in the name of the undersigned or in such other name as is specified below:


 


(4)        
The time of day this Notice of Exercise is being executed is:


 


The Warrant Shares shall be delivered to the following DWAC
Account Number:


 


[SIGNATURE OF HOLDER]


 


	Name of Investing Entity:	 
	Signature of Authorized Signatory of Investing Entity:	 
	Name of Authorized Signatory:	 
	Title of Authorized Signatory:	 
	Date:	 
	 	 	 	 





 






    14


     


    

 


EXHIBIT B


 


ASSIGNMENT FORM


 


(To assign the foregoing Warrant, execute
this form and supply required information.  Do not use this form to exercise the Warrant to purchase shares.)


 


FOR VALUE RECEIVED, the foregoing Warrant
and all rights evidenced thereby are hereby assigned to


 


	Name:	 	 
	 	 	(Please Print)
	 	 	 
	Address:	 	 
	 	 	(Please Print)
	 	 	 
	Phone Number:	 	 
	 	 	 
	Email Address:	 	 
	 	 	 
	Dated:                   ,	 	 
	 	 	 
	Holder’s Signature:	 	 	 
	 	 	 	 
	Holder’s Address:	 	 	 


 






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