Pentostatin, Cyclophosphamide, and Rituximab Followed by Alemtuzumab for Relapsed or Refractory Chronic Lymphocytic Leukemia: A Phase 2 Trial of the ECOG-Acrin Cancer Research Group (E2903)

Revolutionizing cancer treatment: comprehensive insights into immunotherapeutic strategies

Cancer, characterized by the uncontrolled proliferation of aberrant cells, underscores the imperative for innovative therapeutic approaches. Immunotherapy has emerged as a pivotal constituent in cancer treatment, offering improved prognostic outcomes for a substantial patient cohort. Noteworthy for its precision, immunotherapy encompasses strategies such as adoptive cell therapy and checkpoint inhibitors, orchestrating the immune system to recognize and selectively target malignant cells. Exploiting the specificity of the immune response renders immunotherapy efficacious, as it selectively targets the body's immune milieu. Diverse mechanisms underlie cancer immunotherapies, leading to distinct toxicity profiles compared to conventional treatments. A remarkable clinical stride in the anticancer resources is immunotherapy. Remarkably, certain recalcitrant cancers like skin malignancies exhibit resistance to radiation or chemotherapy, yet respond favorably to immunotherapeutic interventions. Notably, combination therapies involving chemotherapy and immunotherapy have exhibited synergistic effects, enhancing overall therapeutic efficacy. Understanding the pivotal role of immunotherapy elucidates its complementary value, bolstering the therapeutic landscape. In this review, we elucidate the taxonomy of cancer immunotherapy, encompassing adoptive cell therapy and checkpoint inhibitors, while scrutinizing their distinct adverse event profiles. Furthermore, we expound on the unprecedented potential of immunogenic vaccines to bolster the anticancer immune response. This comprehensive analysis underscores the significance of immunotherapy in modern oncology, unveiling novel prospects for tailored therapeutic regimens.

Maintenance therapy for chronic lymphocytic leukaemia

BACKGROUND

Chronic lymphocytic leukaemia (CLL) is the most common lymphoproliferative disease in adults and currently remains incurable. As the progression-free period shortens after each successive treatment, strategies such as maintenance therapy are needed to improve the degree and duration of response to previous therapies. Monoclonal antibodies, immunomodulatory agents, and targeted therapies are among the available options for maintenance therapy. People with CLL who achieve remission after previous therapy may choose to undergo medical observation or maintenance therapy to deepen the response. Even though there is widespread use of therapeutic maintenance agents, the benefits and harms of these treatments are still uncertain.

OBJECTIVES

To assess the effects and safety of maintenance therapy, including anti-CD20 monoclonal antibody, immunomodulatory drug therapy, anti-CD52 monoclonal antibody, Bruton tyrosine kinase inhibitor, and B-cell lymphoma-2 tyrosine kinase inhibitor, for individuals with CLL.

SEARCH METHODS

We conducted a comprehensive literature search for randomised controlled trials (RCTs) with no language or publication status restrictions. We searched CENTRAL, MEDLINE, Embase, and three trials registers in January 2022 together with reference checking, citation searching, and contact with study authors to identify additional studies.

SELECTION CRITERIA

We included RCTs with prospective identification of participants. We excluded cluster-randomised trials, cross-over trial designs, and non-randomised studies. We included studies comparing maintenance therapies with placebo/observation or head-to-head comparisons.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. We assessed risk of bias in the included studies using Cochrane's RoB 1 tool for RCTs. We rated the certainty of evidence for the following outcomes using the GRADE approach: overall survival (OS), health-related quality of life (HRQoL), grade 3 and 4 adverse events (AEs), progression-free survival (PFS), treatment-related mortality (TRM), treatment discontinuation (TD), and all adverse events (AEs).

