Comparative Efficacy of First-Line Treatments of Chronic Lymphocytic Leukemia: Network Meta-Analyses of Survival Curves

Comparative safety of novel targeted therapies in relapsed/refractory chronic lymphocytic leukemia: a network meta-analysis

Background

The emergence of new antileukemic drugs, including Bruton tyrosine kinase inhibitors (BTKis), phosphoinositide 3-kinase inhibitors (PI3Kis), and B-cell lymphoma 2 antagonists (BCL-2a), has significantly improved the outcomes for patients with relapsed/refractory chronic lymphocytic leukemia (CLL). Despite advances in treatment efficacy, the comprehensive safety profile of these novel agents versus traditional chemotherapy and immunotherapy has not been adequately explored, and there have been few direct comparisons.

Objectives

This study aimed to compare the safety profiles of novel therapeutic agents, chemotherapy, and immunotherapy in patients with relapsed/refractory CLL using a Bayesian network meta-analysis (NMA).

Methods

A systematic literature review was conducted to identify randomized clinical trials on relapsed/refractory CLL. The search encompassed major medical databases (MEDLINE, Embase, and CENTRAL) and gray literature, with the aim to integrate the findings into a Bayesian NMA framework for safety outcome assessment.

Design

Systematic literature review with Bayesian NMA.

Results

The systematic search identified 14 randomized trials that formed networks for the comparison of safety outcomes. No differences were shown between therapies in terms of overall adverse events (AEs). However, bendamustine + rituximab had a more favorable safety profile for grade ⩾3 AEs when compared with ibrutinib (risk ratio 0.62 (95% credible interval 0.40-0.86)), acalabrutinib (0.69 (0.45-0.94)), zanubrutinib (0.64 (0.42-0.91)), and venetoclax + rituximab (0.87 (0.79-0.96)). The frequency of grade ⩾3 AEs, serious AEs, and treatment discontinuations and deaths due to AEs was comparable between acalabrutinib, zanubrutinib, and venetoclax + rituximab. There were no significant differences in the safety profiles regarding hematological events, events affecting the quality of life, and infections for most comparisons of venetoclax + rituximab with BTKis. Among BTKi-specific events, zanubrutinib was associated with a higher risk of hypertension (2.96 (1.74-5.16)) and bleeding (1.38 (1.06-1.81)) than acalabrutinib. No differences in the risk of atrial fibrillation were found between acalabrutinib and zanubrutinib (1.56 (0.74-3.34)).

Conclusion

Our findings showed that venetoclax + rituximab, acalabrutinib, and zanubrutinib have acceptable safety profiles, which indicates that they may be the preferred therapeutic options in the setting of relapsed/refractory CLL.

Trial registration

PROSPERO CRD42022304330.

Integrating Price Benchmarks and Comparative Clinical Effectiveness to Inform the Medicare Drug Price Negotiation Program

OBJECTIVES

By September 2024, the Centers for Medicare and Medicaid Services (CMS) will publicly report the negotiated prices (Maximum Fair Prices) for the first 10 drugs selected for price negotiation. We estimate initial price offers based on net prices, statutorily defined ceilings, and comparative effectiveness data for the 10 drugs and their therapeutic alternatives.

METHODS

We utilized net prices and other price benchmarks for the 10 drugs and their therapeutic alternatives. We searched for data on comparative clinical effectiveness for the primary indications. We outlined a range of plausible initial price offers based on CMS guidance and our interpretation of regulatory intent.

RESULTS

For ibrutinib and ustekinumab, statutorily defined ceiling prices will likely determine the initial price offers. The integration of net pricing and clinical evidence from comparator branded products will inform the initial price offers for apixaban, empagliflozin, etanercept, and insulin aspart. Rivaroxaban and sacubitril/valsartan have therapeutic alternatives that are generics; therefore, CMS may apply a discount to current net prices. To achieve savings in the negotiation of dapagliflozin and sitagliptin, CMS will have to leverage additional negotiation factors because statutory defined ceilings and net prices of therapeutic alternatives are similar or higher.

CONCLUSIONS

This analysis sheds light on important price benchmarks and clinical evidence factors for the determination of the initial price offers. Although we were not able to simulate the offer and counter-offer process, our findings provide a transparent and systematic way to produce initial offers that are consistent with CMS guidance.

Current Therapeutic Sequencing in Chronic Lymphocytic Leukemia

The treatment landscape of chronic lymphocytic leukemia (CLL), the most frequent leukemia in adults, is constantly changing. CLL patients can be divided into three risk categories, based on their IGHV mutational status and the occurrence of TP53 disruption and/or complex karyotype. For the first-line treatment of low- and intermediate-risk CLL, both the BCL2 inhibitor venetoclax plus obinutuzumab and the second generation BTK inhibitors (BTKi), namely acalabrutinib and zanubrutinib, are valuable and effective options. Conversely, venetoclax-based fixed duration therapies have not shown remarkable results in high-risk CLL patients, while continuous treatment with acalabrutinib and zanubrutinib displayed favorable outcomes, similar to those obtained in TP53 wild-type patients. The development of acquired resistance to pathway inhibitors is still a clinical challenge, and the optimal treatment sequencing of relapsed/refractory CLL is not completely established. Covalent BTKi-refractory patients should be treated with venetoclax plus rituximab, whereas venetoclax-refractory CLL may be treated with second generation BTKi in the case of early relapse, while venetoclax plus rituximab might be used if late relapse has occurred. On these grounds, here we provide an overview of the current state-of-the-art therapeutic algorithms for treatment-naïve patients, as well as for relapsed/refractory disease.

