Chung-Han Lee, MD, PhD
Lenvatinib (Lenvima) combined with pembrolizumab (Keytruda) demonstrated promising antitumor activity in patients with metastatic clear cell renal cell carcinoma (RCC), according to results presented at the ESMO 2017 Congress in Madrid.
In pooled results from a phase Ib/II clinical trial, patients treated with the combination had an objective response rate (ORR) of 63.3% (95% CI, 43-80). Median progression-free survival (PFS) was not yet reached, said Chung-Han Lee, MD, PhD.
“Responses to the combination of lenvatinib and pembrolizumab were seen in both treatment-naïve and previously treated patients,” said Lee, a medical oncologist at Memorial Sloan Kettering Cancer Center, New York City. “Responses were also seen with PD-L1-positive and PD-L1-negative patients.” There was no association between PD-L1 staining status and change in tumor size.
The finding offers further support for the onging phase 3 trial comparing lenvatinib plus pembrolizumab, lenvatinib plus everolimus (Afinitor), and sunitinib (Sutent) monotherapy in the first-line setting for the treatment of metastatic clear cell RCC, he said.
The activity of VEGF-targeted agents in advanced and metastatic RCC includes inhibition of angiogenesis and may also prevent VEGF-mediated immune suppression. In preclinical study, lenvatinib increased the antitumor activity of D-1 blockade by decreasing the tumor-associated macrophage population to induce an upregulation of the PD-1 signaling pathway.
Investigators initiated this study to further examine the efficacy of an anti-PD-1/lenavtinib combination in multiple solid tumor types.
The phase Ib portion of the multicenter open-label study enrolled 13 patients with metastatic solid tumors, 8 of whom had RCC that progressed after treatment with approved therapies and who had an ECOG performance status ≤1.
Patients began treatment with 24 mg daily lenvatinib but the dosage was reduced to 20 mg per day based on toxicity. This dosage of lenvatinib advanced to the phase 2 portion, which included 22 RCC patients with measurable disease who had undergone up to 2 prior lines of systemic therapy.
Patients in phase 2 who experienced intolerable toxicities to lenvatinib could have their lenvatinib dose interrupted, with successive dose reductions to 14 mg, 10 mg, 8 mg, and 4 mg, if necessary. Dose re-escalation was not allowed. Toxicities related to pembrolizumab were managed with dose interruptions.
Pembrolizumab was administered at 200 mg every 3 weeks in both phases.
The combined phase Ib and phase II results (N = 30) had a data cutoff of March 1, 2017. Tumor assessments were performed using irRECIST criteria every 6 weeks until week 24, and then every 9 weeks.
Investigators assessed PD-L1 status in 26 patients. Using a 1% staining cut-off for positivity, 12 patients (40%) were PD-L1-positive.
Twelve patients (40%) were treatment-naïve and therefore treated in the first-line setting. Ten patients (33%) had one prior systemic therapy, 3 (10%) had 2 prior systemic therapies, and 5 (17%) had ≥3. Sixteen (53%) patients had at least 1 prior VEGF-targeted therapy, with the most common agents being sunitinib (n=9), pazopanib (Votrient; n=8), and axitinib (Inlyta; n=6). Five patients were previously treated with an mTOR-targeted agent and 4 patients were previously treated with other agents.
The median duration of therapy was 9.5 months. The mean dosage of lenvatinib received was 15.8 mg/day, with patients receiving 78.3% of the intended starting dose. The mean dosage of pembrolizumab administered was 191.9 mg per cycle, with patients receiving 95.9% of the intended doses.
ORR at 24 weeks was 83% (95% CI, 52-98) in the treatment-naïve cohort, and 50% in those patients who received previous treatment. All responses were partial responses. Two patients in the treatment-naïve group and 8 in the previously-treated population had stable disease. One patient in each cohort had primary progressive disease.
The median duration of response was not yet reached for the total cohort and the treatment-naïve cohort. The median duration of response was 8.5 months in the pretreated cohort.
When stratified by PD-L1 staining status, “objective responses could be seen in both the PD-L1-positive and PD-L1-negative populations, and appear to be similar, with 58% of the PD-L1-positive patients and 71% of PD-L1-negative patients achieving objective responses,” Lee said.
At the time of data cut-off, the median PFS had not yet been reached (95% CI, 9.9 months-not evaluable). Tumor responses assessed by a modified RECIST v1.1 were the same as with irRECIST. The median PFS by RECIST v1.1 was also not yet evaluable.
Ten of 12 patients in the treatment-naïve cohort remain on treatment.