Exhibit 10.6

EMPLOYMENT AGREEMENT

THIS AGREEMENT (the "Agreement") is entered into this 7th day of November, 2003 by and between NaPro BioTherapeutics, Inc., a Delaware corporation (the
"Company"), and Sterling K. Ainsworth, Ph.D. ("Employee"). Certain capitalized terms used in this Agreement have the meaning set forth in Paragraph 17 of this Agreement.

RECITALS

A.    WHEREAS,
Employee is currently employed by the Company pursuant to an employment agreement effective as of October 1, 2001 by and between the Company and the
Employee (the "2001 Employment Agreement");

B.    WHEREAS,
the Company has entered into an agreement to sell the Company's worldwide polyethoxylated castor oil formulated injectable paclitaxel business (the "Sale") to
Faulding Pharmaceutical Co. ("Faulding");

C.    WHEREAS,
in settlement of certain disputed claims under the 2001 Employment Agreement, Employee and the Company have determined that the 2001 Employment Agreement will be
terminated by mutual agreement and the terms of Employee's employment with the Company and its subsidiaries will be changed as provided in this Agreement; and

D.    WHEREAS,
the Company desires to secure the continued services of Employee as an employee of the Company after the Sale, and to provide for certain compensation and
benefit arrangements for Employee in the event of Employee's termination of employment under certain circumstances, and Employee is willing to enter into this Agreement and perform such services.

TERMS AND CONDITIONS

In consideration of the respective covenants and agreements of the parties contained in this Agreement, the parties agree as follows:

1.Employment Services; Effective Date.



2.Performance.



3.Compensation.





4.Reimbursement for Expenses.The Company shall reimburse Employee for reasonable documented direct
costs of maintaining a home office in Employee's home necessary for Employee to provide the Employment Services up to a maximum of $500.00 per calendar month, including electricity, cellular
telephone, separate business telephone, long distance telephone charges, dedicated Internet access and electronic mail, office supplies and any other expense, so long as directly related to the
performance of Employment Services. In addition, the Company shall reimburse those other reasonable documented out-of-pocket expenses incurred by Employee in the course of his
fulfilling his Employment Services, including dues and fees for attending professional meetings and institutes, costs of professional books and periodicals, and travel expenses reasonably related to
the Employment Services, provided that the Company shall not reimburse any expenses exceeding $500.00 in any calendar month as provided in the first sentence of this paragraph 4 unless Employee
has obtained the Company's approval in writing prior to incurring such expenses. Employee agrees to invoice the Company for such expenses within 30 days after they were incurred and provide
supporting documentation reflecting the amount of the expense, the date incurred and the reason for the expense.

5.Benefits.During the Employment Period, Employee shall be entitled to all fringe benefits offered
by the Company and to participate in all of the Company's employee benefit programs both on the same basis as available to employees of the Company, and shall be entitled to such other benefits as may
from time to time be made available to Employee. Employee shall be entitled to indemnification in accordance with the terms and conditions of Article Six, Section (e) of the Amended and
Restated Certificate of Incorporation of the Company, as in effect on the date this Agreement is executed, and the Director and Officer Indemnification Agreement dated April 21, 1994, with
respect to all claims brought against Employee based upon or arising out of his actions or inactions as an officer and/or director of the Company or its affiliates occurring prior to the Effective
Date. Even if Article Six, Section (e) of the Amended and Restated Certificate of Incorporation of the Company is hereafter amended or modified, the Company shall provide indemnification to
Employee in accordance with the terms and conditions of Article Six, Section (e) as they existed on the date this Agreement is executed with respect to any claims, demands or causes of action
brought by third parties against Employee based upon or arising out of his actions or inactions as an officer and/or director of the Company or its affiliates occurring prior to the Effective Date.
Moreover, for a period of three years following the Effective Date, the Company shall use commercially reasonable efforts to maintain directors' and officers' liability insurance, which provides
coverage to Employee as a former officer and director of the Company and its subsidiaries and affiliates in substantially the same magnitude and coverage as is available to current officers and
directors. Employee and the Company acknowledge that the Company is the beneficiary under a $3 million key man life insurance policy (Transamerica Occidental Life Insurance Company, policy
number 41792293) with Employee as the named insured. Within 60 days after the Effective Date, the Company shall deliver such policy to Employee and shall execute any necessary instruments in
order to effect the transfer of such policy, including the sole right to name the beneficiary of such policy, to Employee. Employee shall be responsible for and shall pay all premiums required to keep
this life insurance policy effective after the effective date of such transfer.

