Exhibit 14.1

[CUBIST LOGO]                        Cubist Employee
Policy                        CODE OF CONDUCT AND ETHICS

Introduction

Cubist Pharmaceuticals, Inc., and its affiliates (together "Cubist" or the "Company") is committed to conducting business with a high degree of integrity.
This Code of Conduct and Ethics is your guide to applicable laws and regulations as well as key policies and procedures that provide guidance for conducting business in a legal and ethical manner. It
does not cover every situation that may arise, but establishes important standards, principles, and rules to guide the actions of all employees and Directors. All employees and Directors must act in
accordance with the Code and seek to avoid even the appearance of improper behavior. The Code should also be provided to and followed by consultants to the Company.

If
a law conflicts with a policy in this Code, you must comply with the law; however, if a local custom or policy conflicts with this Code, you must comply with the Code. If you have any
questions about these conflicts, you should seek advice from: (i) your Vice President, (ii) any director-level or higher employee in Human Resources, (iii) any director-level or
higher employee in the Law Department, or (iv) the Chief Compliance Officer.

If
you have a question about the Code or want to report a violation or suspected violation, you may call the Company's internal Compliance Helpline at
781-860-8600.

If
you want to report a violation or suspected violation of this Codeanonymously, including, for example, violations relating to
accounting, internal accounting controls, or auditing matters or violations by an Executive Officer of the Company, you may call the Company's external Corporate Responsibility Hotline at
1-888-690-3869 or on the web at www.silentwhistle.com.

Directors
must report violations or suspected violations of the Code to the Board of Directors.

A good basis for deciding when to get advice is to ask yourself whether the conduct might be embarrassing to the Company or the persons involved if the details
were fully disclosed to the public by the media.

Violations
of the standards in this Code will subject you to disciplinary action up to and including termination.

Section 1.    Compliance with Laws, Rules and Regulations

Obeying the law, both in letter and in spirit, is the foundation on which this Company's ethical standards are built. All employees and Directors must respect and
obey the laws of the jurisdictions in which we operate. Although not all employees and Directors are expected to know the details of these laws, it is important to know enough to determine when to
seek advice from: (i) your Vice President, (ii) any director-level or higher employee in Human Resources, (iii) any director-level or higher employee in the Law Department, or
(iv) the Chief Compliance Officer.

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The
Company holds information and training sessions and has put in place various policies and procedures in order to promote compliance with laws, rules and regulations, including
insider-trading laws. Each department head is responsible for ensuring that his/her employees attend all mandatory training sessions that are related to compliance with laws, rules and regulations
applicable to his/her job functions.

Section 2.    Conflicts of Interest

All employees and Directors are expected to make decisions in the best interest of the Company, and not for personal gain, and therefore are required to avoid
"conflicts of interest."

A
"conflict of interest" exists when a person's private interest interferes in any way with the interests of the Company. A conflict can arise when an employee or Director takes actions
or has interests that may make it difficult to perform his or her Company responsibilities objectively and effectively. Conflicts of interest may also arise when an employee or Director, or members of
his or her family, receives personal benefits as a result of his or her position in the Company. Loans to, or guarantees of obligations of, employees or Directors and their family members may create
conflicts of interest.

It
is almost always a conflict of interest for a Company employee to work simultaneously for a competitor, customer, supplier, or vendor. Employees are not allowed to work for a
competitor in any capacity, including as a consultant or board member. The best policy is to avoid any direct or indirect business connection with customers, suppliers, or competitors, except on the
Company's behalf.

Directors
must comply with the Conflict of Interest provisions set forth in the Amended and Restated Corporate Governance Guidelines.

Conflicts
of interest may not always be clear-cut. If you have a question whether a situation poses a conflict of interest, you should seek advice from: (i) your Vice
President, (ii) any director-level or higher employee in Human Resources, (iii) any director-level or higher employee in the Law Department, or (iv) the Chief Compliance Officer.
Any employee who becomes aware of a conflict or potential conflict should bring it to the attention of: (i) his or her Vice President, (ii) any director-level or higher employee in Human
Resources, (iii) any director-level or higher employee in the Law Department, or (iv) the Chief Compliance Officer.

Section 3.    Insider Trading

Employees and Directors who have access to confidential information are not permitted to use or share that information for stock trading purposes or for any other
purpose except the conduct of the Company's business. All non-public information about the Company should be considered confidential information. To use non-public information
for personal financial benefit or to "tip" others who might make an investment decision on the basis of this information is not only unethical but also illegal. If you have any questions, please refer
to the Company's Policy on Insider Trading and Confidentiality, and then ask the Law Department.

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Section 4.    Corporate Opportunities

Employees and Directors are prohibited from exploiting for their personal advantage opportunities that are discovered through the use of corporate property,
information, or position without the consent of the Board of Directors. No employee or Director may use corporate property, information, or position for personal gain, and no employee or Director may
compete with the Company directly or indirectly. Employees and Directors owe a duty to the Company to advance its legitimate interests when the opportunity to do so arises.

