Solomon, Scott R.

We report correlative circulating tumor DNA (ctDNA) analyses from TRANSFORM (ClinicalTrials.gov identifier: NCT03575351 ) evaluating lisocabtagene maraleucel (liso-cel) versus standard of care (salvage immunochemotherapy, high-dose chemotherapy, autologous stem cell transplantation [ASCT]) in second-line large B-cell lymphoma (LBCL). ctDNA association with efficacy was investigated at predefined time points (random assignment, day 43, day 64, and day 126 [3 months after liso-cel, approximately 2 months after ASCT]) for 136 patients using ultrasensitive PhasED-Seq. ctDNA clearance (measurable residual disease [MRD] neg ) predicted longer event-free survival (EFS) at all time points in both arms, with significantly more liso-cel–treated patients achieving MRD neg . Liso-cel demonstrated superior outcomes versus ASCT, including longer EFS, progression-free survival (PFS), and duration of response among patients in complete response (CR) and MRD neg . ctDNA re-emergence in patients with CR after ASCT confirmed its potential in predicting relapse. MRD neg remained significantly associated with EFS after adjusting for positron emission tomography (PET) response, while interaction testing revealed a significant interaction between PET status and treatment arm for EFS. Liso-cel achieved deeper, more durable molecular clearance by ctDNA, consistent with superior EFS and PFS versus ASCT for second-line LBCL treatment. ctDNA-MRD provided prognostic value beyond PET, supporting its role as a complementary biomarker for treatment response and relapse prediction.

Abstract Introduction: Liso-cel is an autologous, CD19-directed, 4-1BB CAR T cell product. TRANSFORM (NCT03575351) is a global, randomized, open-label, phase 3 study of liso-cel versus SOC as second-line therapy in adults with R/R LBCL. In the TRANSFORM study, liso-cel showed superior, more durable efficacy versus SOC, with a potential long-term survival benefit and a favorable safety profile, highlighting the curative potential of liso-cel for second-line R/R LBCL. Upon completion of TRANSFORM, patients who received liso-cel could enroll into a separate, long-term follow-up (LTFU) study (NCT03435796). Here, we report results after approximately 4 years of follow-up in patients from TRANSFORM who consented to the LTFU study. Methods The TRANSFORM study compared liso-cel versus SOC (chemotherapy [R-DHAP, R-ICE, or R-GDP] followed by high-dose chemotherapy [HDCT] + ASCT) in adults aged ≤ 75 years with LBCL primary refractory to or relapsed within 12 months of first-line therapy and eligible for ASCT. Patients in the liso-cel arm underwent lymphodepletion followed by liso-cel (100 × 106 CAR+ T cells). Crossover to receive liso-cel was allowed for patients in the SOC arm. The LTFU study enrolled patients who received liso-cel and discontinued early or completed TRANSFORM; liso-cel was not administered during the LTFU study and subsequent therapies were administered at investigator discretion. Selected AEs considered related to liso-cel (malignancies, neurologic, hematologic, or rheumatologic/autoimmune disorders) and OS would be assessed at each visit (month 3 and then every 6 months from years 1 to 5, and then annually) for up to 15 years from liso-cel infusion until study withdrawal or death, whichever occurred first. OS for the combined study was defined as the time from randomization to death due to any cause. PFS for the combined TRANSFORM and LTFU studies incorporated data from TRANSFORM, assessed by an independent review committee, and from LTFU, assessed by investigators, and was defined as the time from randomization to disease progression or death from any cause. For LTFU only, OS and PFS were measured from LTFU consent to event or censoring. In cases where the patient was censored at last assessment date (without receiving new therapy) in TRANSFORM and enrolled in LTFU, LTFU data were used. For patients from the liso-cel arm of TRANSFORM who did not enroll in the LTFU study, the data from TRANSFORM were considered (ie, either an event or censored) at their last adequate assessment