6.Term and Termination.



7.Notice of Certain Termination.In the event that either (i) the Company shall terminate
Employee for Cause or for Good Reason or (ii) Employee shall terminate for Good Reason, then any such termination shall be communicated by written notice to the other party hereto. Any such
notice shall specify (x) the effective date of termination of the Employment Period, which, except as otherwise provided in Paragraph 6(e), shall not be more than 30 days after
the date the notice is delivered (the "Termination Effective Date") and (y) in reasonable detail the facts and circumstances underlying a determination that the termination is for Cause or for
Good Reason, as the case may be. If within


15 days after any notice of termination of Employee for Cause or Good Reason by the Company is given, or if within 15 days after the Company's 30 day cure period under
Paragraph 6(e) has expired, the party receiving such notice notifies the other party that a good faith dispute exists concerning the characterization of the termination, the Termination
Effective Date shall be the date on which such dispute is finally resolved either by written agreement of the parties or by binding arbitration conducted pursuant to the rules of the American
Arbitration Association. Notwithstanding the pendency of any such dispute, the Company shall continue Employee and Employee's dependents as participants in all medical, dental and any other health
insurance, life insurance, accidental death and dismemberment insurance and disability protection plans of the Company in which Employee and Employee's dependents were participating when the notice
giving rise to the dispute was given, until the dispute is finally resolved. Benefits provided under this Paragraph 7 are in addition to all other amounts due under this Agreement and shall not
be offset against, or reduce any other amounts due under, this Agreement. In any case other than a termination by the Company for Cause or for Good Reason or by the Employee for Good Reason, the
Termination Effective Date shall be the date on which the termination takes effect.

8.Insurance.The Company may, at its election and for its benefit, insure Employee against accidental
death, and Employee shall submit to such physical examination and supply such information as may be required in connection therewith.

9.Non-disclosure of Confidential Information.Unless Employee first secures written
consent from the Company pursuant to procedures implemented by Company after the date hereof, Employee shall not disclose or use at any time, either during the Employment Period or thereafter, any
Confidential Information (as defined in Paragraph 17) except to the extent Employee reasonably believes it is necessary to disclose or use such Confidential Information in performing the
Employment Services. Employee further agrees that Employee will use Employee's reasonable efforts to safeguard the Confidential Information and protect it against disclosure, misuse, espionage, loss
and theft, including, without limitation, causing recipients of Confidential Information to enter into non-disclosure agreements with the Company. Subject to the provisions of Paragraphs
10 and 13, nothing herein shall be construed to prevent Employee from using Employee's general knowledge and skill after termination of this Agreement, whether Employee acquired such knowledge or
skill before or during the Employment Period. Notwithstanding anything in this Agreement to the contrary, disclosure of Confidential Information shall not be prohibited if such disclosure is in
response to court order or is otherwise required by law; provided, however, that Employee shall make reasonable efforts to (i) give written notice to the Company of such required disclosure as
soon as reasonably practicable, (ii) obtain a protective order for the Confidential Information so disclosed, and (ii) disclose only such Confidential Information as is required to be
disclosed.

10.Company Ownership of Intellectual Property.Subject to the limitations of Paragraph 11,
Employee hereby assigns to the Company all right, title and interest in and to all Intellectual Property (as defined in Paragraph 17) contributed to or conceived or made by Employee during the
Employment Period and prior to the Employment Period during the period Employee was employed by or engaged in research or development activities for or with the Company or its predecessors and
Affiliates (whether alone or jointly with others) to the extent such Intellectual Property is not owned by the Company as a matter of law. Employee shall promptly and fully communicate to the Company
all Intellectual Property conceived, contributed to or made by Employee and shall cooperate with the Company to protect the Company's interests in such Intellectual Property including, without
limitation, providing assistance in securing patent protection and copyright registrations and signing all documents reasonably requested by the Company, even if such request occurs after the
Employment Period. The Company shall pay Employee's reasonable expenses of cooperating with the Company in protecting the Company's interests in such Intellectual Property unless the subject matter of
the requested cooperation is related to actions taken or failed to be taken by Employee wrongfully or otherwise not in good faith.

