Summary
Ibrutinib is an established treatment for relapsed/refractory (R/R) mantle cell lymphoma (MCL) and clinical trial data supports use at second line compared to later relapse. We aimed to ...investigate outcomes and tolerability for ibrutinib when given second line in a real‐world setting. Our multicentre retrospective analysis included 211 R/R MCL patients, median age 73 years, receiving ibrutinib second‐line within the United Kingdom’s National Health Service. Overall response to ibrutinib was 69% (complete response 27%). The median progression‐free survival (PFS) was 17·8 months (95% CI 13·1–22·2) and median overall survival (OS) 23·9 months (95% CI 15·0–32·8). Drug‐related adverse event led to dose reduction in 10% of patients and discontinuation in 5%. In patients with progressive disease, accounting for 100 of 152 patients stopping ibrutinib, 43% received further systemic therapy. Post‐ibrutinib rituximab, bendamustine and cytarabine (R‐BAC) showed a trend toward improved survival compared to alternative systemic treatments (post‐ibrutinib median OS 14·0 months, 95% CI 8·1–19·8, vs. 3·6 months, 95% CI 2·6–4·5, P = 0·06). Our study confirms the clinical benefit and good tolerability of ibrutinib at first relapse in a real‐world population. Patients progressing on ibrutinib had limited survival but outcomes with R‐BAC in select patients were promising.
Prophylactic high-dose methotrexate (HD-MTX) is often used for diffuse large B-cell lymphoma (DLBCL) patients at high risk of central nervous system (CNS) relapse, despite limited evidence ...demonstrating efficacy or the optimal delivery method. We conducted a retrospective, international analysis of 1384 patients receiving HD-MTX CNS prophylaxis either intercalated (i-HD-MTX) (n = 749) or at the end (n = 635) of R-CHOP/R-CHOP-like therapy (EOT). There were 78 CNS relapses (3-year rate 5.7%), with no difference between i-HD-MTX and EOT: 5.7% vs 5.8%, P = .98; 3-year difference: 0.04% (−2.0% to 3.1%). Conclusions were unchanged on adjusting for baseline prognostic factors or on 6-month landmark analysis (n = 1253). In patients with a high CNS international prognostic index (n = 600), the 3-year CNS relapse rate was 9.1%, with no difference between i-HD-MTX and EOT. On multivariable analysis, increasing age and renal/adrenal involvement were the only independent risk factors for CNS relapse. Concurrent intrathecal prophylaxis was not associated with a reduction in CNS relapse. R-CHOP delays of ≥7 days were significantly increased with i-HD-MTX vs EOT, with 308 of 1573 (19.6%) i-HD-MTX treatments resulting in a delay to subsequent R-CHOP (median 8 days). Increased risk of delay occurred in older patients when delivery was later than day 10 in the R-CHOP cycle. In summary, we found no evidence that EOT delivery increases CNS relapse risk vs i-HD-MTX. Findings in high-risk subgroups were unchanged. Rates of CNS relapse in this HD-MTX-treated cohort were similar to comparable cohorts receiving infrequent CNS prophylaxis. If HD-MTX is still considered for certain high-risk patients, delivery could be deferred until R-CHOP completion.
•End of treatment HD-MTX did not increase risk of CNS relapse compared with intercalated delivery and caused fewer delays to R-CHOP therapy.•CNS relapse rates in this large analysis of HD-MTX-treated patients were similar to published cohorts receiving minimal CNS prophylaxis.
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Venetoclax-based therapy is a standard-of-care option in first-line and relapsed/refractory chronic lymphocytic leukemia (CLL). Patient management following venetoclax discontinuation remains ...nonstandard and poorly understood.
To address this, we conducted a large international study to identify a cohort of 326 patients who discontinued venetoclax and have been subsequently treated. Coprimary endpoints were overall response rate (ORR) and progression-free survival for the post-venetoclax treatments stratified by treatment type Bruton's tyrosine kinase inhibitor (BTKi), PI3K inhibitor (PI3Ki), and cellular therapies.
We identified patients with CLL who discontinued venetoclax in the first-line (4%) and relapsed/refractory settings (96%). Patients received a median of three therapies prior to venetoclax; 40% were BTKi naïve (
= 130), and 81% were idelalisib naïve (
= 263). ORR to BTKi was 84% (
= 44) in BTKi-naïve patients versus 54% (
= 30) in BTKi-exposed patients. We demonstrate therapy selection following venetoclax requires prior novel agent exposure consideration and discontinuation reasons.
For BTKi-naïve patients, selection of covalently binding BTKis results in high ORR and durable remissions. For BTKi-exposed patients, covalent BTK inhibition is not effective in the setting of BTKi resistance. PI3Kis following venetoclax do not appear to result in durable remissions. We conclude that BTKi in naïve or previously responsive patients and cellular therapies following venetoclax may be the most effective strategies.
