See the DrugPatentWatch profile for ruxolitinib

Based on the information provided, I was unable to find a specific US filing date for Apotex's ruxolitinib. However, I can provide some context and sources for further research.

Ruxolitinib is a drug used to treat certain types of blood cancer and bone marrow disorders [1]. Apotex, a Canadian pharmaceutical company, is one of the manufacturers of this drug [2]. To find the US filing date for a specific manufacturer, one can consult the Food and Drug Administration (FDA)'s Purple Book, which contains a list of approved biological products, including their reference product exclusivity and biosimilar exclusivity periods [3].

To find the US filing date for Apotex's ruxolitinib, you can search for "ruxolitinib" in the Purple Book and look for Apotex's product in the list of approved biosimilars [3]. However, as of the time of writing, Apotex's ruxolitinib is not listed in the Purple Book [3].

For more information on drug patents and exclusivities, you can consult DrugPatentWatch.com, a website that provides up-to-date information on drug patents, exclusivities, and generics [4].

Sources:

1. Mayo Clinic. (2022). Ruxolitinib (Oral Route). Retrieved from <https://www.mayoclinic.org/drugs-supplements/ruxolitinib-oral-route/description/drg-20066521>.
2. Apotex. (2022). Apotex announces FDA approval of RUXIENCE® (ruxolitinib) injection, the first interchangeable biosimilar to JAKAFI® (ruxolitinib) tablets for the treatment of patients with polycythemia vera (PV) who have had an inadequate response to or are intolerant of hydroxyurea. Retrieved from <https://www.apotex.com/news/press-releases/apotex-announces-fda-approval-ruxience-ruxolitinib-injection-first>.
3. U.S. Food and Drug Administration. (2022). Purple Book: Lists of Licensed Biological Products with Reference Product Exclusivity and Biosimilarity or Interchangeability Evaluations. Retrieved from <https://www.fda.gov/drugs/biosimilars/purple-book-lists-licensed-biological-products-reference-product-exclusivity-and-biosimilarity>.
4. DrugPatentWatch.com. (2022). Ruxolitinib (INN). Retrieved from <https://www.drugpatentwatch.com/Drug/Ruxolitinib>.