11.Employee's Rights.Paragraph 10 of this Agreement does not apply to an invention for which
no equipment, supplies, facilities or trade secret information of the Company was used and which was developed entirely on Employee's own time, unless (a) the invention relates (i) to
the business of the Company, or (ii) to the Company's actual or demonstrably anticipated material research or development, or (b) the invention results from any work performed by
Employee for the Company. Paragraph 10 of this Agreement also does not apply to an invention in a field for which Employee has received a confirmation of no interest from the Company pursuant
to paragraph 11(a).

11(a).
In the event that Employee has a bonafide opportunity to engage in a business which the Company is not engaged in, then Employee may provide the Company with a written description of such
opportunity. Such written description shall be adequate to describe the opportunity, but need not contain confidential information. Upon receipt of such notice, the Company will provide Employee,
within 30 calendar days, with a statement that either (1) the Company has an bonafide interest in entering such field of business, or (2) the Company has no interest in entering such
field of business. If no such notice is given within 30 calendar days, then the Company will have been deemed to have no interest. Employee shall not submit more than two such notices in any calendar
quarter.

12.Return of Materials.Upon Termination of the Employment Period, or at any time reasonably
requested by the Company, Employee shall promptly deliver to the Company all copies of Confidential Information in Employee's possession and control, including written records, manuals, lab notebooks,
customer and supplier lists and all other materials containing any Confidential Information. If the Company requests, Employee shall provide written confirmation that Employee has returned all such
materials. Subject to the provisions of this Agreement, including, without limitation, Paragraph 11, notwithstanding anything in this Agreement to the contrary, upon termination of the
Employment Period, the Company, at Employee's request, shall promptly return to Employee any equipment or other materials owned by Employee then being used by or then in the possession of the Company.

13.Non-Competition.Employee acknowledges and agrees that, in the course of his duties to
the Company, Employee is permitted access to Intellectual Property, which includes, among other things, trade secrets of the Company that the Company seeks to protect from dissemination and
disclosure. Employee acknowledges and agrees that during the Employment Period and for a period of 12 months thereafter (the "Non-Compete Period"), Employee will not, without the
prior written consent of the Company, directly or indirectly, as an employee, agent, independent contractor, consultant, owner, stockholder, partner, officer, director or otherwise, enter into or in
any manner take part in any business or entity that provides or offers or demonstrably plans to provide or offer, products or services that relate to (i) paclitaxel and taxane compounds, either
as single agents or as targeted agents; (ii) quassinoids and epothilone compounds, either as single agents or as targeted compounds; (iii) the use of gene editing in diagnostics,
services or therapeutics; or (iv) relate to any subject matter of the Company's actual or demonstrably anticipated material research and development during the Employment Period, including
without limitation, taxol, taxanes and any other compounds, within any geographical area in which the Company or any of its subsidiaries provide or plan to provide such products or services; provided,
however, that Employee may purchase or otherwise acquire up to (but not more than) one percent (1%) of any class of securities of any such business or entity the securities of which are publicly
traded on an exchange or automated quotation system (but without otherwise participating in the activities of such business or entity). Notwithstanding the foregoing, Employee may continue in any
activity in which the Company has expressed no interest pursuant to paragraph 11(a).

14.Non-Solicitation.Employee acknowledges and agrees that during the
Non-Compete Period, Employee will not (a) solicit, induce or attempt to induce, directly or indirectly, any employee of the Company to leave the employment of the Company to work
for Employee or for any other person, firm or corporation or (b) hire any employee of the Company. Notwithstanding anything herein to the contrary, this Paragraph 14 shall not apply with
respect to Patricia A. Pilia.

15.Acknowledgment of Reasonableness.Employee acknowledges and agrees that the limitations set forth
in Paragraphs 13 and 14 are reasonable with respect to scope, duration and geographic area and are properly required for the protection of the legitimate business interest of the Company.

16.Further Assistance.During the Non-Compete Period, Employee will not make any
disclosure or other communication to any person, issue any public statements or otherwise cause to be disclosed any information which is designed, intended or might reasonably be anticipated to
discourage any persons from doing business with the Company or otherwise have a negative impact or adverse effect on the Company, except to the extent such disclosure is required by law. During the
Non-Compete Period, Employee will provide assistance reasonably requested by the Company in connection with actions taken by Employee during the Employment Period, including but not
limited to assistance in connection with any lawsuits or other claims against the Company arising from events during the Employment Period, provided that the Company shall reimburse all reasonable
expenses (including without limitation, reasonable loss of compensation from other sources resulting from such assistance during normal business hours).

