Myelopreservation with Trilaciclib in Patients Receiving Topotecan for Small Cell Lung Cancer: Results from a Randomized, Double-Blind, Placebo-Controlled Phase II Study

Trilaciclib use in extensive-stage small cell lung cancer (ES-SCLC): are clinical benefits seen in the real-world setting?

BACKGROUND

Trilaciclib, in comparison to placebo plus carboplatin, etoposide, ± atezolizumab (PEA), has shown significant reductions in incidence of severe neutropenia (SN) among patients with extensive-stage small cell lung cancer (ES-SCLC). Despite these findings, real-world utility remains limited.

METHODS

A single-center quasi-experimental study compared trilaciclib + PEA (PEAT) versus PEA in ES-SCLC patients. The study period ranged from April 1, 2021 to July 31, 2022, for the PEAT recipients and February 1, 2020, to February 28, 2021, for PEA recipients. The primary endpoint evaluated was incidence of SN after cycle 1 and during the treatment period. Secondary endpoints included measures related to myelopreservation and patient outcomes.

RESULTS

Among 34 PEAT and 44 PEA patients, baseline characteristics were similar, except for a higher median age (69 vs 64 years) and more males (64.7% vs 38.6%) in the PEAT cohort. The PEAT cohort exhibited a lower SN rate (3%) versus the PEA cohort (18%), with statistical significance demonstrated on multivariate analysis (p = 0.015). Additionally, the PEAT cohort also demonstrated significant reductions in red blood cell transfusion requirements (3% vs 23%; p = 0.02), grade 3-4 anemia (6% vs 25%; p = 0.03), and grade 3-4 thrombocytopenia (0% vs 11%, p = 0.045).

CONCLUSION

Trilaciclib, in combination with PEA, demonstrated an improvement in the safety profile without compromising survival outcomes in ES-SCLC patients. These findings underscore the potential benefits of incorporating trilaciclib in real-world clinical settings for enhanced patient care.

Small cell lung cancer: emerging subtypes, signaling pathways, and therapeutic vulnerabilities

Small cell lung cancer (SCLC) is a recalcitrant cancer characterized by early metastasis, rapid tumor growth and poor prognosis. In recent decades, the epidemiology, initiation and mutation characteristics of SCLC, as well as abnormal signaling pathways contributing to its progression, have been widely studied. Despite extensive investigation, fewer drugs have been approved for SCLC. Recent advancements in multi-omics studies have revealed diverse classifications of SCLC that are featured by distinct characteristics and therapeutic vulnerabilities. With the accumulation of SCLC samples, different subtypes of SCLC and specific treatments for these subtypes were further explored. The identification of different molecular subtypes has opened up novel avenues for the treatment of SCLC; however, the inconsistent and uncertain classification of SCLC has hindered the translation from basic research to clinical applications. Therefore, a comprehensives review is essential to conclude these emerging subtypes and related drugs targeting specific therapeutic vulnerabilities within abnormal signaling pathways. In this current review, we summarized the epidemiology, risk factors, mutation characteristics of and classification, related molecular pathways and treatments for SCLC. We hope that this review will facilitate the translation of molecular subtyping of SCLC from theory to clinical application.

Effect of Hepatic Impairment on Trilaciclib Pharmacokinetics

Trilaciclib is a first-in-class, intravenous cyclin-dependent kinase 4 and 6 inhibitor approved for reducing the incidence of chemotherapy-induced myelosuppression in adult patients with extensive-stage small cell lung cancer receiving a platinum/etoposide-containing or topotecan-containing regimen. No dose adjustment is recommended for participants with mild hepatic impairment (HI) based on previous population pharmacokinetic (PK) analysis. This open-label, parallel-group study examined the impact of moderate and severe HI on the PK of trilaciclib. The study employed a reduced study design. Participants with moderate (Child-Pugh B, n = 8) and severe (Child-Pugh C, n = 5) HI and matched healthy controls (n = 11) received a single intravenous dose of trilaciclib 100 mg/m2. The unbound fraction of trilaciclib was comparable between the HI groups and the matched healthy control group. The unbound trilaciclib extent of exposure (i.e., area under the concentration-time curve) in participants with moderate and severe HI was ∼40% and ∼60% higher, respectively, compared with healthy matched controls based on Child-Pugh classification. Ad hoc analysis using National Cancer Institute classification showed similar results. The US Food and Drug Administration-approved trilaciclib dose of 240 mg/m2 should be reduced by ∼30%, to 170 mg/m2, for patients with moderate or severe HI.

Small molecule anticancer drugs approved during 2021-2022: Synthesis and clinical applications

Drugs have structural homology across similar biological targets. Small molecule drugs have the efficacy to target specific molecular targets within the cancer cells with enhanced cell membrane permeability, oral administration, selectivity, and specific affinity. The objective of this review is to highlight the clinical importance and synthetic routes of new small molecule oncology drugs approved by the FDA during the period 2021-2022. These marketed drugs are listed based on the month and year of approval in chronological order. We believed that an in-depth insight into the synthetic approaches for the construction of these chemical entities would enhance the ability to develop new drugs more efficiently.

Trilaciclib dosage in Chinese patients with extensive-stage small cell lung cancer: a pooled pharmacometrics analysis

This study aimed to analyze potential ethnic disparities in the dose-exposure-response relationships of trilaciclib, a first-in-class intravenous cyclin-dependent kinase 4/6 inhibitor for treating chemotherapy-induced myelosuppression in patients with extensive-stage small cell lung cancer (ES-SCLC). This investigation focused on characterizing these relationships in both Chinese and non-Chinese patients to further refine the dosing regimen for trilaciclib in Chinese patients with ES-SCLC. Population pharmacokinetic (PopPK) and exposure-response (E-R) analyses were conducted using pooled data from four randomized phase 2/3 trials involving Chinese and non-Chinese patients with ES-SCLC. PopPK analysis revealed that trilaciclib clearance in Chinese patients was approximately 17% higher than that in non-Chinese patients with ES-SCLC. Sex and body surface area influenced trilaciclib pharmacokinetics in both populations but did not exert a significant clinical impact. E-R analysis demonstrated that trilaciclib exposure increased with a dosage escalation from 200 to 280 mg/m2, without notable changes in myeloprotective or antitumor efficacy. However, the incidence of infusion site reactions, headaches, and phlebitis/thrombophlebitis rose with increasing trilaciclib exposure in both Chinese and non-Chinese patients with ES-SCLC. These findings suggest no substantial ethnic disparities in the dose-exposure-response relationship between Chinese and non-Chinese patients. They support the adoption of a 240-mg/m2 intravenous 3-day or 5-day dosing regimen for trilaciclib in Chinese patients with ES-SCLC.

Antioxidants activities of phytochemicals perspective modulation of autophagy and apoptosis to treating cancer

The study of chemicals extracted from natural sources should be encouraged due to the significant number of cancer deaths each year and the financial burden imposed by this disease on society. The causes of almost all cancers involve a combination of lifestyle, environmental factors, and genetic and inherited factors. Modern medicine researchers are increasingly interested in traditional phytochemicals as they hold potential for new bioactive compounds with medical applications. Recent publications have provided evidence of the antitumor properties of phytochemicals, a key component of traditional Chinese medicine, thereby opening new avenues for their use in modern medicine. Various studies have demonstrated a strong correlation between apoptosis and autophagy, two critical mechanisms involved in cancer formation and regulation, indicating diverse forms of crosstalk between them. Phytochemicals have the ability to activate both pro-apoptotic and pro-autophagic pathways. Therefore, understanding how phytochemicals influence the relationship between apoptosis and autophagy is crucial for developing a new cancer treatment strategy that targets these molecular mechanisms. This review aims to explore natural phytochemicals that have demonstrated anticancer effects, focusing on their role in regulating the crosstalk between apoptosis and autophagy, which contributes to uncontrolled tumor cell growth. Additionally, the review highlights the limitations and challenges of current research methodologies while suggesting potential avenues for future research in this field.

