Is now the time for molecular driven therapy for diffuse large B-cell lymphoma?

INTRODUCTION: Recent genetic and molecular discoveries regarding alterations in diffuse large B-cell lymphoma (DLBCL) deeply changed the approach to this lymphoproliferative disorder. Novel additional predictors of outcomes and new therapeutic strategies are being introduced to improve outcomes. Areas covered: This review aims to analyse the recent molecular discoveries in DLBCL, the rationale of novel molecular driven treatments and their impact on DLBCL prognosis, especially in ABC-DLBCL and High Grade B Cell Lymphoma. Pre-clinical and clinical evidences are reviewed to critically evaluate the novel DLBCL management strategies. Expert commentary: New insights in DLBCL molecular characteristics should guide the therapeutic approach; the results of the current studies which are investigating safety and efficacy of novel 'X-RCHOP' will probably lead, in future, to a cell of origin (COO) based upfront therapy. Moreover, it is necessary to identify early patients with DLBCL who carried MYC, BCL2 and/or BCL6 rearrangements double hit lymphomas (DHL) because they should not receive standard R-CHOP but high intensity treatment as reported in many retrospective studies. New prospective trials are needed to investigate the more appropriate treatment of DHL

A multicenter total therapy strategy for de novo adult Philadelphia chromosome positive acute lymphoblastic leukemia patients. Final results of the GIMEMA LAL1509 protocol

The GIMEMA LAL1509 protocol, designed for adult (≥18-60 years) de novo Ph+ acute lymphoblastic leukemia patients, was based on a dasatinib plus steroids induction - with central nervous system prophylaxis - followed by dasatinib alone in patients in complete molecular response or chemotherapy and/or allogeneic transplantation in patients not reaching a complete molecular response. Sixty patients (median age 41.9 years) were enrolled: 33 were p190+, 18 p210+ and 9 p190/p210+. At the end of induction (day +85), 58 patients (97%) achieved a complete hematologic remission. No deaths in induction were recorded. Eleven patients (18.3%) obtained a complete molecular response. Among non-complete molecular responders (n=47), 22 underwent an allogeneic transplant. Seventeen hematologic relapses occurred (median 7 months, range 3-40.1), 13 during consolidation and 4 post-transplant. ABL1 mutations (5 T315I, 3 V299L, 1 E281K and 1 G254E) were found in 10/13 relapsed cases. With a median follow-up of 57.4 months (range: 4.2-75.6), overall survival and disease-free survival are 56.3% and 47.2%. A better diseasefree survival was observed in patients who obtained a molecular response at day +85 compared to cases who did not. The presence of additional copy number aberrations - IKZF1 plus CDKN2A/B and/or PAX5 deletions - was the most important unfavorable prognostic factor on overall and disease-free survival (p=0.005 and p=0.0008). This study shows that in adult Ph+ ALL long-term survivals can be achieved with a total-therapy strategy based on a chemo-free induction and, in complete molecular responders, also without further systemic chemotherapy. Finally, the screening of additional copy number aberrations should be included in the diagnostic work-up. EudraCT 2010-019119-39

Lenalidomide in Pretreated Mantle Cell Lymphoma Patients: An Italian Observational Multicenter Retrospective Study in Daily Clinical Practice (the Lenamant Study)

