EX-10.6



 Exhibit 10.6 

FIRST AMENDMENT TO EMPLOYMENT AGREEMENT 

THIS FIRST AMENDMENT TO EMPLOYMENT AGREEMENT (this “Amendment”) is entered into as of May 5, 2017, by and between G1
Therapeutics, Inc., a Delaware corporation (the “Company”) and Gregory Mossinghoff (the “Employee”). 
 WITNESSETH:

 WHEREAS, Employee and the Company entered into an Employment Agreement effective as of February 1, 2015, (the “Employment
Agreement”); 
 WHEREAS, Employee and the Company wish to alter certain terms of the Employment Agreement, particularly with respect to
Employee’s employment compensation, subject to and effective upon the completion of the Company’s initial public offering of its common stock (the “IPO”); and 

WHEREAS, in light of the foregoing, Employee and the Company desire to mutually and voluntarily amend the Employment Agreement pursuant to the
terms as set forth herein. 
 NOW, THEREFORE, in consideration of the foregoing, the mutual promises herein contained, and other good and
valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereto, intending to be legally bound, agree as follows. 

1. AMENDMENT TO SECTION 3(a) OF THE EMPLOYMENT AGREEMENT. Section 3(a) of the Employment Agreement is modified, subject to and
effective upon the completion of the IPO, by replacing the existing Section 3(a) in its entirety with a new Section 3(a) as follows: 
  

	 	a)	BASE SALARY. The Company will pay Employee a base salary (the “Base Salary”) at an annual rate of Three Hundred Thousand Dollars ($300,000.00), payable in equal installments in accordance with the
Company’s customary payroll practices as in effect from time to time. The Base Salary may be reviewed from time to time by the Company and may be increased in the sole discretion of the Board. The Base Salary may also be decreased in connection
with any Company-wide decrease in executive compensation. 

 2. AMENDMENT TO SECTION 3(b) OF THE EMPLOYMENT AGREEMENT.
Section 3(b) of the Employment Agreement is modified, subject to and effective upon the completion of the IPO, by replacing the existing Section 3(b) in its entirety with a new Section 3(b) as follows: 

 

	 	b)	 ANNUAL BONUS. As long as Employee remains employed by the Company, Employee will be eligible to receive an
annual calendar year bonus based upon Employee’s and the Company’s achievement of certain individual and Company goals that will be set for Employee by the Board or its designee (the “Annual Bonus”). The amount of the target
Annual Bonus will be equal to thirty-five percent (35%) of Employee’s then-current Base Salary as of the date of the payment; provided that the actual amount of the Annual Bonus may be greater or less than such











	 	
target amount. One half of the Annual Bonus awarded for any given year will be paid in cash, and the other half of the Annual Bonus awarded for any given year will be paid, in the sole discretion
of the Company, either in cash or in the form of options to acquire shares of the Company’s common stock (or other equity interests as selected by the Company), in any case subject to the terms and conditions of the Company’s 2017
Employee, Director and Consultant Equity Incentive Plan. For any grant of stock options or equity issued pursuant to this Section 3(b), the number of options or other equity interests allocated to the non-cash
portion of the Annual Bonus will be determined by the Company in its sole discretion. The Board or its designee will have the sole discretion to set the applicable individual and Company goals, to determine whether the goals have been met, and to
determine the amount of the Annual Bonus. The Annual Bonus for any given year will be paid between January 1 and January 31 in the year immediately following the year in which the Annual Bonus, if any, is earned. Employee must be employed
by the Company on December 31 of the bonus year in order to receive the Annual Bonus for that year. 

 3. PROPER
AMENDMENT. The parties expressly acknowledge and agree that this Amendment constitutes a proper amendment and modification of the Employment Agreement by written agreement executed by the parties pursuant to Section 11 of the Employment
Agreement. 
 4. REMAINDER OF EMPLOYMENT AGREEMENT. Except as expressly set forth in this Amendment, the provisions of the Employment
Agreement remain in full force and effect, in their entirety, in accordance with their terms. 
 5. MISCELLANEOUS. This Amendment
shall be governed, construed, and interpreted in accordance with the laws of the State of North Carolina, without giving effect to conflicts of laws principles. The parties agree that this Amendment may only be modified in a signed writing executed
by both parties. This Amendment shall be binding upon and shall inure to the benefit of the parties hereto and their respective heirs, successors and assigns. This Amendment may be executed in separate counterparts, each of which is deemed to be an
original and all of which taken together constitute one agreement. Facsimile or PDF reproductions of original signatures will be deemed binding for the purpose of the execution of this Amendment. 

