DYNAMO: A Phase II Study of Duvelisib (IPI-145) in Patients With Refractory Indolent Non-Hodgkin Lymphoma

Recent updates in the indolent lymphomas: Update on marginal zone lymphoma and Waldenström's macroglobulinemia

Marginal Zone Lymphoma (MZL) and Waldenström's Macroglobulinemia (WM) are indolent lymphomas that both arise from post germinal center lymphocytes. Both can secrete a monoclonal protein but high levels are mostly only seen in WM. The MYD88 L256P somatic mutation that is present in an estimated 95% of patients with WM has helped greatly in differentiating the two lymphomas. Several large clinical studies with new drugs have been performed that have provided new treatment options for both MZL and WM patients. In this short review we will discuss the recent literature published and provide some recommendations.

Follicular lymphoma research: an open dialogue for a collaborative roadmap

Follicular lymphoma (FL) is the second most common type of lymphoma (20% of all non-Hodgkin lymphomas), derived from germinal centre (GC) B cells, and is characterised by its significant clinical, prognostic and biological heterogeneity, leading to complexity in management. Despite significant biological investigation and indisputable clinical progress since the advent of the immunotherapy era more than 20 years ago, much remains to be done to understand and cure this lymphoma. Today, FL is metaphorically a giant puzzle on the table with patches of sky, landscape and foliage clearly appearing. However, many of the remaining pieces are held by various stakeholders (e.g. clinicians, pathologists, researchers, drug developers) without global agreement on what the gaps are, or any clear blueprint on how to solve the puzzle of understanding the heterogeneity of this disease and create curative and tailored therapies. With the advent of new investigation and drug technologies, together with recent advances in our capacity to manage big data, the time seems ripe for a change of scale. More than ever, this will require collaboration between and within all stakeholders to overcome the current bottlenecks in the field. As for every investigator, we acknowledge that this first draft is necessarily biased, incomplete and some FL expert readers might recognise some remaining gaps not addressed. We hope they will reply to make this effort a collaborative one to assemble all the pieces in the most ideal fashion. As such, this review intends to be a first step and an interactive platform to a collaborative roadmap towards better understanding and care of FL.

CHRONOS-4: phase 3 study of copanlisib plus rituximab-based immunochemotherapy in relapsed indolent B-cell lymphoma

ABSTRACT

Copanlisib, a pan-class I phosphatidylinositol 3-kinase inhibitor with predominant activity against the α and δ isoforms, previously demonstrated durable responses as monotherapy and improved progression-free survival (PFS) in combination with rituximab in patients with relapsed indolent non-Hodgkin lymphoma (iNHL). CHRONOS-4 was a phase 3, randomized, double-blind, placebo-controlled study to investigate the efficacy and safety of copanlisib in combination with standard immunochemotherapy in patients with relapsed iNHL. Patients (n = 524) were randomized (1:1) to copanlisib (60 mg IV) plus immunochemotherapy (rituximab and bendamustine [R-B] or placebo plus R-B). Copanlisib/placebo were administered with R-B (days 1, 8, and 15 of each 28-day cycle) for ≤6 cycles and as monotherapy from cycle 7 up to 12 months. The primary study end point was PFS. Median exposure was 8.5 months (0.2-12.9) for copanlisib plus R-B and 11.4 months (0.1-12.6) for placebo plus R-B. Median PFS was 32.9 months (95% confidence interval [CI], 24.4-38.6) for copanlisib plus R-B and 33.3 months (95% CI, 27.8-42.8) for placebo plus R-B (hazard ratio, 1.13; 95% CI, 0.88-1.44; P = .83). No differences between treatment arms were observed in overall survival (data not yet mature), objective response rate, and duration of response for the overall population or individual histology types. Overall, copanlisib plus R-B was associated with higher rates of serious treatment-emergent adverse events (TEAEs), grade 4 and 5 TEAEs, and treatment discontinuation. A number of serious TEAEs were infections. Overall, copanlisib plus R-B did not provide clinical benefit vs placebo plus R-B and was associated with worse tolerability in patients with relapsed iNHL. This trial was registered at www.ClinicalTrials.gov as #NCT02626455.

PI3K Inhibitors in Hematology: When One Door Closes…

The PI3K signaling pathway regulates key cellular processes and is one of the most aberrantly activated pathways in cancer. The class I PI3K catalytic subunits p110γ and p110δ are highly enriched in leukocytes, providing an additional rationale for targeting these PI3Ks in hematologic malignancies. In 2014, the PI3Kδ inhibitor idelalisib was the first of four PI3K inhibitors (PI3Ki) to receive regulatory approval for relapsed B-cell malignancies. This was followed by approvals of the pan-class I inhibitor copanlisib (2017), the dual PI3Kγ/δ inhibitor duvelisib (2018), and the PI3Kδ and casein kinase 1ε inhibitor umbralisib (2021). Copanlisib and umbralisib received accelerated approvals, whereas idelalisib and duvelisib received initial accelerated approvals followed by full approvals. The accelerated approvals were based on overall response rates; however, follow-up studies showed increased risk of death and serious side effects. Furthermore, the confirmatory trial with copanlisib failed to show an improvement in progression-free survival when compared with chemoimmunotherapy. These developments led to black box warnings for idelalisib and duvelisib and withdrawal of copanlisib and umbralisib from the market by their manufacturers. Given the uncertain future of this drug class, additional manufacturers terminated ongoing phase III trials with novel PI3Kis. In this study, we review the development and current status of PI3Kis in hematology, limitations to their use, and our perspective on whether there is a future for PI3Kis in hematology.

Duvelisib plus romidepsin in relapsed/refractory T cell lymphomas: a phase 1b/2a trial

PI3K-δ inhibitors have shown impressive activity in lymphoid malignancies but have been hampered by autoimmune and infectious toxicities, leading to market withdrawals. We previously demonstrated activity of the PI3K-δγ inhibitor duvelisib in T cell lymphomas (TCLs) that was associated with inflammatory adverse events. As reported here, we conducted a phase 1b/2a study of duvelisib in combination with either romidepsin (n = 66) or bortezomib (n = 32) in patients with relapsed/refractory TCL and found that the addition of romidepsin, but not bortezomib, appeared to increase efficacy while attenuating PI3K inhibitor-driven toxicity. The primary endpoint of the study was to determine the safety and maximum tolerated dose of duvelisib, which was 75 mg twice daily when combined with romidepsin versus 25 mg twice daily when combined with bortezomib. The most common adverse events were neutropenia (42%, 25/59) and fatigue (37%, 22/59) in patients treated with duvelisib and romidepsin and diarrhea (48%, 11/23) and neutropenia (30%, 7/23) in patients treated with duvelisib and bortezomib. Duvelisib and romidepsin resulted in less grade 3/4 hepatotoxicity (14%, 8/59) compared to 40% (14/35) in our previous study with duvelisib monotherapy. This was associated with reductions in circulating inflammatory mediators and myeloid cell inflammatory gene expression. Secondary endpoints of overall and complete response rates were 55% (35/64) and 34% (22/64) for patients treated with duvelisib and romidepsin and 34% (11/32) and 13% (4/32) for patients treated with duvelisib and bortezomib. Among patients with peripheral T cell lymphomas (PTCLs), overall and complete response rates of duvelisib and romidepsin were 56% (27/48) and 44% (21/48), respectively, with exploratory analyses showing increased response rates in patients with a follicular helper T cell subtype. These findings support further development of combined PI3K and histone deacetylase (HDAC) inhibition in TCLs and suggest a unique strategy to enable PI3K inhibitor-based combinations for additional patient populations. ClinicalTrials.gov identifier: NCT02783625 .

The Therapeutic Mechanisms of Honey in Mitigating Toxicity from Anticancer Chemotherapy Toxicity: A Review

Within the domain of conventional oncochemotherapeutics, anticancer chemotherapy (AC) has emerged as a potent strategy for the treatment of cancers. AC is the mainstay strategy for solid and non-solid cancer treatment. Its mechanistic action targets the blockage of DNA transcription and the dysregulation of cell cycle machinery in cancer cells, leading to the activation of death pathways. However, the attendant side effect of toxicity inflicted by AC on healthy tissues presents a formidable challenge. The crucial culprit in the AC side effect of toxicity is unknown, although oxidative stress, mitochondrial impairment, inflammatory cascades, autophagy dysregulation, apoptosis, and certain aberrant signaling have been implicated. Honey is a natural bee product with significant health benefits and pharmacological properties. Interestingly, the literature reports that honey may proffer a protection mechanism for delicate tissue/organs against the side effect of toxicity from AC. Thus, this review delves into the prospective role of honey as an alleviator of the AC side effect of toxicity; it provides an elucidation of the mechanisms of AC toxicity and honey's molecular mechanisms of mitigation. The review endeavors to unravel the specific molecular cascades by which honey orchestrates its mitigating effects, with the overarching objective of refining its application as an adjuvant natural product. Honey supplementation prevents AC toxicity via the inhibition of oxidative stress, NF-κB-mediated inflammation, and caspase-dependent apoptosis cascades. Although there is a need for increased mechanistic studies, honey is a natural product that could mitigate the various toxicities induced by AC.

