Privacy Policy


Arsanis, Inc. (“Arsanis”, “we”, “us” or “our”) respects the privacy of visitors to our website. This Privacy Policy (the “Policy”) describes how we collect, use, and disclose information in connection with our and websites and their subdomains, and to information that we collect through our social media channels (collectively, the “the Site”). Your use of the Site constitutes your acceptance of this Policy.

Information We Collect

We collect both Personal Information and Other Information about visitors to our Site, as described below. For purposes of this Policy, “Personal Information” means information we can directly associate with a specific person without any additional information, such as an email address. “Other Information” means any information that is not Personal Information. We may combine Other Information and Personal Information, in which case we will treat the combined information as Personal Information.

We may also combine Personal Information or Other Information we have about you with additional information that we or third parties collect in other contexts – like when we communicate with you by email. In those circumstances, we will treat the combined information in accordance with this Policy.

Personal Information. We collect Personal Information from you when you provide it to us via email or when you sign up to receive communications from or about Arsanis. We may collect information such as your:

  • First and last name
  • Company affiliation
  • Email address

We do not collect or process user location information.

Other Information. We also collect Other Information automatically when you visit our Site or receive emails from us. This may include information like your IP address and domain name, your Internet service provider, the time and duration of your visit, how you used the Site (including pages viewed and actions taken), whether you opened or read an email from us, the URLs from the websites you visit before and after navigating to the Site, your operating system and browser type, your software and hardware attributes, and your general geographic location (for example, your city, state, or metropolitan region). We collect this information using the following technologies:

  • Server Logs. When you use the Site, we automatically receive and record certain information from your computer or other device and your browser. To obtain such information, we may use server logs or applications that recognize your device and gather information about its online activity.
  • Cookies. To make our Site work properly, we sometimes place small data files called cookies on your device. Most big websites do this too. A cookie is a small text file that a website saves on your computer or mobile device when you visit the site. It enables the site to remember your actions and preferences (such as login, language, font size and other display preferences) over a period of time, so you don’t have to keep re-entering them whenever you come back to the site or browse from one page to another. On our Site, we use cookies to recognize whether you have visited the Site before, to store user preferences and Other Information, and to facilitate the Site analytics described in this Policy. The cookies we use are permanent first- and third-party cookies, meaning that they remain after you leave the Site and are placed and controlled by Arsanis and by third parties engaged by Arsanis. Cookies will not be used for purposes other than as stated in this Policy. If you are concerned about having cookies on your computer, you can set your browser to refuse all cookies or to indicate when a cookie is being set, allowing you to decide whether to accept it. You can also delete cookies from your computer. However, if you choose to block or delete cookies, certain features of the Site may not operate correctly. For details about managing cookies, see

Our Site currently does not respond to “do not track” browser headers or similar signals.

How We Use Information

We may use Personal and Other Information for a variety of purposes, including to:

  • Respond to your requests by email or a phone call, to fulfill the terms of any agreement we have with you, or to take actions related to our relationship with you;
  • Consider your qualifications for a position at Arsanis if you express interest in one;
  • Send you newsletters, updates, and other materials that you have signed up to receive;
  • Analyze and research user experiences with our Site and emails so that we can improve user experiences and enhance our Site, emails, and other offerings;
  • Prepare aggregated or de-identified information about interactions with our Site and emails; and
  • Comply with any legal or regulatory requirements or to serve the other legal purposes described below in the section entitled “How We Share Information with Third Parties”;

We use Other Information for additional purposes, including to:

  • Count and recognize visitors to the Site, and analyze how visitors use the Site;
  • Engage in analytics as described above; and
  • For any other purpose permitted by law, including any purpose for which we use Personal Information.

How We Share Information with Third Parties

We may share Personal and Other Information with third parties for a variety of purposes, as described below:

Arsanis Entities. We also share your Personal or Other Information with Arsanis affiliated and subsidiaries for any of the purposes described in this Policy.

Third-party service providers. We use third-party service providers to help us host, maintain, operate, and improve our Site. Acting under our instructions, these service providers may collect or use your Personal or Other Information to assist us in achieving the purposes described in this Policy. For example, we may use third parties to collect information about visitors to our Site and report it to us. We may also use third parties (such as Constant Contact) to send our email updates.

Third-party plugins. The Site may have certain third-party plug-ins (such as Twitter and LinkedIn). If you use social media channels, they may collect information about you, such as your IP address and the pages you view, even if you do not click on the plug-in on our Site. They may set or access a cookie. These plugins are governed by the privacy policy of the company providing them, and this Privacy Policy does not apply to information that is collected by other parties through our social media channels.

