Efficacy of avelumab in the treatment of oncourological malignances. Results of registration studies and own experience
Authors: Shevchuk I. M. , Nyushko K. M. , Alekseev B. Ya. 
Published: May 2023

Background. In the JAVELIN Bladder 100 trial, 1st line maintenance with avelumab in combination with best supportive care significantly increased (9.2 months) overall survival compared to best supportive care in patients with locally advanced or metastatic urothelial cancer without progression after 1st line platinum-based chemotherapy: 29.7 months versus 20.5 months, respectively. Trial results led to inclusion of avelumab into the international guidelines as a standard of care with the highest level of evidence. Combined therapy with avelumab + axitinib in patients with previously untreated metastatic renal cell carcinoma showed higher progression-free survival and objective response rate compared to sunitinib in all IMDC (International Metastatic Renal Cancer Database Consortium) groups. Avelumab + axitinib is one of the immuno-oncology combinations with proven effectiveness for progression-free survival and objective response rate.

Aim. To evaluate the effectiveness of avelumab in treatment of oncological urological diseases in routine clinical practice. Materials and methods. At the N.A. Lopatkin Scientific Research Institute of Urology and Interventional Radiology - branch of the National Medical Research Radiology Center, 12 patients with locally advanced inoperable and metastatic urothelial cancer without progression after 1st line platinum-based chemotherapy in combination with gemcitabine received maintenance avelumab therapy. Median follow-up was 10 months. Primary endpoints were overall survival from the start of avelumab maintenance therapy and safety.

Combined therapy with avelumab + axitinib was administered in 18 patients with metastatic renal cell carcinoma. Median follow-up was 9 (3-16) months. Overall survival, progression-free survival, response rate and safety in the overall population and according to IMDC groups were evaluated.

Results. At data cut-off (March 2023) with median follow-up of 10 months, overall survival was 100 %, progression-free survival was 66.7 % (among patients who received more than 3 infusions - 100 %). Progression-free survival was higher in patients with tumors of the lower urinary tract compared to upper (72.5 % versus 60 %), complete response to induction platinum-based chemotherapy compared to partial response and stable disease (100 % versus 66.7 %) and presence of metastases in the lymph nodes only compared to visceral and bone metastases (100 % versus 66.7 %). Adverse events were observed in 4 (66.7 %) patients.

Among 18 patients who received avelumab + axitinib, complete response was observed in 2 (11.1 %) patients, partial response in 6 (33.3 %) patients, stable disease in 9 (50 %) patients, disease progression in 1 (5.6 %) patient. Response to therapy was observed in patients of all prognosis groups; for large (>5 cm) metastases in the lungs, soft tissues, lymph nodes and bones response was observed 3 months after treatment start. Overall survival for this follow-up duration was 100 %, progression-free survival was 96.4 ± 11.2 %. Adverse events were observed in 8 (44.4 %) patients, and in 6 (75 %) of them they were grade I—II and did not require infusion regimen correction or axitinib dose reduction.

Conclusion. Avelumab maintenance therapy in the 1st line is the standard of care for patients with locally advanced and metastatic urothelial cancer without disease progression during 1st line platinum-based chemotherapy. Maintenance therapy allows to achieve better overall survival and progression-free survival irrespective of the choice of platinum regimen (cisplatin or carboplatin), response to platinum-based chemotherapy, number of chemotherapy cycles, tumor localization and advancement.

Experience of the N.A. Lopatkin Scientific Research Institute of Urology and Interventional Radiology confirms results of the JAVELIN Bladder 100 trial on the effectiveness of avelumab maintenance therapy in routine clinical practice. Combination drug therapy with avelumab and axitinib in patients with metastatic renal cell carcinoma is an effective and safe treatment method which allows to achieve fast objective response and has good tolerability in patients irrespective of IMDC group or metastasis location. Effectiveness and favorable safety profile of avelumab + axitinib combination were proven in the context of routine clinical practice.