Targeting PI3K family with small-molecule inhibitors in cancer therapy: current clinical status and future directions

The Phosphatidylinositol-3-kinase (PI3K) family is well-known to comprise three classes of intracellular enzymes. Class I PI3Ks primarily function in signaling by responding to cell surface receptor stimulation, while class II and III are more involved in membrane transport. Under normal physiological conditions, the PI3K signaling network orchestrates cell growth, division, migration and survival. Aberrant activation of the PI3K signaling pathway disrupts cellular activity and metabolism, often marking the onset of cancer. Currently, the Food and Drug Administration (FDA) has approved the clinical use of five class I PI3K inhibitors. These small-molecule inhibitors, which exhibit varying selectivity for different class I PI3K family members, are primarily used in the treatment of breast cancer and hematologic malignancies. Therefore, the development of novel class I PI3K inhibitors has been a prominent research focus in the field of oncology, aiming to enhance potential therapeutic selectivity and effectiveness. In this review, we summarize the specific structures of PI3Ks and their functional roles in cancer progression. Additionally, we critically evaluate small molecule inhibitors that target class I PI3K, with a particular focus on their clinical applications in cancer treatment. Moreover, we aim to analyze therapeutic approaches for different types of cancers marked by aberrant PI3K activation and to identify potential molecular targets amenable to intervention with small-molecule inhibitors. Ultimately, we propose future directions for the development of therapeutic strategies that optimize cancer treatment outcomes by modulating the PI3K family.

The PI3Kδ inhibitor zandelisib on intermittent dosing in relapsed/refractory follicular lymphoma: Results from a global phase 2 study

In this global phase 2 study in patients with relapsed/refractory follicular lymphoma (FL), zandelisib was administered on intermittent dosing to mitigate immune-related adverse events and infections that have been reported with oral PI3Kδ inhibitors administered daily continuously. Eligible patients with measurable disease and progression after at least two prior therapies were administered zandelisib until disease progression or intolerability. The primary efficacy endpoint was objective response rate (ORR) and the key secondary efficacy endpoint was duration of response (DOR). We report on 121 patients with FL administered zandelisib on intermittent dosing after 8 weeks of daily dosing for tumor debulking. The median number of prior therapies was 3 (range, 2-8) and 45% of patients had refractory disease. The ORR was 73% (95% confidence interval [CI], 63.9-80.4), the complete response (CR) rate was 38% (95% CI, 29.3-47.3), and the median DOR was 16.4 months (95% CI, 9.5-not reached). With a median follow-up of 14.3 months (range, 1-30.5), the median progression-free survival was 11.6 months (95% CI, 8.3-not reached). Twenty-one patients (17%) discontinued therapy due to an adverse event. Grade 3-4 class-related toxicities included 6% diarrhea, 5% lung infections, 3% colitis (confirmed by biopsy or imaging), 3% rash, 2% AST elevation, and 1% non-infectious pneumonitis. Zandelisib achieved a high rate of durable responses in heavily pretreated patients with relapsed/refractory FL. The intermittent dosing resulted in a relatively low incidence of severe class-related toxicities, which supports the evaluation of zandelisib as a single agent and in combination with indolent B-cell malignancies.

Efficacy and safety of MIL62, a novel glycoengineered type Ⅱ anti-CD20 monoclonal antibody, combined with lenalidomide in patients with relapsed/refractory follicular lymphoma or marginal zone lymphoma: a multicentre, single-arm, phase 1b/2 trial

Background

MIL62, a novel glycoengineered type Ⅱ anti-CD20 monoclonal antibody, with a nearly completely afucosylated N-glycans in Fc region, has demonstrated superior activity compared with rituximab and obinutuzumab in vitro and in vivo, respectively.

Methods

This multicentre, single-arm, phase 1b/2 trial aimed to explore the efficacy, pharmacokinetics, and safety of MIL62 combined with lenalidomide in patients with relapsed/refractory (R/R) follicular lymphoma (FL) or marginal zone lymphoma (MZL). Eligible patients included those who had histopathologically confirmed CD20 positive FL (grade 1-3a) or MZL and failed to be treated with rituximab. Patients received intravenously infused MIL62 1000 mg (cycle 1: day 1, 15; cycles 2-8: day 1, cycles 10 and 12: day 1) combined with oral lenalidomide (once a day, days 2-22, the initial dose was 10 mg, and the maximum dose was 20 mg) for 12 cycles, 28 days as a cycle. The primary endpoint was objective response rate (ORR) assessed by investigator per Lugano 2014 criteria every 3 cycles. This study was registered in ClinicalTrials.gov (NCT04110301).

Findings

Between November 22, 2019 and December 22, 2020, 54 patients were enrolled from 11 hospitals in China and received study treatment. Fifty patients were included in the efficacy analysis set, and 43 patients (86%, 95% CI: 73, 94) achieved objective response, meeting the pre-specified primary endpoint. Disease control rate was 96% (48/50, 95% CI: 86, 100), proportion of patients with duration of response (DoR) > 6 months was 77% (33/43). The median follow-up for survival was 12.3 months (IQR 12.0-12.6). The 1-year progression-free survival rate was 72% (95% CI: 57, 83), 9-month DoR rate was 74% (95% CI: 58, 85), and 1-year overall survival rate was 98% (95% CI: 85, 100). Most common TRAEs were neutropenia (93%, 50/54), leukopenia (85% 46/54), thrombocytopenia (61% 33/54), lymphopenia (32% 17/54), and alanine aminotransferase increased (20% 11/54).

Interpretation

MIL62 combined with lenalidomide showed promising efficacy in patients with R/R FL and MZL. A multicentre, randomized, open-label, phase Ⅲ trial of MIL62 combined with lenalidomide versus lenalidomide in anti-CD20 monoclonal antibody refractory FL patients is ongoing (NCT04834024).

Funding

Beijing Mabworks Biotech Co. Ltd, Beijing China and the National Science and Technology Major Project for Key New Drug Development (2017ZX09304015).

Safety and efficacy of parsaclisib in combination with rituximab, bendamustine + rituximab, or ibrutinib in patients with previously treated B-cell lymphoma: analysis of a phase 1 dose-finding study (CITADEL‑112)

Parsaclisib, a potent and highly selective phosphoinositide 3-kinase δ inhibitor, has shown clinical activity in relapsed/refractory (R/R) B-cell lymphoma. The phase 1 CITADEL-112 (NCT03424122) study assessed safety and efficacy of parsaclisib in combination with investigator choice standard of care (SOC; rituximab [Treatment A], rituximab plus bendamustine [Treatment B], or ibrutinib [Treatment C]) in 50 patients with R/R B-cell lymphoma. The most common treatment-emergent adverse events included neutropenia (62.5%, 50.0%, and 50.0% of patients in Treatments A, B, and C, respectively); diarrhea (37.5%) and anemia (31.3%) in Treatment A; abdominal pain, asthenia, diarrhea, and nausea (each 33.3%) in Treatment B; and increased alanine and aspartate aminotransferase (each 37.5%) in Treatment C. Objective responses were observed in 13 patients (81.3%) in Treatment A, 10 (55.6%) in Treatment B, and 8 (50.0%) in Treatment C. Parsaclisib combined with SOC therapies had an expected safety profile and promising efficacy in patients with R/R B-cell lymphomas.

