A first-in-class inhibitor of HSP110 to potentiate XPO1-targeted therapy in primary mediastinal B-cell lymphoma and classical Hodgkin lymphoma.

BACKGROUND: Primary mediastinal B-cell lymphoma (PMBL) and classical Hodgkin lymphoma (cHL) are distinct hematological malignancies of B-cell origin that share many biological, molecular, and clinical characteristics. In particular, the JAK/STAT signaling pathway is a driver of tumor development due to multiple recurrent mutations, particularly in STAT6. Furthermore, the XPO1 gene that encodes exportin 1 (XPO1) shows a frequent point mutation (E571K) resulting in an altered export of hundreds of cargo proteins, which may impact the success of future therapies in PMBL and cHL. Therefore, targeted therapies have been envisioned for these signaling pathways and mutations. METHODS: To identify novel molecular targets that could overcome the treatment resistance that occurs in PMBL and cHL patients, we have explored the efficacy of a first-in-class HSP110 inhibitor (iHSP110-33) alone and in combination with selinexor, a XPO1 specific inhibitor, both in vitro and in vivo. RESULTS: We show that iHSP110-33 decreased the survival of several PMBL and cHL cell lines and the size of tumor xenografts. We demonstrate that HSP110 is a cargo of XPO1wt as well as of XPO1E571K. Using immunoprecipitation, proximity ligation, thermophoresis and kinase assays, we showed that HSP110 directly interacts with STAT6 and favors its phosphorylation. The combination of iHSP110-33 and selinexor induces a synergistic reduction of STAT6 phosphorylation and of lymphoma cell growth in vitro and in vivo. In biopsies from PMBL patients, we show a correlation between HSP110 and STAT6 phosphorylation levels. CONCLUSIONS: These findings suggest that HSP110 could be proposed as a novel target in PMBL and cHL therapy.

Analysis of immunoglobulin/T-cell receptor repertoires by high-throughput RNA sequencing reveals a continuous dynamic of positive clonal selection in follicular lymphoma.

Follicular lymphoma (FL) course is highly variable, making its clinical management challenging. In this incurable and recurring pathology, the interval between relapses tends to decrease while aggressiveness increases, sometimes resulting in the transformation to higher-grade lymphoma. These evolutions are particularly difficult to anticipate, resulting from complex clonal evolutions where multiple subclones compete and thrive due to their capacity to proliferate and resist therapies. Here, to apprehend further these processes, we used a high-throughput RNA sequencing approach to address simultaneously the B-cell immunoglobulin repertoires and T-cell immunoglobulin repertoires repertoires of lymphoma cells and their lymphoid microenvironment in a large cohort of 131 FL1/2-3A patients. Our data confirm the existence of a high degree of intra-clonal heterogeneity in this pathology, resulting from ongoing somatic hyper-mutation and class switch recombination. Through the evaluation of the Simpson ecological-diversity index, we show that the contribution of the cancerous cells increases during the course of the disease to the detriment of the reactive compartment, a phenomenon accompanied by a concomitant decrease in the diversity of the tumoral population. Clonal evolution in FL thus contrasts with many tumors, where clonal heterogeneity steadily increases over time and participates in treatment evasion. In this pathology, the selection of lymphoma subclones with proliferative advantages progressively outweighs clonal diversification, ultimately leading in extreme cases to transformation to high-grade lymphoma resulting from the rapid emergence of homogeneous subpopulations.

Impact of second autologous stem-cell transplantation at relapsed multiple myeloma: A French multicentric real-life study.

A second autologous stem-cell transplantation (ASCT2) is considered for relapsed multiple myeloma (RMM) patients showing prolonged response after a first ASCT. However, given breakthrough treatments like anti-CD38 and immunotherapy, its role remains debated. We conducted a real-life study in 10 French centers (1996-2017) involving 267 RMM patients receiving ASCT2. The median age was 61 years, with 49% females. Most patients received melphalan 200 mg/m² before ASCT2, with low early mortality (1%). Very good partial response or better (VGPR+) rate post ASCT2 was 78%. Post ASCT2, 48% received consolidation therapy and 40% maintenance therapy. Median event-free survival (EFS) after ASCT2 was 2.6 years (95% confidence interval [CI]: 2.3-2.8), and 2-year EFS estimate was 63% (95% CI: 57-70). Median overall survival (OS) was 8.1 years (95% CI: 5.9-NA), and 2-year OS estimate was 92% (95% CI: 88-95). Multivariate analysis revealed that VGPR+ status and maintenance therapy post ASCT2 were associated with better EFS (hazard ratio [HR]: 0.6; 95% CI: 0.3-0.9, p = 0.012 and HR: 0.4; 95% CI: 0.3-0.6, p < 0.001, respectively) and OS (HR: 0.4; 95% CI: 0.2-0.9, p = 0.017 and HR: 0.2; 95% CI: 0.1-0.4, p < 0.001, respectively), while male sex correlated with poorer outcomes for EFS (HR: 2.5; 95% CI: 1.7-3.7, p < 0.001) and OS (HR: 2.7; 95% CI: 1.4-4.9, p = 0.002). Overall, ASCT2 appeared efficient with low toxicity in RMM. Maintenance therapy was associated with extended EFS and OS, particularly in patients with VGPR+ status post ASCT2. These findings underscore ASCT2's potential in RMM when coupled with maintenance therapy in selected patients.

