Dose-limiting toxicity and maximum tolerated dose: still fit for purpose?

Effectiveness and Toxicity Profile of Reduced Dose Sorafenib for the Treatment of Hepatocellular Carcinoma: A Retrospective, Single Institutional Experience

Background The treatment with sorafenib in hepatocellular carcinoma (HCC) is affected by toxicity and discontinuation rates. There is limited data on whether ensuring compliance by reducing the dose of sorafenib can influence outcomes. Methods In this retrospective study, we used hospital records to retrieve data on patients treated with low-dose sorafenib (400 mg /day) from July 2017 to June 2022 at the Malabar Cancer Centre, Thalassery. Results During the study period, 80 patients received low-dose sorafenib for HCC. Sixty-eight (85%) patients were males with median age being 62 years, ranging from 17 to 79 years. More than three-fourths (76.2%) of the patients had Barcelona stage C and nearly one-third (31.2%) had Child-Pugh B status. Alcohol consumption and obesity were seen in 36 (45%) and 24 (30%) patients respectively. Clinical benefit rate (at least stable disease) at three months was seen for 45 (56.25%) patients. The median follow-up was six months. The median progression-free survival (PFS) and overall survival (OS) were 3.68 (CI 2.89-4.46) and 5.26 (CI 3.26-7.27) months respectively. Nine patients (11.25%) had grade 3 toxicity, and six (7.5%) patients stopped sorafenib due to toxicity despite dose reduction. Conclusion In comparison to other published landmark studies, our study demonstrates that reduced dose sorafenib in advanced hepatocellular carcinoma has a similar response rate and progression-free survival with lesser toxicity. In the real world, a reduced dose of sorafenib is nevertheless effective when tolerance and cost are concerns. Additionally, since a third of the study cohort has Child-Pugh B, a reduced dose of sorafenib may be a choice for these patients.

Universal CAR 2.0 to overcome current limitations in CAR therapy

Chimeric antigen receptor (CAR) T cell therapy has effectively complemented the treatment of advanced relapsed and refractory hematological cancers. The remarkable achievements of CD19- and BCMA-CAR T therapies have raised high expectations within the fields of hematology and oncology. These groundbreaking successes are propelling a collective aspiration to extend the reach of CAR therapies beyond B-lineage malignancies. Advanced CAR technologies have created a momentum to surmount the limitations of conventional CAR concepts. Most importantly, innovations that enable combinatorial targeting to address target antigen heterogeneity, using versatile adapter CAR concepts in conjunction with recent transformative next-generation CAR design, offer the promise to overcome both the bottleneck associated with CAR manufacturing and patient-individualized treatment regimens. In this comprehensive review, we delineate the fundamental prerequisites, navigate through pivotal challenges, and elucidate strategic approaches, all aimed at paving the way for the future establishment of multitargeted immunotherapies using universal CAR technologies.

Reporting and impact of subsequent cycle toxicities in oncology phase I clinical trials

BACKGROUND/AIMS

As oncology treatments evolve, classic assumptions of toxicity associated with cytotoxic agents may be less relevant, requiring new design strategies for trials intended to inform dosing strategies for agents that may be administered beyond a set number of defined cycles. We describe the overall incidence of dose-limiting toxicities during and after cycle 1, frequency of reporting subsequent cycle toxicities, and the impact of post-cycle 1 dose-limiting toxicities on conclusions drawn from oncology phase 1 clinical trials.

METHODS

We conducted a systematic review of subsequent cycle toxicities in oncology phase I clinical trials published in the Journal of Clinical Oncology from 2000 to 2020. We used chi-square tests and multivariate logistic regression to describe predictors of reporting subsequent cycle toxicity data.

RESULTS

From 2000 to 2020, we identified 489 articles reporting on therapeutic phase 1 clinical trials. Of these, 421 (86%) reported data regarding cycle 1 dose-limiting toxicities and 170 (35%) reported data on cycle 1 dose modifications. Of the trials that reported cycle 1 dose-limiting toxicities, the median percentage of patients that experienced cycle 1 dose-limiting toxicities was 8.89%. Only 47 (9.6%) publications reported on post-cycle 1 dose-limiting toxicities and only 92 (19%) reported on dose modifications beyond cycle 1. Of the trials that reported post-cycle 1 dose-limiting toxicities, the median percentage of patients that experienced post-cycle 1 dose-limiting toxicities was 14.8%. Among the 371 studies with a recommended phase 2 dose, 89% did not report whether post-cycle 1 toxicities impacted the recommended phase 2 dose. More recent year of publication was independently associated with reduced odds of reporting subsequent cycle toxicity.

