Clinical Cases in Pharmacology Clinical Cases  ·  Medical Oncology Vol. II  ·  Genitourinary Cancer  ·  First-Line Metastatic Urothelial Carcinoma in a Patient With Diabetic Neuropathy
Medical Oncology Vol. II, Case 0012 — Genitourinary Cancer

First-Line Metastatic Urothelial Carcinoma in a Patient With Diabetic Neuropathy

EV-302 made enfortumab vedotin plus pembrolizumab the new first-line standard across essentially every subgroup — the actual question is whether that standard still fits a cisplatin-eligible patient whose baseline diabetic neuropathy sits directly in the path of the new regimen's dominant toxicity.

Abbreviations, terms, and other agents mentioned in this case EV — enfortumab vedotin  ·  mUC — metastatic urothelial carcinoma  ·  EV-302 — trial establishing enfortumab vedotin plus pembrolizumab as first-line standard in mUC  ·  CTCAE — Common Terminology Criteria for Adverse Events
Presentation

S.K., a 72-year-old man, has managed type 2 diabetes for over twenty years and has lived with symptomatic peripheral neuropathy in both feet for the last several of those, numbness and occasional burning that he manages with gabapentin and describes, without complaint, as "just part of getting old with this disease." A new diagnosis of metastatic urothelial carcinoma, with nodal and hepatic spread found on staging after months of unexplained weight loss, now puts him at the point of choosing first-line systemic therapy. His renal function, cardiac status, and performance status all clear the threshold for cisplatin eligibility, which matters because it puts every major first-line option on the table rather than narrowing his choices in advance.

EV-302 established enfortumab vedotin plus pembrolizumab as superior to platinum-based chemotherapy across essentially every subgroup analyzed, including cisplatin-eligible patients specifically — a result substantial enough to have replaced platinum chemotherapy as the default first-line choice for most patients. But enfortumab vedotin's dominant, dose-limiting toxicity is peripheral neuropathy, and EV-302 drew its exclusion line at ongoing sensory or motor neuropathy of grade 2 or higher. His deficit sits just under that line, which means the trial's result does describe him — he would have been enrolled. What it does not do is tell the team what the drug does to a foot that already carries years of diabetic damage, since patients starting from a grade 1 baseline were eligible but never analyzed as a group of their own.

His baseline neuropathy is formally grade 1 by CTCAE criteria — sensory symptoms present but not limiting function — which places him inside EV-302's eligible population by a single grade. The label reports what the drug does from any starting point: peripheral neuropathy in 53% of patients treated with enfortumab vedotin, and among those left with a residual deficit at last assessment, 40% had shown no improvement at all. Read against feet that are already numb, that irreversibility fraction, not the eligibility criterion, is the number this decision actually turns on.

S.K. · 72 New Diagnosis, Metastatic
Staging
Nodal and hepatic metastatic disease found on staging
Diabetic neuropathy
Symptomatic peripheral neuropathy, both feet, several years' duration, managed on gabapentin
Cisplatin eligibility
Meets full criteria — renal function, cardiac status, and performance status all adequate
Diabetes control
A1c 7.4%, long-standing type 2 diabetes
Performance status
ECOG 1, mild fatigue attributed to weight loss
Renal function
Creatinine 0.9, eGFR 88

Choosing first-line therapy with a real neuropathy history

Medical Oncologist Opening

EV-302 showed enfortumab vedotin plus pembrolizumab beat platinum chemotherapy across essentially every subgroup, including cisplatin-eligible patients like him — median overall survival 31.5 months against 16.1. And he isn't outside that population: the trial excluded grade 2 neuropathy and above, and he is a grade 1. He would have been randomized. I'd be reluctant to withhold a result that large from a patient the trial actually covers.

Second Medical Oncologist Response

Eligible isn't the same as represented. A grade 1 ceiling let in patients with trace findings on examination; it did not select for men who have had burning feet for years and take gabapentin for them, and nobody reported that slice separately. The number I'd put in front of him is the label's — 53% develop neuropathy on this drug, and of those left with a deficit, 40% never recover it. He is starting that process partway along.

"Inside the eligibility criteria" and "represented in the result" aren't the same thing, especially when the gap between them is exactly the comorbidity most relevant to the drug's own dominant toxicity.

Neurologist Final

He's fully cisplatin-eligible, so platinum chemotherapy is a real option rather than a fallback — though I won't pretend it's neuropathy-free, since cisplatin has its own sensory toxicity and that cost belongs on the table. What it mostly is, is recoverable in a way enfortumab vedotin's often isn't. I'd start there with formal grading each cycle. If his baseline holds, that is real information for revisiting enfortumab vedotin second-line, rather than spending an irreplaceable foot on a first-line choice today.

Regimen selected
Cisplatin
Platinum Chemotherapy · Combined with gemcitabine
Selected as first-line therapy given that his baseline neuropathy, while technically inside EV-302's eligible population, was never separately analyzed as its own subgroup, leaving real uncertainty about enfortumab vedotin's effect on a foot already carrying diabetic damage; his full cisplatin eligibility makes this a genuine, effective option rather than a fallback.
Gemcitabine
Antimetabolite · Combined with cisplatin
Standard chemotherapy backbone paired with cisplatin in this first-line regimen.
Enfortumab Vedotin + Pembrolizumab — Considered, Not Adopted
Antibody-Drug Conjugate + Checkpoint Inhibitor · Considered
The current first-line standard by EV-302, but passed over for now given his pre-existing symptomatic neuropathy, though inside the trial's eligible population by a single grade, was never analyzed as its own subgroup against the drug's dominant toxicity; may be reconsidered if platinum chemotherapy proves inadequate.
Where this was left

Agreed: cisplatin-gemcitabine started as first-line therapy, with formal neuropathy grading at each cycle to track his baseline trajectory independent of any future regimen change.

Not agreed, and stated as an open question to revisit rather than settled today:

If chemotherapy achieves good disease control

The medical oncologist would consider maintenance avelumab per the standard post-platinum pathway, without needing to revisit enfortumab vedotin at all.

If chemotherapy proves inadequate

The second oncologist would want a fresh, individualized neuropathy assessment before offering enfortumab vedotin second-line, rather than assuming his baseline precludes it indefinitely.

Educational content only — a composite teaching case, not a real patient encounter or a substitute for clinical guidance. About These Cases →