Durable response after tisagenlecleucel in adults with relapsed/refractory follicular lymphoma: ELARA trial update

ABSTRACT

Tisagenlecleucel is approved for adults with relapsed/refractory (r/r) follicular lymphoma (FL) in the third- or later-line setting. The primary analysis (median follow-up, 17 months) of the phase 2 ELARA trial reported high response rates and excellent safety profile in patients with extensively pretreated r/r FL. Here, we report longer-term efficacy, safety, pharmacokinetic, and exploratory biomarker analyses after median follow-up of 29 months (interquartile range, 22.2-37.7). As of 29 March 2022, 97 patients with r/r FL (grades 1-3A) received tisagenlecleucel infusion (0.6 × 108-6 × 108 chimeric antigen receptor-positive viable T cells). Bridging chemotherapy was allowed. Baseline clinical factors, tumor microenvironment, blood soluble factors, and circulating blood cells were correlated with clinical response. Cellular kinetics were assessed by quantitative polymerase chain reaction. Median progression-free survival (PFS), duration of response (DOR), and overall survival (OS) were not reached. Estimated 24-month PFS, DOR, and OS rates in all patients were 57.4% (95% confidence interval [CI], 46.2-67), 66.4% (95% CI, 54.3-76), and 87.7% (95% CI, 78.3-93.2), respectively. Complete response rate and overall response rate were 68.1% (95% CI, 57.7-77.3) and 86.2% (95% CI, 77.5-92.4), respectively. No new safety signals or treatment-related deaths were reported. Low levels of tumor-infiltrating LAG3+CD3+ exhausted T cells and higher baseline levels of naïve CD8+ T cells were associated with improved outcomes. Tisagenlecleucel continued to demonstrate highly durable efficacy and a favorable safety profile in this extended follow-up of 29 months in patients with r/r FL enrolled in ELARA. This trial was registered at www.clinicaltrials.gov as #NCT03568461.

Phase II study of novel orally PI3Kα/δ inhibitor TQ-B3525 in relapsed and/or refractory follicular lymphoma

This registration study assessed clinical outcomes of TQ-B3525, the dual phosphatidylinositol-3-kinase (PI3K) α/δ inhibitor, in relapsed and/or refractory follicular lymphoma (R/R FL). This phase II study (ClinicalTrials.gov NCT04324879. Registered March 27, 2020) comprised run-in stage and stage 2. R/R FL patients after ≥2 lines therapies received oral 20 mg TQ-B3525 once daily in a 28-day cycle until intolerable toxicity or disease progression. Primary endpoint was independent review committee (IRC)-assessed objective response rate (ORR). Based on results (ORR, 88.0%; duration of response [DOR], 11.8 months; progression-free survival [PFS], 12.0 months) in 25 patients at run-in stage, second stage study was initiated and included 82 patients for efficacy/safety analysis. Patients received prior-line (median, 3) therapies, with 56.1% refractory to previous last therapies; 73.2% experienced POD24 at baseline. At stage 2, ORR was 86.6% (71/82; 95% CI, 77.3-93.1%), with 28 (34.2%) complete responses. Disease control rate was 95.1% due to 7 (8.5%) stable diseases. Median time to response was 1.8 months. Among 71 responders, median DOR was not reached; 18-month DOR rate was 51.6%. with median follow-up of 13.3 months, median PFS was 18.5 (95% CI, 10.2-not estimable) months. Median overall survival (OS) was not reached by cutoff date; 24-month OS rate was estimated as 86.1%. Response rates and survival data were consistent across all subgroups. Grade 3 or higher treatment-related adverse events were observed in 63 (76.8%) cases, with neutropenia (22.0%), hyperglycemia (19.5%), and diarrhea (13.4%) being common. TQ-B3525 showed favorable efficacy and safety for R/R FL patients after ≥2 lines prior therapies.

A phase 2 study of the PI3Kδ inhibitor parsaclisib in relapsed and refractory marginal zone lymphoma (CITADEL-204)

ABSTRACT

Parsaclisib, a potent and highly selective PI3Kδ inhibitor, has shown clinical benefit in patients with relapsed or refractory (R/R) B-cell lymphomas. The phase 2 CITADEL-204 study (NCT03144674, EudraCT 2017-000970-12) assessed efficacy and safety of parsaclisib in Bruton tyrosine kinase (BTK) inhibitor-experienced (cohort 1) or BTK inhibitor-naive (cohort 2) patients with R/R marginal zone lymphoma (MZL). Patients aged ≥18 years with histologically confirmed R/R MZL, treated with ≥1 prior systemic therapy (including ≥1 anti-CD20 antibody) received parsaclisib 20 mg once daily for 8 weeks then 20 mg once weekly (weekly dosing group [WG]) or parsaclisib 20 mg once daily for 8 weeks then 2.5 mg once daily (daily dosing group [DG]); DG was selected for further assessment. Primary end point of the study was objective response rate (ORR). Owing to slower than expected recruitment, cohort 1 was closed with 10 patients (WG, n = 4; DG, n = 6) enrolled. Based on a planned interim analysis in cohort 2, the futility boundary was not crossed, and enrollment continued to study completion. At data cutoff (15 January 2021), 100 patients were enrolled and treated in cohort 2 (WG, n = 28; DG, n = 72). In the DG, the ORR was 58.3% (95% confidence interval [CI], 46.1-69.8), with a complete response rate of 4.2% (95% CI, 0.9-11.7); the lower bound of the ORR 95% CI exceeded the protocol-defined threshold of 40%. The median duration of response was 12.2 months (95% CI, 8.1-17.5) and progression-free survival was 16.5 months (95% CI, 11.5-20.6); median overall survival was not reached. The most common treatment-emergent adverse events (TEAEs) among all patients were diarrhea (47.0%), cough (23.0%), and rash (18.0%); the most common grade ≥3 TEAEs included diarrhea (12.0%), neutropenia, and pneumonia (9.0% each). TEAEs led to dose interruptions, reductions, and discontinuations in 56.0%, 16.0%, and 29.0% of all patients, respectively. Durable responses and an overall manageable safety profile were demonstrated in patients with R/R MZL treated with parsaclisib monotherapy.

Molecular Targeting of the Phosphoinositide-3-Protein Kinase (PI3K) Pathway across Various Cancers

The dysregulation of the phosphatidylinositol-3-kinase (PI3K) pathway can lead to uncontrolled cellular growth and tumorigenesis. Targeting PI3K and its downstream substrates has been shown to be effective in preclinical studies and phase III trials with the approval of several PI3K pathway inhibitors by the Food and Drug Administration (FDA) over the past decade. However, the limited clinical efficacy of these inhibitors, intolerable toxicities, and acquired resistances limit the clinical application of PI3K inhibitors. This review discusses the PI3K signaling pathway, alterations in the PI3K pathway causing carcinogenesis, current and novel PI3K pathway inhibitors, adverse effects, resistance mechanisms, challenging issues, and future directions of PI3K pathway inhibitors.

Indirect Treatment Comparisons of Mosunetuzumab With Third- and Later-Line Treatments for Relapsed/Refractory Follicular Lymphoma

BACKGROUND

No established standard of care exists for relapsed/refractory (RR) follicular lymphoma (FL) after ≥2 prior therapies. We conducted indirect treatment comparisons (ITCs) to compare the efficacy and tolerability of mosunetuzumab with those of available treatments used in this setting.

METHODS

A systematic literature review (SLR) and subsequent feasibility assessments were conducted to identify the most suitable comparator studies in terms of design, available endpoints and populations. Imbalances in patient characteristics between NCT02500407 and studies featuring aggregate or patient-level data availability were accounted for using matching-adjusted indirect comparison (MAIC) and propensity score-based methodologies, respectively.

RESULTS

ZUMA-5, ELARA, DELTA, DYNAMO, UNITY-NHL, AUGMENT and NCT01897571 passed the MAIC feasibility assessment. Patient-level data were available from GADOLIN, CONTRALTO and NCT02257567. MAIC results generally favored mosunetuzumab over tazemetostat in EHZ2wild-type patients for all outcomes and over PI3K inhibitors for complete response (CR), objective response rate (ORR), discontinuations due to adverse events and progression-free survival (PFS) with umbralisib. MAICs favored CART therapies for PFS and, to a lesser extent, ORR and CR. Comparisons with anti-CD20 antibody-based regimens yielded mixed results.

CONCLUSIONS

ITCs suggest that mosunetuzumab may lead to superior outcomes over tazemetostat (in EHZ2wild-type patients) and PI3K inhibitors and may be a promising alternative to re-challenging with a different anti-CD20 regimen in patients who relapse after ≥2 prior anti-CD20 lines. Although preliminary results somewhat favored CART therapies, limitations and uncertainties remain because of intrinsic differences in study design. Mosunetuzumab could thus be a promising treatment option for patients with RR FL after ≥2 prior therapies.

