Avelumab/Axitinib Combo Shows Promise in Frontline RCC

Toni Choueiri, MD

Combining the PD-L1 inhibitor avelumab (Bavencio) with the VEGF inhibitor axitinib (Inlyta) as a frontline regimen induced a response rate of 58.2% in patients with advanced renal cell carcinoma (RCC), according to findings from the phase Ib JAVELIN Renal 100 trial presented at the 2017 ASCO Annual Meeting.

The complete response (CR) rate was 5.5% and the partial response rate was 52.7%. The disease control rate was 78.2%.

“The combination of avelumab with axitnib shows encouraging antitumor activity as frontline treatment in patients with advanced renal cell carcinoma,” said lead investigator Toni Choueiri, MD, clinical director, Lank Center for Genitourinary Oncology, director, Kidney Cancer Center, senior physician, Dana-Farber Cancer Institute.

The JAVELIN Renal 100 study included 55 patients with advanced clear-cell RCC. Patients had a median age of 60 years (range, 42-76), no prior systemic therapy for advanced RCC, and an ECOG performance status ≤1.

Over 95% of patients had favorable or intermediate risk per MSKCC criteria. Patients had 1 (45.5%), 2 (41.8%), or 3 (12.7%) metastatic sites.

In the dose-finding stage of the study, patients received a lead-in dose of axitinib of 5 mg orally twice daily for 7 days, followed by 10 mg/kg of avelumab IV every 2 weeks plus axitnib at 5 mg orally twice a day.

In the dose-expansion phase, patients could receive the same regimen as the dose-finding phase, or just start with 10 mg/kg of avelumab IV every 2 weeks plus axitnib at 5 mg orally twice a day.

Fifty-four of 55 patients received the combination, with 1 patient never receiving avelumab. At the April 13, 2017, data cutoff, treatment was ongoing in 30 patients receiving avelumab and 31 patients receiving axitinib.

The median duration of avelumab treatment was 36.5 weeks, and the median duration of axitinib treatment was 34 weeks. Thirty-one patients had at least 1 dose reduction of axitinib, and 10 patients had at least 1 dose escalation of axitinib.

Thirty-two patients had confirmed responses, including 3 CRs, and 29 PRs. An additional patient still receiving therapy had an unconfirmed response. Eleven patients had stable disease, 10 had progressive disease, and 2 were not evaluable.

In 20 of 32 responders, the response occurred at the time of the first tumor assessment, and responses were ongoing in 24 of the responders.

Late responses occurred, as well. “Six patients had a late response—on or after week 18—–and 5 of these patients remain on treatment,” said Choueiri.

Forty-five patients had tumor shrinkage, including 34 patients with shrinkage ≥30%.

PD-L1 status was evaluable in 52 patients, and the researchers evaluated responses for PD-L1 cutoffs of ≥1% and ≥5%.

At the 1% cutoff, the ORR was 65.9% (27/41) in PD-L1—positive patients and 36.4% (4/11) in PD-L1–negative patients. At the 5% cutoff, the ORR was 67.9% (19/28) in PD-L1–positive patients and 50.0% (12/25) in PD-L1–negative patients.

Progression-free and overall survival data are not yet mature.

All-grade adverse events (AEs) related to the treatment combination occurred in 53 patients. The most common all-grade AEs were diarrhea (52.7%), hypertension (45.5%), dysphonia (43.6%), and fatigue (43.6%).

Twenty-seven patients experienced grade 3 AEs, and 5 patients had grade 4 AEs. One patient died due to myocarditis. No patients who had a response died.

“Fewer grade 3 or higher AEs were considered related to avelumab than to axitinib,” Choueiri noted.

The majority of infusion-related reactions were grade 1 or 2 and occurred mainly during the first 2 infusions of avelumab.

Seventeen patients experienced an immune-related AE, with only 3 being grade 3. Myocarditis was the only immune-related AE that led to death.

In his concluding remarks, Choueiri said, “These data support the ongoing phase III trial (NCT02684006) investigating the efficacy and safety of avelumab plus axitinib in untreated metastatic clear-cell advanced RCC.”

Choueiri TK, Larkin JMG, Oya M, et al. First-line avelumab + axitinib therapy in patients (pts) with advanced renal cell carcinoma (aRCC): results from a phase Ib trial. J Clin Oncol 35, 2017 (suppl; abstr 4504).

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