In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: All patients received CAB [ leuprolide acetate ( LHRH - A ) 3 . 75 mg , intramuscularly , every 28 days plus 250 mg flutamide , tid , per Os ] and were evaluated for anemia by physical examination and laboratory tests at baseline and 4 subsequent intervals ( 1 , 2 , 3 and 6 months post - CAB ) .
### Output Text:
All patients received CAB [ <span class="chemical">leuprolide acetate</span> ( <span class="chemical">LHRH - A</span> ) 3 . 75 mg , intramuscularly , every 28 days plus 250 mg <span class="chemical">flutamide</span> , tid , per Os ] and were evaluated for anemia by physical examination and laboratory tests at baseline and 4 subsequent intervals ( 1 , 2 , 3 and 6 months post - CAB ) . 