date or before starting new therapy. Results are reported descriptively. Results In total, 184 patients were randomized in TRANSFORM (92 per arm); key demographics and baseline characteristics were previously reported (Abramson, et al. Blood 2023). The LTFU study enrolled 67 patients who received liso-cel (liso-cel arm, n = 43; crossover from SOC arm, n = 24). The median follow-up (range) for the liso-cel arm was 16.9 months (1.3–29.7) in the LTFU study and 40.1 months (2.2–61.9) combining the TRANSFORM and LTFU studies. The median follow-ups for OS and PFS for the liso-cel arm in the LTFU study were 17.1 (16.1–21.9) and 16.9 months (16.0–21.8), respectively. In patients from the LTFU study in the liso-cel arm (n = 43), median PFS and OS were both not reached (NR) with 95% CIs of NR–NR. The 24-month rates (95% CI) of PFS and OS were 94.7% (87.4–100.0) and 95.1% (88.4–100.0), respectively. In the 92 patients randomized to the liso-cel arm, using combined data from the TRANSFORM and LTFU studies, median (95% CI) PFS was NR (12.6–NR); 48-month PFS rate was 52.2% (41.5–62.8). Median (95% CI) OS was NR (NR–NR); 48-month OS rate was 61.5% (51.2–71.7). Safety results from the LTFU study in the liso-cel arm showed no new signals compared with previous reports from TRANSFORM. AEs of any grade occurred in 2 patients (hypogammaglobulinemia and dyspnea; n = 1 each), with no second primary malignancies or serious infections. AEs of grade 3 or 4 occurred in 1 patient (dyspnea). No AEs led to death.Conclusions: After a median follow-up of approximately 4 years combining data from the TRANSFORM and LTFU studies, liso-cel continued to demonstrate long-term clinical benefit with high PFS and OS rates in patients with second-line R/R LBCL. The safety profile of liso-cel continued to be manageable with no new safety signals observed during LTFU. These results further support liso-cel as an effective second-line treatment with curative potential for R/R LBCL.

We report 3-year follow-up results from TRANSFORM comparing lisocabtagene maraleucel (liso-cel) versus standard of care (SOC) for second-line primary refractory/early relapsed (≤12 months) large B-cell lymphoma (LBCL). Adults eligible for autologous stem cell transplantation (N = 184) were randomly assigned 1:1 to liso-cel (100 × 10 6 chimeric antigen receptor–positive T cells) or SOC. Results are reported descriptively. With a median follow-up of 33.9 months, median (95% CI) event-free survival was 29.5 months (9.5 to not reached [NR]) for liso-cel versus 2.4 months (2.2 to 4.9) for SOC (hazard ratio [HR], 0.375; 95% CI, 0.259 to 0.542). Median progression-free survival was NR (12.6-NR) for liso-cel versus 6.2 months (4.3-8.6) for SOC (HR, 0.422; 95% CI, 0.279 to 0.639) with 36-month rates of 51% versus 26.5%. Median overall survival (OS) was NR for both arms (HR, 0.757; 95% CI, 0.481 to 1.191), with 66% of patients crossing over to receive liso-cel; 36-month OS rate was 63% for liso-cel versus 52% for SOC. OS HR (0.566 [95% CI, 0.359 to 0.895]) favored liso-cel when accounting for the treatment effect of crossover. Safety results were consistent with previous reports. At 3-year follow-up, liso-cel confirmed superior, more durable efficacy versus SOC with a favorable safety profile and no new safety signals. These data support liso-cel as an effective second-line treatment with curative potential for relapsed/refractory LBCL.

Background: ctDNA clearance after frontline DLBCL tx has shown strong prognostic value for favorable outcomes, with the potential to improve MRD-driven therapeutic strategies and establish MRD as a surrogate endpoint in future studies (Roschewski M, et al. Blood 2022; Goldstein J, et al. Blood 2023). However, further study is needed to evaluate the association of this noninvasive approach with efficacy outcomes after 2L LBCL tx. We previously reported ctDNA analysis after liso-cel infusion in TRANSFORM (NCT03575351; Stepan L, et al. Blood 2023;142[suppl 1]). Here, we describe the predictive value of pre-tx and on-tx ctDNA levels for durable clinical benefit (CR and event-free survival [EFS]) in both liso-cel and SOC arms from TRANSFORM (Kamdar M, et al. J Clin Oncol 2024), evaluating ctDNA as an earlier surrogate for conventional clinical outcomes. Methods: Baseline (prerandomization) and longitudinal ctDNA levels were assessed in randomized pts treated with liso-cel or SOC in TRANSFORM using the phased variant enrichment and detection sequencing assay (PhasED-Seq; Foresight Diagnostics). Phased variants were identified from baseline plasma samples for longitudinal ctDNA monitoring at multiple on-tx time points, as previously described (Stepan L, et al. Blood 2023;142[suppl 1]). Randomization was defined as study Day 1. Association of ctDNA levels with response per independent review committee using Lugano 2014 criteria and EFS was investigated at various predefined time points, including Day 43 (after 2 cycles of salvage immunochemotherapy for SOC; Day 15 after liso-cel infusion), Day 64 (after 3 cycles of salvage immunochemotherapy for SOC; 1 month after liso-cel infusion), and Day 126 (within 2 months after ASCT; 3 months after liso-cel infusion). To assess the surrogacy value of ctDNA, ctDNA-MRD dynamics and ctDNA clearance were investigated within both arms. Results: In pooled analyses combining the liso-cel and SOC arms, higher baseline ctDNA levels (above the median) were associated with shorter EFS (P = 0.05). Pts achieving Day 126 CR had substantial reductions in ctDNA burden vs baseline, while pts with PD or stable disease had persistently high ctDNA levels vs baseline. Achieving undetectable ctDNA at different time points was associated with significantly longer EFS in pooled analyses, observed as early as study visit Day 43, with the strongest association at Day 126. HR (95% CI) for inferior EFS was 3.0 (1.6-5.7) at Day 43, 3.8 (2.1-7.0) at Day 64, and 4.2 (2.3-7.7) at Day 126 in pts with detectable vs undetectable ctDNA. In the analysis by tx arm, consistent with the pooled analyses, ctDNA clearance was associated with EFS benefit at all measured time points with either liso-cel or SOC. Significantly more pts achieved undetectable ctDNA with liso-cel vs SOC during the study (39/63 [62%] vs 25/65 [38%], respectively; P = 0.013), consistent with superior EFS (primary endpoint) with liso-cel in TRANSFORM. All pts in the SOC arm with evaluable ctDNA at Day 126 (n = 28) had received high-dose chemotherapy (HDCT)/ASCT. However, pts with undetectable ctDNA in the liso-cel vs SOC arm had longer EFS at all predefined time points and had statistically longer EFS at Day 126 (SOC vs liso-cel: HR, 3.9 [95% CI, 1.4-10.6]), indicating a deeper and more durable response with liso-cel vs SOC. In pts with CR, ctDNA showed significant predictive value beyond the response assessment at all time points in the liso-cel arm with a HR (95% CI) of 3.8 (1.3-11.0) at Day 64 and 7.0 (2.0-24.3) at Day 126 for EFS in pts with detectable ctDNA vs undetectable ctDNA. Among pts in the SOC arm who experienced subsequent PD despite achieving CR (all received HDCT/ASCT) and undetectable ctDNA at Day 126, serial ctDNA assessment showed consistent reversion to detectable ctDNA at later time points. Conclusions: ctDNA data from TRANSFORM confirm the value of ctDNA as a biomarker for disease burden monitoring and early prediction of durable clinical benefit after 2L LBCL treatment. Furthermore, longitudinal ctDNA molecular response results agree with previously reported clinical efficacy data and confirm the superiority of liso-cel with deeper responses over the historical SOC in 2L LBCL. ctDNA may have a key role as a surrogate endpoint in future LBCL studies, including after CAR T cell therapies.