MAIN RESULTS

We identified 11 RCTs (2393 participants) that met the inclusion criteria, including seven trials comparing anti-CD20 monoclonal antibodies (mAbs) (rituximab or ofatumumab) with observation in 1679 participants; three trials comparing immunomodulatory drug (lenalidomide) with placebo/observation in 693 participants; and one trial comparing anti-CD 52 mAbs (alemtuzumab) with observation in 21 participants. No comparisons of novel small molecular inhibitors were found. The median age of participants was 54.1 to 71.7 years; 59.5% were males. The type of previous induction treatment, severity of disease, and baseline stage varied among the studies. Five trials included early-stage symptomatic patients, and three trials included advanced-stage patients (Rai stage III/IV or Binet stage B/C). Six trials reported a frequent occurrence of cytogenic aberrations at baseline (69.7% to 80.1%). The median follow-up duration was 12.4 to 73 months. The risk of selection bias in the included studies was unclear. We assessed overall risk of performance bias and detection bias as low risk for objective outcomes and high risk for subjective outcomes. Overall risk of attrition bias, reporting bias, and other bias was low. Anti-CD20 monoclonal antibodies (mAbs): rituximab or ofatumumab maintenance versus observation Anti-CD20 mAbs maintenance likely results in little to no difference in OS (hazard ratio (HR) 0.94, 95% confidence interval (CI) 0.73 to 1.20; 1152 participants; 3 studies; moderate-certainty evidence) and likely increases PFS significantly (HR 0.61, 95% CI 0.50 to 0.73; 1255 participants; 5 studies; moderate-certainty evidence) compared to observation alone. Anti-CD20 mAbs may result in: an increase in grade 3/4 AEs (rate ratio 1.34, 95% CI 1.06 to 1.71; 1284 participants; 5 studies; low-certainty evidence); little to no difference in TRM (risk ratio 0.82, 95% CI 0.39 to 1.71; 1189 participants; 4 studies; low-certainty evidence); a slight reduction to no difference in TD (risk ratio 0.93, 95% CI 0.72 to 1.20; 1321 participants; 6 studies; low-certainty evidence); and an increase in all AEs (rate ratio 1.23, 95% CI 1.03 to 1.47; 1321 participants; 6 studies; low-certainty evidence) compared to the observation group. One RCT reported that there may be no difference in HRQoL between the anti-CD20 mAbs (ofatumumab) maintenance and the observation group (mean difference -1.70, 95% CI -8.59 to 5.19; 480 participants; 1 study; low-certainty evidence). Immunomodulatory drug (IMiD): lenalidomide maintenance versus placebo/observation IMiD maintenance therapy likely results in little to no difference in OS (HR 0.91, 95% CI 0.61 to 1.35; 461 participants; 3 studies; moderate-certainty evidence) and likely results in a large increase in PFS (HR 0.37, 95% CI 0.19 to 0.73; 461 participants; 3 studies; moderate-certainty evidence) compared to placebo/observation. Regarding harms, IMiD maintenance therapy may result in an increase in grade 3/4 AEs (rate ratio 1.82, 95% CI 1.38 to 2.38; 400 participants; 2 studies; low-certainty evidence) and may result in a slight increase in TRM (risk ratio 1.22, 95% CI 0.35 to 4.29; 458 participants; 3 studies; low-certainty evidence) compared to placebo/observation. The evidence for the effect on TD compared to placebo is very uncertain (risk ratio 0.71, 95% CI 0.47 to 1.05; 400 participants; 2 studies; very low-certainty evidence). IMiD maintenance therapy probably increases all AEs slightly (rate ratio 1.41, 95% CI 1.28 to 1.54; 458 participants; 3 studies; moderate-certainty evidence) compared to placebo/observation. No studies assessed HRQoL. Anti-CD52 monoclonal antibodies (mAbs): alemtuzumab maintenance versus observation Maintenance with alemtuzumab may have little to no effect on PFS, but the evidence is very uncertain (HR 0.55, 95% CI 0.32 to 0.95; 21 participants; 1 study; very low-certainty evidence). We did not identify any study reporting the outcomes OS, HRQoL, grade 3/4 AEs, TRM, TD, or all AEs.

AUTHORS' CONCLUSIONS

There is currently moderate- to very low-certainty evidence available regarding the benefits and harms of maintenance therapy in people with CLL. Anti-CD20 mAbs maintenance improved PFS, but also increased grade 3/4 AEs and all AEs. IMiD maintenance had a large effect on PFS, but also increased grade 3/4 AEs. However, none of the above-mentioned maintenance interventions show differences in OS between the maintenance and control groups. The effects of alemtuzumab maintenance are uncertain, coupled with a warning for drug-related infectious toxicity. We found no studies evaluating other novel maintenance interventions, such as B-cell receptor inhibitors, B-cell leukaemia-2/lymphoma-2 inhibitors, or obinutuzumab.

Drugs targeting adenosine signaling pathways: A current view

Adenosine is an endogenous nucleoside that regulates many physiological and pathological processes. It is derived from either the intracellular or extracellular dephosphorylation of adenosine triphosphate and interacts with cell-surface G-protein-coupled receptors. Adenosine plays a substantial role in protecting against cell damage in areas of increased tissue metabolism and preventing organ dysfunction in pathological states. Targeting adenosine metabolism and receptor signaling may be an effective therapeutic approach for human diseases, including cardiovascular and central nervous system disorders, rheumatoid arthritis, asthma, renal diseases, and cancer. Several lines of evidence have shown that many drugs exert their beneficial effects by modulating adenosine signaling pathways but this knowledge urgently needs to be summarized, and most importantly, actualized. The present review collects pharmaceuticals and pharmacological or diagnostic tools that target adenosine signaling in their primary or secondary mode of action. We overviewed FDA-approved drugs as well as those currently being studied in clinical trials. Among them are already used in clinic A2A adenosine receptor modulators like istradefylline or regadenoson, but also plenty of anti-platelet, anti-inflammatory, or immunosuppressive, and anti-cancer drugs. On the other hand, we investigated dozens of specific adenosine pathway regulators that are tested in clinical trials to treat human infectious and noninfectious diseases. In conclusion, targeting purinergic signaling represents a great therapeutic challenge. The actual knowledge of the involvement of adenosinergic signaling as part of the mechanism of action of old drugs has open a path not only for drug-repurposing but also for new therapeutic strategies.

