Thread by @niklas_kluemper

Happy to share our work: Membranous NECTIN-4 expression frequently decreases during metastatic spread of urothelial carcinoma and is associated with enfortumab vedotin resistance @CCR_AACR aacrjournals.org/clincancerres/… Follow our tweetorial about this clinically important data 1/12

First of all, a big thanks to @CCR_AACR for publishing our work! And thanks to all our cooperation partners! Especially @Markuseckstein3, @damian_ralser, @HolzelMichael, @IEO_HolzelLab, @UniklinikBonn 2/12

Intro: The #ADC enfortumab vedotin (EV) releases its cytotoxic agent into tumor cells via binding to the membrane receptor NECTIN-4. EV has been approved for patients with metastatic UC without prior assessment of the NECTIN-4 tumor receptor status by the FDA+EMA, because.. 3/12

In the phase 1 EV-101 clinical trial >95% of patients were reported to have strong tumoral NECTIN-4 expression, defined as H-score > 150, which led to a protocol amendment to omit assessment of NECTIN-4 expression before enrollment in the following pivotal EV-301 trial 4/12

In contrast, other studies reported less pronounced NECTIN-4 expression in UC (especially in variant histology)! Further, most studies did not focus on the prevalence of specific membranous NECTIN-4 protein expression, which is the biological requirement for EV binding 5/12

In addition, the membranous NECTIN-4 protein has not yet been systematically studied in primary tumors (PRIM) and patient-matched distant metastases (MET), although metastatic burden determines morbidity and mortality in patients with metastatic UC 6/12

Results i) Decrease of membranous NECTIN-4 expression during metastatic spread of UC is common! Decrease of NECTIN-4 during metastatic progression in more than 50% of cases (cohort of N=137 matched PRIM+MET). App. 40% of MET lacking membranous NECTIN-4 expression! 7/12

Results ii) To confirm the validity of our clinically relevant data, we have thoroughly validated the specificity of our NECTIN-4 IHC staining protocol by establishing CRISPR-Cas9-induced polyclonal NECTIN-4 knockouts in the urothelial cancer cell line HT1376 8/12

Results iii) In our multicenter cohort of EV-treated patients (N=47), absence or weak membranous NECTIN-4 expression (34% of the cohort with H-score < 100) was associated with EV resistance and shortened PFS (Log-rank P<0.001) 9/12

Conclusion: We believe, that our results are of clinical relevance and argue for a critical reconsideration of the current SoC: We suggest that the membranous NECTIN-4 receptor status should be determined (ideally in a metastatic/ progressive lesion) before initiation of EV 10/12

Discussion: Patients lacking NECTIN-4 expression may be more likely to benefit from other therapies, e.g. anti-Trop2 ADC. We thus need biomarker-driven clinical trials: We suggest the choice of ADC after consideration of the respective target expression on the tumor surface 11/12

Discussion: Patients lacking NECTIN-4 expression may be more likely to benefit from other therapies, e.g. anti-Trop2 ADC. We thus need biomarker-driven clinical trials: We suggest the choice of ADC after consideration of the respective target expression on the tumor surface 11/12

Outlook: We just recently highlighted at @EUplatinum that spatial immunephenotypes of MET but not matched PRIM can also predict response to immunotherapy buff.ly/3DZOyh0, which further supports the concept of a metastatic biopsy to predict treatment responses in UC 12/12