Background: In TRANSCEND CLL 004 (NCT03331198),monotherapy with liso-cel, an autologous, CD19-directed CAR T cell product (100 × 106 CAR+ T cells [dose level (DL) 2]), resulted in 43% ORR and 18% CR/CR with incomplete marrow recovery (CRi) rate per IRC in pts with third-line or later R/R CLL/SLL who had PD on Bruton tyrosine kinase inhibitor (BTKi) and failed venetoclax (Siddiqi T, et al. Lancet 2023). Ibr + other CAR T cell therapies has shown high ORR and reduced cytokine release syndrome (CRS) severity in pts with R/R CLL/SLL. In the phase 1 dose-escalation ibr combination cohort, DL2 was the recommended dose of liso-cel for expansion (Wierda WG, et al. Blood 2020). Here, we report results of liso-cel + ibr in pts with R/R CLL/SLL from TRANSCEND CLL 004. Methods: Eligible pts ≥ 18 y of age with CLL/SLL had ≥ 1 of the following: 1) receiving BTKi with PD at entry, 2) high-risk disease and < CR after ≥ 6 mo on BTKi, 3) BTK/PLCγ2 mutation ± ibr PD, 4) prior BTKi with no contraindications to ibr, and 5) (per amendment) PD on BTKi and received prior venetoclax. At enrollment, pts started or continued ibr (420 mg daily or less for toxicity) through leukapheresis and for up to 90 d (or longer per investigator [inv]) after liso-cel (target dose of 50 × 106 CAR+ T cells [DL1] or DL2). Response was per inv by 2018 iwCLL criteria. Primary endpoint was CR/CRi rate at DL2; secondary endpoints included safety, ORR, duration of response (DOR), duration of CR/CRi (DOCR), time to response, time to CR/CRi, PFS, OS, and undetectable MRD (uMRD) rate in blood. Cellular kinetics was exploratory. Efficacy analyses were at DL2 and safety at DL1 + DL2. Treatment-emergent AEs (TEAE) occurred the latter of ≤ 90 days after liso-cel or ≤ 30 days of ibr completion. Liso-cel-treated pts who completed or withdrew from study could enroll in a separate long-term follow-up (LTFU) study (NCT03435796) for safety and OS ≤ 15 y after liso-cel. Results: A total of 65 pts underwent leukapheresis; 56 received ibr + liso-cel (DL1, n = 5; DL2, n = 51). At data cutoff (01/12/2024), 28 of 56 (50%) pts had discontinued the study, 11 (20%) completed the study, and 17 (30%) were ongoing; 5 of 28 (18%) eligible pts enrolled in LTFU. Median (IQR) on-study follow-up (including LTFU) was 24.8 mo (14.2-34.6). Median (range) age was 65 y (44-77); 55 (98%) pts had high-risk cytogenetics, such as del(17p) (n = 25), TP53 mutation (n = 24), and unmutated IGHV (n = 39); 43% had LDH ≥ ULN; and median (range) SPD was 27 cm2 (1-218). Pts had a median (range) of 5 (1-13) prior therapies (≤ 2, n = 13 [23%]). Median (range) time from leukapheresis to liso-cel availability was 25 d (17-79). Median (range) ibr exposure was 34 d (15-188) before and 94.5 d (6-1517) after liso-cel. At DL2, ORR (95% CI) was 86% (73.7-94.3), median (range) time to first response was 1.0 mo (0.9-6.0), and median (95% CI) DOR was 41.4 mo (23.3-not reached [NR]). CR/CRi rate (95% CI; primary endpoint) was 45% (31.1-59.7), median (range) time to first CR/CRi was 3.1 mo (0.9-12.1), and median (95% CI) DOCR was NR (26.6-NR). Median (95% CI) PFS and OS was 31.4 mo (20.1-NR) and NR (27.5-NR), respectively. uMRD rate (95% CI) in blood and marrow was 86% (73.7-94.3) and 84% (71.4-93.0), respectively. Grade (gr) ≥ 3 TEAEs occurred in 48 (86%) pts (most commonly neutropenia [52%] and anemia [41%]) with no gr 5 TEAEs. Liso-cel-related gr ≥ 3 TEAEs occurred in 32 (57%) pts and ibr-related gr ≥ 3 TEAEs in 24 (43%) pts including cardiovascular events of hypertension (7%) and atrial fibrillation (2%). Any-gr CRS occurred in 45 (80%) pts (gr ≥ 3, n = 2 [4%]) and any-gr neurological events (NE) in 23 (41%) pts (gr ≥ 3, n = 6 [11%]). Eight (14%) pts had gr ≥ 3 infections and 5 (9%) had second primary malignancies. Twenty-five (45%) pts had prolonged cytopenias (gr ≥ 3 at D30); most recovered to gr ≤ 2 by D90. Sixteen pts died after infusion (PD, n = 6; unknown, n = 6; COVID-19, n = 3; mixed septic/cardiogenic shock, n = 1). Liso-cel showed rapid expansion (median tmax, 10 d) and was detected up to 42 mo after infusion. Conclusions: Combined liso-cel + ibr demonstrated substantial efficacy with deep remissions (86% ORR, 45% CR rate, and 86% blood uMRD rate) and manageable safety in pts with R/R CLL/SLL. Though comparisons should be made with caution and there were differences in disease characteristics between cohorts, liso-cel + ibr showed a numerically higher ORR/CR rate and lower gr ≥ 3 CRS/NE rates vs liso-cel monotherapy, supporting the combination as a promising new therapeutic strategy for pts with R/R CLL/SLL.

