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Cancer Research Center
Results from a phase 1 study have provided insights that may help researchers optimize treatment with JCAR014, a chimeric antigen receptor (CAR) T-cell therapy, in patients with advanced non-Hodgkin lymphoma (NHL).
Researchers said they identified a lymphodepleting regimen that improved the likelihood of complete response (CR) to JCAR014.
Although the regimen also increased the risk of severe cytokine release syndrome (CRS) and neurotoxicity, the researchers discovered biomarkers that might allow them to identify patients who have a high risk of these events and could potentially benefit from early interventions.
The researchers reported these findings in Science Translational Medicine. The trial (NCT01865617) was funded, in part, by Juno Therapeutics, the company developing JCAR014.
Previous results from this trial, in patients with acute lymphoblastic leukemia, were published in The Journal of Clinical Investigation.
About JCAR014
JCAR014 is a CD19-directed CAR T-cell therapy in which CD4+ and CD8+ cells are administered in equal proportions.
“The idea . . . is that by [controlling the ratio of T cells], we would get more reproducible data around the effects of the cells—both beneficial effects against the cancer and also any side effects they might cause the patient,” said study author Stanley Riddell, MD, of the Fred Hutchinson Cancer Research Center in Seattle, Washington.
“And then, by adjusting the dose, we could improve what we call the therapeutic index—the benefit against the tumor—without too much toxicity.”
Patients and treatment
Dr Riddell and his colleagues reported results with JCAR014, following lymphodepleting chemotherapy, in 32 patients with NHL who had a median age of 58 (range, 36-70).
The patients had de novo large B-cell lymphoma (n=11), transformed de novo large B-cell lymphoma (n=11), mantle cell lymphoma (n=4), and follicular lymphoma (n=6).
They had received a median of 5 prior treatment regimens (range, 2 to 11), including autologous
(n=14) and allogeneic (n=4) transplant. All patients had measurable disease (≥ 2 cm) in the lymph nodes or other extramedullary sites at baseline.
The patients received JCAR014 at 1 of 3 dose levels, given 36 to 96 hours after lymphodepleting chemotherapy.
Twelve patients received cyclophosphamide (Cy) alone or Cy and etoposide (E), and 20 received Cy plus fludarabine (Flu). Five patients received 2 × 105 CAR T cells/kg, 18 received 2 × 106 CAR T cells/kg, and 9 received 2 × 107 CAR T cells/kg.
Efficacy
In the 30 evaluable patients, the overall response rate (ORR) was 63% (n=19), and the CR rate was 33% (n=10).
Among patients who received Cy or Cy/E, the ORR was 50% (n=6), and the CR rate was 8% (n=1). Among patients who received Cy/Flu, the ORR was 72% (n=13), and the CR rate was 50% (n=9).
The patients who received Cy/Flu had better CAR T-cell expansion and persistence than patients who received Cy or Cy/E, which was reflected in the higher response rates.
Higher response rates were also observed in patients who received 2 × 106 CAR T cells/kg rather than the other 2 dose levels.
The researchers noted that, although follow-up is short, patients who received CAR T cells at ≤ 2 × 106/kg after Cy/Flu had better progression-free survival (P=0.008) than patients who received CAR T cells at ≤ 2 × 106/kg after Cy or Cy/E.
Of the 9 patients who achieved a CR after Cy/Flu and JCAR014, 1 has relapsed, with follow-up ranging from 2.3 months to 11.2 months. (Seven of these 9 patients had received 2 × 106 CAR T cells/kg, and 1 patient each had received the other 2 doses.)
“The main message is that you can treat patients with non-Hodgkin’s lymphoma with CAR T cells and get very good response rates with optimization of the CAR T-cell dose and lymphodepletion,” said study author Cameron Turtle, MBBS, PhD, of the Fred Hutchinson Cancer Research Center.
“Strategies like modifying the lymphodepletion in conjunction with suitable CAR T-cell dosing can have a big impact on clinical outcome.”
Safety
Two patients who were treated with the highest CAR T-cell dose (2 × 107 cells/kg) died—1 of pontine hemorrhage and 1 of gastrointestinal hemorrhage associated with a known gastrointestinal invasive lymphomatous mass.
This dose was also associated with an increased risk of severe CRS and neurotoxicity, as was the Cy/Flu regimen.
Twenty patients (62.5%) developed CRS, and 4 (12.5%) had severe CRS. All 4 of these patients had received Cy/Flu.
Nine patients (28%) developed severe neurotoxicity (grade 3 or higher), 7 of whom had received Cy/Flu.
Three of the 6 patients (50%) treated at 2 × 107 CAR-T cells/kg after Cy/Flu developed severe CRS, and 4 of the 6 patients (67%) developed severe neurotoxicity.
The researchers looked for biomarkers of toxicity in serum collected 1 day after CAR T-cell infusion.
They found that high IL-6, IL-8, IL-10, IL-15, and IFN-γ concentrations were associated with subsequent severe CRS and neurotoxicity, and low TGF-Β concentration was associated with neurotoxicity.
The team said these findings provide an opportunity for studying the use of serum cytokine concentrations to identify patients at the highest risk of toxicity who might benefit from early interventions.
