Poor outcomes for trial-ineligible patients receiving polatuzumab for relapsed/refractory diffuse large B-cell lymphoma in routine care: An Australian Lymphoma and Related Diseases Registry project.

Polatuzumab vedotin (Pola) is an approved therapy in combination with rituximab and bendamustine for relapsed or refractory diffuse large B-cell lymphoma (RR-DLBCL) based on positive results of the landmark phase II randomised G029365 trial. However, trial results for many approved novel therapies in RR-DLBCL have not been replicated in routine care cohorts, as RR-DLBCL patient populations are heterogeneous and trial eligibility is increasingly restrictive. We evaluated outcomes from pola ± bendamustine and rituximab in patients with RR-DLBCL enrolled in a compassionate access program with no alternative treatment options identified via the Australasian Lymphoma and Related Diseases Registry according to their eligibility for the original phase II published study. Of 58 eligible patients, 74% met the criteria deeming them ineligible for the G029365 original study at the time of pola's commencement. Median progression-free survival and overall survival in our cohort were 2.3 and 3.5 months, respectively. In contrast to the landmark trial cohort, more of our patients ceased therapy prior to completion, the majority due to progressive disease and only 8/58 received any subsequent treatment. Dismal outcomes in this Australian real-world population demonstrate trial eligibility is challenging to meet, and newer treatments can be difficult to deliver in routine care. Clinically applicable results from therapeutic studies require trial cohorts to reflect representative clinical populations wherever possible, and more research is required to address the benefit of novel agents in the increasing majority who are ineligible for modern studies.

Update on the management of relapsed/refractory chronic lymphocytic leukemia.

Chronic lymphocytic leukemia (CLL) predominantly affects older adults, characterized by a relapsing and remitting pattern with sequential treatments available for many patients. Identification of progressive/relapsed CLL should prompt close monitoring and early discussion about the next therapies when treatment indications are present. The intervening period represents an opportunity to optimize patient health, including establishing adequate vaccination and surveillance for second primary malignancies, and treating non-CLL-related comorbidities which may impact well-being and CLL therapy. We now see patients with relapsed/refractory (RR) CLL in the clinic who have been previously treated with chemoimmunotherapy (CIT) and/or one or more novel therapies. Continuous covalent inhibitors of Bruton's tyrosine kinase (cBTKi) and fixed-duration venetoclax (Ven)-anti-CD20 monoclonal antibody (mAb) are preferred over CIT given the survival advantages associated with these therapies, although have never been evaluated head-to-head. While both classes are effective for RR CLL, potential side effects and the logistics of administration differ. Few randomized data demonstrate the sequential use of cBTKi and fixed-duration Ven-anti-CD20 mAb; however, they may be used in either sequence. Newer non-covalent BTKi, active against BTK C481 resistance mutations emerging with continuous cBTKi exposure, and novel approaches such as BTK degraders, bispecific antibodies, and chimeric antigen receptor T-cell therapies demonstrate impressive efficacy. In this review of RR CLL we explore relevant investigations, consideration of broader CLL- and non-CLL-related health needs, and evidence for efficacy and safety of B-cell receptor inhibitors and Ven, including available data to support drug sequencing or switching. We describe novel approaches to RR CLL, including rechallenging with fixed-duration therapies, allogeneic stem cell transplant indications in the novel therapy era, and highlight early data supporting the use of T-cell directing therapies and novel drug targets.

Chronic lymphocytic leukaemia Australasian consensus practice statement.

Chronic lymphocytic leukaemia (CLL) is the most common haematological malignancy in Australia and New Zealand (ANZ). Considerable changes to diagnostic and management algorithms have occurred within the last decade. The availability of next-generation sequencing and measurable residual disease assessment by flow cytometry allow for advanced prognostication and response assessments. Novel therapies, including inhibitors of Bruton's tyrosine kinase (BTKi) and B-cell lymphoma 2 (BCL2) inhibitors, have transformed the treatment landscape for both treatment-naïve and relapsed/refractory disease, particularly for patients with high-risk genetic aberrations. Recommendations regarding appropriate supportive management continue to evolve, and special considerations are required for patients with CLL with respect to the global SARS-CoV-2 pandemic. The unique funding and treatment environments in Australasia highlight the need for specific local guidance with respect to the investigation and management of CLL. This consensus practice statement was developed by a broadly representative group of ANZ experts in CLL with endorsement by peak haematology bodies, with a view to providing this standardised guidance.

Unresolved questions in selection of therapies for treatment-naïve chronic lymphocytic leukemia.