17.Certain Definitions.An "Affiliate" of, or a
person "Affiliated" with, a specified person, is a person that directly, or indirectly through one or more intermediaries, controls, or is controlled
by, or is under common control with, the persons specified.

"Beneficial Ownership" has the meaning ascribed to such term in Rule 13d-3 of the General Rules and Regulations under
the Securities Exchange Act of 1934, as in effect on the date of this Agreement (the "Exchange Act Rules").

"Confidential Information" means all information (whether or not specifically labeled or identified as confidential), in any form or
medium, that is disclosed to, or developed or learned by Employee during the Employment Period and prior to the Employment Period during the period Employee was employed by or engaged in research or
development activities for or with the Company or its predecessors and Affiliates that relates to the business, products, services, customers, business opportunities, business contacts, research or
development of the Company, its Subsidiaries, its Affiliates, or third parties with whom the Company, its Subsidiaries or its Affiliates does business or from whom the Company or its Affiliates
receives information. Confidential Information shall not include any information that (i) has become publicly known through no wrongful act or breach of any obligation of confidentiality, as
evidenced by written records or documents; (ii) was rightfully received by Employee on a non-confidential basis from a third party (provided that such third party is not known to
Employee to be bound by a confidentiality agreement with the Company or another party), as evidenced by written records or documents; or (iii) was developed or obtained by Employee through
activities for which Employee has received a confirmation of no interest from the Company pursuant to paragraph 11(a) as evidenced by written records or documents.

"Intellectual Property" means any idea, invention, design, development, device, method or process (whether or not patentable or reduced to
practice or including Confidential Information) and all related patents and patent applications, any copyrightable work or mask work (whether or not including Confidential Information) and all related
registrations and applications for registration, and all other proprietary rights.

"Subsidiaries" means any corporation of which the securities having a majority of the voting power in electing directors are, at the time
of determination, owned by the Company, directly or through one of more Subsidiaries.

18.Employee Representations.Employee hereby represents and warrants to the Company that
(a) the execution, delivery and performance of this Agreement by Employee does not and will not conflict with, breach, violate or cause a default under any contract, agreement, instrument,
order, judgment or decree to which Employee is a party or by which he is bound, and (b) upon the execution and delivery


of this Agreement by the Company, this Agreement shall be the valid and binding obligation of Employee, enforceable in accordance with its terms.

19.Company Representations.The Company hereby represents and warrants to Employee that
(a) the execution, delivery and performance of this Agreement by the Company does not and will not conflict with, breach, violate or cause a default under any contract, agreement, instrument,
order, judgment or decree to which Company is a party or by which it is bound, and (b) upon the execution and delivery of this Agreement by Employee, this Agreement shall be the valid and
binding obligation of the Company, enforceable in accordance with its terms.

20.Severability and Modification.If any provision of this Agreement shall be held or declared to be
illegal, invalid or unenforceable, such illegal, invalid or unenforceable provision shall not affect any other provision of this Agreement, and the remainder of this Agreement shall continue in full
force and effect as though such provision had not been contained in this Agreement. If the scope of any provision in this Agreement is found to be too broad to permit enforcement of such provision to
its full extent, each of the parties consents to judicial modification of such provision and enforcement to the maximum extent permitted by law.

21.Notices.Except as otherwise expressly set forth in this Agreement, all notices, requests and
other communications to be given or delivered under or by reason of the provisions of this Agreement shall be in writing and shall be given (and, except as otherwise provided in this Agreement, shall
be deemed to have been duly given if so given) when delivered if given in person or by telegram, three days after being mailed by first class registered or certified mail, return receipt requested,
postage prepaid, or one business day after being sent prepaid via reputable overnight courier to the parties at the following addresses (or such other address as shall be furnished in writing by like
notice; provided, however, that notice of change of address shall be effective only upon receipt):



His
last known address as shown in the records of the Company



22.Entire Agreement.This Agreement contains the entire agreement between parties with respect to the
subject matter hereof and supersedes any previous understandings or agreements, whether written or oral, regarding such subject matter. Except as otherwise provided in Paragraph 1 of this
Agreement, the 2001 Employment Agreement shall terminate upon the Effective Date.

