MYD88(L265P) and CXCR4(WHIM) mutations are highly prevalent in Waldenström's macroglobulinemia. MYD88(L265P) triggers tumor-cell growth through Bruton's tyrosine kinase, a target of ibrutinib. ...CXCR4(WHIM) mutations confer in vitro resistance to ibrutinib.
We performed a prospective study of ibrutinib in 63 symptomatic patients with Waldenström's macroglobulinemia who had received at least one previous treatment, and we investigated the effect of MYD88 and CXCR4 mutations on outcomes. Ibrutinib at a daily dose of 420 mg was administered orally until disease progression or the development of unacceptable toxic effects.
After the patients received ibrutinib, median serum IgM levels decreased from 3520 mg per deciliter to 880 mg per deciliter, median hemoglobin levels increased from 10.5 g per deciliter to 13.8 g per deciliter, and bone marrow involvement decreased from 60% to 25% (P<0.01 for all comparisons). The median time to at least a minor response was 4 weeks. The overall response rate was 90.5%, and the major response rate was 73.0%; these rates were highest among patients with MYD88(L265P)CXCR4(WT) (with WT indicating wild-type) (100% overall response rate and 91.2% major response rate), followed by patients with MYD88(L265P)CXCR4(WHIM) (85.7% and 61.9%, respectively) and patients with MYD88(WT)CXCR4(WT) (71.4% and 28.6%). The estimated 2-year progression-free and overall survival rates among all patients were 69.1% and 95.2%, respectively. Treatment-related toxic effects of grade 2 or higher included neutropenia (in 22% of the patients) and thrombocytopenia (in 14%), which were more common in heavily pretreated patients; postprocedural bleeding (in 3%); epistaxis associated with the use of fish-oil supplements (in 3%); and atrial fibrillation associated with a history of arrhythmia (5%).
Ibrutinib was highly active, associated with durable responses, and safe in pretreated patients with Waldenström's macroglobulinemia. MYD88 and CXCR4 mutation status affected responses to this drug. (Funded by Pharmacyclics and others; ClinicalTrials.gov number, NCT01614821.).
Single-agent ibrutinib has shown substantial activity in patients with relapsed Waldenström's macroglobulinemia, a rare form of B-cell lymphoma. We evaluated the effect of adding ibrutinib to ...rituximab in patients with this disease, both in those who had not received previous treatment and in those with disease recurrence.
We randomly assigned 150 symptomatic patients to receive ibrutinib plus rituximab or placebo plus rituximab. The primary end point was progression-free survival, as assessed by an independent review committee. Key secondary end points were response rates, sustained hematologic improvement from baseline, and safety. The mutational status of MYD88 and CXCR4 was assessed in bone marrow samples.
At 30 months, the progression-free survival rate was 82% with ibrutinib-rituximab versus 28% with placebo-rituximab (hazard ratio for progression or death, 0.20; P<0.001). The benefit in the ibrutinib-rituximab group over that in the placebo-rituximab group was independent of the MYD88 or CXCR4 genotype. The rate of major response was higher with ibrutinib-rituximab than with placebo-rituximab (72% vs. 32%, P<0.001). More patients had sustained increases in hemoglobin level with ibrutinib-rituximab than with placebo-rituximab (73% vs. 41%, P<0.001). The most common adverse events of any grade with ibrutinib-rituximab included infusion-related reactions, diarrhea, arthralgia, and nausea. Events of grade 3 or higher that occurred more frequently with ibrutinib-rituximab than with placebo-rituximab included atrial fibrillation (12% vs. 1%) and hypertension (13% vs. 4%); those that occurred less frequently included infusion reactions (1% vs. 16%) and any grade of IgM flare (8% vs. 47%). The major hemorrhage rate was the same in the two trial groups (4%).
Among patients with Waldenström's macroglobulinemia, the use of ibrutinib-rituximab resulted in significantly higher rates of progression-free survival than the use of placebo-rituximab, both among those who had received no previous treatment and among those with disease recurrence. Atrial fibrillation and hypertension were more common with ibrutinib-rituximab, whereas infusion reactions and IgM flare were more common with placebo-rituximab. (Funded by Pharmacyclics and Janssen Research and Development; ClinicalTrials.gov number, NCT02165397 .).
Abstract
Background
Ibrutinib is a Bruton tyrosine kinase inhibitor that is used for the treatment of lymphoid cancers, including chronic lymphocytic leukemia, Waldenström macroglobulinemia, and ...mantle cell lymphoma. Several case series have described opportunistic infections among ibrutinib recipients, but the full extent of these infections is unknown. We sought to determine the spectrum of serious infections associated with ibrutinib treatment.