Long-Term Follow-Up of Rituximab Maintenance in Young Patients With Mantle-Cell Lymphoma Included in the LYMA Trial: A LYSA Study.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned coprimary or secondary analyses are not yet available. Clinical trial updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.The LYMA trial demonstrated the benefit of rituximab maintenance (RM) in first-line young patients with mantle-cell lymphoma. In this prolonged follow-up of 7.5 years (95% CI, 7.4 to 7.7) from inclusion, the median progression-free survival (PFS) and overall survival (OS) for the full population were not reached (NR) with a 7-year PFS of 55.5% (95% CI, 49.5 to 61) and OS of 69.5% (95% CI, 63.8 to 74.5). The EFS remained statistically superior in favor of RM (median NR v 5.8 years, P < .0001; HR, 0.39 [95% CI, 0.52 to 0.6] and 7-year estimate, 76.2% versus 46% for RM and observation, respectively). Similarly, RM prolonged PFS (estimated PFS at 7 years, 78.5% v 47.4% and HR, 0.36 [95% CI, 0.23 to 0.56] for RM and observation, respectively, P < .0001). The 7-year OS estimate was 83.2% versus 72.2%, respectively (P = .088, HR, 0.63 [95% CI, 0.37 to 1.08]). Cause of death was not significantly distinct between the two groups, with lymphoma being the leading cause with a very low rate of infection-related death. Overall, the PFS benefit of RM after autologous stem cell transplantation remains after 7-year follow-up, and RM was not associated with an increase in infection-related mortality, making this strategy a safe standard of care with long-term follow-up.

Outcome of large B-cell lymphoma patients treated with tafasitamab plus lenalidomide either before or after CAR-T-cells.

Tafasitamab plus lenalidomide (TAFA-LEN) treatment relevance pre- or post-anti-CD19 CAR T-cell is currently debated. We analyzed large B-cell lymphoma patients in the DESCAR-T registry treated with axi-cel or tisa-cel in ≥3rd line (L3+) and TAFA-LEN before (n=15, 'TL-pre-CAR-T' set) or directly after (n=52, 'TL-post-CAR-T' set) CAR T-cell. We compared TAFA-LEN v. other treatments using inverse probability weighting in the TL-post-CAR-T set. In the TL-post-CAR-T' set, the median follow-up duration (mFUD) was 7 months, and the median progression-free survival, overall survival and duration of response since the 1st treatment for progression (mPFS2/mOS2/mDOR2) were 3, 4.7 and 8.1 months, respectively. The best overall response rate (bORR) and best complete response rate (bCRR) after TAFA-LEN were 13.5% and 7.7%, respectively. Outcomes were better for patients who relapsed >6 months after CAR T-cell (mPFS2: 5.6 vs. 2 months, p=0.0138; mOS2: not reached vs. 3.8 months, p=0.0034). bORR and bCRR between TAFA-LEN and other treatments were 20.6% vs. 24.9% and 11.6% vs. 15.6%, respectively. Outcomes were similar between TAFA-LEN and other treatments (mPFS2: 2.9 [2-2.6] vs. 2.4 [1.5-4.2] months, p=0.91; mOS2: 3.3 [1.8-6.4] vs. 5.5 [4.4-6.3] months, p=0.06). In an exploratory analysis of the TL-pre-CAR-T set (mFUD since CAR T-cell: 2.8 months), the median TAFA-LEN treatment duration prior to CAR-T was 3.7 months and no patients were reported to become CD19 negative. The bORR, bCRR, 6-month PFS and OS rates after CAR T-cell infusion were 45.5%, 36.4%, 20.1% and 58.2%, respectively. Neither TAFA-LEN nor comparative salvage treatments improved outcomes of patients who relapsed after CAR T-cell.