Real-world outcomes in locally advanced or metastatic urothelial carcinoma following platinum and PD-1/L1 inhibitor therapy

Treatment Patterns and Efficacy of Chemotherapy After Pembrolizumab in Advanced Urothelial Cancer-a Real-World Study in the pre-Antibody-Drug Conjugate Era

BACKGROUND

Immune checkpoint inhibitors (ICIs) have been established as a routine treatment in patients with metastatic urothelial cancer (mUC). However, there has been no standard of care after progression on ICIs. We investigated real-world treatment patterns and efficacy of chemotherapy (CHT) after pembrolizumab, in the era before introduction of maintenance avelumab and antibody-drug conjugates (ADC).

PATIENTS AND METHODS

An observational, retrospective study was conducted at twelve Nordic centers. Patients with mUC were treated according to investigator´s choice of CHT after pembrolizumab. Primary endpoint was overall response (ORR) and disease control rate (DCR); secondary endpoints were progression-free (PFS) and overall survival (OS).

RESULTS

In total, 102 patients were included whereof 23 patients received CHT after pembrolizumab as second line treatment (subcohort A) and 79 patients in third line (subcohort B). Platinum-gemcitabine combinations were the most common regimens in subcohort A, and vinflunine in subcohort B. The ORR and DCR were 36% and 47%, respectively. Presence of liver metastases was independently associated with lower ORR and DCR. The PFS and OS were 3.3 months and 7.7 months, respectively. Eastern Cooperative Oncology Group Performance Status (ECOG PS) and number of previous cycles of pembrolizumab were found to be independent prognostic factors associated with OS.

CONCLUSION

In a real-world setting, CHT showed clinically meaningful response rates and survival in mUC patients after progression with pembrolizumab. Clinical benefit may primarily be achieved in patients with favorable ECOG PS, in patients treated with > 6 cycles pembrolizumab as well as in patients without presence of liver metastases.

Physiologically based pharmacokinetic model to predict drug-drug interactions with the antibody-drug conjugate enfortumab vedotin

Enfortumab vedotin is an antibody-drug conjugate (ADC) comprised of a Nectin-4-directed antibody and monomethyl auristatin E (MMAE), which is primarily eliminated through P-glycoprotein (P-gp)-mediated excretion and cytochrome P450 3A4 (CYP3A4)-mediated metabolism. A physiologically based pharmacokinetic (PBPK) model was developed to predict effects of combined P-gp with CYP3A4 inhibitor/inducer (ketoconazole/rifampin) on MMAE exposure when coadministered with enfortumab vedotin and study enfortumab vedotin with CYP3A4 (midazolam) and P-gp (digoxin) substrate exposure. A PBPK model was built for enfortumab vedotin and unconjugated MMAE using the PBPK simulator ADC module. A similar model was developed with brentuximab vedotin, an ADC with the same valine-citrulline-MMAE linker as enfortumab vedotin, for MMAE drug-drug interaction (DDI) verification using clinical data. The DDI simulation predicted a less-than-2-fold increase in MMAE exposure with enfortumab vedotin plus ketoconazole (MMAE geometric mean ratio [GMR] for maximum concentration [Cmax], 1.15; GMR for area under the time-concentration curve from time 0 to last quantifiable concentration [AUClast], 1.38). Decreased MMAE exposure above 50% but below 80% was observed with enfortumab vedotin plus rifampin (MMAE GMR Cmax, 0.72; GMR AUClast, 0.47). No effect of enfortumab vedotin on midazolam or digoxin systemic exposure was predicted. Results suggest that combination enfortumab vedotin, P-gp, and a CYP3A4 inhibitor may result in increased MMAE exposure and patients should be monitored for potential adverse effects. Combination P-gp and a CYP3A4 inducer may result in decreased MMAE exposure. No exposure change is expected for CYP3A4 or P-gp substrates when combined with enfortumab vedotin.ClinicalTrials.gov identifier Not applicable.

Oncological Outcomes in Patients with Metastatic Urothelial Carcinoma after Discontinuing Pembrolizumab as a Second-Line Treatment: A Retrospective Multicenter Real-World Cohort Study

The treatment options are currently limited, and the oncological outcomes remain unclear, for patients with metastatic urothelial carcinoma (mUC) with or without third-line systemic therapy. We aimed to evaluate the oncological outcomes in real-world daily clinical practice after platinum-based chemotherapy followed by pembrolizumab for mUC. This retrospective, multicenter cohort study included patients with mUC who received second-line pembrolizumab in Japan. The patients were divided into the treatment group (those who received third-line treatment) and the BSC group (those who did not receive other treatments). The primary endpoint of this study was to evaluate the oncological outcomes. Of 126 patients enrolled in this study, 40 received third-line therapy. The median follow-up period was 8.0 months. The median overall survival (OS) times were nine months in the BSC group and 17 months in the treatment group (p < 0.001). The median progression-free survival (PFS) times were 4 months in the BSC group and 14 months in the treatment group (p < 0.001). In the multivariate analysis, performance status and liver metastasis were significantly associated with OS. Third-line therapy may have clinical potential advantages for improving the oncological outcomes in patients with mUC.

Subsequent Systemic Therapy following Platinum and Immune Checkpoint Inhibitors in Metastatic Urothelial Carcinoma

Treatment of metastatic urothelial carcinoma (mUC) after failure with platinum-based chemotherapy and immune checkpoint inhibitors (ICIs) remains controversial. To explore the role of subsequent systemic therapy, medical records from 436 patients who were consecutively treated with chemotherapy for mUC between May 2017 and April 2021 were collected from a single-center cancer registry. The primary endpoint was overall survival (OS), and progression-free survival (PFS) and response rate (RR) were also assessed. Among the 318 patients who failed both platinum and ICIs, subsequent therapy was delivered to 166 (52%) patients: taxanes (n = 56), platinum rechallenge (n = 46), pemetrexed (n = 39), and clinical trials (n = 25). Objective responses to third-line therapy were noted in 50 patients (RR, 30%; 95% CI, 23–37%). The patients who were enrolled in clinical trials and treated with platinum rechallenge were significantly more likely to respond than those treated with taxanes or pemetrexed. The median PFS and OS were 3.5 months (95% CI, 2.9–4.2 months) and 9.5 months (95% CI, 8.1–11.0 months), respectively. Similar to RR, PFS and OS were longer for the patients who were enrolled in clinical trials. Based on multivariate analyses, good performance status and enrollment in clinical trials are associated with benefits from subsequent therapy for pretreated mUC.