Synthesis and application of small molecules approved for the treatment of lymphoma

Lymphoma is a form of cancer that impacts the lymphatic system, which plays a crucial role in defending the body against infections and illnesses. It is characterized by the atypical proliferation of lymphocytes, a type of white blood cell, which can form tumors in the lymph nodes, bone marrow, spleen, etc. Lymphoma is usually treated using a combination of targeted therapy, chemotherapy, and radiation therapy. In recent years, there has been a growing interest in the development of new drugs to treat lymphoma, which has led to the discovery of several promising compounds. The primary targets for lymphoma treatment have been identified as Bruton's tyrosine kinase (BTK), phosphoinositide3-kinase (PI3K), histone deacetylase (HDAC), and DNA polymerase (POLA). This review aims to provide an overview of the clinical applications and synthesis of several notable drugs approved to treat lymphoma, to expedite the exploration of more potent novel medications for the management of lymphoma.

Inhibitors of phosphoinositide 3-kinase (PI3K) and phosphoinositide 3-kinase-related protein kinase family (PIKK)

Phosphoinositide 3-kinases (PI3K) and phosphoinositide 3-kinase-related protein kinases (PIKK) are two structurally related families of kinases that play vital roles in cell growth and DNA damage repair. Dysfunction of PIKK members and aberrant stimulation of the PI3K/AKT/mTOR signalling pathway are linked to a plethora of diseases including cancer. In recent decades, numerous inhibitors related to the PI3K/AKT/mTOR signalling have made great strides in cancer treatment, like copanlisib and sirolimus. Notably, most of the PIKK inhibitors (such as VX-970 and M3814) related to DNA damage response have also shown good efficacy in clinical trials. However, these drugs still require a suitable combination therapy to overcome drug resistance or improve antitumor activity. Based on the aforementioned facts, we summarised the efficacy of PIKK, PI3K, and AKT inhibitors in the therapy of human malignancies and the resistance mechanisms of targeted therapy, in order to provide deeper insights into cancer treatment.

Systematical Evaluation of the Structure-Cardiotoxicity Relationship of 7-Azaindazole-based PI3K Inhibitors Designed by Bioisosteric Approach

A growing concern of cardiotoxicity induced by PI3K inhibitors has raised the requirements to evaluate the structure-cardiotoxicity relationship (SCR) in the development process of novel inhibitors. Based on three bioisosteric 7-azaindazole-based candidate inhibitors namely FD269, FD268 and FD274 that give same order of inhibitory concentration 50% (IC50) magnitude against PI3Ks, in this work, we proposed to systematically evaluate the SCR of 7-azaindazole-based PI3K inhibitors designed by bioisosteric approach. The 24-h lethal concentrations 50% (LC50) of FD269, FD268 and FD274 against zebrafish embryos were 0.35, 4.82 and above 50 μM (not detected), respectively. Determination of the heart rate, pericardial and yolk-sac areas and vascular malformation confirmed the remarkable reduction in the cardiotoxicity of from FD269 to FD268 and to FD274. The IC50s of all three compounds against the hERG channel were tested on the CHO cell line that constitutively expressing hERG channel, which were all higher than 20 μM. The transcriptomic analysis revealed that FD269 and FD268 induced the up-regulation of noxo1b, which encodes a subunit of an NADPH oxidase evoking the oxidative stress. Furthermore, immunohistochemistry tests confirmed the structure-dependent attenuation of the overproduction of ROS and cardiac apoptosis. Our results verified the feasibility of bioisosteric replacement to attenuate the cardiotoxicity of 7-azaindazole-based PI3K inhibitors, suggesting that the screening for PI3K inhibitors with both high potency and low cardiotoxicity from bioisosteres would be a beneficial trial.

Point-of-care anti-CD19 chimeric antigen receptor T-cell therapy for relapsed/refractory follicular lymphoma

Patients with relapsed/refractory follicular lymphoma (R/R-FL) often require multiple treatment lines. We performed a phase 1b/2 single-center clinical trial of autologous point-of-care anti-CD19 chimeric antigen receptor (CAR) T-cells in R/R-FL patients treated patients with ≥ 2 treatment lines. All 26 patients enrolled received CAR T-cell infusion at a median of 11 days after leukapheresis. Seventy-seven percent of patients had POD24. At enrollment, disease stage was III-IV in 85% of the patients, 77% had high-risk FLIPI score, and 77% had progressive disease. Grade III-IV cytokine release and immune effector cell-associated neurotoxicity syndromes occurred in 12% and 16% of the patients, respectively. Overall response rate at 1-month was 88%. The median follow-up was 15.4 months. One-year overall and progression-free survival were 100% and 63%, respectively. In conclusion, point-of-care CAR T-cell, manufactured within 11 days, induced a high response rate with an acceptable safety profile in patients with high-risk R/R-FL.

ROSEWOOD: A Phase II Randomized Study of Zanubrutinib Plus Obinutuzumab Versus Obinutuzumab Monotherapy in Patients With Relapsed or Refractory Follicular Lymphoma

PURPOSE

The combination of zanubrutinib plus obinutuzumab (ZO) was found to be well tolerated with an early signal of efficacy in a phase Ib study. ROSEWOOD is a phase II, randomized study that assessed the efficacy and safety of ZO versus obinutuzumab in patients with relapsed/refractory (R/R) follicular lymphoma (FL).

METHODS

Patients with R/R FL who had received ≥2 lines of therapy, including an anti-CD20 antibody and an alkylating agent, were randomly assigned 2:1 to receive ZO or obinutuzumab (O). The primary end point was overall response rate (ORR) by independent central review (ICR). Secondary end points included duration of response (DOR), progression-free survival (PFS), overall survival, and safety.

RESULTS

A total of 217 patients were randomized (ZO, 145; O, 72). Median study follow-up was 20.2 months. The study met its primary end point: ORR by ICR was 69% (ZO) versus 46% (O; P = .001). Complete response rate was 39% (ZO) versus 19% (O); 18-month DOR rate was 69% (ZO) versus 42% (O). Median PFS was 28.0 months (ZO) versus 10.4 months (O; hazard ratio, 0.50 [95% CI, 0.33 to 0.75]; P < .001). The most common adverse events with ZO were thrombocytopenia, neutropenia, diarrhea, and fatigue; incidences of atrial fibrillation and major hemorrhage were 3% and 1%, respectively.

CONCLUSION

The combination of ZO met its primary end point of a superior ORR versus O, and demonstrated meaningful activity and a manageable safety profile in patients with R/R FL. ZO had a favorable benefit-risk profile compared with O, and represents a potential combination therapy for patients with R/R FL.

Anti-tumor activity of selinexor in combination with antineoplastic agents in chronic lymphocytic leukemia

Despite recent relevant therapeutic progresses, chronic lymphocytic leukemia (CLL) remains an incurable disease. Selinexor, an oral inhibitor of the nuclear export protein XPO1, is active as single agent in different hematologic malignancies, including CLL. The purpose of this study was to evaluate the anti-tumor effects of selinexor, used in combination with chemotherapy drugs (i.e. fludarabine and bendamustine) or with the PI3Kδ inhibitor idelalisib in CLL. Our results showed a significant decrease in CLL cell viability after treatment with selinexor-containing drug combinations compared to each single compound, with demonstration of synergistic cytotoxic effects. Interestingly, this drug synergism was exerted also in the presence of the protective effect of stromal cells. From the molecular standpoint, the synergistic cytotoxic activity of selinexor plus idelalisib was associated with increased regulatory effects of this drug combination on the tumor suppressors FOXO3A and IkBα compared to each single compound. Finally, selinexor was also effective in potentiating the in vivo anti-tumor effects of the PI3Kδ inhibitor in mice treated with the drug combination compared to single agents. Our data provide preclinical evidence of the synergism and potential efficacy of a combination treatment targeting XPO1 and PI3Kδ in CLL.

Mosunetuzumab and the emerging role of T-cell-engaging therapy in follicular lymphoma

Follicular lymphoma (FL) is the most common indolent lymphoma. Since the advent of rituximab, FL has seen a progressive improvement in patient prognosis. While chemotherapy combined with an anti-CD20 monoclonal antibody remains standard first-line therapy, most patients will relapse and require subsequent therapy. T-cell-redirecting therapies can be very potent and are transforming the therapeutic landscape in the relapsed and refractory (R/R) setting. T-cell-dependent bispecific antibodies, of which mosunetuzumab is the first to be approved for R/R FL, are proving to be a highly effective, 'off-the-shelf' option with manageable toxicities. This review covers approved treatments for R/R FL and focuses on preclinical and clinical data available for mosunetuzumab (Lunsumio™), with the goal of determining its role in the treatment of R/R FL.