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With the advent of targeted therapies for chronic lymphocytic leukemia (CLL), treatment choice has expanded and patients are living longer. Careful consideration is needed regarding treatment ...duration and sequence, how best to meet patients' needs, balancing toxicities while improving long-term survival and maximizing depth of response. This review addresses these considerations and discusses current targeted treatment dilemmas. Targeted therapies have dramatically transformed the CLL treatment landscape. Two treatment paradigms have emerged using B-cell lymphoma 2 inhibitors (BCL2i) and Bruton's tyrosine kinase (BTK): (i) fixed duration and (ii) continuous treatment. The BCL2i venetoclax can attain deep remissions with a fixed-duration approach, resulting in high rates of undetectable minimal residual disease (uMRD) in treatment-naïve and relapsed/refractory (R/R) patients with CLL. BTKis such as ibrutinib and acalabrutinib achieve high objective response rates and long-term disease control, although they rarely attain complete response or uMRD status as monotherapy. Numerous studies are evaluating the clinical utility of BTKi and BCL2i as combination therapies, where deep remissions have been found to occur. MRD status may also be a useful marker for deciding when to stop continuous therapy, and randomized trials on MRD-guided treatment strategies are currently ongoing. The current treatment choice between continuous or fixed-duration therapy should be based on comorbidities, risks, preferences, and treatment goals, whilst areas of emerging clinical interest include the potential utility of BTKi-BCL2i combination therapies, as well as an MRD-guided treatment strategies in the future.
Summary
Venetoclax is a BCL2 inhibitor with activity in relapsed/refractory (R/R) chronic lymphocytic leukaemia (CLL). We conducted a multi‐centre retrospective analysis of 105 R/R CLL patients who ...received venetoclax pre‐National Health Service commissioning. The median age was 67 years and median prior lines was 3 (range: 1–15). 48% had TP53 disruption. At ≥2 lines, 60% received a Bruton Tyrosine Kinase inhibitor (BTKi) and no prior phosphoinositide 3‐kinase inhibitor (Pi3Ki), 25% received a Pi3Ki and no prior BTKi, and 10% received both. Patients discontinued B cell receptor inhibitor (BCRi) because of toxicity in 44% and progression in 54%. Tumour lysis syndrome risk was low, intermediate or high in 27%, 25%, and 48% respectively. Overall response was 88% (30% complete response CR). The overall response rate was 85% (CR 23%) in BTKi‐exposed patients, 92% (CR 38%) in Pi3Ki‐exposed patients and 80% (CR 20%) in both (P = 0·59). With a median follow‐up of 15·6 months, 1‐year progression‐free survival was 65·0% and 1‐year overall survival was 75·1%. Dose reduction or temporary interruption did not result in an inferior progression‐free or discontinuation‐free survival. Risk of progression or death after stopping a prior BCRi for progression was double compared to those stopping for other reasons (predominantly toxicity) (Hazard Ratio 2·01 P = 0·05). Venetoclax is active and well tolerated in R/R CLL post ≥1 BCRi. Reason(s) for stopping BCRi influences venetoclax outcomes.
We performed an observational study on the efficacy of ben-damustine and rituximab (BR) as first salvage regimen in chronic lymphocytic leukemia (CLL). In an intention-to-treat analysis including 237 ...patients, the median progression-free survival (PFS) was 25 months. The presence of del(17p), unmutated IGHV and advanced stage were associated with a shorter PFS at multivariate analysis. The median time-to-next treatment was 31.3 months. Front-line treatment with a chemoimmunotherapy regimen was the only predictive factor for a shorter time to next treatment at multivariate analysis. The median overall survival (OS) was 74.5 months. Advanced disease stage (i.e. Rai stage III-IV or Binet stage C) and resistant disease were the only parameters significantly associated with a shorter OS. Grade 3-5 infections were recorded in 6.3% of patients. A matched-adjusted indirect comparison with ibrutinib given second-line within Named Patient Programs in the United Kingdom and in Italy was carried out with OS as objective end point. When restricting the analysis to patients with intact 17p who had received chemoimmunotherapy in first line, there was no difference in OS between patients treated with ibrutinib (63% alive at 36 months) and patients treated with BR (74.4% alive at 36 months). BR is an efficacious first salvage regimen in CLL in a real-life population, including the elderly and unfit patients. BR and ibrutinib may be equally effective in terms of OS when used as first salvage treatment in patients without 17p deletion.
Summary
Since the discovery of rapamycin in Easter Island soil in 1975, more has been learnt about the relevance and importance of the mammalian target of rapamycin (mTOR) pathway in cell signalling, ...proliferation and ultimately tumourigenesis. Rapamycin targets the mTORC1 complex alone. Despite initial excitement, rapamycin and its analogues, everolimus and temsirolimus, have displayed limited efficacy in the treatment of lymphoid malignancies. This review highlights the important and well‐described aspects of the critical phosphatidylinositol‐4,5‐bisphosphate 3‐kinase (PI3K)/AKT/mTOR pathway and discusses the mechanisms of action of rapamycin, its clinical efficacy in lymphoid malignancies, and the mechanisms of resistance. Renewed interest in targeting the pathway has evolved through the discovery of mTORC2, a protein complex associated with a key mechanism of resistance to first generation mTOR inhibitors. As such, novel dual inhibitors of mTORC1 and mTORC2 have been developed, along with other dual inhibitors of the mTOR pathway. The evolution in the development of dual inhibitors is described herein, along with the burgeoning in vitro, pre‐clinical data and the early phase clinical data available. Although historically mTOR inhibitors have been used extensively in haematopoietic and solid organ transplant prophylaxis, this review will focus on developments of their use in lymphoid malignancies.