Section 5.    Competition and Fair Dealing

We seek to outperform our competition fairly and honestly. We seek competitive advantages through superior performance, never through unethical or illegal
business practices. Stealing proprietary information, possessing trade secret information that was obtained without the owner's consent, or inducing such disclosures by past or present employees of
other companies is prohibited. Each employee and Director should endeavor to respect the rights of and deal fairly with the Company's customers, suppliers, competitors, vendors, and their employees.
No employee or Director should take unfair advantage of anyone through manipulation, concealment, abuse of privileged information, misrepresentation of material facts, or any other intentional
unfair-dealing practice.

Drug
development is highly competitive, and it is the policy of the Company to compete aggressively, but fairly. A major part of this commitment to compete fairly is a commitment to
abide fully by the antitrust laws. In general, these complex laws prohibit any form of agreement or understandingwhether formal, informal, express, or impliedthat
unreasonably reduces competition and business rivalry. Our commitment in this regard also prohibits any unfair or untrue disparagement of a Company competitor.

All
suppliers, vendors and contractors should be selected on the basis of written competitive bids if the amount of the services or goods to be provided is significant. Employees should
check with Purchasing to determine if a competitive bid is required.

The
purpose of business entertainment and gifts in a commercial setting is to create good will and sound working relationships, not to gain unfair advantage with customers. Gifts or
entertainment should not ever be offered, given, provided to any customer, supplier, or vendor, or accepted from any customer, supplier, or vendor by any Company employee or Director, or family member
of an employee or Director unless it: (1) is not a cash gift, (2) is consistent with customary business practices, (3) is not excessive in value, (4) cannot be construed as
a bribe or payoff, (5) does not violate any laws or regulations, and (6) is offered in compliance with applicable Company policies and procedures.

It
is the policy of the Company to comply with health care "fraud and abuse" laws. This includes Federal and State anti-kickback laws that prohibit offering or giving
kickbacks or other improper inducements to healthcare professionals, which includes anyone who may be in a position to purchase or prescribe or to arrange for or recommend the purchase or prescription
of the Company's products. Any arrangements with healthcare professionals, including, for example, gifts, research grants, and business courtesies, must comply with applicable laws, Company policies,
and procedures, which are available from the Compliance Department.

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If
you are uncertain about offering or accepting a gift or business entertainment, you should seek advice from: (i) your Vice President, (ii) any director-level or higher
employee in Human Resources, (iii) any director-level or higher employee in the Law Department, or (iv) the Chief Compliance Officer.

Section 6.    Discrimination and Harassment

The diversity of the Company's employees is a tremendous asset. We are firmly committed to providing equal opportunity in all aspects of employment and will not
tolerate any discrimination or harassment of any kind. Please refer to Cubist's "Policy Against Sexual Harassment in the Workplace" for additional information and guidance.

Section 7.    Health and Safety

The Company strives to provide each employee with a safe and healthful work environment. Each employee has responsibility for maintaining a safe and healthy
workplace for all employees by following safety and health rules and practices and reporting accidents, injuries and unsafe equipment, practices or conditions.

The
Company will not tolerate violence and threatening behavior. Employees should report to work in condition to perform their duties, free from the influence of illegal drugs or
alcohol. The Company will not tolerate the use of illegal drugs in the workplace or on the Company's property. Please see the Company's policies for further guidance.

Section 8.    Record-Keeping

All business records must be recorded accurately and truthfully. The Company follows the accepted accounting rules and controls set forth by the U.S. Securities
and Exchange Commission and the Financial Accounting Standards Board. The Company requires honest and accurate recording and reporting of information in all circumstances, and without exception. The
Company requires that its certified public accountants have access to any and all information necessary for them to conduct audits properly.

Business
expense accounts must be documented and recorded accurately. If you are not sure whether a certain expense is legitimate, ask your supervisor or the Controller. Rules and
guidelines are available from the Controller.

All
of the Company's books, records, accounts and financial statements must be maintained in reasonable detail, must appropriately reflect the Company's transactions and must conform
both to applicable legal requirements and to the Company's system of internal controls. Unrecorded or "off the books" funds or assets should not be maintained unless permitted by applicable law or
regulation and approved in writing by the Chief Financial Officer.

Business
records and communications often become public, and should not contain exaggeration, derogatory remarks, guesswork, or inappropriate characterizations of people and companies.
This applies equally to e-mail, internal memos, and formal reports. Records should always be retained or destroyed according to the Company's record retention policies. In accordance with
those policies, in the event of litigation or governmental investigation, threatened or known, please consult with a director-level or higher employee in the Law Department.

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Section 9.    Confidentiality

Employees and Directors must maintain the confidentiality of confidential information entrusted to them by the Company, including confidential information that
the Company has received from a third party, except when disclosure is authorized by a director-level or higher employee in the Law Department, or required by laws or regulations. Confidential
information includes all non-public information that might be of use to competitors, or harmful to the Company or its customers, if disclosed. It also includes information that suppliers,
customers, and other third parties have entrusted to the Company. The obligation to preserve confidential information continues even after employment ends.