Cost-effectiveness of targeted treatment vs chemoimmunotherapy in treatment-naive unfit CLL without TP53 aberrations

Several targeted treatments, such as venetoclax + obinutuzumab (VenO) and ibrutinib, have been developed to treat patients with treatment-naive chronic lymphocytic leukemia (CLL) and have been shown to improve progression-free survival compared with chlorambucil + obinutuzumab (ClbO). However, novel targeted agents are associated with a significant cost investment. The objective of this study was to investigate the cost-effectiveness of VenO compared with ClbO and ibrutinib in treatment-naive CLL without del17p/TP53 mutation in Denmark. We used a decision-analytic modeling approach to simulate hypothetical cohorts of patients with CLL from the initiation of first-line treatment to death, including the full treatment pathway and second-line therapy. VenO, ClbO, or ibrutinib was included as first-line therapy followed by either Ven + rituximab or ibrutinib. Model outcomes were expected quality-adjusted life years (QALYs), life years (LYs), and cost per patient, which were used to calculate incremental cost-effectiveness ratios (ICERs) with a willingness to pay from €23 600 to €35 600 per QALY. Compared with ClbO, VenO was associated with a QALY gain of 1.30 (1.42 LYs) over a lifetime. The incremental cost was €12 360, resulting in an ICER of €9491 per QALY gained, indicating that VenO is cost-effective. Compared with VenO, ibrutinib was associated with a QALY gain of 0.82 (1.74 LYs) but at a substantially increased incremental cost of €247 488 over a lifetime horizon. The ICER was €302 156 per QALY, indicating that ibrutinib in first-line treatment would not be considered cost-effective in Danish health care, compared with VenO. Future analyses in fit patients with CLL are needed to determine the cost-effectiveness of VenO.

Molecular-Biology-Driven Frontline Treatment for Chronic Lymphocytic Leukemia: A Network Meta-Analysis of Randomized Clinical Trials

The treatment of chronic lymphocytic leukemia (CLL) currently relies on the use of chemo-immunotherapy, Bruton's tyrosine kinase inhibitors, or BCL2 inhibitors alone or combined with an anti-CD20 monoclonal antibody. However, the availability of multiple choices for the first-line setting and a lack of direct head-to-head comparisons pose a challenge for treatment selection. To overcome these limitations, we performed a systematic review and a network meta-analysis on published randomized clinical trials performed in the first-line treatment setting of CLL. For each study, we retrieved data on progression-free survival (according to del17/P53 and IGHV status), overall response rate, complete response, and incidence of most frequent grade 3-4 adverse event. We identified nine clinical trials encompassing 11 different treatments, with a total of 5288 CLL patients evaluated. We systematically performed separated network meta-analyses (NMA) to evaluate the efficacy/safety of each regimen in the conditions previously described to obtain the surface under the cumulative ranking curve (SUCRA) score, which was subsequently used to build separated ranking charts. Interestingly, the combination of obinutuzumab with acalabrutinib reached the top of the chart in each sub-analysis performed, with the exception of the del17/P53mut setting, where it was almost on par with the aCD20 mAbs/ibrutinib combination (SUCRA aCD20-ibrutinib and O-acala: 93.5% and 91%, respectively) and of the safety evaluation, where monotherapies (acalabrutinib in particular) gave better results. Finally, considering that NMA and SUCRA work for single endpoints only, we performed a principal component analysis to recapitulate in a cartesian plane the SUCRA profiles of each schedule according to the results obtained in each sub-analysis, confirming again the superiority of aCD20/BTKi or BCL2i combinations in a first-line setting. Overall, here we demonstrated that: (1) a chemotherapy-free regimen, such as the combination of aCD20 with a BTKi or BCL2i, should be the preferred treatment choice despite biological/molecular characteristics (preferred regimen O-acala); (2) there is less and less room for chemotherapy in the first line treatment of CLL.

Next Generation BTK Inhibitors in CLL: Evolving Challenges and New Opportunities

Ibrutinib revolutionized the CLL treatment approach and prognosis demonstrating its efficacy and safety even at extended follow-up. During the last few years, several next-generation inhibitors have been developed to overcome the occurrence of toxicity or resistance in patients on continuous treatment. In a head-to-head comparison of two phase III trials, both acalabrutinib and zanubrutinib demonstrated a lower incidence of adverse events in respect to ibrutinib. Nevertheless, resistance mutations remain a concern with continuous therapy and were demonstrated with both first- and next-generation covalent inhibitors. Reversible inhibitors showed efficacy independently of previous treatment and the presence of BTK mutations. Other strategies are currently under development in CLL, especially for high-risk patients, and include BTK inhibitor combinations with BCl2 inhibitors with or without anti-CD20 monoclonal antibodies. Finally, new mechanisms for BTK inhibition are under investigations in patients progressing with both covalent and non-covalent BTK and BCl2 inhibitors. Here we summarize and discuss results from main experiences on irreversible and reversable BTK inhibitors in CLL.