Background: The primary analysis of the phase 1/2, single-arm, multicenter TRANSCEND CLL 004 (NCT03331198) study with a median follow-up of 21.1 mo showed that a single administration of liso-cel achieved rapid, deep, and durable responses and a manageable safety profile in pts with heavily pretreated, high-risk R/R CLL/SLL, including those with progression on a previous Bruton tyrosine kinase inhibitor (BTKi) and venetoclax failure (primary efficacy analysis set [PEAS]; Siddiqi T, et al. Lancet 2023). With 5 mo of additional follow-up (median of 23.5 mo), liso-cel continued to demonstrate durable CR/CR with incomplete marrow recovery (CRi) and high undetectable MRD (uMRD; 10−4 by next-generation sequencing) rates with no new safety signals. Median duration of response (DOR) was 35.3 mo (95% CI, 12.4-not reached [NR]), and median OS was 30.3 mo (95% CI, 15.0-NR) (Siddiqi T, et al. Blood 2023). Here, we report updated results from TRANSCEND CLL 004 with 16 mo of additional follow-up since primary analysis and a median on-study follow-up of 23.8 mo (range, 0.4-59.6). Methods: Pts must have received ≥ 2 prior lines of therapy (LOTs), including a BTKi (full population). Eligible pts received liso-cel at a target dose of either 50 × 106 (dose level [DL] 1) or 100 × 106 (DL2) CAR+ T cells after lymphodepleting chemotherapy. The primary endpoint was CR/CRi per independent review committee in the PEAS at DL2. Key secondary endpoints were ORR and blood uMRD rate. All pts who received liso-cel and completed or discontinued early from the study were asked to enroll in a separate long-term follow-up (LTFU) study (NCT03435796) assessing safety and OS for up to 15 y after liso-cel. Results: As of the data cutoff (01/12/2024), 118 of 137 leukapheresed pts received liso-cel (safety set), 97 (DL1, n = 9; DL2, n = 88) were efficacy evaluable, and 54 (DL1, n = 4; DL2, n = 50) were in the PEAS. A total of 22 pts were ongoing in TRANSCEND CLL 004, and 19 of 60 eligible pts enrolled to the LTFU study. In the safety set, pts had a median age of 65 y (range, 49-82), and 83% had high-risk cytogenetic markers (del[17p], 42%; TP53 mutation, 47%; unmutated immunoglobulin heavy-chain variable gene, 47%). Median prior LOTs was 5 (range, 2-14); 86% of pts had prior chemoimmunotherapy. In the PEAS at DL2, CR/CRi rate remained at 20%, ORR at 44%, blood uMRD rate at 64%, and marrow uMRD rate at 60%. Median DOR was NR (95% CI, 12.4-NR), with a median follow-up of 31.7 mo (95% CI, 21.3-35.5). Estimated 36-mo DOR rate was 61% (95% CI, 30-81). Median (95% CI) DOR was NR in pts with CR/CRi. Median (95% CI) PFS was 11.9 mo (5.7-26.2) overall, 26.2 mo (11.9-NR) in pts with blood uMRD, and 2.8 mo (0.8-3.2) in pts with detectable blood MRD. Median OS, including 19 pts in the LTFU, was 43.2 mo (95% CI, 14.5-NR). Efficacy outcomes were similar in the full population at DL2. A subgroup of 23 pts who had only prior BTKi exposure and were venetoclax naïve was less heavily pretreated, with a median of 3 prior LOTs (range, 2-11); all pts had prior chemoimmunotherapy. In the efficacy-evaluable pts of this subgroup at DL2 (n = 18), the CR/CRi rate was 22%; ORR was 61%; and median (95% CI) DOR was NR (17.1-NR), PFS was NR (18.0-NR), and OS was 52.2 mo (26.9-NR). In the safety set, rates of any-grade/grade ≥ 3 cytokine release syndrome (85%/8%), any-grade/grade ≥ 3 neurological events (45%/19%), prolonged cytopenia (grade ≥ 3 at Day 30 after liso-cel infusion [54%]), grade ≥ 3 infections (18%), and second primary malignancy (9%) remained the same as previously reported (Siddiqi T, et al. Blood 2023); most pts with prolonged cytopenia had resolution to grade ≤ 2 by Month 3. Forty-six (34%) of 137 leukapheresed pts died after CAR T cell infusion, including 1 additional pt since the previous report with an unknown cause of death at ~14.5 mo after infusion. Persistence of the liso-cel transgene was detected up to 48 months after liso-cel infusion (2/5 evaluable pts at DL2 at Month 48). Conclusions: In this updated follow-up, liso-cel continued to demonstrate durable responses with an extended median OS of 43.2 mo in pts with R/R CLL/SLL. The safety results were similar to those previously reported with no new safety signals. These data confirm the sustained clinical benefit and favorable benefit-to-risk profile of a single treatment of liso-cel in pts with R/R CLL/SLL.