Signaling pathways in macrophages: molecular mechanisms and therapeutic targets

Macrophages play diverse roles in development, homeostasis, and immunity. Accordingly, the dysfunction of macrophages is involved in the occurrence and progression of various diseases, such as coronavirus disease 2019 and atherosclerosis. The protective or pathogenic effect that macrophages exert in different conditions largely depends on their functional plasticity, which is regulated via signal transduction such as Janus kinase-signal transducer and activator of transcription, Wnt and Notch pathways, stimulated by environmental cues. Over the past few decades, the molecular mechanisms of signaling pathways in macrophages have been gradually elucidated, providing more alternative therapeutic targets for diseases treatment. Here, we provide an overview of the basic physiology of macrophages and expound the regulatory pathways within them. We also address the crucial role macrophages play in the pathogenesis of diseases, including autoimmune, neurodegenerative, metabolic, infectious diseases, and cancer, with a focus on advances in macrophage-targeted strategies exploring modulation of components and regulators of signaling pathways. Last, we discuss the challenges and possible solutions of macrophage-targeted therapy in clinical applications. We hope that this comprehensive review will provide directions for further research on therapeutic strategies targeting macrophage signaling pathways, which are promising to improve the efficacy of disease treatment.

Metabolic and toxicological considerations for phosphoinositide 3-kinase delta inhibitors in the treatment of chronic lymphocytic leukemia

INTRODUCTION

Phosphoinositide 3-kinase delta (PI3Kδ) inhibitors are a class of novel agents that are mainly used to treat B-cell malignancies. They function by inhibiting one or more enzymes which are part of the PI3K/AKT/mTOR pathway. Idelalisib is a first-in-class PI3Kδ inhibitor effective in patients with B-cell lymphoid malignancies.

AREAS COVERED

This article reviews the chemical structure, mechanism of action, and metabolic and toxicological properties of PI3Kδ inhibitors and discusses their clinical applications in monotherapy and in combination with other agents for the treatment of chronic lymphocytic leukemia (CLL). A search was conducted of PubMed, Web of Science, and Google Scholar for articles in English.

RESULTS/CONCLUSION

PI3Kδ inhibitors hold potential for the treatment of B-cell malignancies, including CLL. However, their use is also associated with severe toxicities, including pneumonia, cytopenias, hepatitis, and rash. Newer drugs are in development to reduce toxicity with novel schedules and/or combinations.

EXPERT OPINION

The development of novel PI3Kδ inhibitors might help to reduce toxicity and improve efficacy in patients with CLL and other B-cell lymphoid malignancies.

Parsaclisib, a PI3Kδ inhibitor, in relapsed and refractory follicular lymphoma (CITADEL-203): a phase 2 study

Background

Parsaclisib, a potent and highly selective PI3Kδ inhibitor, has shown clinical benefit in patients with relapsed or refractory (R/R) B-cell malignancies. This phase 2 study (CITADEL-203; NCT03126019, EudraCT 2017-001624-22) assessed efficacy and safety of parsaclisib monotherapy in patients with R/R follicular lymphoma (FL).

Methods

Patients ≥18 years of age with histologically confirmed R/R FL (grade 1-3a) and prior treatment with ≥2 systemic therapies received parsaclisib 20 mg once daily (QD) for 8 weeks then parsaclisib 20 mg once weekly (weekly dosing group [WG]) or parsaclisib 20 mg QD for 8 weeks then parsaclisib 2.5 mg QD (daily dosing group [DG]); DG was selected for further assessment. Primary endpoint was objective response rate (ORR).

Findings

At data cut-off (January 15, 2021), 126 patients had been treated (WG: n = 23; DG: n = 103). ORR (95% confidence interval [CI]) was 77.7% (68.4-85.3) with a complete response rate (95% CI) of 19.4% (12.3-28.4) in DG; median (95% CI) duration of response was 14.7 months (10.4-not estimable [NE]), median progression-free survival was 15.8 months (11.0-NE), and median overall survival was not reached. The most common any-grade treatment-emergent adverse events (TEAEs) among all treated patients included diarrhoea (n = 48, 38.1%), nausea (n = 31, 24.6%), and cough (n = 28, 22.2%); the most common grade ≥3 TEAEs were diarrhoea (n = 15, 11.9%), neutropenia (n = 13, 10.3%), and colitis (n = 7, 5.6%). Dose interruption, reduction, and discontinuation from TEAEs occurred in 46.8% (n = 59), 17.5% (n = 22), and 23.8% (n = 30) of patients, respectively.

Interpretation

Treatment with parsaclisib demonstrated rapid and durable responses, and a manageable safety profile in patients with R/R FL.

Funding

Incyte Corporation.

Withdrawn accelerated approvals for cancer indications in the USA: what is the marketing authorisation status in the EU?

As of April, 2023, 23 accelerated approvals for cancer indications granted by the US Food and Drug Administration (FDA) since 1992 have been withdrawn from the US market, with 17 (74%) of 23 withdrawn in the past 3 years. The marketing authorisation status of these indications in the EU has not been reported. A review of relevant documents from the FDA and the European Medicines Agency (EMA) was done to investigate whether the accelerated approvals for cancer indications withdrawn by the FDA have a marketing authorisation in the EU to date, and to compare the approval history of these indications by the EMA and FDA. We found that, as of April 20, 2023, nine (39%) of 23 withdrawn accelerated approvals for cancer indications in the USA have a marketing authorisation in the EU for a similar indication. By comparison, only two conditional marketing authorisations for cancer indications have been withdrawn from the EU; both are no longer approved in the USA. These findings indicate a discrepancy in the approval policies between the FDA and EMA and imply either that some patient groups in the USA do not get access to relevant medical treatment, or that some patient groups in the EU are treated with medicine without a positive benefit-risk balance. These discrepancies could potentially be reduced by increased collaboration and information sharing between the two agencies.

PI3K/AKT/mTOR signaling transduction pathway and targeted therapies in cancer

The PI3K/AKT/mTOR (PAM) signaling pathway is a highly conserved signal transduction network in eukaryotic cells that promotes cell survival, cell growth, and cell cycle progression. Growth factor signalling to transcription factors in the PAM axis is highly regulated by multiple cross-interactions with several other signaling pathways, and dysregulation of signal transduction can predispose to cancer development. The PAM axis is the most frequently activated signaling pathway in human cancer and is often implicated in resistance to anticancer therapies. Dysfunction of components of this pathway such as hyperactivity of PI3K, loss of function of PTEN, and gain-of-function of AKT, are notorious drivers of treatment resistance and disease progression in cancer. In this review we highlight the major dysregulations in the PAM signaling pathway in cancer, and discuss the results of PI3K, AKT and mTOR inhibitors as monotherapy and in co-administation with other antineoplastic agents in clinical trials as a strategy for overcoming treatment resistance. Finally, the major mechanisms of resistance to PAM signaling targeted therapies, including PAM signaling in immunology and immunotherapies are also discussed.

Parsaclisib, a PI3Kδ inhibitor, in relapsed and refractory mantle cell lymphoma (CITADEL-205): a phase 2 study

Background

Parsaclisib is a potent and highly selective PI3Kδ inhibitor that has shown clinical benefit in patients with relapsed/refractory (R/R) B-cell malignancies. In this phase 2 study (CITADEL-205; NCT03235544, EudraCT 2017-003148-19), the efficacy and safety of parsaclisib was evaluated in patients with R/R mantle cell lymphoma (MCL).

Methods

Patients ≥18 years old with pathologically confirmed R/R MCL and prior treatment with 1-3 systemic therapies, with (cohort 1) or without (cohort 2) previous Bruton kinase inhibitor (BTKi) treatment, received oral parsaclisib 20 mg once-daily (QD) for 8 weeks, then either parsaclisib 20 mg once-weekly (weekly dosing group [WG]) or parsaclisib 2.5 mg QD (daily dosing group [DG]). The primary endpoint was objective response rate (ORR).

