B2001X is a multicenter global study of Tisagenlecleucel ( Tisa-cel; Kymriah ) to provide access to patients with relapsed / refractory ( r/r ) acute lymphoblastic leukemia ( ALL ) including prior anti-CD19 therapy after enrollment ended in the pivotal ELIANA study.
Researchers have reported clinical outcomes and cellular kinetics in B2001X including patients with prior Blinatumomab exposure or Inotuzumab as bridging therapy ( BT ).
Eligible patients with 21 years or younger at diagnosis with 2 or more relapse, refractory or post allogeneic transplant ( alloSCT ) relapse were enrolled globally.
As of November 4, 2019, 73 patients were enrolled; 67 received Tisa-cel. 91% received lymphodepletion.
Among 65 pts 3 months or more follow up or discontinued earlier ( efficacy analysis set [ EAS ] ); median follow-up was 9.6 months ( range, 0.2-16.5 ).
Median age was 10 years ( range, 2-33 ); prior alloSCT 61%; 15 patients had prior Blinatumomab and 9 patients had Inotuzumab as bridging therapy.
13/14 relapsed patients were medullary ( isolated or combined with extramedullary [ EM ] ) and 1 EM; 9 within 6 months including 4/5 who were CD19(+).
64% had CRS ( G 3/4 13%/15%; Penn scale ); 24% had neurologic events ( G 3/4 9%/2%; CTCAE v4.03 ).
4 deaths 30 days or less: 2 early ALL progression, 1 fatal CRS with refractory ALL, 1 infection with multiorgan failure.
Transgene level in peripheral blood: limited to no in vivo expansion in nonresponders ( n=8 ) versus responders ( n=42 ).
Median duration of persistence ( T last ) of Tisa-cell was 272 days ( range, 27-379 ) in responders.
In patients with CR/CRi, Cmax ( geo-mean [ CV% ] ) and median T last were 9260 ( 124 ) copies/µg DNA and 154 days ( range, 28-349 ), respectively, in patients who received Inotuzumab as bridging therapy ( n=6 ) vs 38,500 ( 215 ) and 273 days ( range, 27-379 ), respectively, in patients with no Inotuzumab as bridging therapy ( n=36 ).
In conclusion, outcomes in B2001X remain consistent with ELIANA.
In patients with prior Blinatumomab or Inotuzumab as bridging therapy, a trend toward suboptimal outcomes was observed but should be interpreted with caution due to small number, short follow-up and potential confounding factors. ( Xagena )
Source: American Society of Clinical Oncology ( ASCO ) Virtual Meeting, 2020