ERBB2 and Hyperbilirubinemia: The adverse event profiles differed notably: DS-8201 was primarily associated with elevated transaminases and fatigue, while RC48 more frequently caused myelosuppression and hyperbilirubinemia.<h4>Conclusion</h4>DS-8201 demonstrates potential as one of the effective salvage therapies following RC48 failure in HER2 altered solid tumors, showing significantly better disease control and a distinct, manageable toxicity profile.