[SIGNATURE PAGE FOLLOWS] 







 IN WITNESS WHEREOF, the parties have executed this Amendment to Employment Agreement to be
effective as of the day and year first above written. 
  

									
	Company:	 		 		 	
			
	G1 THERAPEUTICS, INC.	 		 	Employee:
					
	By:	 	 /s/ Mark A. Velleca
	 		 	By:	 	 /s/ Gregory Mossinghoff

		 	Mark A. Velleca	 		 		 	Gregory Mossinghoff
		 	President and Chief Executive Officer	 		 		 	








 EXECUTIVE EMPLOYMENT AGREEMENT 

This EXECUTIVE EMPLOYMENT AGREEMENT (the “Agreement”), is made and entered into effective as of February 1, 2015 (the
“Effective Date”), by and between G1 Therapeutics, Inc., a Delaware corporation (the “Company”), and Gregory Mossinghoff (“Employee”). 

1. EMPLOYMENT; TERMINATION OF CONSULTING RELATIONSHIP; DUTIES. The Company agrees to employ Employee as its Chief Business Officer, and
Employee agrees to accept such employment upon the terms and conditions hereinafter set forth. In connection with Employee’s employment with the Company, the parties mutually agree that the prior Consulting Agreement between them is terminated
by mutual consent as of the Effective Date. Employee will perform such services for the Company as are customarily associated with such position and as may otherwise be assigned to the Employee from time to time by the Company’s Chief Executive
Officer or his designee. Employee will devote his full business time and attention to the business and affairs of the Company, and will perform his duties diligently and to the best of his ability, in compliance with the Company’s policies and
procedures and the laws and regulations that apply to the Company’s business. Notwithstanding the foregoing, Employee will be permitted during the term of this Agreement, subject to the approval of the Company’s CEO as described below, to
consult on an ad hoc basis with those clients of the Employee which pre-existed the Effective Date of this Agreement. In either case, Employee will disclose to the CEO nature and time commitment associated with any consulting activity or board
service so that the CEO can determine that the position (i) is not competitive with the Business of the Company as described in Section 8(a) below, and (ii) will not interfere with Employee’s duties to the Company hereunder. The
CEO’s approval will not be unreasonably withheld. 
 2. TERM; TERMINATION. Employee’s employment under this Agreement will
commence as of the Effective Date and will continue until terminated by either party. Employee’s employment with the Company is at-will, and either party can terminate the employment relationship and/or this Agreement at any time, for any or no
cause or reason, and with or without prior notice. Upon termination of Employee’s employment by either party for any reason, Employee will resign his position(s), if any, as an officer or director of the Company, as a member of the
Company’s Board of Directors (the “Board”) and any Board committees, as well as any other positions he may hold with or for the benefit of the Company and/or its affiliates. 

3. COMPENSATION. As compensation for the services to be rendered by Employee under this Agreement, the Company will provide the
following compensation and benefits during Employee’s employment hereunder. 
 (a) BASE SALARY. The Company will pay Employee a
base salary (the “Base Salary”) at an annual rate of Two Hundred Forty Thousand Dollars ($240,000.00), payable in equal installments in accordance with the Company’s customary payroll practices as 