The impact of myelosuppression on quality of life of patients treated with chemotherapy

Side effects from chemotherapy-induced myelosuppression can negatively affect patients' quality of life (QoL). Neutropenia increases infection risk, and anemia frequently results in debilitating fatigue. Additionally, the bleeding risk associated with thrombocytopenia can lead to fear and anxiety. However, traditional interventions for myelosuppression fall short of the ideal. Granulocyte colony-stimulating factors reduce the risk of severe neutropenia but commonly lead to bone pain. Erythropoiesis-stimulating agents are not always effective and may cause thromboembolic events, while transfusions to correct anemia/thrombocytopenia are associated with transfusion reactions and volume overload. Trilaciclib, which is approved for reducing myelosuppression in patients with extensive-stage small cell lung cancer, together with several investigational agents in development for managing myelosuppression have the potential to improve QoL for patients on chemotherapy.

Treatment of Abdominal Desmoplastic Small Round Cell Tumor Induces Acute Myeloid Leukemia-M5: A Case Report and Literature Review

Desmoplastic small round cell tumor (DSRCT) is a rare and highly aggressive malignancy. Most patients are diagnosed at a late stage with poor prognosis. The treatment usually includes combined intensive chemotherapy, cytoreductive surgery, radiotherapy, and targeted therapy. Due to the low incidence rate and dismal survival, there is currently a lack of case reports on DSRCT with concurrent leukemia. We report a case of a young patient who achieved disease stabilization for 14 months after receiving 6 cycles of chemotherapy and whole abdominal radiation therapy (WART), followed by consolidation treatment with anlotinib. However, the treatment was terminated due to the development of Acute Myeloid Leukemia-M5 (AML-M5). Multimodal therapy may provide a survival benefit for rare tumors that lack standard treatment. However, intensive chemotherapy and extensive radiotherapy carry a risk of inducing secondary malignancies. This is the first reported case of concurrent DSRCT and AML-M5 with short intervals between onset.

Myeloprotection with trilaciclib in Chinese patients with extensive-stage small cell lung cancer receiving chemotherapy: Results from a randomized, double-blind, placebo-controlled phase III study (TRACES)

INTRODUCTION

Trilaciclib is a transient cyclin-dependent kinase 4/6 inhibitor that decreases the incidence of chemotherapy-induced myelosuppression in extensive-stage small cell lung cancer (ES-SCLC). TRACES study was designed to assess the safety, efficacy and pharmacokinetics (PK) of trilaciclib before chemotherapy in Chinese patients with ES-SCLC.

METHODS

The study included an open-label safety run-in part (Part 1) and double-blinded, placebo-controlled part (Part 2) where patients received trilaciclib or placebo before chemotherapy. Treatment-naïve or previously treated ES-SCLC patients received intravenous trilaciclib (240 mg/m2) or placebo before etoposide/carboplatin or topotecan, respectively. Primary endpoints were PK, safety and duration of severe neutropenia (DSN) in Cycle 1 in Part 1 and Part 2. Exploratory endpoints included the effect of trilaciclib on other myeloprotection endpoints, safety and antitumor efficacy.

RESULTS

Overall, 95 Chinese patients were enrolled, of which 12 and 83 patients were in Part 1 and Part 2, respectively. In Part 1, trilaciclib was well tolerated. Non-compartmental analysis results revealed no substantial differences in the main exposure parameters. In Part 2, 41 patients received trilaciclib, and 42 received placebo. Patients in trilaciclib arm vs placebo arm had a clinically and statistically significant decrease in DSN (mean [SD]) in Cycle 1 (0 [1.7] vs 2 [3.0] days; P = 0.0003), with improvements in additional neutrophil, red blood cell, and platelet measures. After a median follow-up of 14.1 months, the median overall survival was 12.0 months in trilaciclib arm and 8.8 months in placebo arm (HR, 0.69; 95 % CI: 0.40-1.22). Median progression-free survival was 4.8 months and 4.3 months, respectively (HR, 0.86; 95 % CI: 0.53-1.39). Trilaciclib had a well-tolerated safety profile.

CONCLUSIONS

Trilaciclib in the Chinese population demonstrated a similar PK and safety profile as seen in other global trials. There was significant reduction of DSN in Cycle 1, thereby substantiating the myeloprotective effects of trilaciclib in Chinese ES-SCLC patients.

Treating patients with platinum-sensitive extensive-stage small-cell lung cancer in a real-world setting

Extensive-stage small-cell lung cancer (ES-SCLC) is an aggressive disease with poor 5-year survival. The first-line standard-of-care for ES-SCLC is platinum plus etoposide, along with 1 of the immune checkpoint inhibitors atezolizumab or durvalumab. Although SCLC first-line therapy often leads to rapid responses, treatment becomes more challenging at progression, particularly for those with a chemotherapy-free interval (CTFI) of ≤6 months. The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) for SCLC no longer specify treatment recommendations in this setting, but options approved by the US Food and Drug Administration include topotecan and lurbinectedin. Participation in a clinical trial is recommended as an option regardless of CTFI. Other NCCN-recommended regimens are paclitaxel, irinotecan, temozolomide, and cyclophosphamide/doxorubicin/vincristine, among others. Nivolumab and pembrolizumab are options in those not previously treated with a checkpoint inhibitor. For patients with platinum-sensitive SCLC (CTFI >6 months), preferred treatment per the NCCN Guidelines® for SCLC is retreatment with platinum and etoposide, although the use of immune checkpoint inhibitors is discouraged if there is progression on a drug in this class. Further research on immunotherapies and combination regimens is ongoing, and continuing work on the subcharacterization of SCLC may lead to better precision of therapies that promote more durable responses in individual patients with ES-SCLC.

Systemic Therapy for Small-Cell Lung Cancer: ASCO-Ontario Health (Cancer Care Ontario) Guideline

PURPOSE

To provide evidence-based recommendations to practicing clinicians on the management of patients with small-cell lung cancer.

METHODS

An Expert Panel of medical oncology, thoracic surgery, radiation oncology, pulmonary, community oncology, research methodology, and advocacy experts were convened to conduct a literature search, which included systematic reviews, meta-analyses, and randomized controlled trials published from 1990 through 2022. Outcomes of interest included response rates, overall survival, disease-free survival or recurrence-free survival, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

The literature search identified 95 relevant studies to inform the evidence base for this guideline.

RECOMMENDATIONS

Evidence-based recommendations were developed to address systemic therapy options, timing of therapy, treatment in patients who are older or with poor performance status, role of biomarkers, and use of myeloid-supporting agents in patients with small-cell lung cancer.Additional information is available at www.asco.org/thoracic-cancer-guidelines.

Real-World Outcomes of Trilaciclib Among Patients with Extensive-Stage Small Cell Lung Cancer Receiving Chemotherapy

INTRODUCTION

Trilaciclib was recently approved in the USA for reducing chemotherapy-induced myelosuppression (CIM) among adults with extensive-stage small cell lung cancer (ES-SCLC) when administered prior to chemotherapy. There is limited understanding of real-world outcomes of trilaciclib.

METHODS

A comprehensive literature review was conducted using a keyword search in the MEDLINE, Embase, and conference abstracts. Additional studies were identified through communications with the authors of relevant studies. Published and unpublished real-world studies of trilaciclib- and comparable non-trilaciclib-treated patients with ES-SCLC were included. Evidence on myelosuppressive hematologic adverse events (HAEs), cytopenia-related healthcare utilization, and other reported outcomes (e.g., hospitalizations, dose reduction, and treatment delay) were synthesized. If feasible, outcomes were compared qualitatively between the trilaciclib and historical reference groups, and between first-line trilaciclib initiators and the overall trilaciclib population. Weighted averages were estimated for selected outcomes using sample size as the weight.

RESULTS

The literature search identified five unique studies based on eight records-two included trilaciclib only, two non-trilaciclib only, and one both. In trilaciclib cohorts, the weighted average prevalence of grade ≥ 3 myelosuppressive HAEs in ≥ 1 lineage, ≥ 2 lineages, and all three lineages was 40.5%, 14.5%, and 7.5%, respectively. All rates were numerically lower compared to the historical non-trilaciclib cohorts (58.8%, 28.0%, 13.0% respectively). Cytopenia-related healthcare utilization was also lower in the trilaciclib cohorts. In general, first-line trilaciclib initiators had numerically lower myelosuppressive HAEs and cytopenia-related healthcare utilization than the overall trilaciclib patients.

CONCLUSIONS

The existing evidence suggests that trilaciclib may reduce single and multilineage grade ≥ 3 myelosuppressive HAEs and cytopenia-related healthcare utilization among patients with ES-SCLC in the real world. It is a promising new treatment for CIM prevention in ES-SCLC and may bring greater benefits to first-line trilaciclib initiators. Future studies are recommended to further evaluate the real-world effectiveness of trilaciclib.

