Lisocabtagene maraleucel versus standard of care with salvage chemotherapy followed by autologous stem cell transplantation as second-line treatment in patients with relapsed or refractory large B-cell lymphoma (TRANSFORM): results from an interim analysis of an open-label, randomised, phase 3 trial.

BACKGROUND: Patients with large B-cell lymphoma (LBCL) primary refractory to or relapsed within 12 months of first-line therapy are at high risk for poor outcomes with current standard of care, platinum-based salvage immunochemotherapy and autologous haematopoietic stem cell transplantation (HSCT). Lisocabtagene maraleucel (liso-cel), an autologous, CD19-directed chimeric antigen receptor (CAR) T-cell therapy, has previously demonstrated efficacy and manageable safety in third-line or later LBCL. In this Article, we report a prespecified interim analysis of liso-cel versus standard of care as second-line treatment for primary refractory or early relapsed (within 12 months after response to initial therapy) LBCL. METHODS: TRANSFORM is a global, phase 3 study, conducted in 47 sites in the USA, Europe, and Japan, comparing liso-cel with standard of care as second-line therapy in patients with primary refractory or early (≤12 months) relapsed LBCL. Adults aged 18-75 years, Eastern Cooperative Oncology Group performance status score of 1 or less, adequate organ function, PET-positive disease per Lugano 2014 criteria, and candidates for autologous HSCT were randomly assigned (1:1), by use of interactive response technology, to liso-cel (100 × 106 CAR+ T cells intravenously) or standard of care. Standard of care consisted of three cycles of salvage immunochemotherapy delivered intravenously-R-DHAP (rituximab 375 mg/m2 on day 1, dexamethasone 40 mg on days 1-4, two infusions of cytarabine 2000 mg/m2 on day 2, and cisplatin 100 mg/m2 on day 1), R-ICE (rituximab 375 mg/m2 on day 1, ifosfamide 5000 mg/m2 on day 2, etoposide 100 mg/m2 on days 1-3, and carboplatin area under the curve 5 [maximum dose of 800 mg] on day 2), or R-GDP (rituximab 375 mg/m2 on day 1, dexamethasone 40 mg on days 1-4, gemcitabine 1000 mg/m2 on days 1 and 8, and cisplatin 75 mg/m2 on day 1)-followed by high-dose chemotherapy and autologous HSCT in responders. Primary endpoint was event-free survival, with response assessments by an independent review committee per Lugano 2014 criteria. Efficacy was assessed per intention-to-treat (ie, all randomly assigned patients) and safety in patients who received any treatment. This trial is registered with ClinicalTrials.gov, NCT03575351, and is ongoing. FINDINGS: Between Oct 23, 2018, and Dec 8, 2020, 232 patients were screened and 184 were assigned to the liso-cel (n=92) or standard of care (n=92) groups. At the data cutoff for this interim analysis, March 8, 2021, the median follow-up was 6·2 months (IQR 4·4-11·5). Median event-free survival was significantly improved in the liso-cel group (10·1 months [95% CI 6·1-not reached]) compared with the standard-of-care group (2·3 months [2·2-4·3]; stratified hazard ratio 0·35; 95% CI 0·23-0·53; stratified Cox proportional hazards model one-sided p<0·0001). The most common grade 3 or worse adverse events were neutropenia (74 [80%] of 92 patients in the liso-cel group vs 46 [51%] of 91 patients in the standard-of-care group), anaemia (45 [49%] vs 45 [49%]), thrombocytopenia (45 [49%] vs 58 [64%]), and prolonged cytopenia (40 [43%] vs three [3%]). Grade 3 cytokine release syndrome and neurological events, which are associated with CAR T-cell therapy, occurred in one (1%) and four (4%) of 92 patients in the liso-cel group, respectively (no grade 4 or 5 events). Serious treatment-emergent adverse events were reported in 44 (48%) patients in the liso-cel group and 44 (48%) in the standard-of-care group. No new liso-cel safety concerns were identified in the second-line setting. There were no treatment-related deaths in the liso-cel group and one treatment-related death due to sepsis in the standard-of-care group. INTERPRETATION: These results support liso-cel as a new second-line treatment recommendation in patients with early relapsed or refractory LBCL. FUNDING: Celgene, a Bristol-Myers Squibb Company.

Purification and kinetic characterization of human indoleamine 2,3-dioxygenases 1 and 2 (IDO1 and IDO2) and discovery of selective IDO1 inhibitors.