23.Governing Law.All questions concerning the construction, validity and interpretations of this
Agreement will be governed by the internal law, and not the law of conflicts, of the State of Colorado.

24.Survival.Paragraphs 6, 9, 10, 11, 12, 13, 14 and 16 and any other provision of this Agreement
which by its terms could survive termination of the Employment Period shall survive and continue in full force in accordance with their terms notwithstanding any termination of the Employment Period.

25.Counterparts.This Agreement may be executed in separate counterparts, each of which is deemed to
be an original and all of which taken together constitute one and the same agreement.

26.Successors and Assigns.This Agreement is intended to bind and inure to the benefit of and be
enforceable by Employee, the Company and their respective successors and assigns; provided that in no event shall Employee's obligations under this Agreement be delegated or transferred by Employee,
nor


shall Employee's rights be subject to encumbrance or to the claims of Employee's creditors. This Agreement is for the sole benefit of the parties hereto and shall not create any rights in third
parties other than Employee's spouse or beneficiary as expressly set forth herein.

27.Remedies.Except as otherwise provided in this Agreement, (i) each of the parties to this
Agreement will be entitled to enforce its rights under this Agreement specifically, to recover damages by reason of any breach of any provision of this Agreement and to exercise all other rights to
which it may be entitled and (ii) disputes under this Agreement not finally resolved in writing by the parties within sixty days after one party gives notice in good faith to the other party
that a bona fide dispute exists shall be resolved pursuant to binding arbitration conducted in Denver, Colorado in accordance with the rules of the American Arbitration Association. The prevailing
party in any such arbitration shall be entitled to have its costs and expenses (including reasonable attorney's fees and expenses) relating to such arbitration paid by the other party if the
arbitrator(s) conducting such arbitration so determine. Notwithstanding the foregoing, the parties agree and acknowledge that money damages may not be an adequate remedy for breach of the provisions
of this Agreement and that any party may in its sole discretion apply to any court of law or equity of competent jurisdiction for specific performance and/or injunctive relief in order to enforce or
prevent any violations of the provisions of this Agreement. The prevailing party in any suit shall be entitled to recover reasonable attorneys fees and costs from the other party.

28.Modifications and Waivers.No provision of this Agreement may be modified, altered or amended
except by an instrument in writing executed by the parties hereto. No waiver by either party hereto of any breach by the other party hereto of any term or provision of this Agreement to be performed
by such other party shall be deemed a waiver of similar or dissimilar terms or provisions at the time or at any prior or subsequent time.

29.Headings.The headings contained herein are solely for the purpose of reference, are not part of
this Agreement and shall not in any way affect the meaning or interpretation of this Agreement.

30.Notification of Subsequent Employer.Employee agrees that the Company may present a copy of this
Agreement to any third party.

31.UNDERSTAND AGREEMENT.EMPLOYEE REPRESENTS AND WARRANTS THAT (a) EMPLOYEE HAS READ AND
UNDERSTOOD EACH AND EVERY PROVISION OF THIS AGREEMENT, (b) EMPLOYEE HAS HAD THE OPPORTUNITY TO OBTAIN ADVICE FROM LEGAL COUNSEL OF EMPLOYEE'S CHOICE, OTHER THAN COUNSEL TO THE COMPANY (WHO IS
NOT REPRESENTING THE EMPLOYEE), IN ORDER TO INTERPRET ANY AND ALL PROVISIONS OF THIS AGREEMENT, (c) EMPLOYEE HAS HAD THE OPPORTUNITY TO ASK THE COMPANY QUESTIONS ABOUT THIS AGREEMENT AND ANY OF
SUCH QUESTIONS EMPLOYEE HAS ASKED HAVE BEEN ANSWERED TO EMPLOYEE'S SATISFACTION, AND (d) EMPLOYEE HAS BEEN GIVEN A COPY OF THIS AGREEMENT.

[Signature page follows]



IN
WITNESS WHEREOF, the parties hereto have caused this Agreement to be duly executed on the day and year first above written.

|EMPLOYEE:                                                   | 
|----------------------------------------------------------- | 
|/s/STERLING K. AINSWORTH, PH.D.Sterling K. Ainsworth, Ph.D. | 
|THE COMPANY:                                                | 
|NaPro BioTherapeutics, Inc.                                 | 
|By:                                                         | 
|Kai P. Larson, Vice President, General Counsel              | 



QuickLinks