 
in effect from time to time. The Base Salary may be reviewed from time to time by theCompany and may be increased in the sole discretion of the Company. The Base Salary may also be decreased in
connection with any Company-wide decrease in executive compensation. 
 (b) ANNUAL BONUS. Employee will be eligible to receive an
annual calendar year bonus based upon Employee’s and the Company’s achievement of certain individual and Company goals that will be set for Employee by the Board or its designee (the “Annual Bonus”). The amount of the
target Annual Bonus will be equal to twenty percent (20%) of Employee’s then-current Base Salary as of the date of the payment. One half of the Annual Bonus awarded for any given year will be paid in cash, and the other half of the Annual
Bonus awarded for any given year will be paid, in the sole discretion of the Company, either in cash or in the form of options to acquire shares of the Company’s common stock (or other equity interests as selected by the Company), in any case
subject to the terms and conditions of the Company’s 2011 Equity Incentive Plan. For any grant of stock options or equity issued pursuant to this Section 3(b), the number of options or other equity interests allocated to the non-cash
portion of the Annual Bonus will be determined by the Company in its sole discretion. The Board will have the sole discretion to set the applicable individual and Company goals, to determine whether the goals have been met, and to determine the
amount of the Annual Bonus. The Annual Bonus for any given year will be paid between January 1 and January 31 in the year immediately following the year in which the Annual Bonus, if any, is earned. Employee must be employed by the Company
on December 31 of the bonus year in order to receive the Annual Bonus for that year. 
 (c) STOCK OPTIONS. Employee has
previously been granted a non-qualified stock option to purchase 171,900 shares of the Company’s common stock (the “Prior Option”) pursuant to the terms of the Company’s 2011 Equity Incentive Plan (the “Plan”)
and that certain Stock Option Agreement between Company and Employee effective as of July 11, 2014. The Prior Option remains subject to the terms of the Plan and the July 11, 2014 Stock Option Agreement. Subject to approval by the
Board, Employee will be granted, effective as of date of Board approval, an incentive stock option to purchase a number of shares of the Company’s common stock, which taken together with the shares covered by the Prior Option, will represent
1.40% of the Company’s total outstanding shares of common stock, determined on a fully-diluted, as-converted into common stock basis after the conclusion of the first tranche of the Company’s Series B Preferred Stock Financing. (the
“New Option”). The New Option will be granted pursuant to and subject to the terms and conditions of the Plan and will be further subject to the terms of a stock option agreement as approved by the Board setting forth the exercise
price, vesting conditions, and other restrictions. One fourth of the total number of the shares covered by the New Option will vest on the first anniversary of the date hereof, and one forty eighth (1/48th) of the total number of the shares
covered by the New Option will vest each month over the following thirty six (36) months thereafter, so long as Employee remains employed by the Company through each such vesting date. Fifty Percent (50%) of any unvested portion of the New
Option will immediately vest upon the consummation of a Change in Control (as defined below) and any remaining unvested portion of the New Option will immediately vest if Employee’s employment is terminated by the Company without Cause (as
defined below) or Employee resigns with Good Reason (as defined below) within ninety (90) days following a Change in Control. As used herein, “Change in Control” means (i) the Company’s merger or consolidation with or
into another entity such that 







 
the stockholders of the Company prior to such transaction do not or are not expected to own a majority of the voting stock of the surviving entity, (ii) the sale or other disposition of all
or substantially all of the assets of the Company, (iii) the sale or other disposition of greater than 50% of the then-outstanding voting stock of the Company by the holders thereof to one or more persons or entities who are not then
stockholders of the Company. 
 (d) VACATION. Employee will be eligible to accrue up to four (4) weeks of paid time off per
calendar year (prorated for any partial years), which paid time off must be used in accordance with, and is otherwise subject to, the Company’s policies and procedures. 

(e) BENEFITS. Employee will (subject to applicable eligibility requirements) receive such other benefits as are provided from time to
time to other similarly-situated employees of the Company pursuant to the Company’s policies and procedures as they may be instituted from time to time. All such benefits are subject to the provisions of their respective plan documents in
accordance with their terms. Employee acknowledges and agrees that the Company has the unilateral right to amend, modify or terminate its employee benefit plans or policies to the maximum extent allowed by law. 

(f) EXPENSE REIMBURSEMENT. The Company will reimburse Employee for all reasonable business expenses incurred by Employee in connection
with the performance of his duties hereunder, subject to Employee’s compliance with the Company’s reimbursement policies in effect from time to time. 

(g) WITHHOLDINGS. The Company will withhold from any amounts payable under this Agreement, such federal, state and local taxes, as the
Company reasonably determines are required to be withheld pursuant to applicable law. 
 4. EFFECT OF TERMINATION. 