Analytics.   We may engage third parties to collect, analyze, and use some of the information described above. For example, we may allow third parties to collect Other Information through cookies or pixel tags on the Site or in email communications from us for analytics, auditing, research, and reporting purposes. These third parties may use web logs, pixel tags, or other tracking mechanisms and they may set and access cookies on your computer or device.

  • Google Analytics. Our Site uses Google Analytics to help collect and analyze certain information for the purposes discussed above. You may opt out of the use of cookies by Google Analytics here. Google Analytics is a web analytics service provided by Google, Inc. (“Google”). Google Analytics uses cookies, which are text files placed on your computer, to help analyze how users use the Site. The information generated by the cookie about your use of the Site (including your IP address) will be transmitted to and stored by Google on servers in the United States. Google will not associate your IP address with any other data held by Google. Google will use this information for the purpose of evaluating your use of the Site, compiling reports on Site activity and providing other services relating to Site activity and internet usage to us and our hosting service provider. You can prevent Google’s collection and use of data (cookies and IP address) by downloading and installing the browser plug-in available under
  • LeadLander. We engage a third party called Upland LeadLander to track users’ IP addresses and which pages of our Site are visited. LeadLander may associate a user’s IP address with a user’s company affiliation, but does not associate any user’s IP address with the user’s name or email address. LeadLander will place a cookie containing a random number called “trackalyzer” on the user’s computer. The random number and the user’s IP address is stored in LeadLander’s external database. LeadLander will honor “Do Not Track” requests if set on a user’s browser. LeadLander does not retain any user or visit data in web logs or log files, but uses pixel tag images to record which pages of the Site are visited. LeadLander’s privacy policy can be viewed at

Legal purposes. We also may use or share your Personal or Other Information with third parties when we believe, in our sole discretion, that doing so is necessary:

  • To comply with applicable law or a court order, subpoena, request from government or law enforcement, or other legal process;
  • To monitor compliance with or to enforce our Terms of Use;
  • To investigate, prevent, or take action regarding illegal activities, suspected fraud, violations of our terms and conditions, or situations involving threats to our property or the property or physical safety of any person or third party; or
  • To establish, protect, or exercise our legal rights or defend against legal claims.
  • To facilitate the financing, securitization, insuring, merger, acquisition, sale, assignment, bankruptcy, or other disposal of all or part of our business or assets.

De-identified or aggregated information. We may also create and share de-identified or aggregated information about Site users, such as by creating reports on trends in the usage of the Site. This information does not identify individual users.

Reviewing and updating your information

Please contact us by email at if you want to:

  • learn more about the information we have about you,
  • update or change that information, or
  • opt-out of any regular email communications you might receive from us.

You can also follow the “Unsubscribe” instructions in any email you receive from us to stop receiving email updates from us.

Information for Site users from outside the United States

The Personal and Other Information we collect through or in connection with the Site is transferred to and processed in the United States. We may also subcontract the processing of your data, or otherwise share your data with, third parties in the United States or countries other than your country of residence. The data protection laws in these countries may be different from, and less stringent than, those in your country of residence. By accepting this Policy, using the Site, signing up for email updates, or providing information us, you expressly consent to such transfer and processing.

Links to Other Sites

This Policy covers only our Site, and does not cover third-party sites that may be accessible from our Site. Such third party sites are governed by the privacy policies of the companies that maintain them.


Our Site has security measures in place to protect the security and privacy of any of your information that you provide to us. Data that we gather on our Site is stored in a password-protected database. Only we, our hosting provider, and our authorized service providers have direct access to this database. Notwithstanding the security protections that may be implemented by us and our hosting providers, we cannot guarantee the physical or electronic security of the servers and databases on which this Site is hosted.

Children’s Privacy

The Site is not directed to children under the age of 13, and Arsanis does not knowingly collect Personal or Other Information through the Site from anyone it knows is under the age of 13.

Changes to this Policy

We may change the Site or our data-handling practices in the future and therefore need to revise this Policy. We will post the revised Policy with an “effective date” that indicates when the revisions take effect. We encourage you to review this page periodically.

Questions or Unsubscribe

If you have any questions regarding this Policy or wish to access or request amendments of Personal Information that we may maintain about you, please email us at or contact us by mail at: Attention: Business Operations 890 Winter Street Suite 230 Waltham, MA 02451

Effective Date

This Privacy Policy is effective as of February 19, 2018.