Ear­ly pre­dic­tion of out­comes in DL­B­CL clin­i­cal tri­als through MRD test­ing

When as­sess­ing the risk of re­lapse in pa­tients treat­ed for dif­fuse large B-cell lym­phoma, com­bin­ing imag­ing da­ta with tests that de­tect tu­mor DNA can re­sult in an ear­li­er and more ac­cu­rate prog­no­sis.

The pres­ence or ab­sence of min­i­mal resid­ual dis­ease (MRD) can pro­vide a valu­able prog­nos­tic mark­er in many can­cers. In gen­er­al, when MRD is found at de­tectable lev­els post-treat­ment, the risk of re­lapse is sig­nif­i­cant­ly high­er than for pa­tients with neg­a­tive MRD test re­sults. In sev­er­al blood can­cers, new tech­nolo­gies can iden­ti­fy tu­mor cells at lev­els as low as a sin­gle cell in a mil­lion sam­pled cells. In lym­phoid can­cers, where tu­mor cells aren’t rou­tine­ly found in the blood, next-gen­er­a­tion se­quenc­ing (NGS) can be used to mea­sure cir­cu­lat­ing tu­mor DNA (ctD­NA) and pro­vide a more ac­cu­rate prog­no­sis.

The use­ful­ness of MRD test­ing now ex­tends to dif­fuse large B-cell lym­phoma (DL­B­CL). This is the most com­mon type of non-Hodgkin’s lym­phoma, with more than 25,000 new cas­es di­ag­nosed each year in the U.S. alone.¹ The dis­ease oc­curs when B cells of the adap­tive im­mune sys­tem un­der­go a ma­lig­nant trans­for­ma­tion and pro­lif­er­ate. These tu­mor cells ac­cu­mu­late in the lymph nodes where they orig­i­nate and can even­tu­al­ly spread through­out the lym­phat­ic sys­tem and be­yond. A stan­dard front­line ther­a­py is R-CHOP—a com­bi­na­tion of rit­ux­imab, cy­clophos­phamide, dox­oru­bicin, vin­cristine, and pred­nisone—which is of­ten ef­fec­tive in ear­ly-stage dis­ease. How­ev­er, for rough­ly 40% of pa­tients with DL­B­CL, re­frac­to­ry dis­ease or re­lapse oc­curs, and sec­ond-line treat­ments are need­ed.²

While DL­B­CL is a lym­phoid can­cer, the tu­mor cells of­ten stay in the lymph nodes or col­lect in or­gans such as the liv­er and spleen. Imag­ing tech­nolo­gies such as positron emis­sion to­mog­ra­phy (PET) and com­put­ed to­mog­ra­phy (CT) are stan­dard tools for di­ag­nos­ing the dis­ease and as­sess­ing a pa­tient’s re­sponse to ther­a­py.

Adding clar­i­ty to imag­ing re­sults

Imag­ing pro­vides cru­cial in­for­ma­tion for de­ter­min­ing what stage of dis­ease a pa­tient has pro­gressed to and where the can­cer has spread. How­ev­er, the tech­nol­o­gy is known to cap­ture false-pos­i­tive re­sults, par­tic­u­lar­ly in post-treat­ment eval­u­a­tions. Imag­ing can pick up ar­ti­facts that re­sem­ble tu­mor sites but are not ma­lig­nant, in­clud­ing in­flamed or necrot­ic tis­sue left be­hind once an ac­tu­al tu­mor is gone. In many cas­es, a biop­sy is need­ed to ex­tract tis­sue for ge­net­ic se­quenc­ing or a pathol­o­gy re­port, which may re­veal that the sus­pect­ed le­sion is be­nign.

These false pos­i­tives can be clar­i­fied by us­ing a liq­uid biop­sy that mea­sures ctD­NA. In­di­vid­ual B cells have unique re­cep­tors with unique ge­net­ic se­quences, and these DNA sig­na­tures re­main sta­ble even in ma­lig­nant cells and their sub­clones. These mol­e­c­u­lar bar­codes can be used to iden­ti­fy lym­phoma-re­lat­ed DNA in the blood, re­veal­ing the pres­ence of MRD. NGS MRD pro­vides an or­thog­o­nal in­for­ma­tion stream that com­ple­ments imag­ing to give a fuller pic­ture of dis­ease bur­den at a giv­en point in time.

A 2021 study by Frank et al. un­der­scored the prog­nos­tic val­ue of adding MRD test­ing to PET/CT imag­ing in pa­tients un­der­go­ing ther­a­py for re­lapsed or re­frac­to­ry DL­B­CL.³ The study fol­lowed 72 pa­tients who had a me­di­an of three lines of pri­or ther­a­py (range 1-7). These pa­tients re­ceived B cell-de­plet­ing chemother­a­py fol­lowed by in­fu­sion of axi­cab­ta­gene ciloleu­cel (axi-cel), a CAR-T cell ther­a­py. The re­sults showed that pa­tients with high­er pre-treat­ment lev­els of ctD­NA had sig­nif­i­cant­ly poor­er post-treat­ment out­comes in terms of pro­gres­sion-free sur­vival and over­all sur­vival.³