BACKGROUND: The treatment landscape for chronic lymphocytic leukemia (CLL) continues to undergo considerable evolution. Optimal selection of initial therapy from multiple effective options provides a major challenge for clinicians, who need to consider both disease and patient factors in conjunction with a view to sequencing available therapies in event of disease relapse. REVIEW: We explore the most topical clinically relevant unresolved questions through discussion of important available pertinent literature and propose expert opinion based on these data. (1) Shrinking role of chemoimmunotherapy (CIT); while novel therapies are generally superior, we highlight the utility of FCR for IGHV-mutated CLL. (2) Choosing between inhibitors of Bruton's tyrosine kinase (BTKi); while efficacy between agents is likely similar there are important differences in toxicity profiles, including the incidence of cardiac arrhythmia and hypertension. (3) BTKi with or without anti-CD20 monoclonal antibodies (mAb); while obinutuzumab-acalabrutinib (AO) may confer superior progression-free survival to acalabrutinib (Acala), this is not true of rituximab (Ritux) to ibrutinib (Ib)-we highlight that potential for increased side effects should be carefully considered. (4) Continuous BTKi versus time-limited venetoclax-obinutuzumab (VenO); we propose that venetoclax (Ven)-based therapy is generally preferable to BTKi with exception of TP53 aberrant disease. (5) BTKi-Ven versus VenO as preferred time-limited therapy; we discuss comparable efficacies and the concerns about simultaneous 1L exposure to both BTKi and Ven drug classes. (6) Utility of triplet therapy (BTKi-Ven-antiCD20 mAb) versus VenO; similar rates of complete response are observed yet with greater potential for adverse events. (7) Optimal therapy for TP53 aberrant CLL; while limited data are available, there are likely effective novel therapy combinations for TP53 aberrant disease including BTKi, BTKi-Ven ± antiCD20 mAb. CONCLUSION: Frontline therapy for CLL should be selected based on efficacy considering the patient specific biologic profile of their disease and potential toxicities, considering patient comorbidities and preferences. With the present paradigm of sequencing effective agents, 1L combinations of novel therapies should be used with caution in view of potential adverse events and theoretical resistance mechanism concerns in the absence of compelling randomized data to support augmented efficacy.

Diffuse large B-cell lymphoma at risk of secondary CNS involvement: The inefficacy of intravenous high-dose methotrexate CNS prophylaxis and the importance of baseline cerebrospinal fluid analysis.

High-dose intravenous methotrexate (HD-MTX) CNS prophylaxis in high-risk diffuse large B cell lymphoma (DLBCL) remains controversial. We describe real-world CNS relapse incidence following baseline cerebrospinal fluid (CSF) analysis to exclude asymptomatic leptomeningeal involvement in newly diagnosed high-risk DLBCL patients with versus without single-route HD-MTX CNS prophylaxis. Consecutively diagnosed high-risk systemic DLBCL patients without leptomeningeal involvement by CSF analysis (noCNS) were identified retrospectively. Five-year CNS relapse incidence and survival outcomes were examined, as stratified by receipt of HD-MTX prophylaxis. Secondary analysis of survival outcomes in patients with synchronous leptomeningeal involvement (CNSinv) by CSF analysis at diagnosis were compared with the noCNS group. No significant difference in 5-year CNS relapse incidence was observed following HD-MTX prophylaxis versus no prophylaxis (total n = 445) despite similar CNS-IPI risk; 6.2% versus 5.6%, adjusted HR 1.08 (95% CI 0.41-2.85), p = .88; nor in 5-year progression free survival (PFS) or overall survival (OS) risk. Of CNSinv patients, 93.3% had ≥1 extranodal site. Increased CNS relapse/progression risk (5-year risk; HR 10.7 [95% CI 5.35-21.37], p < .0001) and inferior PFS and OS were observed in CNSinv versus all noCNS patients. The CNSinv group had superior OS compared with noCNS patients who later experienced CNS relapse (HR 0.55, p = .052). HD-MTX prophylaxis does not reduce CNS relapse risk in high-risk systemic DLBCL without leptomeningeal involvement by CSF analysis at diagnosis. Asymptomatic patients with synchronous leptomeningeal involvement on baseline CSF examination are at increased risk of further CNS disease events and inferior survival compared to patients without CSF involvement.

SOHO State of the Art Updates and Next Questions | Mechanisms of Resistance to BCL2 Inhibitor Therapy in Chronic Lymphocytic Leukemia and Potential Future Therapeutic Directions.