Findings

At the primary analysis data cutoff on January 15, 2021, 53 patients in cohort 1 (BTKi-experienced) (WG, n = 12; DG: n = 41) and 108 patients in cohort 2 (BTKi-naive) (WG, n = 31; DG: n = 77) had received parsaclisib monotherapy. The BTKi-experienced cohort was closed after an interim analysis demonstrated limited clinical benefit. In the BTKi-naive cohort, the ORR (95% CI) for DG (dosing selected for further study) was 70.1% (58.6%-80.0%), with a complete response rate (95% CI) of 15.6% (8.3%-25.6%) and a median duration of response (95% CI) of 12.1 (9.0-not evaluable) months. Treatment-emergent adverse events (TEAEs) occurred among 90.7% (98/108) of all treated patients in the BTKi-naive cohort. Grade ≥3 TEAEs occurred among 62.0% (67/108) of patients, including diarrhoea (13.9%, 15/108) and neutropenia (8.3%, 9/108). Parsaclisib interruption, reduction, or discontinuation due to TEAEs occurred among 47.2% (51/108), 8.3% (9/108), and 25.0% (27/108) of patients, respectively. Fatal TEAEs were experienced by six patients and determined to be treatment-related in one patient.

Interpretation

Parsaclisib, a potent, highly selective, PI3Kδ inhibitor demonstrated meaningful clinical benefits and a manageable safety profile (25.0% discontinuation rate, low incidences of individually reported grade ≥3 or serious adverse events) in R/R MCL patients with no prior BTKi therapy. Limited clinical benefit was observed with parsaclisib monotherapy in patients who had previously received BTKi treatment. Future development of PI3K inhibitors for NHL will require further investigation of dose optimisation to improve safety and long-term survival.

Funding

Incyte Corporation.

Developing our knowledge of the quinolone scaffold and its value to anticancer drug design

INTRODUCTION

The quinolone scaffold is a bicyclic benzene-pyridinic ring scaffold with nitrogen at the first position and a carbonyl group at the second or fourth position. It is endowed with a diverse spectrum of pharmacological activities, including antitumor activity, and has progressed into various development phases of clinical trials for their target-specific anticancer activity.

AREAS COVERED

The present review covers both classes of quinolones, i.e. quinolin-2(H)-one and quinolin-4(H)-one as anticancer agents, along with their possible mode of binding. Furthermore, their structure-activity relationships, molecular mechanisms, and pharmacokinetic properties are also covered to provide insight into their structural requirements for their rational design as anticancer agents.

EXPERT OPINION

Synthetic feasibility and ease of derivatization at multiple positions, has allowed medicinal chemists to explore quinolones and their chemical diversity to discover newer anticancer agents. The presence of both hydrogen bond donor (-NH) and acceptor (-C=O) functionality in the basic scaffold at two different positions, has broadened the research scope. In particular, substitution at the -NH functionality of the quinolone motif has provided ample space for suitable functionalization and appropriate substitution at the quinolone's third, sixth, and seventh carbons, resulting in selective anticancer agents binding specifically with various drug targets.

Tisagenlecleucel: CAR-T cell therapy for adult patients with relapsed or refractory follicular lymphoma

INTRODUCTION

Tisagenlecleucel (tisa-cel) is an anti CD19 CAR-T therapy that has demonstrated clinical activity in R/R large B-cell lymphoma and R/R B-cell acute lymphoblastic leukemia. It showed particularly high efficacy in R/R follicular lymphoma (FL) with a manageable toxicity profile. The pivotal ELARA study in R/R FL confirmed these findings and led to the FDA approval of tisa-cel in R/R FL after two lines of systemic therapies.

AREAS COVERED

We start with an introduction of FL and the current treatment landscape with emphasis on the R/R setting. We review the role of CAR-T in R/R FL with focus on currently available products. We describe the ELARA study at a high level to give a perspective of the patient population that was treated. Finally, we discuss aspects related to product selection and whether bispecific antibodies will challenge the role of CAR-T in FL given their similar efficacy.

EXPERT OPINION

Tisa-cel is a highly effective therapy for heavily pretreated R/R FL with a toxicity profile that is low grade and manageable. Durable remissions (including high-risk patients) are seen in the pivotal ELARA study. Clinicians should consider early referral of R/R FL patients for assessment and discussion.

Efficacy and safety-related factors of BTK inhibitors as a bridge to CAR-T therapy in R/R FL

Although anti-CD19 chimeric antigen receptor (CAR) T cell therapy has achieved satisfactory results in relapsed/refractory (R/R) follicular lymphoma (FL), patients with R/R FL and high-risk disease characteristics, previous hematopoietic stem cell transplantation, bulky disease, and progression of disease within 2 years (POD24) had a low complete response (CR). Twenty-seven patients with R/R FL, later disease stages, higher tumor burden, or higher previous treatment lines who had received Bruton tyrosine kinase (BTK) inhibitors before anti-CD19 CAR T cell therapy, or received BTK inhibitors as combination therapy, were included in this study. The clinical response and adverse events (AEs) in anti-CD19 CAR T cell therapy were observed. All patients with R/R FL who received BTK inhibitors combined with anti-CD19-CAR T cell therapy had later disease stages, higher tumor burden, and higher treatment lines than those who did not receive BTK inhibitor combination therapy. However, no difference in the clinical response was found between the two groups. The clinical response in the POD24 group was lower than that in the non-POD24 group; however, no difference in the clinical response was found between the FL and transformed FL (tFL) groups, between the follicular lymphoma international prognostic index (FLIPI) 1 1-2 and FLIPI 1 3-5 groups, and between the FLIPI 2 1-2 and FLIPI 2 3-5 groups. The mean anti-CD19 CAR T cell peak was higher in the CAR-T group with BTK inhibitor than in the CAR-T group without BTK inhibitor. Meanwhile, a higher proportion of patients in the non-POD24 group, FL group, and PR group achieved CR after 2 months. No difference in cytokine secretion was found between the CAR-T group with and without BTK inhibitors. It was higher in the non-POD24 group, FLIPI 1 3-5 group, and FLIPI 2 3-5 group. No difference in cytokine release syndrome and immune effector cell-associated neurotoxic syndrome grades was found between the CAR-T groups with or without BTK inhibitors and between the other groups. Poor prognostic factors, other than POD24, did not affect the clinical response to BTK inhibitors in combination with anti-CD19 CAR T cell therapy in patients with R/R FL. Therefore, BTK inhibitors combined with anti-CD19 CAR-T therapy may be an effective and safe approach for patients with R/R FL and high-risk factors.Trial registration: The study was registered at http://www.chictr.org.cn/index.aspx as ChiCTR-ONN-16009862 and http://www.chictr.org.cn/index.aspx as ChiCTR1800019622.

Novel targeted drugs for follicular and marginal zone lymphoma: a comprehensive review

Although mostly incurable, indolent non-Hodgkin lymphomas (iNHL) are chronic diseases with a median overall survival approaching 20 years. In recent years, important advances in the knowledge of the biology of these lymphomas have led to the development of new drugs, mostly chemotherapy-free, with promising outcomes. With a median age of around 70 years at diagnosis, many patients with iNHL suffer from comorbid conditions that may limit treatment options. Therefore, nowadays, in the transition towards personalized medicine, several challenges lie ahead, such as identifying predictive markers for the selection of treatment, the adequate sequencing of available therapies, and the management of new and accumulated toxicities. In this review, we include a perspective on recent therapeutic advances in follicular and marginal zone lymphoma. We describe emerging data on approved and emerging novel therapies, such as targeted therapies (PI3K inhibitors, BTK inhibitors, EZH2 inhibitors), monoclonal antibodies and antibody-drug conjugates. Finally, we describe immune-directed approaches such as combinations with lenalidomide or the even more innovative bispecific T-cell engagers and chimeric antigen receptor T-cell therapy, which can achieve a high rate of durable responses with manageable toxicities, further obviating the need for chemotherapy.

Enhancing prognostication and personalizing treatment of extranodal marginal zone lymphoma

INTRODUCTION

Extranodal marginal zone lymphoma (EMZL) of mucosa-associated lymphoid tissue is an indolent lymphoma originating from marginal zone B-cells and associated with chronic inflammation. EMZL demonstrates distinct genomic alterations according to the primary extranodal site of disease but commonly affects signaling pathways including NF-ĸB, B-cell receptor, and NOTCH. Treatment with radiation therapy is commonly implemented in localized diseases, and multiple agents are available for patients with advanced-stage diseases in need of therapy. Bendamustine with rituximab is a frontline platform associated with high efficacy.

AREAS COVERED

Clinical features, diagnosis, genomics, models enabling risk stratification, treatment options, and future directions.