Section 10.    Protection and Proper Use of Company Assets

All employees and Directors should endeavor to protect the Company's assets and ensure their efficient use. Theft, carelessness, and waste have a direct impact on
the Company's profitability. Any suspected incident of fraud or theft should be immediately reported for investigation. Company equipment should not be used for non-Company business,
though incidental personal use may be permitted. The obligation of employees and Directors to protect the Company's assets includes its proprietary information. Proprietary information includes
intellectual property such as trade secrets, patents, trademarks, and copyrights, as well as business, marketing and service plans, engineering and manufacturing ideas, designs, databases, records,
salary information and any unpublished financial data and reports. Unauthorized use or distribution of this information would violate Company policy. It could also be illegal and result in civil or
even criminal penalties. Please see the Company's policies on IT usage and confidentiality for further guidance.

Section 11.    Payments to Government Personnel

The U.S. Foreign Corrupt Practices Act prohibits giving anything of value, directly or indirectly, to officials of foreign governments or foreign political
candidates in order to obtain or retain business. It is strictly prohibited to make payments to government officials of any country.

In
addition, the U.S. government has a number of laws and regulations regarding the provision of business gratuities to U.S. government personnel, including, for example, employees of
Medicare, Medicaid, and the Veterans Administration. The promise, offer or delivery to an official or employee of the U.S. government of a gift, favor or other gratuity in violation of these rules
would not only violate Company policy but could also be a criminal offense. State and local governments, as well as foreign governments, may have similar rules.

The
Company does not contribute, directly or indirectly, to any political campaign or party.

Employees
and Directors are not prohibited from making personal political contributions to candidates or parties of their choice, but may not use Company expense accounts to pay for any
political contributions, seek any other form of company reimbursement, nor use company facilities or company assets for the benefit of any party or candidate, including an employee or Director
individually running for office.

Section 12.    Misrepresentations and False Statements

Employees and Directors must never make a deliberate misrepresentation concerning the Company or its business operations. No employee or Director shall create, or
assist another in creating, a false or misleading entry on the Company's books or business records.

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Section 13.    Responding to Government Requests

It is the Company's policy to cooperate with all reasonable requests from Governmental agencies concerning the Company's business operations. Employees and
Directors are expected to respond truthfully to Governmental inquiries. All government inquiries, whether initiated by telephone, subpoena, or other request, must be immediately communicated to a
director-level or higher member of the Law Department before taking any action.

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Section 14.    Compliance Procedures

We must all work to ensure prompt and consistent action against violations of this Code. However, in some situations it may be difficult to know right from wrong.
Since we cannot anticipate every situation that will arise, it is important that we have a way to approach a new question or problem. These are the steps to keep in mind:



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Section 15.    Reporting Violations or Suspected Violations

Employees must promptly report any violations or suspected violations of this Code or any illegal activities they observe. Reports may be
made in confidence and without fear of retaliation.

Reports
can be made to your Vice President, (ii) any director-level or higher employee in Human Resources, (iii) any director-level or higher employee in the Law
Department, or (iv) the Chief Compliance Officer.

You
may also report violations or suspected violations by calling the Company's internal Compliance Helpline at 781-860-8600 or the Company's external Corporate
Responsibility Hotline at 888-690-3869 or on the web at www.silentwhistle.com. Calls to the external Corporate Responsibility Hotline may be made anonymously if you prefer. The
Company does not permit retaliation of any kind against employees for good faith reports of ethical violations.

All
employees are expected to cooperate in internal investigations of misconduct.

Employees
are encouraged to seek advice from: (i) their respective Vice President, (ii) any director-level or higher employee in Human Resources, (iii) any
director-level or higher employee in the Law Department, or (iv) the Chief Compliance Officer about observed illegal or unethical behavior and, when in doubt, about the best course of action in
a particular situation.

Directors
must report any observed illegal or unethical behavior to the Board of Directors.

We
take all reports of misconduct seriously. We will confidentially investigate all alleged misconduct to determine if any law, regulation, policy or procedure has been violated.

Section 16.    No Retaliation

The Company will not retaliate in any manner, including, but not limited to, discharging, demoting, suspending, threatening, harassing, or otherwise
discriminating against an employee who reports in good faith violations or suspected violations of this Code, including, but not limited to, accounting fraud or securities law violations.

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Section 17.    Waivers of the Code of Business Conduct and Ethics

While some standards in this Code require strict application and exceptions or waivers are not allowed, others do allow for waivers. Any waiver of this Code for
Executive Officers or Directors may be made only by the Board of Directors and will be promptly disclosed as required by law or Nasdaq regulation.

Employees
other than Executive Officers who believe they may merit a waiver should first consult their supervisor. If the supervisor agrees that a waiver is warranted, the supervisor
should forward the request to the Chief Compliance Officer. The Chief Compliance Officer and CEO will jointly approve or disapprove the request.

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