Methods
We reviewed the electronic medical records of patients with lymphoid cancer at Memorial Sloan Kettering Cancer Center who received ibrutinib during a 5-year period from 1 January 2012 to 31 December 2016. Serious infections were identified by review of the relevant microbiology, clinical laboratory, and radiology data. Risk factors for infection were determined by means of univariate and multivariate analyses.
Results
We analyzed findings in 378 patients with lymphoid cancer who received ibrutinib. The most common underlying cancers were chronic lymphocytic leukemia and mantle cell lymphoma. 84% of patients received ibrutinib as monotherapy. Serious infection developed in 43 patients (11.4%), primarily during the first year of ibrutinib treatment. Invasive bacterial infections developed in 23 (53.5%) of these patients, and invasive fungal infections (IFIs) in 16 (37.2%) .The majority of patients with IFIs during ibrutinib therapy (62.5%) lacked classic clinical risk factors for fungal infection (ie, neutropenia, lymphopenia, and receipt of corticosteroids). Infection resulted in death in 6 of the 43 patients (14%).
Conclusions
Patients with lymphoid cancer receiving ibrutinib treatment are at risk for serious infections, including IFIs.
We reviewed the spectrum of serious infections among 378 patients with lymphoid cancer who received treatment with ibrutinib, a Bruton tyrosine kinase inhibitor. Serious infection occurred in 43 (11.4%) of the patients, invasive fungal infections in 16 (37.2%).
Covalent (irreversible) Bruton's tyrosine kinase (BTK) inhibitors have transformed the treatment of multiple B-cell cancers, especially chronic lymphocytic leukemia (CLL). However, resistance can ...arise through multiple mechanisms, including acquired mutations in BTK at residue C481, the binding site of covalent BTK inhibitors. Noncovalent (reversible) BTK inhibitors overcome this mechanism and other sources of resistance, but the mechanisms of resistance to these therapies are currently not well understood.
We performed genomic analyses of pretreatment specimens as well as specimens obtained at the time of disease progression from patients with CLL who had been treated with the noncovalent BTK inhibitor pirtobrutinib. Structural modeling, BTK-binding assays, and cell-based assays were conducted to study mutations that confer resistance to noncovalent BTK inhibitors.
Among 55 treated patients, we identified 9 patients with relapsed or refractory CLL and acquired mechanisms of genetic resistance to pirtobrutinib. We found mutations (V416L, A428D, M437R, T474I, and L528W) that were clustered in the kinase domain of BTK and that conferred resistance to both noncovalent BTK inhibitors and certain covalent BTK inhibitors. Mutations in BTK or phospholipase C gamma 2 (PLCγ2), a signaling molecule and downstream substrate of BTK, were found in all 9 patients. Transcriptional activation reflecting B-cell-receptor signaling persisted despite continued therapy with noncovalent BTK inhibitors.
Resistance to noncovalent BTK inhibitors arose through on-target BTK mutations and downstream PLCγ2 mutations that allowed escape from BTK inhibition. A proportion of these mutations also conferred resistance across clinically approved covalent BTK inhibitors. These data suggested new mechanisms of genomic escape from established covalent and novel noncovalent BTK inhibitors. (Funded by the American Society of Hematology and others.).
CD19 chimeric antigen receptors (CARs) have demonstrated great efficacy against a range of B cell malignancies. However, antigen escape and, more generally, heterogeneous antigen expression pose a ...challenge to applying CAR therapy to a wide range of cancers. We find that low-dose radiation sensitizes tumor cells to immune rejection by locally activated CAR T cells. In a model of pancreatic adenocarcinoma heterogeneously expressing sialyl Lewis-A (sLeA), we show that not only sLeA+ but also sLeA– tumor cells exposed to low-dose radiation become susceptible to CAR therapy, reducing antigen-negative tumor relapse. RNA sequencing analysis of low-dose radiation-exposed tumors reveals the transcriptional signature of cells highly sensitive to TRAIL-mediated death. We find that sLeA-targeted CAR T cells produce TRAIL upon engaging sLeA+ tumor cells, and eliminate sLeA− tumor cells previously exposed to systemic or local low-dose radiation in a TRAIL-dependent manner. These findings enhance the prospects for successfully applying CAR therapy to heterogeneous solid tumors. Local radiation is integral to many tumors’ standard of care and can be easily implemented as a CAR conditioning regimen.
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Tumor antigen escape is a major challenge for CAR T cell therapy, especially for solid tumors. DeSelm et al. demonstrate how low-dose radiation conditioning sensitizes pancreatic cancer to CAR T cell killing and allows CAR T cells to eliminate heterogeneous tumors.