Monitoring the Cell Cycle of Tumor Cells in Mouse Models of Human Cancer

Cell division is obligatory to tumor growth. However, both cancer cells and noncancer cells in tumors can be found in distinct stages of the cell cycle, which may inform the growth potential of these tumors, their propensity to metastasize, and their response to therapy. Hence, it is of utmost importance to monitor the cell cycle of tumor cells. Here we discuss well-established methods and new genetic advances to track the cell cycle of tumor cells in mouse models of human cancer. We also review recent genetic studies investigating the role of the cell-cycle machinery in the growth of tumors in vivo, with a focus on the machinery regulating the G1/S transition of the cell cycle.

Investigating potential immune mechanisms of trilaciclib administered prior to chemotherapy in patients with metastatic triple-negative breast cancer

PURPOSE

In a phase II trial in patients with metastatic triple-negative breast cancer (mTNBC; NCT02978716), administering trilaciclib prior to gemcitabine plus carboplatin (GCb) enhanced T-cell activation and improved overall survival versus GCb alone. The survival benefit was more pronounced in patients with higher immune-related gene expression. We assessed immune cell subsets and used molecular profiling to further elucidate effects on antitumor immunity.

METHODS

Patients with mTNBC and ≤ 2 prior chemotherapy regimens for locally recurrent TNBC or mTNBC were randomized 1:1:1 to GCb on days 1 and 8, trilaciclib prior to GCb on days 1 and 8, or trilaciclib alone on days 1 and 8, and prior to GCb on days 2 and 9. Gene expression, immune cell populations, and Tumor Inflammation Signature (TIS) scores were assessed in baseline tumor samples, with flow cytometric analysis and intracellular and surface cytokine staining used to assess immune cell populations and function.

RESULTS

After two cycles, the trilaciclib plus GCb group (n = 68) had fewer total T cells and significantly fewer CD8+ T cells and myeloid-derived suppressor cells compared with baseline, with enhanced T-cell effector function versus GCb alone. No significant differences were observed in patients who received GCb alone (n = 34). Of 58 patients in the trilaciclib plus GCb group with antitumor response data, 27 had an objective response. RNA sequencing revealed a trend toward higher baseline TIS scores among responders versus non‑responders.

CONCLUSION

The results suggest that administering trilaciclib prior to GCb may modulate the composition and response of immune cell subsets to TNBC.

The impact of new and emerging agents on outcomes for febrile neutropenia: addressing clinical gaps

PURPOSE OF REVIEW

While chemotherapy treatment options for patients with solid and hematologic malignancies have dramatically improved over recent years, chemotherapy-induced neutropenia (CIN) and febrile neutropenia (FN) remain major barriers to delivering treatment at full doses and optimal timing. Despite concurrent advances in granulocyte colony-stimulating factor (G-CSF) administration, multiple barriers to the administration of and disparities in the access to these agents remain. The introduction of new, emerging agents, including biosimilars and novel therapies show promise in improving outcomes for CIN.

RECENT FINDINGS

The introduction of biosimilar filgrastim products has improved access to G-CSF administration by driving marketplace competition and has reduced costs for both patients and healthcare systems without sacrificing efficacy. Emerging therapies to address similar issues include long-acting G-CSF products, efbemalenograstim alfa and eflapegrastin-xnst, as well as agents with novel mechanisms of action, plinabulin and trilaciclib. These agents have shown efficacy and cost-saving benefits in certain populations and disease groups.

SUMMARY

Multiple emerging agents show promise in decreasing the burden of CIN. Use of these therapies will reduce access disparities and will improve outcomes for patients with cancer receiving cytotoxic chemotherapy. Many ongoing trials are underway to evaluate the roles of these agents for more widespread use.

Thromboembolism profiles associated with cyclin-dependent kinase 4/6 inhibitors: a real-world pharmacovigilance study and a systematic review

BACKGROUND

Thrombosis is the second leading cause of mortality in cancer patients. This study aimed to investigate the association between cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6i) and thrombosis.

RESEARCH DESIGN AND METHODS

A retrospective pharmacovigilance analysis based on real-world data combined with a systematic review was used to explore the thrombotic risk profiles of CDK4/6i. The study has been registered with Prospero (CRD42021284218).

RESULT

In the pharmacovigilance analysis, CDK4/6i showed a higher rate of reported venous thromboembolism (VTE) (ROR = 2.78, 95% CI = 2.64-2.92), with the highest signal for trilaciclib (ROR = 27.55, 95% CI = 13.43-56.52) but only 9 cases, followed by abemaciclib (ROR = 3.73, 95% CI = 3.19-4.37). For arterial thromboembolism (ATE), only ribociclib increased the reporting rate (ROR = 2.14, 95% CI = 1.91-2.41). In the meta-analysis, palbociclib, abemaciclib, and trilaciclib all increased the risk of VTE (OR = 2.23, 3.17, and 3.90). In the subgroup analysis, only abemaciclib increased the risk of ATE (OR = 2.11, 95% CI = 1.12-3.99)    .

CONCLUSIONS

CDK4/6i had different profiles of thromboembolism. Palbociclib, abemaciclib, or trilaciclib increased the risk of VTE. Ribociclib and abemaciclib showed a weak association with the risk of ATE.

Update on Classic and Novel Approaches in Metastatic Triple-Negative Breast Cancer Treatment: A Comprehensive Review

Triple-negative breast cancer (TNBC) accounts for almost 15% of all diagnosed breast cancers and often presents high rates of relapses and metastases, with generally poor prognosis despite multiple lines of treatment. Immunotherapy has radically changed the approach of clinicians towards TNBC in the last two to three years, even if targeted and specific therapeutic options are still missing; this unmet need is further justified by the extreme molecular and clinical heterogeneity of this subtype of breast cancer and by the weak response to both single-agent and combined therapies. In March 2023, the National Comprehensive Cancer Network (NCCN), the main association of cancer centers in the United States, released the last clinical practice guidelines, with an update on classic and novel approaches in the field of breast cancer. The purpose of this comprehensive review is to summarize the latest findings in the setting of metastatic TNBC treatment, focusing on each category of drugs approved by the Food and Drug Administration (FDA) and included in the NCCN guidelines. We also introduce part of the latest published studies, which have reported new and promising molecules able to specifically target some of the biomarkers involved in TNBC pathogenesis. We searched the PubMed and Scopus databases for free full texts reported in the literature of the last 5 years, using the words "triple-negative breast cancer" or "TNBC" or "basal-like". The articles were analyzed by the authors independently and double-blindly, and a total of 114 articles were included in the review.

The efficacy and safety of Trilaciclib in preventing chemotherapy-induced myelosuppression: a systematic review and meta-analysis of randomized controlled trials

Background: This study aims to assess the clinical efficacy and safety of Trilaciclib in preventing chemotherapy-induced myelosuppression in adult patients through meta-analysis. Methods: The PubMed, Embase, Cochrane Library, Clinical Trials, EU Clinical Trials Register, and International Clinical Trials Registry Platform were searched up to 25 October 2022. Only randomized controlled trials (RCTs) comparing the clinical outcomes of Trilaciclib and Trilaciclib plus chemotherapy for treating malignant cancers in adult patients were included. The primary outcome included the incidence of SN, FN, the DSN, and administration of ESAs, G-CSFs, and RBC or platelet transfusions, while the secondary outcomes included the risk of adverse events (AEs) and severe adverse events (SAEs). Results: In total, four randomized controlled trials (RCTs) involving 345 patients with SCLC or breast cancer were included in this meta-analysis. Results showed that administration of Trilaciclib significantly reduced the occurrence of SN (19.3% vs. 42.2%, OR = 0.31), FN (3.22% vs. 6.72%, OR = 0.47), anemia (20.5% vs. 38.2%, OR = 0.38) and shortened the DSN during treatment. The proportion of patients receiving therapeutic use of ESAs (4.03% vs. 11.8%, OR = 0.31), G-CSF (37.0% vs. 53.5%, OR = 0.52), RBC transfusions (19.8% vs. 29.9%, OR = 0.56) was also statistically lower in the experimental group than in the control group. Meanwhile, the ORR, overall survival, and progress-free survival of the two groups were identical, and no negative impact of Trilaciclib on the clinical outcomes of chemotherapy treatments was found. Other chemotherapy-induced adverse events (AEs) and severe adverse events (SAEs) like diarrhea, fatigue, nausea, and vomiting were identical regardless of Trilaciclib usage. Conclusion: Trilaciclib demonstrated its efficacy in reducing the occurrence of chemotherapy-induced myelosuppression and utilization of supportive care interventions without undermining the clinical benefits of chemotherapy regimens during treatment with an acceptable safety profile.