Background: Mantle cell lymphoma (MCL) has the worst prognosis of B-cell subtypes owing to its aggressive clinical disease course and incurability with standard chemo-immunotherapy. Options for relapsed MCL are limited, although several single agents have been studied. Lenalidomide is available in Italy for patients with MCL based on a local disposition of the Italian Drug Agency. Subjects, Materials, and Methods: An observational retrospective study was conducted in 24 Italian hematology centers with the aim to improve information on effectiveness and safety of lenalidomide use in real practice. Results: Seventy patients received lenalidomide for 21/28 days with a median of eight cycles. At the end of therapy, there were 22 complete responses (31.4%), 11 partial responses, 6 stable diseases, and 31 progressions, with an overall response rate of 47.1%. Eighteen patients (22.9%) received lenalidomide in combination with either dexamethasone (n = 13) or rituximab (n = 5). Median overall survival (OS) was reached at 33 months and median disease-free survival (DFS) at 20 months: 14/22 patients are in continuous complete response with a median of 26 months. Patients who received lenalidomide alone were compared with patients who received lenalidomide in combination: OS and DFS did not differ. Progression-free survivals are significantly different: at 56 months, 36% in the combination group versus 13% in patients who received lenalidomide alone. Toxicities were manageable, even if 17 of them led to an early drug discontinuation. Conclusion: Lenalidomide therapy for relapsed MCL patients is effective and tolerable even in a real-life context. Implication for Practice: Several factors influence treatment choice in relapsed/refractory mantle cell lymphoma (rrMCL), and the therapeutic scenario is continuously evolving. In fact, rrMCL became the first lymphoma for which four novel agents have been approved: temsirolimus, lenalidomide, ibrutinib, and bortezomib. The rrMCL therapeutic algorithm is not so well established because data in the everyday clinical practice are still poor. Lenalidomide for rrMCL patients is effective and tolerable even in a real-life context

Primary mediastinal large B-cell lymphoma

Primary mediastinal large B-cell lymphoma (PMLBCL) is a distinct clinical and biological disease from other types of DLBCL. It is more frequent in young female and constitutes 6%-10% of all DLBCL. PMLBCL is characterized by a diffuse proliferation of medium to large B-cells associated with sclerosis. Molecular analysis shows it to be a distinct entity from other DLBCL. Rituximab CHOP/MACOP-B-like regimens followed by mediastinal radiotherapy (RT) were associated with a 5-years PFS of 75%-85%. More intensive regimens, as DA-EPOCH-R without mediastinal RT, have shown very promising results, but this therapeutic advance needs to be confirmed in further prospective trials. The role of consolidative mediastinal RT should be still better assess in prospective comparative studies. PET-CT scan is a powerful tool to define the real quality of response and it is hoped that future prospective trials may allow its role in the de-escalation of mediastinal RT.</p

CENTRAL NERVOUS SYSTEM (CNS) INVOLVEMENT IN DIFFUSE LARGE B-CELL LYMPHOMA. A SINGLE CENTER ANALYSIS OF THE RISK FACTORS AND THE IMPACT OF CNS PROPHYLAXIS IN THE RITUXIMAB ERA