CONCLUSION

Reporting of subsequent cycle toxicity is uncommon in oncology phase I clinical trial publications and becoming less common over time. Guidelines for reporting of phase I oncology clinical trials should expand to include toxicity data beyond the first cycle.

Dose-limiting mucositis: friend or foe?

Dose-limiting toxicities are ubiquitous to cancer-directed therapy, presenting with severity to a degree that necessitates therapy de-escalation, pause, or discontinuation. To date, there is incredible limited understanding if these therapy de-escalations present risk for survival by limiting delivery of intensive therapy, or if they indicate physiologic susceptibility and are a favorable prognostic indicator. Mucositis is an excellent illustration of the current paradox of dose-limiting toxicities-it has existed alongside therapy for eight decades, but despite its presence, there is an incomplete understanding of how it develops, why it varies between oncologic populations, and if it relates to cancer survival. Rigorous methodologic approaches in symptom science holds potential to better understand mucositis, to determine if it is a marker of response or threat, and evaluate if it holds potential to guide therapy delivery.

Special considerations in the design and implementation of pediatric otoprotection trials

PURPOSE

Cisplatin-induced hearing loss (CIHL) is a common late effect after childhood cancer treatment having profound, lifelong consequences that lower quality of life. The recent identification of intravenous sodium thiosulfate (STS) as an effective agent for preventing pediatric CIHL represents a paradigm shift that has created new opportunities for expanding STS usage and developing additional otoprotectants. The purpose of this paper is to discuss key considerations and recommendations for the design and implementation of future pediatric otoprotection trials.

METHODS

An approach synthesizing published data and collective experience was used.

RESULTS

Key issues were identified in the categories of translational research, trial designs for systemic and intratympanic agents, measurement of ototoxicity, and biostatistical challenges.

CONCLUSIONS

Future pediatric otoprotection trials should emphasize (1) deep integration of preclinical and early-phase studies; (2) an embedded or free-standing design for systemic agents based on mechanistic considerations; (3) use of suitable audiologic testing batteries for children, SIOP grading criteria, and submission of raw audiologic data for central review; and (4) novel endpoints and innovative study designs that maximize trial efficiency for limited sample sizes. Additional recommendations include routine collection of DNA specimens for assessing modifying effects of genetic susceptibility and meaningful inclusion of patient/family advocates for informing trial development.

IMPLICATIONS FOR CANCER SURVIVORS

Changing the historical paradigm from acceptance to prevention of pediatric CIHL through expanded research with existing and emerging otoprotectants will dramatically improve quality of life for future childhood cancer survivors exposed to cisplatin.

Experimental Medicine Approaches in Early-Phase CNS Drug Development

Traditionally, Phase 1 clinical trials were largely conducted in healthy normal volunteers and focused on collection of safety, tolerability, and pharmacokinetic data. However, in the CNS therapeutic area, with more drugs failing in later phase development, Phase 1 trials have undergone an evolution that includes incorporation of novel approaches involving novel study designs, inclusion of biomarkers, and early inclusion of patients to improve the pharmacologic understanding of novel CNS-active compounds early in clinical development with the hope of improving success in later phase pivotal trials. In this chapter, the authors will discuss the changing landscape of Phase 1 clinical trials in CNS, including novel trial methodology, inclusion of pharmacodynamic biomarkers, and experimental medicine approaches to inform early decision-making in clinical development.

A Phase I/IIa Randomized Trial Evaluating the Safety and Efficacy of SNK01 Plus Pembrolizumab in Patients with Stage IV Non-Small Cell Lung Cancer

PURPOSE

The aim of this study is to evaluate the safety and efficacy of ex vivo activated and expanded natural killer (NK) cell therapy (SNK01) plus pembrolizumab in a randomized phase I/IIa clinical trial.

MATERIALS AND METHODS

Overall, 18 patients with advanced non-small cell lung cancer (NSCLC) and a programmed death ligand 1 tumor proportion score of 1% or greater who had a history of failed frontline platinum-based therapy were randomized (2:1) to receive pembrolizumab every 3 weeks +/- 6 weekly infusions of SNK01 at either 2×109 or 4×109 cells per infusion (pembrolizumab monotherapy vs. SNK01 combination). The primary endpoint was safety, whereas the secondary endpoints were the objective response rate (ORR), progression-free survival (PFS), overall survival, and quality of life.