Targeting the tumor microenvironment: Potential strategy for cancer therapeutics

Cellular and stromal components including tumor cells, immune cells, mesenchymal cells, cancer-linked fibroblasts, and extracellular matrix, constituent tumor microenvironment (TME). TME plays a crucial role in reprogramming tumor initiation, uncontrolled proliferation, invasion and metastasis as well as response to therapeutic modalities. In recent years targeting the TME has developed as a potential strategy for treatment of cancer because of its life-threatening functions in restricting tumor development and modulating responses to standard-of-care medicines. Cold atmospheric plasma, oncolytic viral therapy, bacterial therapy, nano-vaccine, and repurposed pharmaceuticals with combination therapy, antiangiogenic drugs, and immunotherapies are among the most effective therapies directed by TME that have either been clinically authorized or are currently being studied. This article discusses above-mentioned therapies in light of targeting TME. We also cover problems related to the TME-targeted therapies, as well as future insights and practical uses in this rapidly growing field.

Novel therapeutic strategies for recurrent SCLC

Therapeutic options for patients with relapsed SCLC are limited, and the prognosis in this setting remains poor. While clinical outcomes for frontline treatment have modestly improved with the introduction of immunotherapy, treatment in the second-line setting persists almost unchanged. In this review, current treatment options and recent advances in molecular biology are described. Emerging therapeutic options in this setting and potential strategies to improve clinical outcomes of these patients are also addressed.

Functions and regulatory mechanisms of resting hematopoietic stem cells: a promising targeted therapeutic strategy

Hematopoietic stem cells (HSCs) are the common and essential precursors of all blood cells, including immune cells, and they are responsible for the lifelong maintenance and damage repair of blood tissue homeostasis. The vast majority (> 95%) of HSCs are in a resting state under physiological conditions and are only activated to play a functional role under stress conditions. This resting state affects their long-term survival and is also closely related to the lifelong maintenance of hematopoietic function; however, abnormal changes may also be an important factor leading to the decline of immune function in the body and the occurrence of diseases in various systems. While the importance of resting HSCs has attracted increasing research attention, our current understanding of this topic remains insufficient, and the direction of clinical targeted treatments is unclear. Here, we describe the functions of HSCs, analyze the regulatory mechanisms that affect their resting state, and discuss the relationship between resting HSCs and different diseases, with a view to providing guidance for the future clinical implementation of related targeted treatments.

What Is New in Small Cell Lung Cancer

Small cell lung cancer (SCLC) is a rare yet aggressive lung cancer subtype with an extremely poor prognosis of around 1 year. SCLC accounts for 15% of all newly diagnosed lung cancers and is characterized by rapid growth with high potential for metastatic spread and treatment resistance. In the article the authors review some of the most notable efforts to improve outcomes, including trials of novel immunotherapy agents, novel disease targets, and multiple drug combinations.

Targeting Protein-Protein Interactions to Inhibit Cyclin-Dependent Kinases

Cyclin-dependent kinases (CDKs) play diverse and critical roles in normal cells and may be exploited as targets in cancer therapeutic strategies. CDK4 inhibitors are currently approved for treatment in advanced breast cancer. This success has led to continued pursuit of targeting other CDKs. One challenge has been in the development of inhibitors that are highly selective for individual CDKs as the ATP-binding site is highly conserved across this family of proteins. Protein-protein interactions (PPI) tend to have less conservation amongst different proteins, even within protein families, making targeting PPI an attractive approach to improving drug selectivity. However, PPI can be challenging to target due to structural and physicochemical features of these interactions. A review of the literature specific to studies focused on targeting PPI involving CDKs 2, 4, 5, and 9 was conducted and is presented here. Promising lead molecules to target select CDKs have been discovered. None of the lead molecules discovered have led to FDA approval; however, the studies covered in this review lay the foundation for further discovery and develop of PPI inhibitors for CDKs.

Progress in the clinical application of immune checkpoint inhibitors in small cell lung cancer

Small cell lung cancer (SCLC) is a refractory cancer with poor prognosis due to its aggressive malignancy and high rates of metastasis, recurrence and drug resistance. These characteristics have also greatly impeded the identification of new treatment methods and drugs. The traditional model of SCLC treatment that has been reliant on platinum combined with etoposide for decades has been superseded by the emergence of immune checkpoint inhibitors (ICIs), which have shown significant therapeutic effects and broad application prospects as a monotherapy. This has led to the evaluation of ICIs with different mechanisms of action and their use in combination with radiotherapy or a variety of molecular targeted drugs to achieve synergy, complementary advantages, and reduce adverse reactions. Here, we review the progress in the use of ICIs as a monotherapy or in combination therapy for SCLC and consider the current limitations of these approaches as well as prospects for future developments.

Selective protection of normal cells from chemotherapy, while killing drug-resistant cancer cells

Cancer therapy is limited by toxicity in normal cells and drug-resistance in cancer cells. Paradoxically, cancer resistance to certain therapies can be exploited for protection of normal cells, simultaneously enabling the selective killing of resistant cancer cells by using antagonistic drug combinations, which include cytotoxic and protective drugs. Depending on the mechanisms of drug-resistance in cancer cells, the protection of normal cells can be achieved with inhibitors of CDK4/6, caspases, Mdm2, mTOR, and mitogenic kinases. When normal cells are protected, the selectivity and potency of multi-drug combinations can be further enhanced by adding synergistic drugs, in theory, eliminating the deadliest cancer clones with minimal side effects. I also discuss how the recent success of Trilaciclib may foster similar approaches into clinical practice, how to mitigate systemic side effects of chemotherapy in patients with brain tumors and how to ensure that protective drugs would only protect normal cells (not cancer cells) in a particular patient.

Grade 4 Neutropenia Frequency as a Binary Risk Predictor for Adverse Clinical Consequences of Chemotherapy‑Induced Neutropenia: A Meta-analysis

Neutropenia is the major toxicity of myelosuppressive cancer chemotherapy. Grade 4 neutropenia (Gr4N) is a measure of chemotherapy-induced neutropenia (CIN) severity. We conducted a meta-analysis of CIN data. Gr4N incidence was significantly correlated with febrile neutropenia (FN), days of severe neutropenia (DSN), and nadir absolute neutrophil count (ANC), which are all important predictors of morbidity. With a Gr4N threshold of 65%, both FN and DSN were below levels for low risk of adverse CIN outcomes. Gr4N was highly predictive for adverse CIN outcomes, and a 65% threshold demarcated low vs. high risk for FN and other adverse CIN outcomes.

A Proactive Approach to Prevent Hematopoietic Exhaustion During Cancer Chemotherapy in Older Patients: Temporary Cell-Cycle Arrest

Age is associated with the decline of multiple organ systems. In older patients, hematological toxicities associated with chemotherapy are often dose limiting, impairing dose intensity and treatment efficacy. Contrary to the classical path using growth factors to activate tissue regeneration, a novel strategy is emerging to prevent chemotherapy toxicity that involves temporary cell-cycle arrest of normal cells, such as hematopoietic or epithelial precursors. This proactive approach may allow the sparing of the stem cell reserve of these tissues. Two molecules are included in this new category, trilaciclib and ALRN-6924, which induce cell-cycle arrest by two different pathways. Previous approaches, such as the use of myelopoietic growth factors, were reactive and they might even have accelerated the depletion of stem cells by enhancing the commitment of these elements. Trilaciclib causes cell-cycle arrest by CDK 4/6 inhibition and ALRN-6924 by p53 activation. In a pooled analysis of three randomized phase II studies of patients with small cell lung cancer, trilaciclib prevented neutropenia, thrombocytopenia, and anemia. Similar chemoprotective results were observed with ALRN-6924 in an open-label phase Ib study of patients with p53-mutated small cell lung cancer. Trilaciclib is now approved as a myelopreservation agent in patients with extensive-stage small cell lung cancer. ALRN-6924 is currently in phase Ib clinical development in patients with p53-mutated cancer. In addition to preserving the normal hemopoietic pool, these drugs promise to preserve the stem cell reserve of other normal tissues with high turnover, preventing potentially other dose-limiting toxicities, such as mucositis and diarrhea. An "ex vivo" study provided early evidence that ALRN-6924 may prevent chemotherapy-induced alopecia. By affording protection from multiple toxicities with a single drug, trilaciclib and ALRN-6924 have the potential to transform the current standards of supportive care for oncology patients and may prevent the depletion of tissue stem cells already compromised with age.