Lisocabtagene maraleucel (liso-cel) is an autologous, CD19-directed, chimeric antigen receptor (CAR) T-cell product. We aimed to assess the activity and safety of liso-cel in patients with relapsed ...or refractory large B-cell lymphomas.
We did a seamless design study at 14 cancer centres in the USA. We enrolled adult patients (aged ≥18 years) with relapsed or refractory large B-cell lymphomas. Eligible histological subgroups included diffuse large B-cell lymphoma, high-grade B-cell lymphoma with rearrangements of MYC and either BCL2, BCL6, or both (double-hit or triple-hit lymphoma), diffuse large B-cell lymphoma transformed from any indolent lymphoma, primary mediastinal B-cell lymphoma, and follicular lymphoma grade 3B. Patients were assigned to one of three target dose levels of liso-cel as they were sequentially tested in the trial (50 × 106 CAR+ T cells one or two doses, 100 × 106 CAR+ T cells, and 150 × 106 CAR+ T cells), which were administered as a sequential infusion of two components (CD8+ and CD4+ CAR+ T cells) at equal target doses. Primary endpoints were adverse events, dose-limiting toxicities, and the objective response rate (assessed per Lugano criteria); endpoints were assessed by an independent review committee in the efficacy-evaluable set (comprising all patients who had confirmed PET-positive disease and received at least one dose of liso-cel). This trial is registered with ClinicalTrials.gov, NCT02631044.
Between Jan 11, 2016, and July 5, 2019, 344 patients underwent leukapheresis for manufacture of CAR+ T cells (liso-cel), of whom 269 patients received at least one dose of liso-cel. Patients had received a median of three (range 1–8) previous lines of systemic treatment, with 260 (97%) patients having had at least two lines. 112 (42%) patients were aged 65 years or older, 181 (67%) had chemotherapy-refractory disease, and seven (3%) had secondary CNS involvement. Median follow-up for overall survival for all 344 patients who had leukapheresis was 18·8 months (95% CI 15·0–19·3). Overall safety and activity of liso-cel did not differ by dose level. The recommended target dose was 100 × 106 CAR+ T cells (50 × 106 CD8+ and 50 × 106 CD4+ CAR+ T cells). Of 256 patients included in the efficacy-evaluable set, an objective response was achieved by 186 (73%, 95% CI 66·8–78·0) patients and a complete response by 136 (53%, 46·8–59·4). The most common grade 3 or worse adverse events were neutropenia in 161 (60%) patients, anaemia in 101 (37%), and thrombocytopenia in 72 (27%). Cytokine release syndrome and neurological events occurred in 113 (42%) and 80 (30%) patients, respectively; grade 3 or worse cytokine release syndrome and neurological events occurred in six (2%) and 27 (10%) patients, respectively. Nine (6%) patients had a dose-limiting toxicity, including one patient who died from diffuse alveolar damage following a dose of 50 × 106 CAR+ T cells.
Use of liso-cel resulted in a high objective response rate, with a low incidence of grade 3 or worse cytokine release syndrome and neurological events in patients with relapsed or refractory large B-cell lymphomas, including those with diverse histological subtypes and high-risk features. Liso-cel is under further evaluation at first relapse in large B-cell lymphomas and as a treatment for other relapsed or refractory B-cell malignancies.
Juno Therapeutics, a Bristol-Myers Squibb Company.
Summary Background Pre-transplantation18 F-fluorodeoxyglucose (FDG) PET-negativity is one of the strongest predictors of outcome after high-dose therapy and autologous stem-cell transplant (HDT/ASCT) ...for patients with relapsed or refractory Hodgkin's lymphoma. In this study, we assessed the feasibility and activity of PET-adapted salvage therapy with brentuximab vedotin, followed by augmented ifosfamide, carboplatin, and etoposide (ICE). Methods In this non-randomised, open-label, single-centre, phase 2 trial, we enrolled patients with relapsed or refractory Hodgkin's lymphoma who had failed one previous doxorubicin-containing chemotherapy regimen. All patients received weekly infusions of 1·2 mg/kg brentuximab vedotin on days 1, 8, and 15 for two 28 day cycles. After completion of brentuximab vedotin treatment, patients received a PET scan. Patients who achieved PET-negative status (a Deauville score of 1 or 2) proceeded directly to HDT/ASCT; those with persistent abnormalities on PET received two cycles of augmented ICE (augICE; two doses of ifosfamide 5000 mg/m2 in combination with mesna 5000 mg/m2 continuous infusion over 24 h, days 1 and 2; one dose of carboplatin AUC 5, day 3; three doses of etoposide 200 mg/m2 every 12 h, day 1) before consideration for HDT/ASCT. Only patients with