MRD test­ing was al­so more ac­cu­rate in pre­dict­ing dis­ease pro­gres­sion at 28 days post-treat­ment in a sub­set of pa­tients with a par­tial treat­ment re­sponse or sta­ble dis­ease. In this sub­set, just one of 10 who test­ed MRD-neg­a­tive went on to suf­fer a re­lapse, while 15 of 17 pa­tients who test­ed MRD-pos­i­tive re­lapsed (P=.0001). In the broad­er study pop­u­la­tion, all pa­tients with a durable treat­ment re­sponse test­ed MRD-neg­a­tive with­in three months or soon­er af­ter CAR T ther­a­py. In pa­tients who re­lapsed, 29 of 30 had a pos­i­tive MRD test be­fore or con­cur­rent­ly with the de­tec­tion of re­lapse via imag­ing.³

In an­oth­er study by Phillips et al., that eval­u­at­ed the bis­pe­cif­ic an­ti­body ep­cori­ta­m­ab in 157 pa­tients with DL­B­CL and re­lat­ed non-Hodgkin’s lym­phomas, MRD neg­a­tiv­i­ty was al­so strong­ly pre­dic­tive of durable, pro­gres­sion-free sur­vival.⁴

High­ly sen­si­tive and spe­cif­ic MRD test­ing

Both the axi-cel and ep­cori­ta­m­ab stud­ies em­ployed a ctD­NA as­say from Adap­tive Biotech­nolo­gies, a leader in the de­vel­op­ment of MRD test­ing tech­nol­o­gy for lym­phoid ma­lig­nan­cies. The DL­B­CL as­say us­es a tu­mor-in­formed ap­proach and works by iden­ti­fy­ing the dom­i­nant lym­phoma clono­type in each pa­tient and se­lect­ing a unique se­quence of re­cep­tor DNA from that clono­type to serve as an MRD mark­er. In run­ning the as­say, Adap­tive se­quences the pa­tient’s en­tire B-cell reper­toire and pro­vides a pre­cise count of all tu­mor-re­lat­ed mol­e­cules in the sam­ple.

The as­say is high­ly sen­si­tive and spe­cif­ic, with a lim­it of de­tec­tion of 1.9 and a lim­it of blank, or back­ground, of 0. In prac­ti­cal terms, this means that the as­say can de­tect one or two mol­e­cules of lym­phoma-re­lat­ed DNA in up to 10 mililiters of plas­ma, with lit­tle to no risk of a false pos­i­tive. The test can’t com­plete­ly rule out the risk of re­lapse, be­cause the can­cer might still be present in the body at lev­els so low that a sin­gle sam­ple may not be MRD-pos­i­tive. How­ev­er, a neg­a­tive re­sult in­di­cates a very low risk of re­lapse.

MRD test­ing has sev­er­al oth­er key ad­van­tages that make it a valu­able ad­di­tion to imag­ing for DL­B­CL. In the Frank et al. study, re­searchers took MRD mea­sure­ments at 10 time points over the course of one year to bet­ter un­der­stand MRD dy­nam­ics.³ Imag­ing can’t be con­duct­ed with such fre­quen­cy, due to ra­di­a­tion ex­po­sure lim­its, as well as cost and re­im­burse­ment con­straints. Giv­en the de­sire to mon­i­tor DL­B­CL more close­ly, liq­uid biop­sies open the door to more fre­quent post-treat­ment as­sess­ments to im­prove long-term sur­veil­lance.

In clin­i­cal prac­tice, Adap­tive’s DL­B­CL as­say, clonoSEQ, is val­i­dat­ed un­der the Clin­i­cal Lab­o­ra­to­ry Im­prove­ment Amend­ments (CLIA) and is el­i­gi­ble for Medicare re­im­burse­ment. In the clin­i­cal de­vel­op­ment are­na, more than 30 clin­i­cal tri­als are cur­rent­ly em­ploy­ing NGS MRD as an end­point to study DL­B­CL and oth­er B-cell lym­phomas.

To learn more about MRD test­ing in DL­B­CL, con­tact bd@adap­tive­biotech.com.

Ref­er­ences:

¹Su­sani­bar‐Adaniya S, Bar­ta SK. 2021 up­date on dif­fuse large B cell lym­phoma: A re­view of cur­rent da­ta and po­ten­tial ap­pli­ca­tions on risk strat­i­fi­ca­tion and man­age­ment. Amer­i­can Jour­nal of Hema­tol­ogy. 2021;96(5):617-629. doi: 10.1002/ajh.26151

²Sarkozy C, Sehn LH. Man­age­ment of re­lapsed/re­frac­to­ry DL­B­CL. Best Prac­tice & Re­search Clin­i­cal Haema­tol­ogy. 2018;31(3):209-216. doi: 10.1016/j.be­ha.2018.07.014

³Frank MJ, et al. Mon­i­tor­ing of cir­cu­lat­ing tu­mor DNA im­proves ear­ly re­lapse de­tec­tion af­ter axi­cab­ta­gene ciloleu­cel in­fu­sion in large B-cell lym­phoma: Re­sults of a prospec­tive mul­ti-in­sti­tu­tion­al tri­al. Jour­nal of Clin­i­cal On­col­o­gy. 2021;39(27):3034-3043. doi: 10.1200/JCO.21.00377

⁴Phillips T, et al. Ep­cori­ta­m­ab monother­a­py pro­vides deep and durable re­spons­es in­clud­ing min­i­mal resid­ual dis­ease (MRD) neg­a­tiv­i­ty: Nov­el sub­group analy­ses in pa­tients with re­lapsed/re­frac­to­ry (R/R) large B-cell lym­phoma (LB­CL). Blood. 2022;140(Sup­ple­ment 1):9443-9445. doi: 10.1182/blood-2022-158245