Summary
With 10+ years follow‐up in the Leukaemia Research Fund (LRF)
CLL
4 trial, we report the effect of salvage therapy, and the clinical/biological features of the 10‐year survivors treated for ...chronic lymphocytic leukaemia (
CLL
). Overall survival (
OS
) was similar in the three randomized arms. With fludarabine‐plus‐cyclophosphamide (
FC
), progression‐free survival (
PFS
) was significantly longer (
P
< 0·0001), but
OS
after progression significantly shorter, than in the chlorambucil or fludarabine arms (
P
< 0·0001). 614/777 patients progressed; 524 received second‐line and 260 third‐line therapy, with significantly better complete remission (
CR
) rates compared to first‐line in the chlorambucil arm (7% vs. 13% after second‐, 18% after third‐line), but worse in the
FC
arm (38% vs. 15% after both second and third‐line).
OS
10 years after progression was better after a second‐line
CR
versus
a partial response (36% vs. 16%) and better with
FC
‐based second‐line therapy (including rituximab in 20%) or a stem cell transplant (28%)
versus
all other treatments (10%,
P
< 0·0001). The 176 (24%) 10‐year survivors tended to be aged <70 years, with a “good risk” prognostic profile, stage A‐progressive, achieving at least one
CR
, with a first‐line
PFS
>3 years and receiving ≤2 lines of treatment. In conclusion, clinical/biological features and salvage treatments both influence the long‐term outcome. Second‐line therapies that induce a
CR
can improve
OS
in
CLL
patients.
Intravenous alemtuzumab is an effective and well-tolerated treatment for T-cell prolymphocytic leukemia (T-PLL). Alemtuzumab given intravenously as first-line treatment in 32 patients resulted in an ...overall response rate of 91% with 81% complete responses. Studies in B-cell chronic lymphocytic leukemia have shown subcutaneous alemtuzumab to be equally as effective as intravenous alemtuzumab. The UKCLL05 pilot study examined the efficacy and toxicity of this more convenient method of administration in 9 previously untreated patients with T-PLL. Only 3 of 9 patients (33%) responded to treatment. Furthermore, 2 of 9 patients (22%) died while on treatment. Recruitment was terminated because of these poor results. After rescue therapy with intravenous alemtuzumab and/or pentostatin, median progression-free survival and overall survival were similar to the intravenous group. Alemtuzumab delivered intravenously, but not subcutaneously, remains the treatment of choice for previously untreated T-PLL. This study is registered at www.eudract.ema.europa.eu as #2004-004636-31.
Hairy cell leukemia (HCL) is marked by near 100% mutational frequency of BRAFV600E mutations. Recurrent cooperating genetic events that may contribute to HCL pathogenesis or affect the clinical ...course of HCL are currently not described. Therefore, we performed whole exome sequencing to explore the mutational landscape of purine analog refractory HCL. In addition to the disease-defining BRAFV600E mutations, we identified mutations in EZH2, ARID1A, and recurrent inactivating mutations of the cell cycle inhibitor CDKN1B (p27). Targeted deep sequencing of CDKN1B in a larger cohort of HCL patients identify deleterious CDKN1B mutations in 16% of patients with HCL (n = 13 of 81). In 11 of 13 patients the CDKN1B mutation was clonal, implying an early role of CDKN1B mutations in the pathogenesis of HCL. CDKN1B mutations were not found to impact clinical characteristics or outcome in this cohort. These data identify HCL as having the highest frequency of CDKN1B mutations among cancers and identify CDNK1B as the second most common mutated gene in HCL. Moreover, given the known function of CDNK1B, these data suggest a novel role for alterations in regulation of cell cycle and senescence in HCL with CDKN1B mutations.
•Somatic CDKN1B (p27) mutations were identified in 16% (13/81) of HCL patients and coexist with BRAFV600E mutations.•CDKN1B is the second most common mutated gene in HCL implicating altered cell cycle regulation and/or senescence in HCL.
Despite advances in chronic lymphocytic leukaemia (CLL) treatment, globally chemotherapy remains a central treatment modality, with chemotherapy trials representing an invaluable resource to explore ...disease-related/genetic features contributing to long-term outcomes. In 499 LRF CLL4 cases, a trial with >12 years follow-up, we employed targeted resequencing of 22 genes, identifying 623 mutations. After background mutation rate correction, 11/22 genes were recurrently mutated at frequencies between 3.6% (NFKBIE) and 24% (SF3B1). Mutations beyond Sanger resolution (<12% VAF) were observed in all genes, with KRAS mutations principally composed of these low VAF variants. Firstly, employing orthogonal approaches to confirm <12% VAF TP53 mutations, we assessed the clinical impact of TP53 clonal architecture. Whilst ≥ 12% VAF TP53mut cases were associated with reduced PFS and OS, we could not demonstrate a difference between <12% VAF TP53 mutations and either wild type or ≥12% VAF TP53mut cases. Secondly, we identified biallelic BIRC3 lesions (mutation and deletion) as an independent marker of inferior PFS and OS. Finally, we observed that mutated MAPK-ERK genes were independent markers of poor OS in multivariate survival analysis. In conclusion, our study supports using targeted resequencing of expanded gene panels to elucidate the prognostic impact of gene mutations.