Background: Central nervous system (CNS) relapse is a serious and generally fatal complication of diffuse large B-cell lymphoma (DLBCL) occurring in almost 5-7% of patients in the pre-rituximab era. The median time from diagnosis to detection of CNS disease is less than 1 year, suggesting that seeding in the CNS occurs early in the course of disease, with the exception of primary testis lymphoma in which it can occur up to 10 years after diagnosis. Up to date, there is no general consensus on how to define high-risk patients and what is the optimal CNS prophylaxis. The addition of rituximab to CHOP chemotherapy (RCHOP) has improved the clinical outcome of DLBCL. Nevertheless, the impact of rituximab on the incidence of CNS complications is still unclear. Aims: This retrospective study aimed to analyze the predictive factors of CNS relapse and the impact of CNS prophylaxis in DLBCL patients treated at our Institute over a 12-years period. and 2014. The patients with all stage of disease, regardless of the IPI score, were eligible and all received RCHOP every 14 or 21 days for at least 4/6 cycles. Patients with HIV or CNS involvement at diagnosis were excluded. Prophylaxis with intrathecal methotrexate (IT-MTX) was administered in patients with a high risk of CNS relapse according to the Italian Society of Hematology’s guidelines. The diagnosis of CNS relapse was based on CT/MRI assessment and/or cerebrospinal fluid cytology. Results: The median age was 58 years (IQR 47-68), 54% were males; 212/393 patients (54%) had stage III-IV, a bone marrow (BM) involvement was found in 51/393 patients (13%), while 49 (12%) had an involvement of more than 1 extranodal site, testis involvement was in 20/393 patients (5%). B symptoms were experienced by 100/393 patients (25%) and an elevated LDH was present in 115/393 patients (29%). According to the IPI score, 197/393 patients (50%) had a IPI2. Twelve/393 patients (3%) experienced a CNS relapse: 7 of them had a brain mass, 2 had a leptomeningeal involvement and 3 had both. CNS prophylaxis was carried out in 81/393 patients (21%): 27 with a IPI2 (p=0.009), presence of B symptoms (p=0.000), elevated LDH (p=0.006), involvement of >1 extranodal sites (p=0.000), BM involvement plus elevated LDH (p=0.003), testis localization (p=0.019) and IPI>=2 (p=0.000) were associated with an increased risk of CNS relapse. At multivariate analysis, only PS>2 (p=0.031, 95%CI: 0.009-0.189), testis involvement (p=0.001, 95%CI: 0.048-0.2) and BM involvement plus elevated LDH (p=0.016, 95%CI: 0.021- 0.2) were predictive factors of high risk of CNS relapse. The 2-year overall survival of the CNS relapsed patients was 9%, with a median follow-up of 8 months from diagnosis (IQR 4-28). Summary/Conclusions: CNS relapse remains a fatal event for patients with DLBCL even in the rituximab era. Poor PS, testis and BM involvement combined relapse. In our experience, single IT-MTX prophylaxis did not reduced CNS

EFFICACY, SAFETY AND COST ANALYSIS OF SUBCUTANEOUS VS INTRAVENOUS RITUXIMAB IN PATIENTS WITH DIFFUSE LARGE B-CELL LYMPHOMA TREATED WITH RCHOP

Introduction: Rituximab (R) in combination with cyclophosphamide, doxorubicin and prednisone (R-CHOP) is the standard of care for patients (pts) with diffuse large B-cell lymphoma (DLBCL). A subcutaneous (sc) formulation that provides a fixed dose of R is being tested in a number of studies. Results indicate that the pharmacokinetics is not inferior and the response rates comparable to those obtained with the intravenous (iv) formulation. In August 2014, the Italian Medicine Agency (AIFA) approved the sc formulation for follicular lymphoma and DLBCL. We performed a retrospective analysis at our Centre in pts with DLBCL treated with RCHOP. The aim was to evaluate the costs of the 2 different formulations of R (sc vs iv) combined with CHOP and the efficacy in terms of complete response (CR) rates and toxicity. Meth- ods: We collected data from 71 consecutive pts with untreated DLBCL who received 6 cycles of RCHOP plus 2 doses of R between January 2014 and January 2016; 35 pts received iv R (375mg/mq) and 36 sc R (1400 mg) from May 2015. We compared the direct costs of the 2 for- mulations of R, the rate of CR and of adverse events (AEs) of the two subgroups of patients. Univariate analysis was used to evaluate efficacy and toxicity. Results: The clinical characteristics were well balanced be- tween the iv and sc RCHOP groups: mean age 61 years in both groups, with a mean BSA of 1.8 (1.4-2.2); IPI score ≥3, 20% vs 30%; Ann Arbor stage III-IV, 62% vs 69%. There was no significant difference in terms of efficacy: the CR rates were 30/35 (85%) and 29/36 (83%), p=0.177, respectively. Grade ≥3 AEs (45% vs 47%) were almost all hematologic (90% in both groups) and the most common AE was grade 3/4 neu- tropenia in both groups. The cost of the treatment was 472.227€ for the iv R group and 449.870€ for sc R group; with a decrease of 4.73% only of the direct costs of R. In addition, the calculated infusion time for the sc RCHOP was 135 min compared to 240 min for the iv RCHOP; this translated into a 44% chair time reduction. Conclusions: In our analysis, the use of a sc formulation of R allowed a gain of 22.357€ in terms of only direct costs compared to the schedule with iv R, with comparable response rates and similar safety profile. Given the shorter delivery time, the sc formulation could also improve pts’ comfort and reduce the burden on health care resources. Finally, the reduction in required chair time allows for a greater number of pts to be treated daily