EXPERT OPINION

The lack of consistent genotyping profile in EMZL precludes the development of tissue and circulatory biomarkers for the diagnosis, risk stratification, and monitoring of minimal residual disease. Furthermore, the biological heterogeneity observed in extranodal sites associated with overall limited genomic data prevents the testing of druggable pathways aiming for a personalized treatment approach. Future clinical trials should focus on EMZL considering the unique clinical characteristics in the eligibility criteria and response assessment to better inform efficacy of novel agents and delineate sequences of therapies.

Integration of molecular testing for the personalized management of patients with diffuse large B-cell lymphoma and follicular lymphoma

Diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) are the most common forms of aggressive and indolent lymphoma, respectively. The majority of patients are cured by standard R-CHOP immunochemotherapy, but 30%–40% of DLBCL and 20% of FL patients relapse or are refractory (R/R). DLBCL and FL are phenotypically and genetically hereterogenous B-cell neoplasms. To date, the diagnosis of DLBCL and FL has been based on morphology, immunophenotyping and cytogenetics. However, next-generation sequencing (NGS) is widening our understanding of the genetic basis of the B-cell lymphomas. In this review we will discuss how integrating the NGS-based characterization of somatic gene mutations with diagnostic or prognostic value in DLBCL and FL could help refine B-cell lymphoma classification as part of a multidisciplinary pathology work-up. We will also discuss how molecular testing can identify candidates for clinical trials with targeted therapies and help predict therapeutic outcome to currently available treatments, including chimeric antigen receptor T-cell, as well as explore the application of circulating cell-free DNA, a non-invasive method for patient monitoring. We conclude that molecular analyses can drive improvements in patient outcomes due to an increased understanding of the different pathogenic pathways affected by each DLBCL subtype and indolent FL vs R/R FL.

Management of Gastro-Intestinal Toxicity of the Pi3 Kinase Inhibitor: Optimizing Future Dosing Strategies

The phosphatidylinositol 3-kinase (PI3K) pathway plays a key role in cancer progression and in host immunity. Idelalisib was the first of this class to be approved with the second-generation Pi3 kinase inhibitors copanlisib, duvelisib and umbralisib, subsequently being approved in the United States. Real-world data are lacking, however, in relation to the incidence and toxicity of Pi3 kinase inhibitor-induced colitis. We here review, in the first instance, the general landscape of the Pi3K inhibitors in the context of hematological malignancies, with a focus on the adverse gastrointestinal side effects reported by various clinical trials. We further review the available worldwide pharmacovigilance data in relation to these drugs. Finally, we describe our own real-world experience with idelalisib-induced colitis management in our center and in a national setting.

Development and safety of PI3K inhibitors in cancer

The phosphatidylinositol 3-kinase (PI3K) signalling pathway regulates cell survival, proliferation, migration, metabolism and other vital cellular life processes. In addition, activation of the PI3K signalling pathway is important for cancer development. As a result, a variety of PI3K inhibitors have been clinically developed to treat malignancies. Although several PI3K inhibitors have received approval from the Food and Drug Administration (FDA) for significant antitumour activity, frequent and severe adverse effects have greatly limited their clinical application. These toxicities are mostly on-target and immune-mediated; nevertheless, the underlying mechanisms are still unclear. Current management usually involves intervention through symptomatic treatment, with discontinuation if toxicity persists. Therefore, it is necessary to comprehensively understand these adverse events and ensure the clinical safety application of PI3K inhibitors by establishing the most effective management guidelines, appropriate intermittent dosing regimens and new combination administration. Here, the focus is on the development of PI3K inhibitors in cancer therapy, with particular emphasis on isoform-specific PI3K inhibitors. The most common adverse effects of PI3K inhibitors are also covered, as well as potential mechanisms and management approaches.

Impact of positron emission tomography - computed tomography status on progression-free survival for relapsed follicular lymphoma patients undergoing autologous stem cell transplantation

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.

Management of Marginal Zone Lymphoma: A Canadian Perspective

Marginal zone lymphomas (MZL) are a rare, heterogenous group of lymphomas, accounting for 5-17% of indolent non-Hodgkin lymphomas in the western world. They can be further divided into three subtypes: extranodal MZL, splenic MZL, and nodal MZL. These subtypes differ in clinical presentation and behavior, which influences how they are managed. There is currently no standard of care for the treatment of MZL, owing to the difficulty in conducting phase 3 randomized trials in MZL, and the fact that there are limited data on the efficacy of therapy in individual subtypes. Treatment practices are thus largely borrowed from other indolent lymphomas and are based on patient and disease characteristics, as well as access to therapy. This review summarizes the Canadian treatment landscape for MZL and how these therapies may be sequenced in practice.

Management of indolent B-cell Lymphomas: A review of approved and emerging targeted therapies

The indolent B-cell non-Hodgkin lymphomas (B-NHL) comprise a heterogenous group of lymphoproliferative disorders characterized by slow growth kinetics and a relapsing/remitting course. Management has, until recently, been uniform across all indolent B-NHL subtypes. Improving insight into pathophysiological and molecular features of each disease has led to development of several targeted therapies. Consequently, each subtype must now be considered an individual entity. In this review, we consider the three commonest indolent B-NHLs: follicular lymphoma, marginal zone lymphoma and Waldenstrom's macroglobulinemia and review in detail the data on approved and emerging targeted therapeutic agents for each B-NHL subtype.

Targeted Quantification of Protein Phosphorylation and Its Contributions towards Mathematical Modeling of Signaling Pathways

Post-translational modifications (PTMs) are key regulatory mechanisms that can control protein function. Of these, phosphorylation is the most common and widely studied. Because of its importance in regulating cell signaling, precise and accurate measurements of protein phosphorylation across wide dynamic ranges are crucial to understanding how signaling pathways function. Although immunological assays are commonly used to detect phosphoproteins, their lack of sensitivity, specificity, and selectivity often make them unreliable for quantitative measurements of complex biological samples. Recent advances in Mass Spectrometry (MS)-based targeted proteomics have made it a more useful approach than immunoassays for studying the dynamics of protein phosphorylation. Selected reaction monitoring (SRM)-also known as multiple reaction monitoring (MRM)-and parallel reaction monitoring (PRM) can quantify relative and absolute abundances of protein phosphorylation in multiplexed fashions targeting specific pathways. In addition, the refinement of these tools by enrichment and fractionation strategies has improved measurement of phosphorylation of low-abundance proteins. The quantitative data generated are particularly useful for building and parameterizing mathematical models of complex phospho-signaling pathways. Potentially, these models can provide a framework for linking analytical measurements of clinical samples to better diagnosis and treatment of disease.

The Non-Hodgkin Lymphoma Treatment and Side Effects: A Systematic Review and Meta-Analysis

OBJECTIVE

This paper aims to review studies regarding side effects found during Non-Hodgkin Lymphoma treatment, to suggest the drug class most associated with these effects, as well as the most prevalent side effect grade.

METHODS

This review is registered in PROSPERO (IDCRD42022295774) and followed the PICOS strategy and PRISMA guidelines. The search was carried out in the databases PubMed/MEDLINE, Scientific Electronic Library Online, and DOAJ. Medical Subject Headings Terms were used and quantitative studies with conclusive results regarding side effects during the non-Hodgkin lymphoma treatment were selected. Patent information was obtained from google patents.

RESULTS

Monoclonal antibodies were the main drug class associated with side effects during NHL therapy. The combination of Rituximab (Rituxan®; patent EP1616572B) and iInotuzumab (Besponsa®; patent EP1504035B3) was associated with a higher incidence of thrombocytopenia (p<0.05), while the combination of Rituximab and Venetoclax (Venclexta®; patent CN107089981A) was associated with a higher incidence of neutropenia (p<0.05) when compared to Bendamustine combinations (Treanda ™; patent US20130253025A1). Meta-analysis revealed a high prevalence of grade 3-4 neutropenia and thrombocytopenia in men. Finally, Americans and Canadians experienced a higher prevalence of these side effects, when compared to others nationalities (p<0.05).

CONCLUSION

Patents regarding the use of monoclonal antibodies in NHL treatment were published in the last year. Monoclonal antibodies associated with neutropenia (grade 3-4) and thrombocytopenia, especially in North American men treated for NHL, and with an average age of 62 years demonstrated importance in this study.