Current and Emerging Treatment Options for Patients With Relapsed Small-cell Lung Carcinoma: A Systematic Literature Review

Second-line treatment options are limited for patients with small-cell lung cancer (SCLC). We conducted a PRISMA-standard systematic literature review to evaluate the treatment landscape for patients with relapsed SCLC (PROSPERO number: CRD42022299759). Systematic searches of MEDLINE, Embase, and Cochrane Library were performed (October 2022) to identify publications (prior 5 years) from prospective studies of therapies for relapsed SCLC. Publications were screened against predetermined eligibility criteria; data were extracted to standardized fields. Publication quality was assessed using GRADE. The data were analyzed descriptively, grouped by drug class. Overall, 77 publications involving 6349 patients were included. Studies of tyrosine kinase inhibitors (TKIs) with established cancer indications accounted for 24 publications; topoisomerase I inhibitors for 15; checkpoint inhibitors (CPIs) for 11, and alkylating agents for 9 publications. The remaining 18 publications featured chemotherapies, small-molecule inhibitors, investigational TKIs and monoclonal antibodies, and a cancer vaccine. According to GRADE assessment, 69% of the publications reported low-/very-low-quality evidence; quality limitations included lack of randomization and small sample sizes. Only 6 publications/6 trials reported phase 3 data; 5 publications/2 trials reported phase 2/3 results. Overall, the clinical potential of alkylating agents and CPIs remained unclear; investigations of combination approaches and biomarker-directed usage are warranted. Phase 2 data from TKI trials were consistently promising; no phase 3 data were available. Phase 2 data for a liposomal formulation of irinotecan were promising. We confirmed an absence of promising investigational drug/regimens in late-stage development; thus, relapsed SCLC remains an area of high unmet need.

Chemotherapy-induced thrombocytopenia: literature review

Chemotherapy-induced thrombocytopenia (CIT) is a common condition that frequently results in reduced chemotherapy dosages, postponed treatment, bleeding, and unfavorable oncological outcomes. At present, there is no clear suggestions for preventing or treating CIT. Thrombopoietin (TPO) replacement therapy has been invented and used to treat CIT to promote the production of megakaryocytes and stimulate the formation of platelets. However, this treatment is limited to the risk of immunogenicity and cancer progression. Therefore, an unmet need exists for exploring alternatives to TPO to address the clinical issue of CIT. Application of appropriate therapeutic drugs may be due to understanding the potential mechanisms of CIT. Studies have shown that chemotherapy significantly affects various cells in bone marrow (BM) microenvironment, reduces their ability to support normal hematopoiesis, and may lead to BM damage, including CIT in cancer patients. This review focuses on the epidemiology and treatment of cancer patients with CIT. We also introduce some recent progress to understand the cellular and molecular mechanisms of chemotherapy inhibiting normal hematopoiesis and causing thrombocytopenia.

LP2, a stable lanthipeptide derived from cAng-(1-7), exerts myeloprotective action in mice

OBJECTIVES

Linear unstable angiotensins stimulate hematopoiesis. Here we address: (1) Is cyclic angiotensin-(1-7) myeloprotective in mice? (2) Is cyclic angiotensin-(1-7) stable in rat? (3) Does LP2, a cyclic angiotensin-(1-7) with an N-terminal d-lysine, exert myeloprotective action in tumor-bearing mice?

MATERIALS AND METHODS

Cyclic angiotensin-(1-7)'s capacity to restore levels of blood platelets and white blood cells was studied in gemcitabine-treated mice. The stability of cyclic angiotensin-(1-7) in rat was measured in blood samples taken after injection or infusion. The capacity of LP2 to restore total bone marrow cell levels in mice after treatment with 5-fluoruracil was measured. In addition, the capacity of LP2 to counter anemia in tumor-bearing mice treated with erlotinib was measured.

RESULTS

Cyclic angiotensin-(1-7) dose-dependently restored blood platelet levels in gemcitabine-treated mice, whereas its capacity to restore levels of white blood cells was less. In vivo aminoterminal breakdown of cyclic angiotensin-(1-7) yielded cyclic angiotensin-(2-7) and cyclic angiotensin-(3-7). LP2 significantly (p < .0001 at 100 μg/kg/day) restored bone marrow cell counts in mice after treatment with 5-fluoruracil. LP2 also significantly (p < .05) countered anemia in tumor-bearing mice treated with erlotinib.

CONCLUSIONS

LP2 exerts myeloprotective action with perspectives for continuation of its clinical development.

CDK inhibitors from past to present: A new wave of cancer therapy

Deregulation of the cell cycle machinery, which has been linked to dysregulation of cyclin-dependent kinases (CDKs), is a defining characteristic of cancer, eventually promoting abnormal proliferation that feeds tumorigenesis and disease development. In this regard, several CDK inhibitors (CDKIs) have been developed during the last few decades (1st, 2nd, and 3rd generation CDKIs) to inhibit cancer cell proliferation. 1st and 2nd generation CDKIs have not received much clinical attention for the treatment of cancer patients because of their limited specificity and high toxicity. However, the recent development of combination strategies allowed us to reduce the toxicity and side effects of these CDKIs, paving the way for their potential application in clinical settings. The 3rd generation CDKIs have yielded the most promising results at the preclinical and clinical levels, propelling them into the advanced stages of clinical trials against multiple malignancies, especially breast cancer, and revolutionizing traditional treatment strategies. In this review, we discuss the most-investigated candidates from the 1st, 2nd, and 3rd generations of CDKIs, their basic mechanisms of action, the reasons for their failure in the past, and their current clinical development for the treatment of different malignancies. Additionally, we briefly highlighted the most recent clinical trial results and advances in the development of 3rd generation FDA-approved selective CDK4/6 inhibitors that combat the most prevalent cancer. Overall, this review will provide a thorough knowledge of CDKIs from the past to the present, allowing researchers to rethink and develop innovative cancer therapeutic regimens.

Review of novel and supplemental approvals of the targeted cancer drugs by the Food and Drug Administration in 2021

OBJECTIVE

This review aims to present the most recent results from clinical trials of targeted cancer drugs that led to the Food and Drug Administration approval in 2021 and reflect the changing treatment landscape of solid malignancies.

DATA SOURCES

Novel approvals and supplemental approvals in 2021 were retrieved from the official web page of the Food and Drug Administration (Drugs@FDA). This review did not include approvals for generics, biosimilars, imaging, and diagnostics agents.

DATA SUMMARY

This review included 10 novel drugs approved for 11 indications and 10 already-approved drugs approved for 21 indications by the Food and Drug Administration in 2021. Novel approvals mainly were related to treating an orphan disease. In addition, one-third of the supplemental approvals were given for neoadjuvant or adjuvant treatment, while the number of indications for each tumor site was as follows: gastrointestinal (7), genitourinary (5), skin (3), lung (2), breast (2), thyroid (1), and cervix (1).

CONCLUSIONS

Targeted cancer treatments are gaining more importance than ever in treating malignant diseases. As the approval of targeted cancer drugs provides a possibility for patients and this trend is expected to continue in the future, it remains vital for healthcare providers to stay up-to-date with newer therapeutic options.

Therapy sculpts the complex interplay between cancer and the immune system during tumour evolution

Cancer development is an evolutionary process. A key selection pressure is exerted by therapy, one of the few players in cancer evolution that can be controlled. As such, an understanding of how treatment acts to sculpt the tumour and its microenvironment and how this influences a tumour's subsequent evolutionary trajectory is critical. In this review, we examine cancer evolution and intra-tumour heterogeneity in the context of therapy. We focus on how radiotherapy, chemotherapy and immunotherapy shape both tumour development and the environment in which tumours evolve and how resistance can develop or be selected for during treatment.