(a) GENERALLY. When Employee’s employment with the Company is terminated for any reason, Employee, or his estate, as the case may
be, will be entitled to receive the compensation and benefits earned through the effective date of termination, along with reimbursement for any approved business expenses that Employee has timely submitted for reimbursement in accordance with the
Company’s expense reimbursement policy or practice. 
 (b) SEPARATION BENEFITS UPON CERTAIN TERMINATIONS. If the Company
terminates Employee’s employment without Cause (as defined below), or if Employee resigns his employment for Good Reason (as defined below), then conditioned upon Employee executing a Release (as defined below) following such termination,
Employee will be entitled to receive the continued payment of Employee’s then-current Base Salary for a period of six (6) months after termination (the “Separation Benefits”). The Separation Benefits are conditioned upon
Employee executing a release of claims in a form satisfactory to the Company (the “Release”) within the time specified therein, which Release is not revoked within any time period allowed for revocation under applicable law. The
Salary Continuation will be payable to Employee over time in accordance with the Company’s payroll practices and procedures beginning on the sixtieth (60th) day following the termination of Employee’s employment with








 
the Company, provided that the Company, in its sole discretion, may begin the payments earlier. For avoidance of doubt, the termination of Employee’s employment as a result of his death or
disability (meaning the inability of Employee, due to the condition of his physical, mental or emotional health, effectively to perform the essential functions of his job with or without reasonable accommodation for a continuous period of more than
90 days or for 90 days in any period of 180 consecutive days, as determined by the Board in its sole discretion in consultation with a physician retained by the Company) will not constitute a termination without Cause triggering the rights described
in this Section 4(b). 
 (c) CAUSE. For purposes of this Agreement, “Cause” means: (i) Employee’s
fraud, embezzlement or misappropriation with respect to the Company; (ii) Employee’s material breach of fiduciary duties to the Company; (iii) Employee’s willful or negligent misconduct that has or may reasonably be expected to
have a material adverse effect on the property, business, or reputation of the Company; (iv) Employee’s material breach of this Agreement; (v) Employee’s willful failure or refusal to perform his material duties under this
Agreement or failure to follow any specific lawful instructions of the CEO; (vi) Employee’s conviction or plea of nolo contendere in respect of a felony or of a misdemeanor involving moral turpitude; (vii) Employee’s alcohol or
substance abuse which has a material adverse effect on Employee’s ability to perform his duties under this Agreement; or (viii) Employee’s engagement in a form of discrimination or harassment prohibited by law (including, without
limitation, discrimination or harassment based on race, color, religion, sex, national origin, age or disability). In the event that the Company concludes that Employee has engaged in acts constituting in Cause as defined in clause (iii), (iv), (v),
or (vii) above, prior to terminating this Agreement for Cause the Company will provide Employee with at least fifteen (15) days’ advance written notice of the specific circumstances constituting such Cause, and an opportunity to
correct such circumstances. 
 (d) GOOD REASON. In order for Employee to resign for Good Reason, Employee must provide written notice
to the Company of the existence of the Good Reason condition within thirty (30) days of the initial existence of such Good Reason condition. Upon receipt of such notice, the Company will have fifteen (15) days during which it may attempt
to remedy the Good Reason condition and not be required to provide for the benefits described in Section 4(b) above as a result of such proposed resignation if successfully remedied. If the Good Reason condition is not remedied within such
fifteen (15) day period, Employee may resign based on the Good Reason condition specified in the notice effective no later than thirty (30) days following the expiration of the fifteen (15) day cure period. For purposes of this
Agreement, “Good Reason” means the occurrence of any of the following events without Employee’s consent: (i) a material reduction of Employee’s Base Salary not generally applicable to other executive-level employees
of the Company, (ii) a material diminution of the Employee’s authority, duties, or responsibilities, (iii) a relocation of Employee’s primary workplace to a location that is more than fifty (50) miles from the location of
Employee’s primary workplace as of the date hereof, or (iv) the Company’s material breach of this Agreement. 
 (e)
APPLICATION OF INTERNAL REVENUE CODE SECTION 409A. Notwithstanding anything to the contrary set forth herein, any payments and benefits provided 







