Somatic alterations of TP53 and MDM2 associated with response to enfortumab vedotin in patients with advanced urothelial cancer

Strategies to overcome resistance to enfortumab vedotin and pembrolizumab for patients with urothelial carcinoma: harnessing present knowledge for future advances

The combination of enfortumab vedotin and pembrolizumab (EVP) has been recently approved for patients with locally advanced and metastatic urothelial carcinoma. This combination showed a higher objective response rate and superior progression-free survival and overall survival over traditional platinum-based chemotherapy in the frontline setting in the pivotal EV-302 trial. Despite the success, a subset of patients has primary refractory disease, and another subset will develop secondary resistance over time. Resistance to enfortumab vedotin may include the downregulation of nectin-4 expression to minimize antibody binding, upregulation of efflux pumps against the toxin, or direct resistance by the tubulin against the toxin. Resistance to pembrolizumab includes several methods to downregulate the immune system. Additionally, the type of histology of the urothelial carcinoma likely plays an important role in resisting EVP. This review summarizes these possible mechanisms of primary and secondary resistance, potential biomarkers predictive of response and resistance, and methods to overcome the resistance to EVP.

Genomic Biomarkers Associated with Enfortumab Vedotin Outcomes for Patients with Advanced Urothelial Carcinoma: Analysis of UNITE Study Data

Enfortumab vedotin (EV) is used as monotherapy or combined with pembrolizumab in advanced urothelial carcinoma (aUC), but biomarker data associated with EV outcomes are limited. We identified 170 patients in the UNITE study who received EV monotherapy and had molecular biomarker data available. Outcomes for groups with and without a particular biomarker were compared using logistic regression (unadjusted) for the objective response rate (ORR), and a log-rank test and Cox proportional-hazard models (CPHMs) for progression-free survival (PFS) and overall survival (OS) from EV initiation. Molecular biomarkers were also evaluated in separate multivariable analyses using CPHMs that accounted for clinical characteristics. Median patient age was 70 yr; 78% of the cohort were male and 65% had pure UC histology. Median PFS was shorter for patients with CDKN2A alterations (4.6 vs 6 mo; p = 0.024) and for patients with CDKN2B alterations (4.4 vs 6 mo; p = 0.008). Median OS was longer for patients with high tumor mutational burden (13.6 vs 8.3 mo; p = 0.014). ORR was higher for patients with TSC1 alterations (87% vs 51%; p = 0.018). In multivariable analyses, CDKN2A and CDKN2B alterations were associated with inferior median PFS. This multi-institutional retrospective study of patients with aUC identified potential biomarkers associated with EV monotherapy outcomes that should be further investigated. PATIENT SUMMARY: We investigated genetic changes in urinary tract tumors that might be associated with response to enfortumab vedotin (EV) treatment in patients with advanced disease. Survival after EV treatment was longer for tumors with a higher number of mutations than for tumors with fewer mutations. However, mutations in two genes (CDKN2A and CDKN2B) were associated with worse outcomes after EV treatment. These findings will not affect current clinical practice, but should be investigated further in future studies.

The Role of Antibody-Drug Conjugates in Urothelial Cancer: A Review of Recent Advances in the Treatment of Locally Advanced and Metastatic Urothelial Cancer

Locally advanced and metastatic urothelial cancer (la/mUC) is an aggressive disease with poor prognosis. Platinum-based chemotherapy has remained the first-line treatment for decades and until recently no other treatment options existed. Today, novel agents called antibody drug conjugates (ADCs), including enfortumab vedotin (EV) and sacituzumab govitecan (SG), have been approved for la/mUC offering patients treatment options following or instead of traditional chemotherapy. The EV consists of the chemotherapy monomethyl auristatin E linked to anti-nectin-4 antibody. Single-agent response rates for EV are 40% to 52% including activity in patients with liver metastases, a phenotype associated with worse outcomes. In 2023, EV in combination with pembrolizumab almost doubled progression-free and overall survival versus platinum-based chemotherapy, which led to accelerated FDA approval as first-line treatment for all patients with la/mUC. Safety profile of EV monotherapy and combination with pembrolizumab is generally manageable with peripheral neuropathy and cutaneous toxicity among the most common treatment-related adverse events (TRAEs). The SG is another ADC targeting TROP-2 with SN-38 as payload. It is approved as late-line treatment for la/mUC with ORR 27% and most common TRAEs include gastrointestinal symptoms and neutropenia. Finally, a recent cancer agnostic accelerated approval for trastuzumab deruxtecan (T-DXd) in HER2-positive (IHC3+) solid tumors provides another active ADC option for biomarker-selected patients with treatment refractory la/mUC. Several new ADCs are being investigated in urothelial cancer (UC) clinical trials. This review summarizes the clinical studies and real-world data regarding the use of ADCs in UC.