Chronic lymphocytic leukaemia (CLL) constitutively overexpresses B-cell lymphoma 2 (BCL2) with consequent dysregulation of intrinsic apoptosis leading to abnormal cellular survival. Therapeutic use of BCL2 inhibitors (BCL2i, eg, venetoclax) in CLL, as both continuous monotherapy or in fixed duration combination, has translated scientific rationale into clinical benefit with significant rates of complete responses, including those without detectable minimal residual disease. Unlike with chemotherapy, response rates to venetoclax do not appear to be influenced by pre-existing chromosomal abnormalities or somatic mutations present, although the duration of response observed remains shorter for those with traditional higher risk genetic aberrations. This review seeks to describe both the disease factors that influence primary venetoclax sensitivity/resistance and those resistance mechanisms that may be acquired secondary to BCL2i therapy in CLL. Baseline venetoclax-sensitivity or -resistance is influenced by the expression of BCL2 relative to other BCL2 family member proteins, microenvironmental factors including nodal T-cell stimulation, and tumoral heterogeneity. With selection pressure applied by continuous venetoclax exposure, secondary resistance mechanisms develop in oligoclonal fashion. Those mechanisms described include acquisition of BCL2 variants, dynamic aberrations of alternative BCL2 family proteins, and mutations affecting both BAX and other BH3 proteins. In view of the resistance described, this review also proposes future applications of BCL2i therapy in CLL and potential means by which BCL2i-resistance may be abrogated.

Enrichment of BTK Leu528Trp mutations in patients with CLL on zanubrutinib: potential for pirtobrutinib cross-resistance.

The covalent Bruton's tyrosine kinase inhibitors (BTKis) are highly effective for the treatment of chronic lymphocytic leukemia (CLL). The dominant resistance mechanism observed with the BTKi ibrutinib is the development of BTK Cys481 codon mutations. Whether a similar resistance mutation profile exists for the newer-generation, more selective BTKi zanubrutinib is unknown. In samples referred for diagnostic next-generation sequencing in patients with progressive CLL, we observed an enrichment in the kinase-dead BTK Leu528Trp mutation in patients treated with zanubrutinib compared with ibrutinib (54%; 7 of 13 vs 4%; 1 of 24, P = .001). We describe 2 patients with BTK Leu528Trp mutations who showed clinical cross-resistance and progressive enrichment of the BTK Leu528Trp mutation over time when treated with the noncovalent BTKi pirtobrutinib. Both patients subsequently responded to venetoclax-based treatment. In summary, we have identified an enrichment of the BTK Leu528Trp mutation arising in patients treated with zanubrutinib that may impart cross-resistance to the noncovalent inhibitor pirtobrutinib and therefore may have implications for sequencing of these treatments in CLL.

Value of cerebrospinal fluid white cell count and protein level in predicting leptomeningeal involvement by systemic aggressive B-cell lymphoma.

INTRODUCTION: Diagnostic cerebrospinal fluid (CSF) analysis for patients with newly diagnosed aggressive B-cell lymphoma at risk of secondary central nervous system involvement typically includes multiparametric flow cytometry (MFC), cytology (CC), white cell count (WCC) and total protein. The strength of relationships between MFC results and the remaining variables has been disputed in small studies. We explored these relationships in a large homogeneous cohort of patient samples, aiming to establish the relationship between WCC and protein level and MFC results. METHODS: Adult patients with aggressive B-cell lymphoma at risk of CNS involvement who underwent staging CSF analysis by MFC were identified retrospectively from institutional electronic records between October 2011 and December 2020. RESULTS: Three hundred and seventy eight samples, including 45 (11.9%) MFC+ samples, were analysed. The relative sensitivity of CC for MFC positivity was 0.38, with PPV of 0.68. Significantly higher median WCC (p < .001) and protein levels (p = .011) were seen in MFC+ vs. MFC- samples. MFC + CC+ (vs. MFC + CC- samples) demonstrated higher median neoplastic events and neoplastic cell concentration. WCC ≥36 × 106 /L and protein ≥1.12 g/L cut-off values demonstrated the highest PPVs for MFC positivity (0.67 and 0.88, respectively). CONCLUSIONS: Statistically significant associations exist between elevated WCC and protein and MFC positivity, and selected WCC and protein cut-off values have PPVs comparable to that of cytological assessment. Whilst routine WCC and protein analysis may be unnecessary, WCC/protein values above these levels could be regarded as reasonable evidence of CSF involvement in the appropriate setting.