A 35 year single center transplant experience in chronic myeloid leukemia

Background: Allogeneic hematopoietic stem cell transplantation (HSCT) has been considered for decades the only curative approach for patients with chronic myeloid leukemia (CML). In the tyrosine kinase inhibitors (TKIs) era, HSCT for CML has been reserved only to patients not achieving a cytogenetic remission or showing progressive disease after multiple TKI treatment lines. However, a progressive improvement in the long-term survival has been obtained in the overall HSCT population. The present study aimed at evaluating whether in CML patients transplanted at our Center over a long time period - from 1983 to 2018 - the outcome improved over time. Methods: 136 consecutive patients who underwent a transplant between 1983 and 1999 were compared to 43 patients who received the transplant between 2000 and 2018. Overall survival (OS), leukemia-free survival (LFS) and graft-leukemia-free survival (GLFS) were estimated using the Kaplan-Meier method and the log-rank test was used to compare risk factors categories. Results: Of the 179 patients [median age 35 years (range7-66)], 148 (82.7%) were in 1st or 2nd chronic phase, 25 (13.9%) in accelerated phase and six (3.4%) in blast crisis. Matched related donors and alternative donors (matched unrelated donors, cord blood or mismatched related donors) were used in 156 and 23 cases, respectively. As stem cell source, bone marrow was used in 142 patients, peripheral blood in 33 and umbilical cord blood in 4. TBI- based conditioning regimens were used in 89 patients, while in the other 90 cases irradiation-free conditioning regimens were used. Both in univariate and multivariate analysis, irradiation- free conditioning regimens (HR 1.8; 95%CI 1.1-3.0, p=.0014) and transplants performed in 1st chronic phase (accelerate phase HR 2.1; 95%CI 1.2-3.8, p=.008 - 2nd chronic phase HR 4.9; 95%CI 2.3-10.3, p=.0001 - blast crisis HR 2.5; 95%CI 1.0-6.4, p&lt; .05) were associated with a better OS. Patients transplanted before 2000 had a worse OS (HR 6.5; 95%CI 2.7-15.5, p &lt; .0001) and DFS (HR 2.2; 95%CI 1.0-4.8, p=.045). A trend for a worse GLFS was observed in univariate analysis (HR 1.6; 95%CI 1.0-2.7, p=0.05), in the first period of observation. Conclusions: Our single center experience confirms that higher OS, DFS and GLFS are observed in CML patients allografted in more recent years. Improvement of con- ditioning regimens, use of TBI-free conditioning regimens and supportive therapy, have presumably contributed to these results, together with the more recent strategy of close monitoring of minimal residual disease, and prompt use of TKI or donor lymphocyte infusion in case of relapse. HSCT is nowadays a safer therapeutic procedure in CML patients that should be considered timely in TKI-resistant patients to avoid progression into a more advanced disease phase. Disclosure: The authors declare no conflict of interest

Multiparametric Magnetic Resonance Enterography for the Diagnosis and Staging of Intestinal Acute Graft-Versus-Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation

Background: Intestinal Acute graft-versus-host disease (i-aGVHD) is a major complication of allogeneic hematopoietic stem cell transplantation (HSCT). The clinical diagnosis of i-aGVHD is usually based on symptoms and CT findings but a definite diagnosis is made by endoscopic biopsies. To date, there are few data on the use of magnetic resonance enterography (MRE) in this setting. We hereby investigated the value of MRE in the diagnosis of i-aGVHD. Methods: A retrospective observational study was carried out on 35 patients (16 men, 19 women; age 9-69 years) with hematologic malignancies who underwent a MRE for a suspect of i-aGvHD according to the Glucksberg criteria between 2015 and 2017. MRE examinations were performed with a 1.5 Tesla scanner (Siemens, MagnetomAvanto), equipped with 16-channels phased-array coils. We used a protocol including axial and coronal T2-weighted Half Fourier Acquisition Single Shot Turbo Spin Echo sequences, with and without fat saturation; T2 weighted axial and coronal TrueFISP sequences; DWI (Diffusion Weighted Imaging) sequences with b- values of 0, 500 and 1000; axial and coronal T1 weighted VIBE sequences, before and 70 seconds after the intravenous administration of contrast media (0.1 mmol gadolinium per kilogram of body weight, Gd-DOTA, Dotarem®, Guerbet, Aulnays-sous-Bois, France). In adult patients without contraindications, a 10 ml IV dose of hyoscine butylbromide was administered before contrast injection, in order to reduce motion artefacts. To evaluate the presence and severity of the disease, the following parameters were assessed and qualitatively scored for all intestinal segments (from stomach to rectum): a) MRI inflammation-activity including mural T2 signal (oedema), mesenteric T2 signal (oedema), gadolinium wall enhancement on T1 (vascularity), DWI signal (inflammation); b) morphologic parameters of activity and severity, including maximum wall thickness, increased number and/or size of local mesenteric lymph nodes, comb sign (mesenteric vessels dilation), presence of peritoneal effusion. Results: Out of 35 patients, 21 had a definite histologic diagnosis of i-aGVHD while in the remaining 14 patients i-aGVHD was excluded. The above MRE parameters were observed in 19 out of 21(90.5%) patients with a definite diagnosis of i-aGVHD and in none of the 14 patients in which a diagnosis of i-aGVHD was excluded. A stratified mucosal wall enhancement after gadolinium injection was found in 90% of patients. Parietal enhancement was associated with high-grade oedema of mesenteric fat tissue and comb sign in 76% of cases. In 52.4% of cases, mesenteric lymph nodes were not found. Free intra-peritoneal fluid was observed in 57.2% of patients. The most commonly involved intestinal segments were distal ileum (85.7%), mean ileum (66.6%) and proximal ileum (57.1%), followed by ascending colon and sigmoid equally (38%). Spearman's test showed a statistically significant correlation between clinical stage of i- aGVHD and mural T2 signal, number of involved intestinal segments, wall thickness, T1 enhancement, peritoneal effusion (p &lt; .001). Conclusions: In our experience MRE parameters showed a good correlation with a definite i- aGVHD diagnosed and with the stage of disease. Therefore, in patients with a clinical suspect of i-aGVHD MRE examination may be considered in order to replace endoscopic biopsy to confirm the diagnosis