Immunohistochemical Expression of p53 and FGFR3 Predicts Response to Enfortumab Vedotin in Metastatic Urothelial Carcinoma

Locally advanced or metastatic urothelial carcinoma is a genomically and molecularly heterogeneous disease associated with various clinical outcomes. We aimed to evaluate the association between the status of p53/FGFR3 expression and the efficacy of enfortumab vedotin (EV) in metastatic urothelial carcinoma. We evaluated the association between p53 (abnormal vs. wild-type) or FGFR3 (high vs. low) expression determined by immunohistochemistry and response to EV in 28 patients with metastatic urothelial carcinoma. Overall, 60.7% showed abnormal p53, and 17.9% had high FGFR3 expression. The rates of objective response to EV were statistically higher in patients with abnormal p53 than in those with wild-type p53 (p = 0.038). Patients with pure urothelial carcinoma (n = 18) and low FGFR3 showed significantly better response to EV than those with high FGFR3. When the statuses of p53 and FGFR3 were combined, abnormal p53/low FGFR3 (vs. wild-type p53/high FGFR3) was strongly associated with favorable outcomes in both the entire cohort (p = 0.002) and in cases of pure urothelial carcinoma only (p = 0.023). Immunohistochemically abnormal p53 tumors were found to respond well to EV, while high FGFR3 tumors had a poorer response. Thus, p53 and FGFR3 are potential biomarkers for predicting response to EV treatment in patients with urothelial carcinoma.

Mechanistic Insights into the Successful Development of Combination Therapy of Enfortumab Vedotin and Pembrolizumab for the Treatment of Locally Advanced or Metastatic Urothelial Cancer

Antibody-drug conjugates (ADCs) consist of an antibody backbone that recognizes and binds to a target antigen expressed on tumor cells and a small molecule chemotherapy payload that is conjugated to the antibody via a linker. ADCs are one of the most promising therapeutic modalities for the treatment of various cancers. However, many patients have developed resistance to this form of therapy. Extensive efforts have been dedicated to identifying an effective combination of ADCs with other types of anticancer therapies to potentially overcome this resistance. A recent clinical study demonstrated that a combination of the ADC enfortumab vedotin (EV) with the immune checkpoint inhibitor (ICI) pembrolizumab can achieve remarkable clinical efficacy as the first-line therapy for the treatment of locally advanced or metastatic urothelial carcinoma (la/mUC)-leading to the first approval of a combination therapy of an ADC with an ICI for the treatment of cancer patients. In this review, we highlight knowledge and understanding gained from the successful development of EV and the combination therapy of EV with ICI for the treatment of la/mUC. Using urothelial carcinoma as an example, we will focus on dissecting the underlying mechanisms necessary for the development of this type of combination therapy for a variety of cancers.

Oncologic Outcomes of Patients with Immune Checkpoint Inhibitor Resistant Urothelial Carcinoma Treated with Enfortumab Vedotin and the Impact of Neutrophil-to-Lymphocyte Ratio and Dysgeusia on Overall Survival: A Retrospective Multicenter Cohort Study in Japan