New Advances in Supportive Care: Chemoprotective Agents as Novel Opportunities in Geriatric Oncology

PURPOSE OF REVIEW

To explore the effectiveness of trilaciclib and ALRN-6924 in the prevention of cancer chemotherapy-induced toxicity in older patients. New chemoprotective agents are necessary because age is the main risk factor for chemotherapy complications that account largely for the poorer outcome of cancer in the elderly. Trilaciclib and ALRN-6924 cause a reversible block of the proliferation of normal cells through cell cycle arrest (CCA). With this mechanism, they may prevent the toxicity of cycle-active cancer treatment including neutropenia, anemia, thrombocytopenia, lymphopenia, mucositis, and alopecia.

RECENT FINDINGS

Myelopoietic growth factors may prevent neutropenia in the aged, but they may cause severe bone pain, may aggravate thrombocytopenia and anemia, and may cause myelodysplasia and acute leukemia as a late complication. The prevention of thrombocytopenia, anemia, mucositis, and alopecia is unsatisfactory at present. These complications may jeopardize the treatment outcome as they require a reduction of treatment dose/intensity and because many patients find the resulting symptoms intolerable. In three studies of patients with extensive disease small cell lung cancer (ES-SCLC), trilaciclib reduced the severity and duration of neutropenia and thrombocytopenia as well as the need for blood transfusions. In addition, it produced a significant expansion of T-cell clones. Trilaciclib received FDA approval for the prevention of chemotherapy-induced myelosuppression in patients with ES-SCLC. ALRN-6924 is currently studied in phase II study of ES-SCLC. In a phase IB of 38 patients, ALRN-6924 prevented myelosuppression to an extent comparable with trilaciclib. Both drugs proved as effective in patients 65 and older as they were in the younger ones. In an "ex vivo" study, ALRN-6924 protected the epithelial stem cells of hair follicles from taxanes and promised to prevent alopecia. The possibility that CCA of tumor cells may reduce the effectiveness of cycle-active chemotherapy is a major concern. For this reason, the use of trilaciclib, an inhibitor of CDK 4/6, should be limited to tumors with inactivated RB1, and the use of ALRN-6924, an inhibitor of P53, should be limited to tumors with inactivated P53. Chemotherapy-related toxicities limit dose intensity and contribute to significant morbidity and mortality in elderly cancer patients. Trilaciclib and ALRN-6924 are of particular interest to geriatric oncologists because of their novel mechanism of action. Ameliorating chemotherapy-induced toxicities holds the promise of transforming the practice of geriatric oncology by enabling chemotherapeutic regimens that are currently not feasible for this patient population. Specifically, these agents may prevent chemotherapy-induced neutropenia and thrombocytopenia, perhaps the most life-threatening complications of cytotoxic chemotherapy, thereby obviating the need for the use of rescue strategies such as hematopoietic growth factors. In addition, these agents offer the potential for broad tissue protection from other chemotherapy-related toxicities, including mucositis, diarrhea, and alopecia, which historically have been poorly managed. Importantly, by preventing a spectrum of chemotherapy-related toxicities, these agents may permit the administration of chemotherapy at full-dose intensity, prevent functional decline, and grant maintenance of resilience to older cancer patients. As a result, the successful prevention of chemotherapy-induced side effects may not only mitigate the costs of care but also improve patient outcomes and quality of life. Finally, chemoprotective strategies offer the opportunity to apply geriatric principles to clinical trials of cancer treatment. In particular, they may allow the testing of prolongation of "active life expectancy" as a major goal of clinical trials in elderly patients. They may also enable novel and more practical forms of clinical trials. By assessing the risk of chemotherapy-related toxicity with the Chemotherapy Risk Assessment Scale for High Age Patients (CRASH) or the Cancer and Aging Research Group (CARG) instruments, these agents may permit researchers to utilize patients as their own controls and endorse the approval of supportive care drugs based upon the risk profile of individual patients.

Burden of chemotherapy-induced myelosuppression among patients with ES-SCLC in US community oncology settings

Aim: To describe the burden of chemotherapy-induced myelosuppression among chemotherapy-treated patients with extensive-stage small-cell lung cancer (ES-SCLC). Materials & methods: Occurrence of grade ≥3 myelosuppressive hematological adverse events (HAEs), treatment patterns and healthcare resource utilization (HCRU) after chemotherapy initiation were evaluated using data from The US Oncology Network and Non-network clinics (1/1/2015-12/31/2020). Results: Among patients with laboratory values (Network: N = 1,374/1,574; Non-network: N = 661/959), over half-experienced grade ≥3 HAEs after chemotherapy initiation (Network = 56.6%; Non-network = 64.1%), and approximately one-third had grade ≥3 HAEs in at least two lineages (Network = 33.0%; Non-network = 31.3%). Patients with grade ≥3 HAEs had greater dose reductions, treatment delays and HCRU than those without. Conclusion: Myelosuppression is a burden to patients with ES-SCLC treated with chemotherapy and the healthcare system.

Targeting the epigenetic processes to enhance antitumor immunity in small cell lung cancer

Dysregulation of the epigenetic processes, such as DNA methylation, histone modifications, and modulation of chromatin states, drives aberrant transcription that promotes initiation and progression of small cell lung cancer (SCLC). Accumulating evidence has proven crucial roles of epigenetic machinery in modulating immune cell functions and antitumor immune response. Epigenetics-targeting drugs such as DNA methyltransferase inhibitors, histone deacetylase inhibitors, and histone methyltransferase inhibitors involved in preclinical and clinical trials may trigger antitumor immunity. Herein, we summarize the impact of epigenetic processes on tumor immunogenicity and antitumor immune cell functions in SCLC. Furthermore, we review current clinical trials of epigenetic therapy against SCLC and the mechanisms of epigenetic inhibitors to boost antitumor immunity. Eventually, we discuss the opportunities of developing therapeutic regimens combining epigenetic agents with immunotherapy for SCLC.

Trilaciclib prior to gemcitabine plus carboplatin for metastatic triple-negative breast cancer: phase III PRESERVE 2

Triple-negative breast cancer (TNBC) is an aggressive malignancy for which cytotoxic chemotherapy remains the backbone of treatment. Trilaciclib is an intravenous cyclin-dependent kinase 4/6 inhibitor that induces transient cell cycle arrest of hematopoietic stem and progenitor cells and immune cells during chemotherapy exposure, protecting them from chemotherapy-induced damage and enhancing immune activity. Administration of trilaciclib prior to gemcitabine plus carboplatin (GCb) significantly improved overall survival (OS) compared with GCb alone in an open-label phase II trial in patients with metastatic TNBC, potentially through protection and direct activation of immune function. The randomized, double-blind, placebo-controlled, phase III PRESERVE 2 trial will evaluate the efficacy and safety of trilaciclib administered prior to GCb in patients with locally advanced unresectable or metastatic TNBC. Clinical Trial Registration: NCT04799249 (ClinicalTrials.gov).

Identification of Potential Parkinson's Disease Drugs Based on Multi-Source Data Fusion and Convolutional Neural Network

Parkinson’s disease (PD) is a serious neurodegenerative disease. Most of the current treatment can only alleviate symptoms, but not stop the progress of the disease. Therefore, it is crucial to find medicines to completely cure PD. Finding new indications of existing drugs through drug repositioning can not only reduce risk and cost, but also improve research and development efficiently. A drug repurposing method was proposed to identify potential Parkinson’s disease-related drugs based on multi-source data integration and convolutional neural network. Multi-source data were used to construct similarity networks, and topology information were utilized to characterize drugs and PD-associated proteins. Then, diffusion component analysis method was employed to reduce the feature dimension. Finally, a convolutional neural network model was constructed to identify potential associations between existing drugs and LProts (PD-associated proteins). Based on 10-fold cross-validation, the developed method achieved an accuracy of 91.57%, specificity of 87.24%, sensitivity of 95.27%, Matthews correlation coefficient of 0.8304, area under the receiver operating characteristic curve of 0.9731 and area under the precision–recall curve of 0.9727, respectively. Compared with the state-of-the-art approaches, the current method demonstrates superiority in some aspects, such as sensitivity, accuracy, robustness, etc. In addition, some of the predicted potential PD therapeutics through molecular docking further proved that they can exert their efficacy by acting on the known targets of PD, and may be potential PD therapeutic drugs for further experimental research. It is anticipated that the current method may be considered as a powerful tool for drug repurposing and pathological mechanism studies.