persistent abnormalities on PET after brentuximab vedotin received augICE; however, all patients in the intention-to-treat population were assessed for the primary outcome, which was the proportion of patients who were PET-negative after brentuximab vedotin alone or brentuximab vedotin followed by augICE. This study is registered with ClinicalTrials.gov , number NCT01508312 , and is no longer accruing patients. Findings Between Jan 5, 2012, and Oct 4, 2013, we enrolled 46 patients. One patient was deemed ineligible, and not evaluable, before treatment initiation owing to having nodular, lymphocyte-predominant Hodgkin's lymphoma and thus 45 patients received treatment. After brentuximab vedotin, 12 patients (27%, 95% CI 13–40) were PET-negative and proceeded to HDT/ASCT. 33 (73%, 95% CI 60–86) patients were PET-positive after brentuximab vedotin; one PET-positive patient withdrew consent, therefore 32 PET-positive patients received augICE, 22 (69%, 95% CI 53–85) of whom were PET-negative. Overall, 34 patients (76%, 95% CI 62–89) achieved PET-negativity. All 44 patients who completed treatment as per protocol proceeded to receive HDT/ASCT. Brentuximab vedotin was well tolerated and associated with few grade 3–4 adverse events including hyperglycaemia (two 4% patients, grade 3), nausea (one 2%, grade 3), hypoglycaemia (one 2%, grade 3 and one 2%, grade 4), and hypocalcaemia (one 2%, grade 3 and one 2%, grade 4). Interpretation PET-adapted sequential salvage therapy with brentuximab vedotin followed by augICE resulted in a high proportion of patients with relapsed or refractory Hodgkin's lymphoma achieving PET-negativity, and therefore could optimise the chance of cure after HDT/ASCT. Funding Seattle Genetics.
Summary
CXCR4WHIM somatic mutations are distinctive to Waldenström Macroglobulinaemia (WM), and impact disease presentation and treatment outcome. The clonal architecture of CXCR4WHIM mutations ...remains to be delineated. We developed highly sensitive allele‐specific polymerase chain reaction (AS‐PCR) assays for detecting the most common CXCR4WHIM mutations (CXCR4S338X C>A and C>G) in WM. The AS‐PCR assays detected CXCR4S338X mutations in WM and IgM monoclonal gammopathy of unknown significance (MGUS) patients not revealed by Sanger sequencing. By combined AS‐PCR and Sanger sequencing, CXCR4WHIM mutations were identified in 44/102 (43%), 21/62 (34%), 2/12 (17%) and 1/20 (5%) untreated WM, previously treated WM, IgM MGUS and marginal zone lymphoma patients, respectively, but no chronic lymphocytic leukaemia, multiple myeloma, non‐IgM MGUS patients or healthy donors. Cancer cell fraction analysis in WM and IgM MGUS patients showed CXCR4S338X mutations were primarily subclonal, with highly variable clonal distribution (median 35·1%, range 1·2–97·5%). Combined AS‐PCR and Sanger sequencing revealed multiple CXCR4WHIM mutations in many individual WM patients, including homozygous and compound heterozygous mutations validated by deep RNA sequencing. The findings show that CXCR4WHIM mutations are more common in WM than previously revealed, and are primarily subclonal, supporting their acquisition after MYD88L265P in WM oncogenesis. The presence of multiple CXCR4WHIM mutations within individual WM patients may be indicative of targeted CXCR4 genomic instability.
Bruton tyrosine kinase (BTK) links the B-cell antigen receptor (BCR) and Toll-like receptors with NF-κB. The role of BTK in primary central nervous system (CNS) lymphoma (PCNSL) is unknown. We ...performed a phase I clinical trial with ibrutinib, the first-in-class BTK inhibitor, for patients with relapsed or refractory CNS lymphoma. Clinical responses to ibrutinib occurred in 10 of 13 (77%) patients with PCNSL, including five complete responses. The only PCNSL with complete ibrutinib resistance harbored a mutation within the coiled-coil domain of CARD11, a known ibrutinib resistance mechanism. Incomplete tumor responses were associated with mutations in the B-cell antigen receptor-associated protein CD79B.
-mutant PCNSLs showed enrichment of mammalian target of rapamycin (mTOR)-related gene sets and increased staining with PI3K/mTOR activation markers. Inhibition of the PI3K isoforms p110α/p110δ or mTOR synergized with ibrutinib to induce cell death in
-mutant PCNSL cells.
Ibrutinib has substantial activity in patients with relapsed or refractory B-cell lymphoma of the CNS. Response rates in PCNSL were considerably higher than reported for diffuse large B-cell lymphoma outside the CNS, suggesting a divergent molecular pathogenesis. Combined inhibition of BTK and PI3K/mTOR may augment the ibrutinib response in
-mutant human PCNSLs.
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