RESULTS

Since no dose-limiting toxicity was observed, the maximum tolerated dose was determined as SNK01 4×109 cells/dose. The safety data did not show any new safety signals when SNK01 was combined with pembrolizumab. The ORR and the 1-year survival rate in the NK combination group were higher than those in patients who underwent pembrolizumab monotherapy (ORR, 41.7% vs. 0%; 1-year survival rate, 66.7% vs. 50.0%). Furthermore, the median PFS was higher in the SNK01 combination group (6.2 months vs. 1.6 months, p=0.001).

CONCLUSION

Based on the findings of this study, the NK cell combination therapy may consider as a safe treatment method for stage IV NSCLC patients who had a history of failed platinum-based therapy without an increase in adverse events.

New strategies for targeting kinase networks in cancer

Targeted strategies against specific driver molecules of cancer have brought about many advances in cancer treatment since the early success of the first small-molecule inhibitor Gleevec. Today, there are a multitude of targeted therapies approved by the Food and Drug Administration for the treatment of cancer. However, the initial efficacy of virtually every targeted treatment is often reversed by tumor resistance to the inhibitor through acquisition of new mutations in the target molecule, or reprogramming of the epigenome, transcriptome, or kinome of the tumor cells. At the core of this clinical problem lies the assumption that targeted treatments will only be efficacious if the inhibitors are used at their maximum tolerated doses. Such aggressive regimens create strong selective pressure on the evolutionary progression of the tumor, resulting in resistant cells. High-dose single agent treatments activate alternative mechanisms that bypass the inhibitor, while high-dose combinatorial treatments suffer from increased toxicity resulting in treatment cessation. Although there is an arsenal of targeted agents being tested clinically and preclinically, identifying the most effective combination treatment plan remains a challenge. In this review, we discuss novel targeted strategies with an emphasis on the recent cross-disciplinary studies demonstrating that it is possible to achieve antitumor efficacy without increasing toxicity by adopting low-dose multitarget approaches to treatment of cancer and metastasis.

Metabolic Modulation of the Tumor Microenvironment Leads to Multiple Checkpoint Inhibition and Immune Cell Infiltration

Cancer cells are known to be glycolytic, driving increased glucose consumption and its conversion to lactate. This process modulates the tumor microenvironment (TME). In the TME, glycolytically activated immune cells often become anergic, leading to an increase in immune checkpoint proteins such as programmed cell death protein-1 (PD-1) and cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4). Most glycolytic inhibitors not only inhibit glycolysis of cancer but also of immune cells. Therefore, using a nanoparticle-delivered agent to preferentially inhibit glycolysis in tumor cells, and not in immune cells, has the potential to attenuate the expression of checkpoint proteins. Pyruvate dehydrogenase kinase 1 (PDK1) can be an important target to achieve tumor specific glycolysis inhibition. We report TME modulation by a mitochondrion-targeted nanoparticle (NP) containing a prodrug of dichloroacetate (DCA), a PDK1 inhibitor. We demonstrated that the targeted NP alters the TME which results in increased immunological activation against cancer cells, causing a decrease in mean tumor volume. Here, we also show findings that when Mito-DCA, a prodrug of DCA, was combined with anti-PD-1, a checkpoint inhibitor, results from in vivo syngeneic models showed an upregulation in the number of tumor infiltrating lymphocytes. This work provides a platform to bring therapeutic efficacy by selectively inhibiting glycolysis of cancer cells.

Immune cells as tumor drug delivery vehicles

This review article describes the use of immune cells as potential candidates to deliver anti-cancer drugs deep within the tumor microenvironment. First, the rationale of using drug carriers to target tumors and potentially decrease drug-related side effects is discussed. We further explain some of the current limitations when using nanoparticles for this purpose. Next, a comprehensive step-by-step description of the migration cascade of immune cells is provided as well as arguments on why immune cells can be used to address some of the limitations associated with nanoparticle-mediated drug delivery. We then describe the benefits and drawbacks of using red blood cells, platelets, granulocytes, monocytes, macrophages, myeloid-derived suppressor cells, T cells and NK cells for tumor-targeted drug delivery. An additional section discusses the versatility of nanoparticles to load anti-cancer drugs into immune cells. Lastly, we propose increasing the circulatory half-life and development of conditional release strategies as the two main future pillars to improve the efficacy of immune cell-mediated drug delivery to tumors.