DROPLET DIGITAL PCR DETECTION OF THE T315I BCR::ABL1 KD MUTATION IN ADULT PH-POSITIVE ACUTE LYMPHOBLASTIC LEUKEMIA

Background: Philadelphia chromosome-positive(Ph+) acutelymphoblastic leukemia (ALL) is characterized by thereciprocal translocation t(9;22)(q34;q11).Theadvent of tyrosinekinaseinhibitors (TKIs) has markedly improved the outcome of Ph+ ALL patients and indeed changed the natural history of the disease. At present,TKIs represent the gold standard treatment for patients with Ph+ ALL, with or without chemotherapy 1 . Despitetheefficacy of targeted therapy with TKIs, some patients show drug resistance dueto the onset of BCR::ABL1 kinase domain (KD) point mutations. In particular, the most deleterious oneis represented by theT315I, which causetreatment failure with firstand second generation TKI-based therapies.Sanger sequencing (SS) is the gold standard tool for BCR::ABL1 KD mutational screening.The digital droplet PCR (ddPCR) technology,a third generation PCR, may representa valid alternativeto SS for the detection of BCR::ABL1 KD mutations. Aims: Theaim of this study was to evaluateif ddPCR is at leastas sensitiveas SS for the detection of theT315I mutation, and if the ddPCR can detect the mutation also atvery low levels of minimal residual disease(MRD), ultimately anticipating molecular relapse. Methods: Thestudy comprised samples from patients enrolled in the phaseII GIMEMA LAL2116 chemotherapy-free protocol for newly diagnosed adult Ph+ ALL and based on theadministration of thesecond generation TKI dasatinib followed by the bispecific monoclonal antibody blinatumomab 2 . A BCR::ABL1 KD mutational screening was carried out in all patients with a MRD increase by both SS and ddPCR. In mutation-positive patients, thetimepoint (TP) preceding the MRD increase was evaluated by ddPCR to assess theearlier presence of the mutation. DdPCR was performed as described 3 . Results: Wecarried outa BCR::ABL1 KD mutational screening by SS in 16 patients enrolled in the GIMEMA LAL2116 protocol. Overall, of the 16 patients with a MRD increase(10 during theinduction phase, 6 in theconsolidation phase), 8 resulted wild type(WT) while mutations were detected in 8 patients (7 harboring theT315I mutation and 1 theE255K). In theT315I positive patients, theevaluation by ddPCR of thesameTP samples,confirmed in all cases the presence of the mutation. Moreimportantly, theanalysis ata previous TP, when MRD levels werelower, showed that ddPCR could detect theT315I BCR::ABL1 KD mutation in 6/7 cases, while 1 positive non-quantifiable (PNQ) case proved WT(Table 1). In order to determineif ddPCR could anticipatethe detection of mutations compared to SS, the previous TPs werealso evaluated by SS in 4 cases with available material. In 2 cases the mutation was detected also by SS, whilein 2 it could not befound (Table 1).Likewise, ddPCR for theT315I mutation was also performed in samples that proved negative by SS,and theabsence of mutations was confirmed; this is particularly relevant from a clinical standpointand was corroborated by thefact that only 1/8 experienced a central nervous system relapsein this last cohort,and is currently alivein second complete remission (CR). Summary/Conclusion:The ddPCR proved as reliableand accurateas SS to detect theT315I BCR::ABL1 KD mutation.Furthermore, the ddPCR proved to be moresensitivefor predict molecular relapse beforetheincrease in MRD where, in somecases, theSS failed to detect theT315I mutation.Further efforts are ongoing to expand this screening also to other ABL1 mutations,considering thealways morefrequent use of ponatinib in thefirst-line setting. 1.Foà &amp; Chiaretti, NEJM 2022 2.Foà et al, NEJM 2020 3.Soverini et al,Leukemia 202

Short-course R-CHOP followed by 90Y-Ibritumomab tiuxetan in previously untreated high-risk elderly diffuse large B-cell lymphoma patients: 7-year long-term results

An update at 7 years was conceived for our multicenter phase II study in which 55 elderly high-risk untreated diffuse large B-cell lymphoma patients were treated with (90)Y-ibritumomab tiuxetan after a short course of rituximab, cyclophosphamide, doxorubicin, vincristine and prednisolone (R-CHOP) as long-term follow-up analyses of this combined therapeutic modality are lacking. The overall response rate to the entire regimen was 80%, including 73% (40/55) of complete response (CR) rate and 7% (4/55) of partial response rate. At the time of writing, 24/55 (43.6%) patients experienced a progression disease and 20 of 40 (50%) patients who obtained a CR are still alive in continuous CR. With a median follow-up of 7 years, the disease-free survival was 43.3% and the progression-free survival was 36.1%. The overall survival at 7.9 years was 38.9% (27 deaths mainly because of lymphoma). Two patients developed secondary hematological malignancies, an acute myeloid leukemia and a myelodysplastic syndrome, at 4 and 3 years from radioimmunotherapy, respectively. Our data confirm the feasibility, efficacy and safety of four cycles of R-CHOP followed by radioimmunotherapy consolidation even in the long term: this combination allows dispensing less chemotherapy in a frail group of patients without invalidating response quality and duration