NATIONAL HARBOR, MD. – The combination of bempegaldesleukin and nivolumab produced durable responses in a phase 1/2 trial of patients with previously untreated metastatic melanoma.
Jennifer Smith/MDedge News
Dr. Adi Diab
The overall response rate was 53%, and most responders were still in response at a median follow-up of about 19 months. The median progression-free survival was not reached, and the combination was considered well tolerated.
Adi Diab, MD, of the University of Texas MD Anderson Cancer Center, Houston, presented these results from the PIVOT-02 study at the annual meeting of the Society for Immunotherapy of Cancer.
Dr. Diab explained that bempegaldesleukin (bempeg) is a CD122-preferential interleukin-2 pathway agonist, and earlier results from the PIVOT-02 trial showed that adding bempeg to nivolumab can convert baseline tumors from programmed death–ligand 1 (PD-L1) negative to PD-L1 positive (SITC 2018, Abstract O4).
Dr. Diab presented updated results from PIVOT-02 (NCT02983045) in 41 patients with metastatic melanoma who received bempeg plus nivolumab as first-line treatment. The patients had a median age of 63 years (range, 22-80 years) at baseline, and 58.5% were male. Most patients (58.5%) were PD-L1 positive, although PD-L1 status was unknown in 7.3% of patients.
Patients received bempeg at 0.006 mg/kg and nivolumab at 360 mg every 3 weeks. They received a median of nine cycles (range, 1-34), and the median follow-up was 18.6 months.
Efficacy
In the 38 patients who were evaluable for efficacy, the overall response rate was 53% (n = 20), and the complete response rate was 34% (n = 13). The median time to response was 2.0 months, and the median time to complete response was 7.9 months.
Dr. Diab noted that responses were seen regardless of PD-L1 expression at baseline. The response rate was 39% among PD-L1-negative patients, 64% among PD-L1-positive patients, and 33% among patients whose PD-L1 status was unknown.
Dr. Diab also pointed out that responses were durable and deepened over time. The median duration of response was not reached, and 17 of the 20 responders had ongoing responses at last follow-up. The median progression-free survival has not been reached.
Safety
“This combination is safe and tolerable, there’s no overlapping immune-related adverse events, and the most common side effects are grade 1/2 flu-like symptoms,” Dr. Diab said.
The most common grade 1/2 treatment-related adverse events (AEs) were flu-like symptoms (80.5%), rash (70.7%), fatigue (65.9%), pruritus (48.8%), nausea (46.3%), arthralgia (43.9%), decreased appetite (36.6%), and myalgia (36.6%).
Dr. Diab noted that cytokine-related AEs (flu-like symptoms, rash, and pruritus) were easily managed with NSAIDs; decreased with subsequent cycles of treatment; and did not necessitate dose delays, reductions, or discontinuations.
Grade 3/4 treatment-related AEs included two cases of acute kidney injury, two cases of atrial fibrillation, one case of dizziness, one case of dyspnea, one case of hypoxia, one case of hyperglycemia, and one case of hypernatremia.
Five patients discontinued treatment because of related AEs, including cerebrovascular accident, peripheral edema, blood creatinine increase, malaise, and pharyngitis. There were no treatment-related deaths.
Dr. Diab said these results were used to support the recent breakthrough therapy designation granted to bempeg in combination with nivolumab. The results have also prompted a phase 3 trial in which researchers are comparing the combination with nivolumab alone (NCT03635983).
The phase 1/2 trial is sponsored by Nektar Therapeutics in collaboration with Bristol-Myers Squibb. Dr. Diab reported relationships with Nektar, Celgene, CureVac, Idera, and Pfizer.
SOURCE: Diab A et al. SITC 2019, Abstract O35.