Pharmacokinetic Drug-Drug Interaction Studies Between Trilaciclib and Midazolam, Metformin, Rifampin, Itraconazole, and Topotecan in Healthy Volunteers and Patients with Extensive-Stage Small-Cell Lung Cancer

Background and Objective

Trilaciclib is a cyclin-dependent kinase 4/6 inhibitor indicated to decrease the incidence of chemotherapy-induced myelosuppression in patients with extensive-stage small-cell lung cancer. Trilaciclib is a substrate and time-dependent inhibitor of cytochrome P450 3A4 and an inhibitor of multidrug and toxin extrusion 1, multidrug and toxin extrusion 2-K, organic cation transporter 1, and organic cation transporter 2. Here, we investigate the pharmacokinetic drug–drug interaction potential of trilaciclib.

Methods

Two phase I studies were conducted as prospective, open-label, fixed-sequence drug–drug interaction studies in healthy subjects (n = 57, n = 20) to investigate potential interactions between intravenously administered trilaciclib (200 or 240 mg/m²) and orally administered midazolam (5 mg), metformin (1000 mg), itraconazole (200 mg), and rifampin (600 mg). A population pharmacokinetic model was fit to phase Ib/IIa data in patients with extensive-stage small-cell lung cancer (n = 114) to assess the impact of trilaciclib dose and exposure (area under the plasma concentration–time curve) on topotecan clearance.

Results

Coadministration with trilaciclib had minimal effects on the exposure (area under the plasma concentration–time curve from time 0 to infinity) of midazolam (geometric least-square mean ratio [GMR] vs midazolam alone 1.065; 90% confidence interval [CI] 0.984–1.154) but statistically significantly increased plasma exposure (GMR 1.654; 90% CI 1.472–1.858) and decreased renal clearance (GMR 0.633; 90% CI 0.572–0.701) of metformin. Coadministration of trilaciclib with rifampin or itraconazole decreased trilaciclib area under the plasma concentration–time curve from time 0 to infinity by 17.3% (GMR 0.827; 90% CI 0.785–0.871) and 14.0% (GMR 0.860; 0.820–0.902), respectively, vs trilaciclib alone. Population pharmacokinetic modeling showed no significant effect of trilaciclib on topotecan clearance.

Conclusions

Overall, the drug–drug interaction and safety profiles of trilaciclib in these studies support its continued use in patients with extensive-stage small-cell lung cancer.

Clinical Trial Registration

Study 106: EudraCT number: 2019-002303-18; Study 114: not applicable; Study 03: Clinicaltrials.org: NCT02514447; August 2015.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40261-022-01179-x.

Repurposing of anti-lung cancer drugs as multi-target inhibitors of SARS-CoV-2 proteins: An insight from molecular docking and MD-simulation study

Herein we have selected seventeen anti-lung cancer drugs to screen against Mpro, PLpro and spike glycoproteins of SARS-CoV-2to ascertain the potential therapeutic agent against COVID-19. ADMET profiling were employed to evaluate their pharmacokinetic properties. Molecular docking studies revealed that Capmatinib (CAP) showed highest binding affinity against the selected proteins of SARS-CoV-2. Molecular Dynamics (MD) simulation and the analysis of RMSD, RMSF, and binding energy confirmed the abrupt conformational changes of the proteins due to the presence of this drug. These findings provide an opportunity for doing advanced experimental research to evaluate the potential drug to combat COVID-19.

Two birds with one stone: YQSSF regulates both proliferation and apoptosis of bone marrow cells to relieve chemotherapy-induced myelosuppression

ETHNOPHARMACOLOGICAL RELEVANCE

Yiqi Shengsui formula (YQSSF) is a commonly used formula to treat chemotherapy-induced myelosuppression, but little is known about its therapeutic mechanisms.

AIM OF THIS STUDY

This study aims to examine the effect of YQSSF in treating myelosuppression and explore its mechanism.

MATERIALS AND METHODS

A myelosuppression BALB/c mouse model was established by intraperitoneal (i.p.) injection of cyclophosphamide (CTX). The efficacy of YQSSF in alleviating chemotherapy-induced myelosuppression was evaluated by blood cell count, immune organ (thymus, spleen, liver) index, bone marrow nucleated cell (BMNC) count and histopathological analysis of bone marrow and spleen. Then, ultra-performance liquid chromatograph quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) was performed to analyze the ingredients of YQSSF extract. Key effects and potential mechanism of YQSSF extract in alleviating myelosuppression were predicted by network pharmacology method. Finally, cell cycle and TUNEL staining of bone marrow cells was detected to verify the key effects, and RT-qPCR or Western blotting were performed to measure the gene and protein expressions of the effect targets respectively to confirm the predicted mechanism of YQSSF for myelosuppression.

RESULTS

YQSSF up-regulated the number of peripheral blood leukocytes and BMNC, reduced spleen index and liver index, improved the pathological morphology of bone marrow and spleen. A total of 40 ingredients were isolated from YQSSF extract using UPLC-Q/TOF-MS analysis. Network pharmacology revealed that YQSSF regulated both proliferation and apoptosis to alleviate myelosuppression. Finally, YQSSF decreased G0/G1 ratio, increased the proportion of bone marrow cells in S phase and proliferation index (PI), and reduced apoptotic cells in femur bone marrow. RT-qPCR and Western blotting showed that YQSSF up-regulated the expression levels of CDK4, CDK6, CyclinB1, c-Myc and Bcl-2, as well as down-regulated the expression levels of Cyt-c, Fas, Caspase-8/3 and p53.

CONCLUSIONS

YQSSF promotes the proliferation and inhibits the apoptosis of bone marrow cells to relieve chemotherapy-induced myelosuppression.

Cytokinetic-driven myeloprotection after cytotoxic chemotherapy: from an old idea to a new clinical approach

Chemotherapy is the backbone of the treatment of several solid tumours and lymphomas. Myelotoxicity is often a dose-limiting toxicity and myeloprotection has always been investigated. In fact, over the years, several approaches have been studied in order to reduce the incidence of haematological toxicities and allow patients to receive effective, full-dose, chemotherapy. After the use of stimulating factors, such as granulocyte colony-stimulating factors and erythropoiesis-stimulating agents, in the very last years, a new approach has emerged. Trilaciclib, a cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor, has been studied and it has been demonstrated in several clinical trials to reduce the incidence of myelotoxicity in small-cell lung cancer patients treated with chemotherapy or chemo-immunotherapy. Its potential role has not been fully studied yet, but it represents a highly effective tool to reduce myelotoxicity, widen the applicability of full-dose chemotherapy, even in frailer patients, and finally to increase the efficacy of chemotherapy in those tumours where relative dose intensity is a standard to achieve to get the best clinical results.

Treatment patterns and burden of myelosuppression for patients with small cell lung cancer: A SEER-medicare study

PURPOSE

To depict the treatment journey for patients with small cell lung cancer (SCLC) and evaluate health care resource utilization (HCRU) associated with myelosuppression, a complication induced by chemotherapy or chemotherapy plus radiation therapy.

PATIENTS AND METHODS

This was a descriptive, retrospective study of patients with SCLC aged ≥65 years, identified from linked Surveillance, Epidemiology, and End Results (SEER)-Medicare data curated between January 2012 and December 2015. Treatment types (chemotherapy, radiation therapy, surgery) were classified as first, second, or third line, depending on the temporal sequence in which regimens were prescribed. For each year, the proportions of patients completing 4- or 6-cycle chemotherapy regimens, with hospital admissions associated with myelosuppression, or who used granulocyte colony-stimulating factors (G-CSFs), blood/platelet transfusions, or erythropoiesis-stimulating agents (ESAs), were calculated.

RESULTS

Chemotherapy was administered as initial treatment in 7,807/11,907 (65.6%) patients whose treatment journey was recorded. Approximately one-third (n = 3,985) subsequently received radiation therapy. In total, 5,791 (57.8%) patients completed the guideline-recommended 4-6 cycles of chemotherapy. Among all chemotherapy-treated patients, 10,370 (74.3%) experienced ≥1 inpatient admission associated with myelosuppression (anemia, 7,366 [52.8%]; neutropenia, 4,642 [33.3%]; thrombocytopenia, 2,375 [17.0%]; pancytopenia, 1,983 [14.2%]). Supportive care interventions included G-CSF (6,756 [48.4%] patients), ESAs (1,534 [11.0%]), and transfusions (3,674 [26.3%]).

