Summary
Since the discovery of rapamycin in Easter Island soil in 1975, more has been learnt about the relevance and importance of the mammalian target of rapamycin (mTOR) pathway in cell signalling, ...proliferation and ultimately tumourigenesis. Rapamycin targets the mTORC1 complex alone. Despite initial excitement, rapamycin and its analogues, everolimus and temsirolimus, have displayed limited efficacy in the treatment of lymphoid malignancies. This review highlights the important and well‐described aspects of the critical phosphatidylinositol‐4,5‐bisphosphate 3‐kinase (PI3K)/AKT/mTOR pathway and discusses the mechanisms of action of rapamycin, its clinical efficacy in lymphoid malignancies, and the mechanisms of resistance. Renewed interest in targeting the pathway has evolved through the discovery of mTORC2, a protein complex associated with a key mechanism of resistance to first generation mTOR inhibitors. As such, novel dual inhibitors of mTORC1 and mTORC2 have been developed, along with other dual inhibitors of the mTOR pathway. The evolution in the development of dual inhibitors is described herein, along with the burgeoning in vitro, pre‐clinical data and the early phase clinical data available. Although historically mTOR inhibitors have been used extensively in haematopoietic and solid organ transplant prophylaxis, this review will focus on developments of their use in lymphoid malignancies.
The optimum management approach for patients with relapsed or refractory follicular lymphoma remains uncertain. Autologous stem cell transplantation (autoSCT) is considered a standard option in ...suitable, younger patients with relapsed follicular lymphoma. AutoSCT is associated with very durable remissions in a minority of subjects, but also with significant, well-established toxicities. Although positron emission tomography (PET) status prior to autoSCT is an established prognostic factor in diffuse large B-cell lymphoma and Hodgkin lymphoma, no data exist in follicular lymphoma. We describe survival outcomes according to pre-transplant PET status, classified by the Lugano criteria into complete metabolic remission (CMR) versus non-CMR, in 172 patients with relapsed or refractory follicular lymphoma within a national, multicenter, retrospective British Society of Blood and Marrow Transplantation and Cellular Therapy registry study. The median number of lines of therapy prior to SCT was three (range, 1-6). The median follow-up after SCT was 27 months (range, 3-70). The median progression-free survival for all patients after autoSCT was 28 months (interquartile range, 23- 36). There was no interaction between age at transplantation, sex, number of months since last relapse, Karnofsky performance status or comorbidity index and achieving CMR prior to autoSCT. Superior progression-free survival was observed in 115 (67%) patients obtaining CMR versus 57 (33%) non-CMR patients (3-year progression-free survival 50% vs. 22%, P=0.011) and by pre-SCT Deauville score (continuous variable 1-5, hazard ratio HR=1.32, P=0.049). PET status was independently associated with progression-free status (non-CMR HR=2.02, P=0.003), overall survival (non-CMR HR=3.08, P=0.010) and risk of relapse (non-CMR HR=1.64, P=0.046) after autoSCT by multivariable analysis. Our data suggest that pre- SCT PET status is of clear prognostic value and may help to improve the selection of patients for autoSCT.
Objectives: Daratumumab is the first anti-CD38 monoclonal antibody (Mab) used to treat myeloma in the newly diagnosed setting and in the relapsed setting. Isatuximab, another Mab targeting a specific ...epitope on the CD38 receptor, was recently approved in the UK in combination with pomalidomide and dexamethasone (IsaPomDex) to treat myeloma patients who received three prior lines of therapy. However, there is a lack of understanding of whether using a prior anti-CD38 Mab (e.g. daratumumab) can affect the efficacy of another Mab (e.g. isatuximab), when the latter is used to treat a subsequent relapse.
Methods: We performed a UK-wide outcomes study of IsaPomDex in the real-world. In this case series, we report a detailed descriptive analysis of the characteristics and clinical outcomes of five IsaPomDex patients in UK routine practice (Patients I to V), with a prior exposure to daratumumab.
Results: Age range was 51-77 years with two patients >70 and three patients <70 years. The cytogenetic risk was standard in two patients, high in two patients and not known in one patient. Prior daratumumab regimen were monotherapy (dara-mono) in one patient (II), and daratumumab with bortezomib and dexamethasone (DVd) in four patients. Responses to prior daratumumab were: very good partial response (VGPR) in two patients (I and III), minor response-stable disease (MR-SD) in one patient (II), and progressive disease (PD) in two patients (IV and V). Median (range) number of IsaPomDex cycles received was 2 (1-4). Outcomes of IsaPomDex were PD in three patients (II, IV and V) and a response in two patients. Response categories were: MR-SD in patient I and PR in patient III.