 
under this Section 4 that constitute “deferred compensation” within the meaning of Section 409A of the Internal Revenue Code and the regulations and other guidance thereunder
and any state law of similar effect (collectively “Section 409A”) will not commence in connection with Employee’s termination of employment unless and until Employee has also incurred a “separation from service” (as
such term is defined in Treasury Regulation Section 1.409A-1(h) (a “Separation From Service”), unless the Company reasonably determines that such amounts may be provided to Employee without causing Employee to incur the
additional 20% tax under Section 409A. The parties intend that each installment of the Separation Benefits payments provided for in this Agreement is a separate “payment” for purposes of Treasury Regulation
Section 1.409A-2(b)(2)(i). For the avoidance of doubt, the parties intend that payments of the Separation Benefits set forth in this Agreement satisfy, to the greatest extent possible, the exemptions from the application of Section 409A
provided under Treasury Regulation Sections 1.409A-1(b)(4), 1.409A-1(b)(5) and 1.409A-1(b)(9). However, if the Company determines that the Separation Benefits constitute “deferred compensation” under Section 409A and Employee is, on
the termination of service, a “specified employee” of the Company or any successor entity thereto, as such term is defined in Section 409A, then, solely to the extent necessary to avoid the incurrence of the adverse personal tax
consequences under Section 409A, the timing of the Separation Benefits payments will be delayed until the earlier to occur of: (i) the date that is six months and one day after Employee’s Separation From Service, or (ii) the date
of Employee’s death (such applicable date, the “Specified Employee Initial Payment Date”), and the Company (or the successor entity thereto, as applicable) will (A) pay to Employee a lump sum amount equal to the sum of the
Separation Benefits payments that Employee would otherwise have received through the Specified Employee Initial Payment Date if the commencement of the payment of the Separation Benefits had not been so delayed pursuant to this Section, and
(B) commence paying the balance of the Separation Benefits in accordance with the applicable payment schedules set forth in this Agreement. 

(f) NO FURTHER OBLIGATIONS. Except as expressly provided above or as otherwise required by law, the Company will have no obligations to
Employee in the event of the termination of this Agreement for any reason. 
 5. EMPLOYEE REPRESENTATIONS. Employee represents and
warrants that he is not obligated or restricted under any agreement (including any non-competition or confidentiality agreement), judgment, decree, order or other restraint of any kind that could impair Employee’s ability to perform the duties
and obligations required of Employee hereunder. Employee further agrees that he will not divulge to the Company any confidential information and/or trade secrets belonging to others, including Employee’s former employers, nor will the Company
seek to elicit from Employee such information. Consistent with the foregoing, Employee will not provide to the Company, and the Company will not request, any documents or copies of documents containing such information. 







 6. CONFIDENTIALITY. 

(a) Employee acknowledges that the Company will give Employee access to certain highly-sensitive, confidential, and proprietary information
belonging to the Company or third parties who may have furnished such information under obligations of confidentiality, relating to and used in the Company’s business (collectively, “Confidential Information”). Employee
acknowledges that, unless otherwise available to the public, Confidential Information includes, but is not limited to, the following categories of Company related confidential or proprietary information and material, whether in electronic, print, or
other form, including all copies, notes, or other reproductions or replicas thereof: financial statements and information; budgets, forecasts, and projections; business and strategic plans; marketing, sales, and distribution strategies; research and
development projects; records relating to any intellectual property developed by, owned by, controlled, or maintained by the Company; information related to the Company’s inventions, research, products, designs, methods, formulae, techniques,
systems, processes; customer lists; non-public information relating to the Company’s customers, suppliers, distributors, or investors; the specific terms of the Company’s agreements or arrangements, whether oral or written, with any
customer, supplier, vendor, or contractor with which the Company may be associated from time to time; and any and all information relating to the operation of the Company’s business which the Company may from time to time designate as
confidential or proprietary or that Employee reasonably knows should be, or has been, treated by the Company as confidential or proprietary. Confidential Information encompasses all formats in which information is preserved, whether electronic,
print, or any other form, including all originals, copies, notes, or other reproductions or replicas thereof. 
 (b) Confidential
Information does not include any information that: (i) at the time of disclosure is generally known to, or readily ascertainable by, the public; (ii) becomes known to the public through no fault of Employee or other violation of this
Agreement; or (iii) is disclosed to Employee by a third party under no obligation to maintain the confidentiality of the information. 

(c) Employee acknowledges that the Confidential Information is owned or licensed by the Company; is unique, valuable, proprietary and
confidential; and derives independent actual or potential commercial value from not being generally known or available to the public. Employee hereby relinquishes, and agrees that he will not at any time claim, any right, title or interest of any
kind in or to any Confidential Information, 
 (d) During and after his employment with the Company, Employee will hold in trust and
confidence all Confidential Information, and will not disclose any Confidential Information to any person or entity, except in the course of performing duties assigned by the Company or as authorized in writing by the Company. Employee further
agrees that during and after his employment with the Company, Employee will not use any Confidential Information for the benefit of any third party, except in the course of performing duties assigned by the Company or as authorized in writing by the
Company. 
 (e) The restrictions in Section 6(d) above will not apply to any information to the extent that Employee is required to
disclose such information by law, provided that the Employee (i) notifies the Company of the existence and terms of such obligation, (ii) gives the Company a reasonable opportunity to seek a protective or similar order to prevent or limit
such disclosure, and (iii) only discloses that information actually required to be disclosed. 







