CD30-Directed Chimeric Antigen Receptor (CAR)-T Cells for Treatment of Hodgkin Lymphoma and Non-Hodgkin Lymphoma in Pediatric Patients

Background:

Chimeric antigen receptor (CAR)-T cell therapy targeting the CD19 antigen has been effective in treating B-cell acute lymphoblastic leukemia. As CAR-T cells targeting new antigens are being explored for the treatment of other cancers in adults, parallel studies are warranted for pediatric cohorts. We have previously shown the safety and efficacy in adults of CAR-T cells targeting CD30, which is expressed in classical Hodgkin Lymphoma (HL) and in some Non-Hodgkin Lymphoma (NHL). We have therefore sought to study the feasibility and the safety of CD30.CAR-T cells in pediatric patients with relapsed/refractory CD30-expressing HL and Anaplastic Large Cell Lymphoma (ALCL).

Design/Methods:

Six pediatric patients (ages 9 to 17 years) with CD30+ HL (4) and NHL (2) were enrolled on two trials at the University of North Carolina. One NHL patient with ALK+ ALCL was enrolled on both trials. Two patients, one HL and one NHL, were enrolled on a phase I study and received 2x10 ⁷ CD30.CAR-T cells/m ² as consolidation for high-risk of relapse after autologous stem cell transplant (ASCT, NCT02663297). Five patients, 3 HL and 2 NHL, were enrolled on a phase Ib/II study and received 1x10 ⁸ CD30.CAR-T cells/m ², as treatment for relapsed disease, after lymphodepletion with bendamustine and fludarabine (NCT02690545). HL patients had failed multiple lines of therapies (5-6), including 2 with prior pembrolizumab, 2 with prior ASCT, and all 3 with prior brentuximab vedotin (BV) and radiation therapy. The two NHL patients both had ALCL, one was ALK positive and one was ALK negative. Both had been treated with prior BV. The ALK negative patient had been treated with 3 prior lines of therapy and the ALK positive patient had been treated with 6 lines of prior therapy including ASCT and two ALK inhibitors, crizotinib and brigatinib. The brigatinib was stopped 3 weeks prior to starting lymphodepletion.

Results:

CD30.CAR-T cells were successfully manufactured for all 7 patients and no differences were observed as compared to products manufactured for adults, based on cell number, transduction, potency or immunophenotype. For all patients, infusions were well-tolerated and no neurotoxicity experienced.

On the post-ASCT study, 1 patient with HL and 1 with ALCL were treated. All adverse events (AE) were less than grade 4. The patient with HL remains in complete remission (CR) 41 months following therapy, while the patient with ALCL progressed.

Five patients with relapsed/refractory disease (3 HL and 2 ALCL) were treated on the post-lymphodepletion study. Most grade 3 or higher AEs were anticipated hematologic toxicity secondary to lymphodepletion. The youngest HL patient on the study developed symptoms consistent with grade 2 cytokine release syndrome (CRS) and a concomitant pneumonia based on imaging, accompanied by a marked inflammatory response based on labs with maximum ferritin 9,920 ng/mL and CRP 150.7 mg/L. He responded to antibacterial agents and two doses of tocilizumab, as well as brief supplemental oxygen by nasal cannula. He did not require vasopressors. One patient with ALK+ ALCL had symptoms compatible with CRS and macrophage activation syndrome (maximum ferritin >100,000 ng/mL and CRP 39.7 mg/L), which were ultimately determined to be secondary to progressive disease, confirmed at autopsy 5 weeks post therapy. The other four patients (3 HL and 1 ALCL) achieved CR and remain in CR 4 to 27 months post CAR-T cell infusion. Of note, 2 of the HL patients chose to come off study while in CR to receive treatment with checkpoint inhibitor therapy.

Conclusion:

Our studies show that CD30.CAR-T cells are well tolerated in pediatric patients. CRs were observed in all heavily pre-treated and refractory HL patients, highlighting the potential of this strategy. All patients treated on both studies had previously received BV, which suggests CD30.CAR-T cells are effective even post BV progression. We continue to investigate how to better tailor CD30.CAR-T cells in NHL given the need for better therapies in ALCL, which is often aggressive at relapse. One patient with ALK negative ALCL remains in CR while the patient with ALK+ ALCL had rapid relapse.

After study initiation, UNC entered into a research collaboration with Tessa Therapeutics.