Prepared by R.R. Donnelley Financial -- EX-4.1




 Exhibit 4.1 
 




 
 CALITHERA BIOSCIENCES 
CB
NUMBER SHARES 
INCORPORATED UNDER THE LAWS OF THE STATE OF DELAWARE 
CUSIP
13089P 10 1 
SEE REVERSE FOR CERTAIN DEFINITIONS 
This certifies that

is the record holder of 
FULLY PAID AND NONASSESSABLE SHARES OF COMMON STOCK,
$0.001 PAR VALUE, OF 
CALITHERA BIOSCIENCES, INC. 
transferable on the books of
the Corporation in person or by duly authorized attorney upon surrender of this Certificate properly endorsed. This Certificate is not valid until countersigned by the Transfer Agent and registered by the Registrar. 
WITNESS the facsimile seal of the Corporation and the facsimile signatures of its duly authorized officers. 
Dated: 
PRESIDENT, CHIEF EXECUTIVE OFFICER AND DIRECTOR 
SENIOR VICE PRESIDENT, CHIEF FINANCIAL OFFICER, TREASURER AND SECRETARY 
CALITHERA BIOSCIENCES,
INC. CORPORATE 
SEAL 
MARCH 9, 2010 
DELAWARE 
COUNTERSIGNED AND REGISTERED: AMERICAN STOCK TRANSFER & TRUST COMPANY, LLC

(NEW YORK, NY) 
TRANSFER AGENT AND REGISTRAR 
BY: AUTHORIZED SIGNATURE 








 



 
 The Corporation shall furnish without charge to each stockholder who so requests a statement of the powers, designations, preferences
and relative, participating, optional or other special rights of each class of stock of the Corporation or series thereof and the qualifications, limitations or restrictions of such preferences and/or rights. Such requests shall be made to the
Corporation’s Secretary at the principal office of the Corporation. 
The following abbreviations, when used in the inscription on the face of this certificate,
shall be construed as though they were written out in full according to applicable laws or regulations: 
TEN COM – as tenants in common 
TEN ENT – as tenants by the entireties 
JT TEN – as joint tenants with right of
survivorship and not as tenants in common 
COM PROP – as community property

UNIF GIFT MIN ACT – 
UNIF TRF MIN ACT – 
(State) 
Custodian 
(Cust) (Minor) 
under Uniform Gifts to Minors Act 
Custodian (until age) 
(Cust) under Uniform Transfers 
(Minor) to Minors Act 
(State) 
Additional abbreviations may also be used though not in the above list. 
FOR VALUE RECEIVED,
hereby sell(s), assign(s) and transfer(s) unto 
PLEASE INSERT SOCIAL SECURITY OR OTHER IDENTIFYING NUMBER OF ASSIGNEE 
(PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS, INCLUDING ZIP CODE, OF ASSIGNEE) 
shares

of the capital stock represented by within Certificate, and do hereby irrevocably constitute and appoint 
attorney-in-fact 
to transfer the said stock on the books of the within named Corporation with
full power of the substitution in the premises. Dated Signature(s) Guaranteed: X X 
NOTICE: 
THE SIGNATURE TO THIS ASSIGNMENT MUST CORRESPOND WITH THE NAME AS WRITTEN UPON THE FACE OF THE CERTIFICATE IN EVERY PARTICULAR, WITHOUT ALTERATION OR ENLARGEMENT OR ANY CHANGE
WHATSOEVER. 
By THE SIGNATURE(S) SHOULD BE GUARANTEED BY AN ELIGIBLE GUARANTOR INSTITUTION, (BANKS, STOCKBROKERS, SAVINGS AND LOAN ASSOCIATIONS AND CREDIT UNIONS
WITH MEMBERSHIP IN AN APPROVED SIGNATURE GUARANTEE MEDALLION PROGRAM), PURSUANT TO S.E.C. RULE 17Ad-15. GUARANTEES BY A NOTARY PUBLIC ARE NOT ACCEPTABLE. SIGNATURE GUARANTEES MUST NOT BE DATED.