 (f) Any trade secrets of the Company will be entitled to all of the protections and benefits
under the North Carolina Trade Secrets Protection Act, N.C. Gen. Stat. § 66-152 et seq., and any other applicable law. If any information that the Company deems to be a trade secret is found by a court of competent jurisdiction not to be
a trade secret, such information will, nevertheless, be considered Confidential Information for purposes of this Agreement. 
 (g) Upon
request during employment and immediately at the termination of this Agreement, Employee will return to the Company all Confidential Information in any form (including all copies and reproductions thereof) and all other property whatsoever of the
Company in his possession or under his control. If requested by the Company, Employee will certify in writing that all such materials have been returned to the Company. Employee also expressly agrees that immediately upon the termination of his
employment with the Company for any reason, Employee will cease using any secure website, web portals, e-mail system, or phone system or voicemail service provided by the Company for the use of its employees. 

7. INTELLECTUAL PROPERTY. 

(a) Employee agrees that all developments or inventions (including without limitation any and all software programs (source and object code),
algorithms and applications, concepts, designs, discoveries, improvements, processes, techniques, know-how and data) that result from work performed by Employee for the Company, whether or not patentable or registrable under copyright or similar
statutes or subject to analogous protection (“Inventions”), will be the sole and exclusive property of the Company or its nominees, and Employee will and hereby does assign to the Company all rights in and to such Inventions upon the
creation of any such Invention, including, without limitation: (i) patents, patent applications and patent rights throughout the world; (ii) rights associated with works of authorship throughout the world, including copyrights, copyright
applications, copyright registrations, mask work rights, mask work applications and mask work registrations; (iii) rights relating to the protection of trade secrets and confidential information throughout the world; (iv) rights analogous
to those set forth herein and any other proprietary rights relating to intangible property; and (v) divisions, continuations, renewals, reissues and extensions .of the foregoing (as applicable), now existing or hereafter filed, issued or
acquired (collectively, the “IP Rights”). 
 (b) For avoidance of doubt, if any Inventions fall within the definition of
“work made for hire”, as such term is defined in 17 U.S.C. § 101, such Inventions will be considered “work made for hire” and the copyright of such Inventions will be owned solely and exclusively by the Company. If any
Inventions does not fall within such definition of “work made for hire”, then Employee’s right, title and interest in and to such Inventions will be assigned to the Company pursuant to Section 7(a) above. 

(c) The Company and its nominees will have the right to use and/or to apply for statutory or common law protections for such Inventions in any
and all countries. Employee further agrees, at the Company’s expense, to: (i) reasonably assist the Company in obtaining and from time to time enforcing such IP Rights relating to Inventions, and (ii) execute and deliver to the
Company or its nominee upon reasonable request all such documents as the Company or its 







 
nominee may reasonably determine are necessary or appropriate to effect the purposes of this Section 7, including assignments of inventions. Such documents may be necessary to: (1) vest
in the Company or its nominee clear and marketable title in and to Inventions; (2) apply for, prosecute and obtain patents, copyrights, mask works rights and other rights and protections relating to Inventions; or (3) enforce patents,
copyrights, mask works rights and other rights and protections relating to Inventions. Employee’s obligations pursuant to this Section 7 will continue beyond the termination of Employee’s employment with the Company. If the Company is
unable for any reason to secure Employee’s signature to any lawful and necessary document required to apply for or execute any patent, trademark, copyright or other applications with respect to any Inventions (including renewals, extensions,
continuations, divisions or continuations in part thereof), Employee hereby irrevocably designates and appoints the Company and its then current Chief Executive Officer as Employee’s agent and attorney-in-fact to act for and in behalf and
instead of Employee, to execute and file any such application and to do all other lawfully permitted acts to further the prosecution and issuance of patents, trademarks, copyrights or other rights thereon with the same legal force and effect as if
executed by Employee. In the event the Company utilizes the power of attorney set forth in the preceding sentence, the Company will provide Employee with written notice of the terms and circumstances of such utilization within thirty (30) days
following such utilization. 
 (d) The obligations of Employee under Section 7(a) will not apply to any Invention that Employee
developed entirely on his own time without using the Company’s equipment, supplies, facility or trade secret information, except for those Inventions that (i) relate to the Company’s business or actual or demonstrably anticipated
research or development, or (ii) result from any work performed by Employee for Company. Employee will bear the burden of proof in establishing the applicability of this subsection to a particular circumstance. 

