A practice gap exists in managing side effects of Trastuzumab-Deruxtecan (TDXD) between specialties. Breast oncologists, with more experience, are far more aggressive with prophylactic anti-emetics and frequent imaging to detect asymptomatic ILD. This proactive approach is a key lesson for lung cancer specialists and others now adopting the drug.

Beyond efficacy, new therapies like bispecifics require significant institutional support. Clinicians need training for unfamiliar side effects like CRS, and facilities need resources like observation units and admission protocols, creating a steep implementation curve for clinical practice.

While better tolerated than chemotherapy, daraxon-rasib's unique toxicity profile (rash, stomatitis) requires a clinical management shift. Oncologists must proactively use strategies like prophylactic antibiotics, a departure from managing typical chemotherapy-induced myelosuppression.

The potential for urologists to administer PD-1 inhibitors for bladder cancer raises a significant safety issue: surgeons may not be equipped to manage severe, systemic immune-related toxicities like hypophysitis or hepatitis, which traditionally fall under the purview of medical oncologists.

The POTOMAC trial's success adding durvalumab to BCG for non-muscle invasive bladder cancer introduces a major logistical hurdle. Urologists, who typically manage these patients, often lack the expertise to handle systemic immunotherapy side effects, creating uncertainty about which specialty will administer this new standard of care.

Major trials in prostate (PEACE-2), bladder (Keynote B15), and kidney cancer (LITESPARK-022) showcase a common strategy: moving potent systemic therapies into earlier, curative-intent settings. This approach of using the best drugs sooner aims to improve long-term outcomes, though it also raises questions about toxicity and overtreatment.

New targeted therapies like Zanidatamab and Zolbetuximab show great promise but cause significant side effects like diarrhea and nausea. Their successful clinical adoption hinges on proactive management using detailed guidelines and prophylactic medications, as toxicity can be severe enough to force treatment discontinuation despite the drug's efficacy.

For novel drugs like tarlatumab, the role of oncology pharmacists extends far beyond dispensing. They are systems architects who design crucial toxicity management protocols (for CRS/ICANS), create standardized order sets, and lead the essential in-service training for inpatient hospital teams to ensure safe and consistent administration.

When managing toxicities from trastuzumab deruxtecan (TDXD) in urothelial cancer, clinicians should refer to established protocols and literature from breast cancer, where experience is more extensive. This cross-disciplinary approach is necessary for managing side effects like nausea, vomiting, and lung disease until more bladder cancer-specific data becomes available.