Beyond ibrutinib: novel BTK inhibitors for the treatment of chronic lymphocytic leukemia

PURPOSE OF THE REVIEW

Ibrutinib was the first Bruton tyrosine kinase inhibitor (BTKi) approved for clinical use, contributing to a dramatic change in the treatment landscape of chronic lymphocytic leukemia (CLL). This review provides an overview of next-generation BTKi that have been recently approved or are being investigated for the treatment of CLL, specifically highlighting differences and similarities compared to ibrutinib.

RECENT FINDINGS

Acalabrutinib presented comparable response rates to ibrutinib with lower rates of adverse events and is currently approved for the treatment of CLL. Zanubrutinib displayed excellent response rates with a lower incidence of BTKi-related adverse events, but major rates of neutropenia, and its approval is awaited. With the aim of overcoming drug resistance, noncovalent BTKi have been developed. Of all the explored agents to date, pirtobrutinib has shown promising results with manageable toxicities.

SUMMARY

For the treatment of CLL, several effective therapeutic strategies to target BTK are or will soon be available: these drugs present different safety profiles, thus making it possible to tailor the treatment choice according to patient's characteristics. Importantly, noncovalent BTKi will provide a therapeutic chance also for those relapsed/refractory CLL patients who are BTKi-resistant and are considered an unmet clinical need.

Cost-Effectiveness and Economic Burden Analyses on All First-Line Treatments of Chronic Lymphocytic Leukemia

OBJECTIVES

Several chemoimmunotherapy and targeted treatment regimens are approved as front-line therapies in chronic lymphocytic leukemia. We estimated for the 10-year cost-effectiveness of these treatment regimens and the economic burden of following the estimated risk-stratified 21 040 patients with chronic lymphocytic leukemia diagnosed in 2020 for 10 years.

METHODS

A Markov model with 7 exclusive health states was specified over a 10-year time horizon. Treatment effectiveness inputs were obtained from a novel network meta-analysis on the progression-free survival, overall survival curves, and time to next treatment. Costs and utilities inputs were included for each health state for each treatment and discounted at 3.0%/year. Life-years (LYs) and quality-adjusted LYs (QALYs) for each treatment were determined. Using the lowest cost regimen as reference, the incremental cost-effectiveness ratio (ICER) and incremental cost-utility ratio (ICUR) were estimated. The 10-year per-patient cost was determined by risk status and by initial treatment.

RESULTS

Venetoclax-plus-obinutuzumab was the lowest cost regimen, hence the reference. Superior in effectiveness to all chemoimmunotherapies, it was cost saving. With the highest effectiveness gains at 6.26 LYs and 5.01 QALYs and despite being the most expensive regimen ($1 298 638 per patient), acalabrutinib-plus-obinutuzumab yielded the best ICER ($409 343/LY gained) and ICUR ($501 236/QALY gained). The remaining ICERs of targeted therapies ranged from $512 101/LY gained to $793 236/LY gained and the ICURs from $579 737/QALY gained to $869 300/QALY gained. The 10-year postdiagnosis low/high (venetoclax-plus-obinutuzumab/acalabrutinib-plus-obinutuzumab) economic burden ranges were $42 690 to $98 665 for low-risk, $141 339 to $326 660 for intermediate-risk, and $273 650 to $632 453 for high-risk patients.

CONCLUSIONS

Compared with venetoclax-plus-obinutuzumab, chemoimmunotherapies are associated with less health benefits at higher cost. The targeted therapies achieve greater benefits at higher cost.

Targeted Treatment of Chronic Lymphocytic Leukemia: Clinical Utility of Acalabrutinib

In chronic lymphocytic leukemia (CLL), a deeper understanding of the disease biology led over the last decade to the development and clinical use of different targeted drugs, including Bruton tyrosine kinase (BTK) inhibitors. The first BTK inhibitor approved for clinical use is ibrutinib, which showed excellent efficacy and good tolerability. More recently, the interest is growing for novel more selective BTK inhibitors that may reduce the off-target effects of the drug, thus minimizing side effects and subsequent treatment interruptions or discontinuations. Acalabrutinib is an orally administered irreversible BTK inhibitor, characterized by the lack of inhibition towards other kinases. In this review, we present the most recent data from clinical trials on the clinical efficacy of acalabrutinib and acalabrutinib-based combinations for the treatment of patients with relapsed/refractory and treatment-naïve CLL. We delineate the safety profile of the drug, describe side effects of interest and discuss the clinical management of patients receiving acalabrutinib. Due to its efficacy and the favorable safety profile, acalabrutinib has emerged as a viable therapy option in the current landscape of multiple approved treatments for CLL.