Avelumab is a fully human anti-PD-L1 IgG1 antibody being investigated in multiple clinical trials.
Safety and clinical activity of Avelumab as a second-line therapy in patients with metastatic urothelial carcinoma ( mUC ) based on level of PD-L1 expression were reported.
Patients with mUC unselected for PD-L1 expression received Avelumab at 10 mg/kg Q2W by IV infusion until confirmed progression, unacceptable toxicity, or any criterion for withdrawal occurred.
Tumors were assessed every 6 weeks ( RECIST 1.1 ). Best overall response rate ( ORR ) and progression-free survival ( PFS ) were evaluated.
Adverse events were graded by NCI-CTCAE v4.0.
PD-L1 expression was assessed by immunohistochemistry.
As of 19 Mar 2015, 44 pts ( 30 men, 14 women ) with metastatic urothelial carcinoma were treated with Avelumab ( median 13 wks [ range 2-28 ] ) and followed for a median of 3.5 months ( range 3.0-5.0 ).
Median age was 68y ( range 30-84 ), ECOG performance status was 0 ( 43.2% ) or 1 ( 56.8% ), and patients had received a median of 2 prior therapies ( range 1- more or equal to 4 ).
Treatment-related treatment-emergent adverse effects ( TR-TEAEs ) of any grade occurred in 26 patients ( 59.1% ); those occurring greater than or equal to 10% were grade 1/2 infusion-related reactions ( 8 [ 18.2% ] ) and fatigue ( 7 [ 15.9% ] ).
One patient had grade 3 asthenia.
There were no treatment-related deaths.
Overall response rate was 15.9% ( 7 patients; 95% CI: 6.6, 30.1 ) with 1 complete response ( CR ) and 6 partial responses ( PRs ); 6 responses were ongoing at data cutoff.
Stable disease ( SD ) was observed in 19 patients ( 42.3% ) and disease-control rate ( CR+PR+SD ) was 59.1%.
PD-L1 expression was evaluable in 32 patients. Using a greater than or equal to 5% cutoff ( 10/32 [ 31.3% ] were PD-L1+ ), Overall response rate was 40.0% in PD-L1+ patients ( 4/10 ) vs 9.1% in PD-L1– patients ( 2/22; p= 0.060 ).
Progression-free survial rate at 12 weeks was 70.0% ( 95% CI: 32.9, 89.2 ) in PD-L1+ patients vs 45.5% ( 95% CI 22.7, 65.8 ) in PD-L1− patients.
In conclusion, Avelumab showed an acceptable safety profile and had clinical activity in patients with metastatic urothelial carcinoma.
There was a trend towards higher overall response rate and prolonged progression-free survival rate at 12 weeks in patients with PD-L1+ metastatic urothelial carcinoma. ( Xagena )
Apolo AB et al, J Clin Oncol 34, 2016 ( suppl 2S; abstr 367 )