Abstract Outcomes are poor in triple-class–exposed (TCE) relapsed and refractory multiple myeloma (R/RMM). In the phase 3 KarMMa-3 trial, patients with TCE R/RMM and 2 to 4 prior regimens were randomized 2:1 to idecabtagene vicleucel (ide-cel) or standard regimens (SRs). An interim analysis (IA) demonstrated significantly longer median progression-free survival (PFS; primary end point; 13.3 vs 4.4 months; P < .0001) and higher overall response rate (ORR) with ide-cel vs SRs. At final PFS analysis (median follow-up, 30.9 months), ide-cel further improved median PFS vs SRs (13.8 vs 4.4 months; hazard ratio [HR], 0.49; 95% confidence interval [CI], 0.38-0.63). PFS benefit with ide-cel vs SRs was observed regardless of number of prior lines of therapy, with greatest benefit after 2 prior lines (16.2 vs 4.8 months, respectively). ORR benefit was maintained with ide-cel vs SRs (71% vs 42%; complete response, 44% vs 5%). Patient-centric design allowed crossover from SRs (56%) to ide-cel upon progressive disease, confounding overall survival (OS) interpretation. At IA of OS, median was 41.4 (95% CI, 30.9 to not reached [NR]) vs 37.9 (95% CI, 23.4 to NR) months with ide-cel and SRs, respectively (HR, 1.01; 95% CI, 0.73-1.40); median OS in both arms was longer than historical data (9-22 months). Two prespecified analyses adjusting for crossover showed OS favoring ide-cel. This trial highlighted the importance of individualized bridging therapy to ensure adequate disease control during ide-cel manufacturing. Ide-cel improved patient-reported outcomes vs SRs. No new safety signals were reported. These results demonstrate the continued favorable benefit-risk profile of ide-cel in early-line and TCE R/RMM. This trial was registered at www.ClinicalTrials.gov as #NCT03651128.

7013 Background: Liso-cel is an autologous, CD19-directed, 4-1BB CAR T cell product. In prespecified interim and primary analyses of TRANSFORM (NCT03575351), liso-cel showed significant improvements in efficacy vs SOC in pts with R/R LBCL. Here we report results after ~3-y FU. Methods: TRANSFORM is a randomized phase 3 study comparing liso-cel vs SOC (CT [R-DHAP, R-ICE, or R-GDP] then high-dose CT [HDCT] + ASCT) in adults aged ≤ 75 y with LBCL primary refractory to or relapsed ≤ 12 mo after first-line therapy and eligible for ASCT. Liso-cel arm pts underwent lymphodepletion followed by liso-cel (100 × 10 6 CAR + T cells). Bridging therapy was allowed. SOC arm pts received 3 cycles of CT; responding pts proceeded to HDCT + ASCT. Crossover to receive liso-cel was allowed for SOC arm pts if criteria were met. The primary endpoint was event-free survival (EFS) per independent review committee (IRC). Key secondary endpoints included CR rate and PFS per IRC, and OS. Endpoints were not statistically retested and are reported descriptively. Results: In total, 184 pts were randomized (92 per arm); baseline characteristics were reported (Abramson et al. Blood 2023). Median (range) FU was 33.9 mo (0.9–53.0). Median EFS, PFS, and duration of response (DOR) were longer for liso-cel vs SOC, similar to the primary analysis (Table). A total of 61 (66%) SOC arm pts crossed over to receive liso-cel. Median OS was not reached (NR) in either arm; 36-mo OS rates were numerically higher for liso-cel. Of 76 total deaths (liso-cel, n = 34; SOC, n = 42 [crossover pts, n = 33]), 10 occurred since the primary analysis (liso-cel, n = 6; SOC, n = 4 [all crossover pts]); most were due to disease progression or complications (n = 6). Safety results were consistent with the primary analysis. Cellular kinetics and B-cell aplasia will be presented. Conclusions: After median FU of 33.9 mo, liso-cel as 2L treatment in pts with primary refractory or early relapsed LBCL resulted in deepening of response and continued improvement in efficacy endpoints over SOC, confirming the ongoing benefit of liso-cel. Clinical trial information: NCT03575351 . [Table: see text]