8. NON-COMPETITION AND NON-SOLICITATION. 

(a) DEFINITIONS. As used in this Agreement, the following terms have the meanings given to such terms below. 

(i) “Business” means the discovery, development and commercialization of pharmaceutical products that are CDK4/6 inhibitors
for chemoprotection, renalprotection, or radioprotection activity, or also for anti-neoplastic activity. 
 (ii)
“Customer” means any person or entity who, at the time of, or in the twelve (12) months prior to the termination of Employee’s employment with the Company for any reason, was an actual customer of the Company with whom the
Employee had dealings in the course of Employee’s employment with the Company, or about whom Employee learned or received Confidential Information in the course of Employee’s employment with Company. 

(iii) “Company Employee” means any person who is or was an employee or independent contractor of the Company at the time of,
or during the twelve (12) month period prior to, the termination of Employee’s employment with the Company for any reason. 







 (iv) “Restricted Period” means the period commencing on the date of termination
of Employee’s employment with the Company for any reason and ending twelve (12) months after such date, provided, however, that this period will be tolled and will not run during any time Employee is in violation of this Section 8, it
being the intent of the parties that the Restricted Period will be extended for any period of time in which Employee is in violation of this Section 8 so as to provide the Company with the full benefit of the twelve-month period. 

(v) “Restricted Territory” means the (A) the United States of America; (B) the State of North Carolina; and
(C) any state, province, or similar geographic subdivision to which Employee directed or in which Employee performed employment-related activities on behalf of the Company at the time of, or during the twelve (12) month period prior to,
the termination of Employee’s employment with the Company for any reason. 
 (b) NON-COMPETITION. During Employee’s
employment with the Company, Employee will not, on Employee’s own behalf or on behalf of any other person, engage in any business competitive with or adverse to that of the Company. In addition, Employee will not hold a position based in or
with responsibility for all or part of the Restricted Territory, with any person or entity engaging in the Business, whether as employee, consultant, or otherwise, in which Employee will have duties, or will perform or be expected to perform
services for such person or entity, that is or are the same as or substantially similar to the position held by Employee or those duties or services actually performed by Employee for the Company within the twelve (12) month period immediately
preceding the termination of Employee’s employment with the Company, or in which Employee will use or disclose or be reasonably expected to use or disclose any Confidential Information of the Company for the purpose of providing, or attempting
to provide, such person or entity with a competitive advantage with respect to the Business. Notwithstanding the foregoing, Employee may, as a passive investor, own capital stock of a publicly held corporation engaging in or affiliated with an
entity engaging in the Business, so long as the Employee’s ownership is not in excess of five percent (5%) of the total outstanding capital stock of such corporation. 

(c) NON-SOLICITATION OF COMPANY EMPLOYEES. Employee agrees that during Employee’s employment and during the Restricted Period,
Employee will not, directly or indirectly, solicit, induce, or encourage any Company Employee to terminate his or her employment with or engagement by the Company. 

(d) NON-SOLICITATION OF CUSTOMERS. Employee agrees that during Employee’s employment and during the Restricted Period, Employee
will not, directly or indirectly, solicit, take away or otherwise interfere with any Customer, supplier or vendor of the Company on Employee’s own behalf or on behalf of any other party. 

(e) ACKNOWLEDGEMENT. Employee acknowledges and agrees that (i) the restrictive covenants in this Agreement are essential elements
of Employee’s employment by the Company and are reasonable given Employee’s access to the Company’s confidential information and the substantial knowledge and goodwill Employee will acquire with respect to the business of the Company
as a result of Employee’s employment with the Company; (ii) the restrictive covenants contained in this Agreement are reasonable in time, territory, scope, and all other respects; and (iii) enforcement of the restrictions contained
herein will not deprive the Employee 