Randomized phase III trial results have demonstrated enfortumab vedotin (EV), an antibody-drug conjugate (ADC) consisting of an anti-Nectin-4 human IgG1 monoclonal antibody and monomethyl auristatin E, is a useful treatment for patients with locally advanced or metastatic urothelial carcinoma (la/mUC) that progressed after immune checkpoint inhibitor (ICI) therapies. This multicenter retrospective cohort study aimed to identify predictive factors for the efficacy of EV therapy and prolonged overall survival (OS) of patients in clinical practice. This study included patients with la/mUC who received ICI treatment. Patients who subsequently received EV treatment, those who received non-EV chemotherapy, and those who received no treatment were defined as EV, non-EV, and best supportive care (BSC) groups, respectively. The median OS was 20, 15, and 7 months in the EV, non-EV, and BSC groups, respectively (p < 0.001). Patients with la/mUC who had a complete or partial response after EV treatment had a significantly prolonged OS compared with those with stable or progressive disease. Univariate analysis showed age, neutrophil-to-lymphocyte ratio (NLR), dysgeusia, and rash as independent predictors of OS improvement. NLR and dysgeusia were independent predictors of OS after EV in multivariate analysis. Patients without these factors had a significantly prolonged OS compared to those with both factors. In real-world practice, EV therapy is an effective treatment for patients with la/mUC after ICI treatment.

Enfortumab vedotin-related cutaneous toxicity correlates with overall survival in patients with urothelial cancer: a retrospective experience

Introduction

Enfortumab vedotin (EV) is an antibody drug conjugate approved for advanced urothelial cancer, consisting of a monomethyl auristatin E payload linked to a human monoclonal antibody targeting nectin-4. No validated biomarker predictive of or correlated with response exists for EV. Cutaneous toxicity is among the most common EV-related toxicities and typically emerges in early cycles. This retrospective experience of patients with urothelial cancer treated with EV monotherapy evaluated whether EV-related cutaneous toxicity correlated with improved outcomes including progression-free (PFS) and overall (OS) survival and overall response rate (ORR).

Patients and methods

Patients treated with EV monotherapy at Johns Hopkins were identified, and baseline characteristics, treatment, and toxicity details were extracted through chart review. Univariable Cox hazard ratios (HRs) were calculated for assessing the effect of baseline patient characteristics and cutaneous toxicity in PFS and OS. Based on the univariable analysis and known risk factors, all subsequent analyses were adjusted for: Eastern Cooperative Oncology Group performance status, visceral metastases at baseline, gender as well as EV dose, and weight to account for dosing differences. Multivariable Cox proportional HRs were used for comparing PFS and OS between patients with and without cutaneous toxicity, assessing toxicity and EV dose as a time-dependent variables. Adjusted p-values were calculated to compare ORR and disease control rate (DCR) between groups using the Poisson regression model.

Results

Of the 78 patients analyzed, 42 (53.8%) experienced EV-related cutaneous toxicity that appeared early during treatment (median time to occurrence 0.5 months from EV initiation). Cutaneous toxicity correlated with significantly improved OS [HR, 0.48; 95% confidence interval (CI), 0.25, 0.9; P = 0.0235], ORR (68.3% vs. 20.7%, P = 0.0033) and DCR (82.9% vs. 48.3%, P = 0.0122). Median PFS was numerically longer in the cutaneous toxicity group (6.3 vs. 1.7 months), although no significance was achieved in the multivariable analysis (HR, 0.62; 95% CI: 0.35, 0.108; P = 0.0925).

Conclusion

In this retrospective study, EV-related cutaneous toxicity was associated with improved patient outcomes. Confirming this observation and understanding its mechanism could lead to discovery of a new clinical biomarker of EV response that can emerge in the first cycle.

Antibody-Drug Conjugates in the Treatment of Genitourinary Cancers: An Updated Review of Data

The treatment landscape of genitourinary cancers has significantly evolved over the past few years. Renal cell carcinoma, bladder cancer, and prostate cancer are the most common genitourinary malignancies. Recent advancements have produced new targeted therapies, particularly antibody-drug conjugates (ADCs), due to a better understanding of the underlying oncogenic factors and molecular mechanisms involved. ADCs function as a 'drug delivery into the tumor' system. They are composed of an antigen-directed antibody linked to a cytotoxic drug that releases cytotoxic components after binding to the tumor cell's surface antigen. ADCs have been proven to be extremely promising in the treatment of several cancer types. For GU cancers, this novel treatment has only benefited patients with metastatic urothelial cancer (mUC). The rest of the GU cancer paradigm does not have any FDA-approved ADC treatment options available yet. In this study, we have thoroughly completed a narrative review of the current literature and summarized preclinical studies and clinical trials that evaluated the utility, activity, and toxicity of ADCs in GU cancers, the prospects of ADC development, and the ongoing clinical trials. Prospective clinical trials, retrospective studies, case reports, and scoping reviews were included.