The need for additional alkylating agents and antimetabolites.
D000477:Alkylating Agents / Q000627:therapeutic use*; D000963:Antimetabolites / Q000627:therapeutic use*; D004339:Drug Compounding; D005493:Folic Acid Antagonists; D009369:Neoplasms / Q000188:drug therapy*; D011119:Polynucleotides / Q000037:antagonists & inhibitors; D011687:Purines / Q000037:antagonists & inhibitors; D011743:Pyrimidines / Q000037:antagonists & inhibitors
D000477:Alkylating Agents; D000963:Antimetabolites; D005493:Folic Acid Antagonists; D011119:Polynucleotides; D011687:Purines; D011743:Pyrimidines