Toward targeting B cell cancers with CD4+ CTLs: identification of a CD19-encoded minor histocompatibility antigen using a novel genome-wide analysis

Some minor histocompatibility antigens (mHags) are expressed exclusively on patient hematopoietic and malignant cells, and this unique set of antigens enables specific targeting of hematological malignancies after human histocompatability leucocyte antigen (HLA)–matched allogeneic stem cell transplantation (allo-SCT). We report the first hematopoietic mHag presented by HLA class II (HLA-DQA1*05/B1*02) molecules to CD4+ T cells. This antigen is encoded by a single-nucleotide polymorphism (SNP) in the B cell lineage-specific CD19 gene, which is an important target antigen for immunotherapy of most B cell malignancies. The CD19L-encoded antigen was identified using a novel and powerful genetic strategy in which zygosity-genotype correlation scanning was used as the key step for fine mapping the genetic locus defined by pairwise linkage analysis. This strategy was also applicable for genome-wide identification of a wide range of mHags. CD19L-specific CD4+ T cells provided antigen-specific help for maturation of dendritic cells and for expansion of CD8+ mHag-specific T cells. They also lysed CD19L-positive malignant cells, illustrating the potential therapeutic advantages of targeting this novel CD19L-derived HLA class II–restricted mHag. The currently available immunotherapy strategies enable the exploitation of these therapeutic effects within and beyond allo-SCT settings

Efficacy and safety of daratumumab combined with all-trans retinoic acid in relapsed/refractory multiple myeloma

The efficacy of daratumumab depends partially on CD38 expression on multiple myeloma (MM) cells. We have previously shown that all-trans retinoic acid (ATRA) upregulates CD38 expression and reverts daratumumab-resistance ex vivo. We therefore evaluated the optimal dose, efficacy, and safety of daratumumab combined with ATRA in patients with daratumumab-refractory MM in a phase 1/2 study (NCT02751255). In part A of the study, 63 patients were treated with daratumumab monotherapy. Fifty patients with daratumumabrefractory MM were subsequently enrolled in part B and treated with daratumumab (reintensified schedule) combined with ATRA until disease progression. The recommended phase 2 dose of ATRA in combination with daratumumab was defined as 45 mg/m2. At this dose, the overall response rate (ORR) was 5%, indicating that the primary endpoint (ORR $15%) was not met. However, most patients (66%) achieved at least stable disease. After a median follow-up of 43 months, the median progression-free survival (PFS) for all patients was 2.8 months. Patients who previously achieved at least a partial response or minimal response/stable disease with prior daratumumab monotherapy had a significantly longer PFS compared with patients who immediately progressed during daratumumab as single agent (median PFS 3.4 and 2.8 vs 1.3 months). The median overall survival was 19.1 months. The addition of ATRA did not increase the incidence of adverse events. Flow cytometric analysis revealed that ATRA temporarily increased CD38 expression on immune cell subsets. In conclusion, the addition of ATRA and reintensification of daratumumab had limited activity in patients with daratumumab-refractory MM, which may be explained by the transient upregulation of CD38 expression. This trial was registered at www.clinicaltrials.gov as #NCT02751255

Survival, neurocognitive function, and health-related quality of life outcomes after rituximab-methotrexate, BCNU, teniposide, and prednisolone for primary CNS lymphoma:Final results of the HOVON 105/ALLG NHL 24 study

Background. Studies on the efficacy of rituximab in primary CNS lymphoma (PCNSL) reported conflicting results. Our international randomized phase 3 study showed that the addition of rituximab to high-dose methotrexate, BCNU, teniposide, and prednisolone (MBVP) in PCNSL was not efficacious in the short term. Here we present long-term results after a median follow-up of 82.3 months. Methods. One hundred and ninety-nine eligible newly diagnosed, nonimmunocompromised patients with PCNSL aged 18–70 years with WHO performance status 0–3 was randomized between treatment with MBVP chemotherapy with or without rituximab, followed by high-dose cytarabine consolidation in responding patients, and reduced-dose WBRT in patients aged ≤ 60 years. Event-free survival was the primary endpoint. Overall survival rate, neurocognitive functioning (NCF), and health-related quality of life (HRQoL) were additionally assessed, with the IPCG test battery, EORTC QLQ-C30 and QLQ-BN20 questionnaires, respectively. Results. For event-free survival, the hazard ratio was 0.85, 95% CI 0.61–1.18, P = .33. Overall survival rate at 5 years for MBVP and R-MBVP was 49% (39–59) and 53% (43–63) respectively. In total, 64 patients died in the MBVP arm and 55 in the R-MBVP arm, of which 69% were due to PCNSL. At the group level, all domains of NCF and HRQoL improved to a clinically relevant extent after treatment initiation, and remained stable thereafter up to 60 months of follow-up, except for motor speed which deteriorated between 24 and 60 months. Although fatigue improved initially, high levels persisted in the long term. Conclusions. Long-term follow-up confirms the lack of added value of rituximab in addition to MBVP and HD-cytarabine for PCNSL.</p

Survival, neurocognitive function, and health-related quality of life outcomes after rituximab-methotrexate, BCNU, teniposide, and prednisolone for primary CNS lymphoma:Final results of the HOVON 105/ALLG NHL 24 study

Background. Studies on the efficacy of rituximab in primary CNS lymphoma (PCNSL) reported conflicting results. Our international randomized phase 3 study showed that the addition of rituximab to high-dose methotrexate, BCNU, teniposide, and prednisolone (MBVP) in PCNSL was not efficacious in the short term. Here we present long-term results after a median follow-up of 82.3 months. Methods. One hundred and ninety-nine eligible newly diagnosed, nonimmunocompromised patients with PCNSL aged 18–70 years with WHO performance status 0–3 was randomized between treatment with MBVP chemotherapy with or without rituximab, followed by high-dose cytarabine consolidation in responding patients, and reduced-dose WBRT in patients aged ≤ 60 years. Event-free survival was the primary endpoint. Overall survival rate, neurocognitive functioning (NCF), and health-related quality of life (HRQoL) were additionally assessed, with the IPCG test battery, EORTC QLQ-C30 and QLQ-BN20 questionnaires, respectively. Results. For event-free survival, the hazard ratio was 0.85, 95% CI 0.61–1.18, P = .33. Overall survival rate at 5 years for MBVP and R-MBVP was 49% (39–59) and 53% (43–63) respectively. In total, 64 patients died in the MBVP arm and 55 in the R-MBVP arm, of which 69% were due to PCNSL. At the group level, all domains of NCF and HRQoL improved to a clinically relevant extent after treatment initiation, and remained stable thereafter up to 60 months of follow-up, except for motor speed which deteriorated between 24 and 60 months. Although fatigue improved initially, high levels persisted in the long term. Conclusions. Long-term follow-up confirms the lack of added value of rituximab in addition to MBVP and HD-cytarabine for PCNSL.</p