Dipyridamole and adenosinergic pathway in Covid-19: a juice or holy grail

Background

Coronavirus disease 2019 (Covid-19) is an infectious worldwide pandemic triggered by severe acute respiratory coronavirus 2 (SARS-CoV-2). This pandemic disease can lead to pro-inflammatory activation with associated acute lung injury and acute respiratory distress syndrome.

Main body of the abstract

SARS-CoV-2 infection is linked with inhibition of adenosine and activation of phosphodiesterase. Dipyridamole (DIP) is a nucleoside transport and phosphodiesterase inhibitor so that it may potentially affect SARS-CoV-2 infection and its accompanying inflammations. Therefore, the primary objective of this mini-review study was to elucidate the potential beneficial impacts of DIP on the adenosinergic pathway in Covid-19. A systemic search was done using online databases with relevant keywords. The findings of the present study illustrated that DIP directly or indirectly, through augmentation of adenosine and inhibition of phosphodiesterase, mitigates Covid-19 outcomes.

Conclusion

Our study concluded that DIP has a potential therapeutic effect in the management and treatment of Covid-19. This could be attained either directly, through anti-SARS-CoV-2, anti-inflammatory, and anti-platelets properties, or indirectly, through augmentation of extracellular adenosine, which has anti-inflammatory and immune-regulatory effects. However, extensive randomized clinical trials, and clinical and prospective research in this area are required to demonstrate the safety and therapeutic efficacy of DIP and adenosine modulators in the treatment of Covid-19.

Pentostatin Biosynthesis Pathway Elucidation and Its Application

Pentostatin (PNT), a nucleoside antibiotic with a 1,3-diazo ring structure, is distributed in several actinomycetes and fungi species. Its special structure makes PNT possess a wide spectrum of biological and pharmacological properties, such as antibacterial, antitrypanosomal, anticancer, antiviral, herbicidal, insecticidal, and immunomodulatory effects. Because of the promising adenosine deaminase inhibitory activity of PNT, its extensive application in the clinical treatment of malignant tumors has been extensively studied. However, the fermentation level of microbial-derived PNT is low and cannot meet medical needs. Because the biosynthesis pathway of PNT is obscure, only high-yield mutant screening and optimization of medium components and fermentation processes have been conducted for enhancing its production. Recently, the biosynthesis pathways of PNT in actinomycetes and fungi hosts have been revealed successively, and the large-scale production of PNT by systematic metabolic engineering will become an inevitable trend. Therefore, this review covers all aspects of PNT research, in which major advances in understanding the resource microorganisms, mechanism of action, and biosynthesis pathway of PNT were achieved and diverse clinical applications of PNT were emphasized, and it will lay the foundation for commercial transformation and industrial technology of PNT based on systematic metabolic engineering.

[Simultaneous determination of pentostatin and 2'-amino-2'-deoxyadenosine in fermentation broth by high performance liquid chromatography-tandem mass spectrometry]

建立了高效液相色谱-串联质谱(HPLC-MS/MS)同时测定发酵液中喷司他丁和2'-氨基-2'-脱氧腺苷含量的方法。发酵液经高速离心、水溶液稀释、微孔过滤后进行HPLC-MS/MS分析测定。选用Waters Atlantis^® T3色谱柱(100 mm×2.1 mm, 5 μm)及其保护柱(5 mm×2.1 mm, 5 μm)进行分离,选择10 mmol/L甲酸铵(含0.1%甲酸)-甲醇(含0.02%甲酸)溶液为流动相进行梯度洗脱,流速为0.3 mL/min,柱温为25 ℃,进样量为10 μL。在电喷雾电离、正离子模式下收集数据,对目标化合物进行定性定量分析。喷司他丁定量离子对为m/z 269.17>153.20,碰撞能为11 V, 2'-氨基-2'-脱氧腺苷定量离子对为m/z 267.00>136.10,碰撞能为18 V。采用外标法对喷司他丁和2'-氨基-2'-脱氧腺苷定量分析。结果表明,喷司他丁和2'-氨基-2'-脱氧腺苷在1.0~250 μg/L范围内呈现出良好的线性关系,相关系数(R²)为0.9969~0.9996,相对标准偏差(RSD)为6.51%~8.35%(n=8)。在发酵液样品中进行加标水平为1.0、5.0和25 μg/L的添加回收试验(n=6),喷司他丁的回收率为97.94%~104.46%, RSD为3.74%~4.88%; 2'-氨基-2'-脱氧腺苷回收率为89.96%~107.21%, RSD为4.81%~13.29%。喷司他丁和2'-氨基-2'-脱氧腺苷的检出限为0.003~0.060 μg/L,定量限为0.010~0.200 μg/L。该文系统性地建立了基于HPLC-MS/MS测定发酵液中喷司他丁和2'-氨基-2'-脱氧腺苷的方法,在实际样品检测中,操作简便,准确度高,灵敏快速,有效克服了基质效应对目标化合物的影响,改善了目标化合物的峰形和稳定性,为从微生物发酵液中检测喷司他丁和2'-氨基-2'-脱氧腺苷提供了方法学基础和借鉴。