After researching the provided sources, I was unable to find the exact filing date for Apotex's Ruxolitinib ANDA (Abbreviated New Drug Application). However, I can share some information on the drug Ruxolitinib and the process of filing an ANDA.

Ruxolitinib is a medication used to treat certain types of blood cancer and bone marrow disorders. It is often sold under the brand name Jakafi or Jakavi, and it is a Janus kinase (JAK) inhibitor that helps regulate the immune system and reduce inflammation.

The process of filing an ANDA involves submitting an application to the U.S. Food and Drug Administration (FDA) to manufacture and market a generic version of an already approved drug. The application must demonstrate that the generic drug is bioequivalent to the brand-name drug, meaning it has the same active ingredient, strength, dosage form, and route of administration.

Here are the steps I took to find the filing date:

1. I checked the DrugPatentWatch website [${1}] to find information on Ruxolitinib's tradename. This site provides details on drug patents and exclusivities, but it does not list the ANDA filing date.
2. I then consulted the FDA's list of Abbreviated New Drug Applications [${2}] to search for Apotex's Ruxolitinib ANDA. However, the FDA's list does not provide the filing date for pending applications.
3. Lastly, I looked at Health Canada's Generic Submissions Under Review [${3}] to see if the filing date was available from the Canadian regulatory agency. Unfortunately, the site does not provide the filing date for Apotex's Ruxolitinib ANDA.

Sources:

1. [DrugPatentWatch](https://www.drugpatentwatch.com/p/tradename/RUXOLITINIB)
2. [FDA Abbreviated New Drug Applications](https://www.fda.gov/drugs/abbreviated-new-drug-application-anda/patent-certifications-and-suitability-petitions)
3. [Health Canada Generic Submissions Under Review](https://www.canada.ca/en/health-canada/services/drug-health-product-review-approval/generic-submissions-under-review.html)