Discussion: Despite the limitations of our case series, we described the first UK real-world report of IsaPomDex outcomes in myeloma patients with a prior exposure to daratumumab.
Conclusion: Large prospective studies are required to further evaluate myeloma outcomes in this setting.
Summary
Central nervous system (CNS) relapse following R‐CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisolone) occurs in 2–5% of patents with diffuse large B‐cell lymphoma ...(DLBCL). Many patients aged ≥70 years are unsuitable for high‐dose methotrexate (HDMTX) prophylaxis and therefore often receive stand‐alone intrathecal prophylaxis. The CNS international prognostic index (CNS‐IPI) is a clinical CNS relapse risk score that has not specifically been validated in elderly patients. The value of CNS prophylaxis in patients aged ≥70 years remains uncertain. Data on 690 consecutively R‐CHOP‐treated DLBCL patients aged ≥70 years were collected across 8 UK centres (2009–2018). CNS prophylaxis was administered per physician preference. Median age was 77·2 years and median follow‐up was 2·8 years. CNS‐IPI was 1–3 in 60·1%, 4 in 23·8%, 5 in 13·0% and 6 in 3·3%. Renal and/or adrenal (R/A) involvement occurred in 8·8%. Two‐year overall CNS relapse incidence was 2·6% and according to CNS‐IPI, 1–3:0·8%, 4:3·6%, 5:3·8% and 6:21·8%. Two‐year CNS relapse incidence for R/A was 10·0%. When excluding HDMTX (n = 31) patients, there remained no change in unadjusted/adjusted CNS relapse for intrathecal prophylaxis effect according to CNS‐IPI. CNS‐IPI is valid in elderly R‐CHOP‐treated DLBCL patients, with the highest risk in those with CNS‐IPI 6 and R/A involvement. We observed no clear benefit for stand‐alone intrathecal prophylaxis but observed an independent increased risk of infection‐related admission during R‐CHOP when intrathecal prophylaxis was administered.
Transformation of chronic lymphocytic leukaemia (CLL) to diffuse large B-cell lymphoma (DLCBL) type Richter's syndrome (RS) carries a dismal prognosis. Standard-of-care chemoimmunotherapy for de novo ...RS is inadequate with median survival of less than one year. Patients are frequently elderly or have co-morbidities limiting dose-intense chemotherapy. Treatment of relapsed/refractory (R/R) RS and RS emerging after CLL-directed therapy represent urgent unmet clinical needs. Agents targeting Bruton's tyrosine kinase (BTK) deliver improved outcomes for patients with high-risk CLL and expand effective treatments to frailer patients. Acalabrutinib is an oral, second-generation BTK inhibitor with a favourable toxicity profile and demonstrated activity in CLL and B-cell lymphomas. Combination of acalabrutinib with standard-of-care CHOP-R chemoimmunotherapy offers a sound rationale to test in a prospective trial for de novo RS.
The prospective multicentre STELLAR study is designed in two elements, consisting of a randomised study to evaluate the safety and activity of CHOP-R chemoimmunotherapy in combination with acalabrutinib in newly diagnosed RS and single-arm studies of novel agents for other RS patient cohorts. Eligible patients with newly diagnosed DLBCL-type RS are randomised between six cycles of CHOP-R therapy and six cycles CHOP-R plus acalabrutinib, followed by acalabrutinib maintenance. The primary endpoint of the randomised component is progression free survival (PFS). Cohort 1 enrols RS patients with progressive disease following chemoimmunotherapy for acalabrutinib monotherapy. Patients with RS diagnosed while on ibrutinib may enrol in Cohort 2, a single-arm study of CHOP-R plus acalabrutinib. The primary endpoint for the single-arm studies is overall response rate (ORR). Secondary endpoints for all cohorts are overall survival (OS), quality of life and proportion of patients proceeding to stem cell transplantation. The study will be accompanied by exploratory analysis of the mutational landscape of RS and the relationship between dynamic changes in sequential circulating tumour DNA samples and clinical outcomes.
The STELLAR randomised trial evaluates the role of CHOP-R plus acalabrutinib in newly diagnosed RS patients. The single-arm platform studies enable the incorporation of promising novel therapies into the protocol. The STELLAR study has potential to identify novel biomarkers of treatment response in this high-risk malignancy.
EudraCT: 2017-004401-40 , registered on the 31-Oct-2017. IRSCTN: https://www.isrctn.com/ISRCTN52839057 , registered on the 04-Mar-2019. ClinicalTrials.gov : NCT03899337 , registered on 02-April-2019.
PDF