Indoleamine 2,3-dioxygenase (IDO1) catalyzes the first step in tryptophan breakdown along the kynurenine pathway. Therapeutic inhibition of IDO1 is receiving much attention due to its proposed role in the pathogenesis of several diseases including cancer, hypotension and neurodegenerative disorders. A related enzyme, IDO2 has recently been described. We report the first purification and kinetic characterization of human IDO2 using a facile l-tryptophan consumption assay amenable to high throughput screening. We found that the K(m) of human IDO2 for l-tryptophan is much higher than that of IDO1. We also describe the identification and characterization of a new IDO1 inhibitor compound, Amg-1, by high throughput screening, and compare the inhibition profiles of IDO1 and IDO2 with Amg-1 and previously described compounds. Our data indicate that human IDO1 and IDO2 have different kinetic parameters and different inhibition profiles. Docking of Amg-1 and related analogs to the known structure of IDO1 and to homology-modeled IDO2 suggests possible rationales for the different inhibition profiles of IDO1 and IDO2.

Phase 2 results of lisocabtagene maraleucel in Japanese patients with relapsed/refractory aggressive B-cell non-Hodgkin lymphoma.

The autologous anti-CD19 chimeric antigen receptor (CAR) T-cell product, lisocabtagene maraleucel (liso-cel), is administered at equal target doses of CD8+ and CD4+ CAR+ T cells. This analysis assessed safety and efficacy of liso-cel in Japanese patients with relapsed or refractory (R/R) aggressive large B-cell lymphoma (LBCL) in Cohort 3 of TRANSCEND WORLD (NCT03484702). Liso-cel (100 × 106 total CAR+ T cells) was administered 2-7 days after lymphodepletion. The primary efficacy endpoint was objective response rate (ORR; Lugano 2014 criteria) assessed by an independent review committee. Fourteen patients were enrolled; 10 received liso-cel infusion (median time to liso-cel availability, 23 days) and were evaluable at data cutoff (median follow-up, 12.5 months). Grade ≥ 3 treatment-emergent adverse events were neutropenia (90%), leukopenia (80%), anemia (70%), and thrombocytopenia (70%). All-grade cytokine release syndrome (CRS) was observed in 50% of patients, though no grade ≥3 CRS events were reported. Grade 1 neurological events occurred in 1 patient but were resolved without any intervention. Prolonged cytopenia (grade ≥ 3 at day 29) was reported for 60% of patients. The ORR was 70%, and complete response rate was 50%. The median duration of response was 9.1 months (95% confidence interval [CI], 2.1-not reached), and overall survival was 14.7 months (95% CI, 1.7-not reached). One patient diagnosed with central nervous system involvement after screening but before liso-cel infusion, responded to liso-cel. Liso-cel demonstrated meaningful efficacy and a manageable safety profile in Japanese patients with R/R LBCL.

Specific stimulation of MHC-transgenic mouse T-cell hybridomas with xenogeneic APC.

From the recombinant human leukocyte antigen (HLA)-DR1/H2-E(k) major histocompatibility complex (MHC) class II-transgenic mice, we have generated two CD4(+) T-cell hybridomas specific for peptides which were derived from human prostatic acid phosphatase (PAP) complexed to the human class II molecule HLA-DR1. Both hybridomas strongly react to PAP-pulsed antigen-presenting cells (APC) from transgenic mice. Interestingly, these hybridomas also responded to PAP antigen presented by HLA-DR1-positive human APC. The species-mismatched T-cell stimulation occurs despite the biologic discordance in participating accessory molecules, which are required for the optimal T-cell-APC interaction. Our results demonstrate various degrees of functional interaction between coreceptors, costimulatory molecules, and integrins, which are expressed on the surface of T-cell hybridomas and heterologous APC.

Expression of Trop2 cell surface glycoprotein in normal and tumor tissues: potential implications as a cancer therapeutic target.

Trop2 is a cell-surface glycoprotein reported to be overexpressed in various types of adenocarcinomas with minimal expression in normal tissues. Recent findings that Trop2 expression correlates with tumor aggressiveness have increased interest in Trop2 as a potential target for cancer immunotherapy. The goal of this study was to extensively evaluate Trop2 expression at the transcript and protein levels in normal and tumor tissues. It was determined that Trop2 is overexpressed on some carcinomas relative to the corresponding normal tissue. However, in human and mouse, Trop2 is highly expressed at both the transcript and protein levels on several essential normal tissues. The findings suggest that the development of therapeutic agents to target Trop2 may require strategies that target Trop2 on malignant tissues in order to minimize potential toxicities to essential normal tissues that also express high levels of Trop2.

Antitumor vaccination with HER-2-derived recombinant antigens.

Certain types of malignant tumors overexpress HER-2, a transmembrane glycoprotein of the class I receptor tyrosine kinase erbB family. To develop an effective HER-2 vaccine for the selective immunotherapy of these malignancies, we have genetically engineered fusion proteins containing portions of extra- and intracellular HER-2 domains. Activated dendritic cells (DC) cocultured with these novel antigens (Ag) could induce potent responses of Ag-specific T-cell lines in vitro and a protection against HER-2-expressing tumor in vivo. The protective capabilities of HER-2-derived fusion proteins correlated with the efficiency of their presentation to Ag-specific T-cell hybridomas. The most effective Ag contained GM-CSF, the presence of which facilitated their internalization by antigen-presenting cells (APC) in a receptor-mediated manner.