 
of the ability to earn a reasonable living. The Parties further agree that if any portion of this Section 8 is found to be invalid or unenforceable by a court of competent jurisdiction
because its duration, territory, or other restrictions are deemed to be invalid or unreasonable in scope, the invalid or unreasonable terms will be replaced by terms that are valid and enforceable and that come closest to expressing the intention of
such invalid or unenforceable terms. 
 9. ENFORCEMENT. Employee acknowledges and agrees that the Company will suffer irreparable
harm in the event that Employee breaches any of Employee’s obligations under Sections 6, 7, or 8 of this Agreement and that monetary damages would be inadequate to compensate the Company for such breach. Accordingly, Employee agrees that, in
the event of a breach by Employee of any of Employee’s obligations under Sections 6, 7, or 8 of this Agreement, the Company will be entitled to obtain from any court of competent jurisdiction preliminary and permanent injunctive relief, and
expedited discovery for the purpose of seeking relief, in order to prevent or to restrain any such breach. The Company will be entitled to recover its costs incurred in connection with any action to enforce Sections 6, 7, or 8 of this Agreement,
including reasonable attorneys’ fees and expenses, to the maximum extent permitted by law. 
 10. NOTICES. Any notice required
to be given hereunder will be sufficient if in writing and hand delivered or sent by mail, return receipt requested, postage prepaid, in the case of Employee, to his address shown on the Company’s records, and in the case of the Company, to 79
T.W. Alexander Drive, 4401 Research Commons, Suite 105, Research Triangle Park, NC 27709, or to such other addresses as either party shall specify to the other. 

11. AMENDMENT; WAIVER. No amendment of any provision of this Agreement will be valid unless the amendment is in writing and signed by
the Company and Employee. No waiver of any provision of this Agreement will be valid unless the waiver is in writing and signed by the waiving party. The failure of a party at any time to require performance of any provision of this Agreement will
not affect such party’s rights at a later time to enforce such provision. No waiver by a party of any breach of this Agreement will be deemed to extend to any other breach hereunder or affect in any way any rights arising by virtue of any other
breach. 
 12. GOVERNING LAW; VENUE. This Agreement will be governed by and construed in accordance with the laws of the State of
North Carolina, without regard to that body of law known as choice of law. The parties agree that any litigation arising out of or related to this Agreement or Employee’s employment by the Company will be brought exclusively in any state or
federal court in Durham County, North Carolina. Each party (i) consents to the personal jurisdiction of said courts, (ii) waives any venue or inconvenient forum defense to any proceeding maintained in such courts, and (iii) agrees not
to bring any proceeding arising out of or relating to this Agreement or Employee’s employment by the Company in any other court. 
 13.
BENEFIT. This Agreement will be binding upon and will inure to the benefit of each of the parties hereto, and to their respective heirs, representatives, successors and permitted assigns. Employee may not assign any of his rights or delegate
any of his duties under this Agreement. 







 14. ENTIRE AGREEMENT. This Agreement contains the entire agreement and understanding by
and between the Company and Employee with respect to the subject matter hereof, and any representations, promises, agreements or understandings, written or oral, not herein contained will be of no force or effect. 

15. CAPTIONS; RULE OF CONSTRUCTION. The captions in this Agreement are for convenience only and in no way define, bind or describe the
scope or intent of this Agreement. The terms and provisions of this Agreement will not be construed against the drafter or drafters hereof. All parties hereto agree that the language of this Agreement will be construed as a whole according to its
fair meaning and not strictly for or against any of the parties hereto. 
 16. COUNTERPARTS. This Agreement may be executed in one or
more counterparts, each of which will be deemed an original but all of which together will constitute one and the same agreement. Facsimile or PDF reproductions of original signatures will be deemed binding for the purpose of the execution of this
Agreement. 
 17. SEVERABILITY. Each provision of this Agreement is severable from every other provision of this Agreement. Any
provision of this Agreement that is determined by any court of competent jurisdiction to be invalid or unenforceable will not affect the validity or enforceability of any other provision. Any provision of this Agreement held invalid or unenforceable
only in part or degree will remain in full force and effect to the extent not held invalid or unenforceable. 
 18. SURVIVAL. The
terms of Sections 4 through 18 will survive the termination or expiration of this Agreement for any reason. 
 IN WITNESS WHEREOF, the
parties have executed this Agreement effective as of the Effective Date. 
  

			
	G1 THERAPEUTICS, INC.:
		
	By:	 	 /s/ Mark A. Velleca

		 	Mark A. Velleca
		 	Chief Executive Officer
	
	EMPLOYEE:
	
	 /s/ Gregory Mossinghoff

	Gregory Mossinghoff