Results of the phase 2 ZUMA-12 trial suggest that axicabtagene ciloleucel (axi-cel), a chimeric antigen receptor (CAR) T-cell therapy approved to treat certain types of lymphoma, also shows promise as a treatment for another group of lymphoma patients – those with high-risk large B-cell lymphoma (LBCL) who failed two rounds of standard chemoimmunotherapy. In fact, a study author said, first-line treatment with this therapy could help usher some patients toward a cure.
The results appeared March 21, 2022, in Nature Medicine.
“The high efficacy with manageable safety profile suggest that further evaluation of axi-cel in first-line setting in patients with high-risk LBCL is warranted in a randomized, phase 3 trial comparing it to standard chemoimmunotherapy,” study lead author Sattva S. Neelapu, MD, of the University of Texas MD Anderson Cancer Center, Houston, said in an interview.
According to Dr. Neelapu, “patients with high-risk LBCL include those with high-intermediate or high International Prognostic Index score and those with certain molecular subtypes such as double- or triple-hit lymphoma. These patients have lower response rates and lower progression-free and overall survival with standard chemoimmunotherapy.”
Treatment of these patients can be especially challenging because they are underrepresented in clinical research, hematologist Michael Dickinson, MBBS, of the Peter MacCallum Cancer Center in Melbourne, said in an interview. “They often have disease that requires urgent treatment, so there is no time to recruit them into trials. A feature of ZUMA-12 is that it allowed patients to be recruited after short exposure to chemotherapy, which means that higher-risk patients could successfully be recruited into the trial.”
Axi-cel is already Food and Drug Administration approved for treatment of relapsed or refractory LBCL after 2 or more lines of systemic therapy plus relapsed or refractory follicular lymphoma, also after two or more lines of systemic therapy, Dr. Neelapu said.
For this study, researchers administered the treatment to 40 subjects with high-risk disease from 2019-2020 (median age, 61 years; 68% male; 95% at disease stage III or IV).
The researchers reported that 78% of 37 patients in the primary efficacy analysis reached complete response rate (95% confidence interval, 62-90); the median time to first complete response rate was 30 days (range, 27-207). About 89% of these subjects reached the secondary endpoint of objective response rate (95% CI, 75-97); the median time to first objective response was 29 days (range, 27-207).
At a median follow-up of 15.9 months, 73% were still in objective response.
“This is quite remarkable,” Dr. Neelapu said. “The durability of more than 70% is far higher than what would be expected with standard chemoimmunotherapy in these patients – under 40% durability with standard chemoimmunotherapy. Also, axi-cel induces durable responses in about 40% of patients in second- and third-line setting. However, when used as part of first-line therapy in this study, durable responses were observed in more than 70% of patients, suggesting that the efficacy of axi-cel may be much higher when used in first-line setting.”
Dr. Neelapu added: “Although the follow-up is short, it is highly likely that the majority of the patients with ongoing response beyond 1 year will likely be cured of their lymphoma.”
As for side effects, no treatment-related grade 5 events occurred, but 18 patients (45%) experienced serious adverse events. Grade 3 or higher cytokine release syndrome occurred in three patients (8%) and nine experienced neurologic events (23%).
“The majority of the higher-grade adverse events observed were due to cytopenias, which were expected due to the conditioning therapy,” Dr. Neelapu said. “Such cytopenias would also have been expected if these patients had received standard chemoimmunotherapy.”
Six patients (15%) died, 4 of progressive disease after going forward to other therapies.
As for cost, Dr. Neelapu said it should be similar to that of axi-cel as an FDA-approved third-line therapy. Axi-cel is highly expensive. Research has suggested that CAR T-cell therapy can boost costs beyond standard chemotherapy by $350,000-$490,000 with gains of 2-8 years of life (J Med Econ. Jan-Dec 2021;24[1]:458-68).
The study was funded by Kite. The authors reported various disclosures.