Safety and efficacy of dual PI3K-δ, γ inhibitor, duvelisib in patients with relapsed or refractory lymphoid neoplasms: A systematic review and meta-analysis of prospective clinical trials

Background

Duvelisib is the first FDA-approved oral dual inhibitor of phosphatidylinositol-3-kinase PI3K-delta (PI3K-δ) and PI3K-gamma (PI3K-γ). Although many clinical studies support the efficacy of duvelisib, the safety of duvelisib remains with great attention. This systematic review and meta-analysis aimed to evaluate the safety and efficacy of duvelisib in treating different relapsed or refractory (RR) lymphoid neoplasm types.

Methods

We searched prospective clinical trials from PUBMED, EMBASE, Cochrane Library, and ClinicalTrials.gov. For efficacy analysis, Overall response rate (ORR), complete response rate (CR), partial response rate (PR), rate of stable disease (SDR), rate of progressive disease (PDR), median progression-free survival (mPFS), 12-/24-month PFS, and 12-month overall survival (OS) were assessed. For safety analysis, the incidences of any grade and grade ≥3 adverse events (AEs), serious AEs, and treatment-related discontinuation and death were evaluated. Subgroup analysis based on the disease type was performed.

Results

We included 11 studies and 683 patients, including 305 chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), 187 B-cell indolent non-Hodgkin lymphoma (iNHL), 39 B-cell aggressive non-Hodgkin lymphoma (aNHL), and 152 T-cell non-Hodgkin lymphoma (T-NHL) patients. The pooled ORR in CLL/SLL, iNHL, aNHL and T-NHL was 70%, 70%, 28% and 47%, respectively. Additionally, the pooled ORR in CLL/SLL patients with or without TP53 mutation/17p-deletion (62% vs. 74%, p=0.45) and in follicular lymphoma (FL) or other iNHL (69% vs. 57%, p=0.38) had no significant differences. Mantle cell lymphoma (MCL) patients had higher pooled ORR than other aNHL (68% vs. 17%, p=0.04). Angioimmunoblastic TCL (AITL) patients had higher pooled ORR than other PTCL patients (67% vs. 42%, p=0.01). The pooled incidence of any grade, grade ≥3, serious AEs, treatment-related discontinuation and death was 99%, 79%, 63%, 33% and 3%, respectively. The most frequent any-grade AEs were diarrhea (47%), ALT/AST increase (39%), and neutropenia (38%). The most frequent grade ≥3 AEs were neutropenia (25%), ALT/AST increased (16%), diarrhea (12%), and anemia (12%).

Conclusion

Generally, duvelisib could offer favorable efficacy in patients with RR CLL/SLL, iNHL, MCL, and AITL. Risk and severity in duvelisib treatment may be mitigated through proper identification and management.

Targeted Treatment of Relapsed or Refractory Follicular Lymphoma: Focus on the Therapeutic Potential of Mosunetuzumab

Follicular lymphoma is the most common indolent non-Hodgkin's lymphoma, and because of the incurable nature of this disorder, new therapies are constantly needed. The recently approved T-cell-dependent bispecific antibody mosunetuzumab showed promising results and manageable toxicities for patients with relapsed or refractory follicular lymphoma. Namely, as opposed to cellular immunotherapy options, this agent has the potential of being effective in patients with unfavorable features with a tolerable rate and severity of cytokine release syndrome, immune effector cell-associated neurotoxicity, and infectious complications. Given the recent withdrawal from the market of PI3K inhibitors and the practical challenges in utilizing with chimeric antigen receptor T-cells (CAR-T) for some patients, mosunetuzumab represents a "breath of fresh air" for both patients and hemato-oncologists. More data are required to better define the real potential of this molecule, either alone or in combination with other agents, including antibody drug conjugates, immunomodulators, and checkpoint inhibitors. Future studies will also shed light on the efficacy of mosunetuzumab compared with CAR-T, in well-designed registries or ideally in randomized controlled trials.

PI3k Inhibitors in NHL and CLL: An Unfulfilled Promise

Phosphatidylinositol 3-kinases (PI3Ks) are a family of intracellular signal transducer enzymes that can attach a phosphate group to the 3'-hydroxyl of the inositol moiety of membrane-embedded phosphatidylinositol (PI). PI3Ks have been shown to play important roles in cell proliferation, growth, survival, motility, and metabolism. Nonetheless, the PI3K pathway has also shown to be overactivated in several tumors, particularly B-cell malignancies. In recent years, the PI3K signaling pathway has become the major focus of substantial drug discovery and development efforts. Selective (PI3K) inhibitors have been approved for the treatment of chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL), and indolent non-Hodgkin lymphomas (iNHL), such as follicular lymphoma and marginal-zone lymphoma. Four selective PI3K inhibitors have received accelerated FDA approvals for the treatment of patients with relapsed/refractory (R/R) CLL and/or iNHL based mainly on single-arm Phase II studies: Idelalisib (PI3K-δ inhibitor), copanlisib (dual PI3K-α and PI3K-δ inhibitor), duvelisib (dual PI3K-γ and PI3K-δ inhibitor), and umbralisib (dual PI3Kδ and CK1ε inhibitor). Conversely, recent interim results of randomized control trials (RCTs) involving some of these agents, showed a worrisome trend of decrease in overall survival (OS), and an increase in fatal and severe adverse effects, in comparison with patients in the control arms. Consequently, the class of PI3K inhibitors came under scrutiny, with an FDA expert panel voting on April 21, 2022, recommending that future FDA approvals of PI3K inhibitors be supported by randomized data, rather than single-arm data only, and further discontinuing the use of almost all the PI3K inhibitors in hematologic malignancies. As we believe further research is needed to help potentialize PI3K inhibitors by improving their safety profiles, this mini-review aims at revisiting the clinical successes, the failures, and the promising aspect of this class of drugs, while presenting possible ways that could benefit its successful development.

Management of marginal zone lymphomas

Marginal zone lymphomas (MZLs) represent about 7% of B-cell non-Hodgkin lymphomas and include 3 different subtypes-namely, extranodal (EMZL), nodal, and splenic (SMZL). The initial assessment requires specific diagnostic and staging procedures depending on organ-related peculiarities. In particular, although positron emission tomography/computed tomography was not initially recommended, recent data have reassessed its role in the routine staging of MZL, especially when only localized treatment is planned or there is a suspicion of histologic transformation. Recent findings have improved the risk stratification of MZL patients, highlighting the association of early progression after frontline therapy with worse overall survival. A significant fraction of MZL cases may be related to specific bacterial (ie, Helicobacter pylori in gastric EMZL) or viral infections (hepatis C virus), and in the earlier phases of disease, a variable percentage of patients may respond to anti-infective therapy. Involved-site radiotherapy has a central role in the management of localized EMZL not amenable to or not responding to anti-infective therapy. Although rituximab-based treatments (bendamustine- rituximab in advanced EMZL or rituximab monotherapy in SMZL) have demonstrated favorable results, the current therapeutic scenario is predicted to rapidly change as emerging novel agents, especially Bruton's tyrosine kinase inhibitors, have demonstrated promising efficacy and safety profiles, leading to their approval in the relapsed setting. Moreover, a large variety of novel agents (phosphatidylinositol 3-kinase inhibitors, chimeric antigen receptor T-cells, bispecific antibodies) are being tested in MZL patients with encouraging preliminary results.

Divergent paths: management of early relapsed follicular lymphoma

Follicular lymphoma (FL) is the second most common non-Hodgkin lymphoma in the United States and Western Europe. Overall outcomes for patients with FL have continued to improve over the last several decades-most notably, with the addition of the CD20 monoclonal antibody rituximab to the treatment armamentarium. More recently, we have seen advances in the management of patients with relapsed/refractory FL with the approval of several new treatments including lenalidomide, axicabtagene ciloleucel, copanlisib, umbralisib, and tazemetostat. Unfortunately, there remains a group of patients for which treatment outcomes, especially overall survival (OS), are suboptimal. This group has been identified as patients who relapse within 24 months (POD24) of completion of chemoimmunotherapy (CIT). Data indicate that patients who relapse within this window have a 5-year OS of around 50%, compared to 80% for those who remain in remission beyond 24 months. POD24 patients have been included and evaluated in the studies of the novel agents mentioned. While not specifically designed to treat this high-risk group, early data suggest that outcomes are not significantly impacted by this designation, unlike CIT. While to date the optimal management of POD24 patients has not been elucidated, the future appears bright with the continued use of the approved agents and several others in clinical development.