Efficacy
At median follow-up of 30 months patients treated with MATRix had a CR rate of 49% (95% CI 38–60), compared with 23% (14–31) of those treated with methotrexate–cytarabine alone (hazard ratio 0.46, 95% CI 0.28–0.74) and 30% (21–42) of those treated with methotrexate–cytarabine plus rituximab (0.61, 0.40–0.94). Furthermore, 96 (44%) of 219 patients remain progression free: 22 (29%) of 75 in those treated with methotrexate–cytarabine alone, 30 (43%) of 69 with addition of rituximab, and 44 (59%) of 75 with addition of rituximab and thiotepa.r
According to the treatment group (figure 1A), the 2-year PFS was 36% (95% CI 31–41) for group A, 46% (40–52) for group B, and 61% (55–67) for group C (MATRix). Overall, 113 (52%) of 219 patients were still alive at a median follow-up of 30 months 27 (36%) of 75 in group A, 36 (52%) of 69 in group B, and 50 (67%) of 75 in group C (MATRix).r
The 2-year OS rate was 42% (95% CI 36–48) in group A, 56% (50–62) in group B, and 69% (64–74) in group C (MATRix) (figure 1B).r
Figure 1: Survival outcomes (A) Progression-free survival and (B) overall survival curves of registered patients divided according to induction treatment group. Tick marks represent censored patients.r
© Lancet 2016
Furthermore, longer term follow-up data from the IELSG32 trialr has been published in patients treated with MATRix. At a median follow up of 88 months (~7 years), the OS was found to be 56% (95% CI 52-60), compared with 21% (95% CI 4-47) in patients treated with methotrexate-cytarabine alone (hazard ratio 0.42, 95% CI 0.24-0.64) and 37% (95% CI 26-48) in patients treated with methotrexate-cytarabine plus rituximab (hazard ratio 0.66, 95% CI 0.44-0.98).r
In addition, 52% (95% CI 47-57) patients treated with MATRix remained progression free at a median of 88 months. This was significantly higher compared to a PFS of 20% (95% CI 3-48) in those treated with methotrexate-cytarabine alone and 29% (95% CI 13-47) in those treated with methotrexate-cytarabine plus rituximab.r
Outside of a clinical trial setting, data on patients receiving MATRix recapitulated similar outcomes. Out of 156 patients treated with MATRix, 79% (n=123, 95% CI 71-85) achieved a response (35% complete response, 44% partial response), 4% (n=6) had stable disease and 10% (n=16) had documented progressive disease. Stem cell mobilisation was performed in 94% of the responders, and majority (67.5%) proceeded to receive consolidation treatment with an autologous stem cell transplant, WBRT or further chemotherapy. The remainder of responders did not receive consolidation due to infectious complications, lowered performance status, co-morbidities or due to decision by the patient and/or treating physician. At a median follow-up of 27.4 months, the overall survival was 64% (100 out of 156) and the median OS was not reached.r
Of note, there was a significant improvement in PFS and OS for patients who fulfilled IELSG32 eligibility criteria, compared with those who were included in the series but would have otherwise been ineligible for MATRix in IELSG32 study.r
Figure 2: Progression-free survival and overall survival r
© British Journal of Haematology 2020