CONCLUSION

Chemotherapy remains a cornerstone of care for patients with SCLC. Slightly over half of patients completed the recommended number of cycles, underscoring the frailty of patients and aggressiveness of SCLC. HCRU associated with myelosuppression was prominent, suggesting a substantial burden on older patients with SCLC.

CDK4/6 inhibitors induce replication stress to cause long-term cell cycle withdrawal

CDK4/6 inhibitors arrest the cell cycle in G1-phase. They are approved to treat breast cancer and are also undergoing clinical trials against a range of other tumour types. To facilitate these efforts, it is important to understand why a cytostatic arrest in G1 causes long-lasting effects on tumour growth. Here, we demonstrate that a prolonged G1 arrest following CDK4/6 inhibition downregulates replisome components and impairs origin licencing. Upon release from that arrest, many cells fail to complete DNA replication and exit the cell cycle in a p53-dependent manner. If cells fail to withdraw from the cell cycle following DNA replication problems, they enter mitosis and missegregate chromosomes causing excessive DNA damage, which further limits their proliferative potential. These effects are observed in a range of tumour types, including breast cancer, implying that genotoxic stress is a common outcome of CDK4/6 inhibition. This unanticipated ability of CDK4/6 inhibitors to induce DNA damage now provides a rationale to better predict responsive tumour types and effective combination therapies, as demonstrated by the fact that CDK4/6 inhibition induces sensitivity to chemotherapeutics that also cause replication stress.

Cyclin-dependent Kinases 4/6 Inhibitors in Neuroendocrine Neoplasms: from Bench to Bedside

PURPOSE OF REVIEW

Cyclin-dependent kinases (CDKs) are key regulators that play an important role in cell division. Palbociclib, ribociclib and abemaciclib showed significant antitumor activity in several malignancies and, recently, also a myeloprotective effect for trilaciclib when added to chemotherapy. The purpose of this review is to highlight the current evidence for CDK4/6 inhibitors in neuroendocrine neoplasms (NENs).

RECENT FINDINGS

Preclinical results showed a promising antitumor activity of CDK4/6 inhibitors in neuroendocrine tumors (NETs), but so far, the very few small clinical trials did not show a strong impact on progression free survival (PFS) and objective response in NETs. Meanwhile, the CDK4/6 inhibitor trilaciclib revealed significant effects in reducing chemotherapy-induced myelosuppression in small cell lung cancer (SCLC). Up to date, CDK4/6 inhibitors are still considered investigational in NETs as antitumor agents, whereas trilaciclib can be used in the routine clinical practice in extensive stage SCLC patients for reducing myelotoxicity of standard chemotherapy.

Trilaciclib Prior to Chemotherapy in Patients with Metastatic Triple-Negative Breast Cancer: Final Efficacy and Subgroup Analysis from a Randomized Phase II Study

PURPOSE

We report final antitumor efficacy results from a phase II study of trilaciclib, an intravenous cyclin-dependent kinase 4/6 (CDK4/6) inhibitor, administered prior to gemcitabine plus carboplatin (GCb) in patients with metastatic triple-negative breast cancer (NCT02978716).

PATIENTS AND METHODS

Patients were randomized (1:1:1) to group 1 [GCb (days 1, 8); n = 34], group 2 [trilaciclib prior to GCb (days 1, 8); n = 33], or group 3 [trilaciclib (days 1, 8) and trilaciclib prior to GCb (days 2, 9); n = 35]. Subgroup analyses were performed according to CDK4/6 dependence, level of programmed death-ligand 1 (PD-L1) expression, and RNA-based immune signatures using proportional hazards regression. T-cell receptor (TCR) β CDR3 regions were amplified and sequenced to identify, quantify, and compare the abundance of each unique TCRβ CDR3 at baseline and on treatment.

RESULTS

Median overall survival (OS) was 12.6 months in group 1, not reached in group 2 (HR = 0.31; P = 0.0016), 17.8 months in group 3 (HR = 0.40; P = 0.0004), and 19.8 months in groups 2 and 3 combined (HR = 0.37; P < 0.0001). Efficacy outcomes were comparable regardless of cancer CDK4/6 dependence status and immune signatures. Administering trilaciclib prior to GCb prolonged OS irrespective of PD-L1 status but had greater benefit in the PD-L1-positive population. T-cell activation was enhanced in patients receiving trilaciclib.

CONCLUSIONS

Administering trilaciclib prior to GCb enhanced antitumor efficacy, with significant improvements in OS. Efficacy outcomes in immunologic subgroups and enhancements in T-cell activation suggest these improvements may be mediated via immunologic mechanisms.

Budget impact analysis of trilaciclib for decreasing the incidence of chemotherapy-induced myelosuppression in patients with extensive-stage small cell lung cancer in the United States

BACKGROUND: Chemotherapy-induced myelosuppression, which commonly manifests as neutropenia, anemia, and/or thrombocytopenia, is a frequent and severe complication of standard treatment regimens for patients with extensive-stage small cell lung cancer (ES-SCLC). Trilaciclib is a first-in-class myeloprotective therapy indicated to decrease the incidence of chemotherapy-induced myelosuppression when administered prior to a platinum-/etoposide-containing regimen or topotecan-containing regimen for ES-SCLC. OBJECTIVE: To estimate the budget impact of administering trilaciclib prior to chemotherapy to manage chemotherapy-induced myelosuppression in adults with ES-SCLC from a US payer perspective. METHODS: A budget impact model was developed to assess the impact of introducing trilaciclib to a hypothetical 1 million-member health insurance plan. The model compared 2 market scenarios: a current scenario of standard treatments for ES-SCLC without trilaciclib, and an alternative scenario of standard treatment plus trilaciclib. Population, clinical, and cost inputs were derived from published literature and trilaciclib clinical trial data. Model outcomes included the number of myelosuppressive adverse events (AEs), costs of treatment, costs of AE management, total cost, and per-member per-month (PMPM) costs. The budget impact of trilaciclib was calculated as the difference in cost (2021 US dollars) between the 2 scenarios over a 1- to 5-year time horizon. Scenario and deterministic sensitivity analyses were conducted to assess uncertainty around key model inputs. RESULTS: An estimated total of 301 patients were eligible for treatment with trilaciclib over a 5-year period. The use of trilaciclib was estimated to reduce the number of myelosuppressive AEs over a 5-year period (events avoided included 108 for neutropenia, 7 for febrile neutropenia, 23 for anemia, and 46 for thrombocytopenia) compared with the scenario without trilaciclib. The adoption of trilaciclib was associated with a cost saving of $801,254 ($0.013 PMPM) over 5 years. The acquisition cost for trilaciclib ($3,704,199) was offset by the reduction in AE management cost ($4,282,748) and reduction in prophylactic granulocyte colony-stimulating factor use ($222,704). The cost savings associated with trilaciclib began in year 1 (total $34,388; $0.003 PMPM) and accrued over time. CONCLUSIONS: The acquisition cost of trilaciclib is projected to be offset by a reduction in the costs of managing AEs related to myelosuppression when added to standard chemotherapy regimens for ES-SCLC. The net budget impact of trilaciclib is estimated to be a cost saving. DISCLOSURES: This research was funded by G1 Therapeutics, Inc., and implemented by ZS Associates, an independent consultancy that collated the model inputs and performed the budget impact analysis. The study sponsor was involved in the study design; collection, analysis, and interpretation of data; writing of the report; and the decision to submit the report for publication. The journal open access fee was funded by G1 Therapeutics, Inc. Moran, Chioda, and Huang are employed by G1 Therapeutics, Inc. Chioda and Huang report stocks and stock options for G1 Therapeutics, Inc. Goyal and Deniz are employed by ZS Associates. Goyal reports consulting fees from G1 Therapeutics, Inc. Abraham reports consulting fees from Coherus, G1 Therapeutics, Inc. (unrelated to this study and manuscript), Mylan/Viatris, and Sandoz and participation on a data safety monitoring board or advisory board for G1 Therapeutics, Inc. MacDonald reports consulting fees from Coherus, G1 Therapeutics, Inc. (unrelated to this study and manuscript), Mylan/Viatris, and Sandoz. Deniz reports no disclosures. A synopsis of the current study was presented in poster format at the Virtual AMCP Annual Meeting, April 12-16, 2021.