Also, what I have learned:
Infusions are a medical treatment, therefore paid by your medical insurance.
Oral drugs are pharmaceutical, therefore paid by your pharmacy coverage. Medicare may pay for certain oral anti-cancer drugs
Also, reading the "Medicare and You" book for 2022. Chemotherapy is covered by medicare. You pay 20%.
Call Medicare with all your questions. I am impressed with how kind they have been. Maybe your doctor can suggest an alternative treatment that is covered.

It took me 6 months to get my insurances to work! Both (medicare and the secondary ins) denied being the primary. What a mess. I held fast and finally they worked out their differences.

There are a multitude of grants available to help pay medical Bill's. Do a search for medical Bill's grants!

Thank you!

Go to one of the many Co-pay assistance programs such as LLS.org and PAN Network. There are lists of finial assistance resources through Google