The biosimilar's entrance effect $RHHBY sales in the US. 
Avastin and Herceptin have many Biosimilar versions (3-5).
Rituxan only 2:
Teva launched rituxan biosimilar in 11/07/19
Pfizer launched rituxan biosimilar in 01/23/20  

$PFE $BIIB $TEVA $MYL $AMGN https://t.co/uPa59PCbOw