Abstract Although chlorambucil has been used in the management of chronic lymphocytic leukemia (CLL) for 55 years, the optimal dose and treatment duration have not been established. We summarized ...data from 4 UK randomized CLL trials over the past 30 years in which chlorambucil, as a single agent, was one of the study arms. Overall response rates (ORR) ranged from 57% to 75% when using doses of 60–70 mg/m2 per 28-day cycle. This compares favorably with an ORR of 31% to 55% in other studies that used lower doses. Response rates improved when patients received 6 or more courses. Studies that used chlorambucil as a comparator, at lower doses or with fewer courses, resulted in consistently lower ORR. Comparisons with single-agent fludarabine in 2 randomized trials (LRF CLL4 and German CLL5) showed similar progression-free survival. Chlorambucil compares favorably with fludarabine and bendamustine with respect to myelotoxicity, neutropenia, and fever, even at 70 mg/m2 per cycle and in the elderly. Resistance to chlorambucil does not preclude a good response to newer treatments used as second-line treatment, which explains the good survival after progression observed in patients randomized to chlorambucil in LRF CLL4. Chlorambucil is currently being combined with anti-CD20 monoclonal antibodies in several phase II and III trials. It remains a useful drug for patients unfit to receive more intensive combinations. However, both the dose and duration of treatment are important.
Summary
Hairy cell leukaemia (HCL) was first described 50 years ago. Median survival was then 4 years. The purine analogues, introduced in the 1980s, transformed this prognosis. We reviewed data ...retrospectively from 233 patients, treated with pentostatin (n = 188) or cladribine (n = 45), to investigate the current long‐term outlook. Median follow‐up was 16 years. There were no significant differences in outcome between the two agents. Overall, the complete response (CR) rate was 80% and median relapse‐free survival was 16 years. After relapse (n = 79) or non‐response (n = 5), 26 patients received pentostatin and 58 cladribine; 69% achieved CR and median relapse‐free survival was 11 years. After third‐line therapy (n = 23), 50% achieved CR and median relapse‐free survival was 6·5 years. However, CRs were equally durable, whether after first, second or third‐line therapy. Complete responders and those with both haemoglobin >100 g/l and platelet count >100 × 109/l before treatment had the longest relapse‐free survival (P < 0·0001). Patients still in CR at 5 years had only a 25% risk of relapse by 15 years. Outcomes for patients with recurrent disease improved with the monoclonal antibody rituximab, combined with either purine analogue. Overall only eight patients died of HCL‐related causes. Patients achieving a CR can expect a normal lifespan.
Summary
We describe three cases of relapsed hairy cell leukaemia (HCL) treated with pentostatin plus rituximab. All three achieved bone marrow complete remission but had persistent splenomegaly and ...hypersplenism. Because of the clinical uncertainty of its significance, they were all splenectomized. The spleen histology showed no evidence of HCL, but a five‐fold thickening of the splenic capsule and areas of fibrosis in the red pulp. This process may have contributed to the lack of elasticity and caused the persistent splenomegaly. We discuss the clinical implications for future patient management. The three patients remain in remission at 1 + , 5 + and 9 + years.
Key Points
Cladribine is regarded as the first treatment of choice for symptomatic hairy cell leukemia. This large international study reports a complete response in 72% of cases and a continuous ...complete response in 20% of patients.
Hairy cell leukemia (HCL) is a rare lymphoproliferative disorder, comprising only 2% of all leukemias. The Hairy Cell Leukemia Foundation (HCLF) has developed a patient data registry to enable ...investigators to better study the clinical features, treatment outcomes, and complications of patients with HCL. This system utilizes a centralized registry architecture. Patients are enrolled at HCL Centers of Excellence (COE) or via a web-based portal. All data are de-identified, which reduces regulatory burden and increases opportunities for data access and re-use. To date, 579 patients have been enrolled in the registry. Efforts are underway to engage additional COE's to expand access to patients across the globe. This international PDR will enable researchers to study outcomes in HCL in ways not previously possible due to the rarity of the disease and will serve as a platform for future prospective research.
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