Ribociclib (LEE011) suppresses cell proliferation and induces apoptosis of MDA-MB-231 by inhibiting CDK4/6-cyclin D-Rb-E2F pathway

Triple-negative breast cancer (TNBC) stands for a refractory subtype, which predicts poor prognosis and has no effective therapies yet for improving it. Given the restrictions of traditional treatments, novel therapeutic strategies need excavating to alleviate the intrinsic or acquired resistance. Ribociclib, a selective CDK4/6 inhibitor, has successfully prevented cancers from deteriorating by intervening the CDK4/6-cyclin D-Rb-E2F pathway, especially for estrogen receptor-positive (ER +) breast cancer. However, there still remains limited accessibility referring to TNBC. Performing experiments on MDA-MB-231 cells, we found that LEE011 could suppress cell proliferation, and this suppression tended to be dose-dependently. Western blotting analysis presented significant decrease with the expression of CDK4/6 after LEE011 treated, and other proteins associated with this axis such as cyclin D1, p-Rb, Rb, E2F1 showed aberrant changes. Moreover, LEE011 induced G₀-G₁ phase cell cycle arrest, promoted cell apoptosis, and reduced cell migration in vitro. In addition, tumor growth was remarkably impeded without obvious side-effects in MDA-MB-231 xenograft models. Our research has identified that LEE011 was not completely invalid for MDA-MB-231. Considering its pivotal status in TNBC, the CDK4/6-cyclin D-Rb-E2F pathway informed us the possibility and practicality of Ribociclib (LEE011) as pharmacological intervention, but challenges warrant further validation in prospective studies.

Dacomitinib in non-small-cell lung cancer: a comprehensive review for clinical application

Dacomitinib is a second-generation EGFR tyrosine kinase inhibitor (TKI) that irreversibly binds to and inhibits EGFR/Her1, Her2 and Her4 subtypes with an efficacy comparable to other TKIs. In the ARCHER 1050 trial, progression-free survival was improved by dacomitinib compared with gefitinib, supporting dacomitinib as a first-line treatment option for advanced non-small-cell lung cancer with sensitive EGFR mutation. Regarding to the higher adverse events rate, dose reductions did not reduce the efficacy of dacomitinib and could effectively decreased the incidence and severity of adverse events. Considering the evolving landscape of EGFR-mutant non-small-cell lung cancer, future head to head comparison between dacomitinib and osimertinib could provide key information to determine the optimal TKI treatment schedule.

Trends in the characteristics, dose-limiting toxicities and efficacy of phase I oncology trials: The Cancer Research UK experience

INTRODUCTION

Phase I oncology trials have evolved over the years, and these changes could have implications for future studies and patients.

METHODS

Adult trials sponsored by Cancer Research UK Centre for Drug Development between 1995 and 2013 were analysed. Forty-nine trials were divided into two groups based on the starting date for recruitment: 1995-2003 (24 trials, n = 603) and 2004-2013 (25 trials, n = 750) for comparative purposes.

RESULTS

From 1995-2003 to 2004-2013, there was a shift towards studying non-cytotoxic agents that are administered orally. In later trials, patients tended to have better performance status, were older, had greater disease burden, and were more likely to have received prior treatment. In 2004-2013, wider variety of dose escalation designs were used, and studies were more likely to be multicentre, target/disease specific, conducted in first-/any-line setting and to require tumour biopsy. The overall incidence of dose-limiting toxicities (DLTs) was unchanged (10.9%; risk of death 0.4%), but DLTs such as neuropathy, stomatitis and thrombocytopaenia were less frequent in the more recent trials, while elevated liver enzymes were more frequent. Non-classical DLTs emerged in the later trials, including hypertension, hypophosphataemia, cardiac and ophthalmic toxicities. Disease control rate (DCR) increased from 27.9% (1995-2003) to 36.0% (2004-2013; P = 0.0033) due to higher rates of disease stabilisation.

CONCLUSION

Changes in trial designs, therapeutic agents, patient characteristics and DLTs were observed. Although the nature of DLTs changed, the incidence was similar in the two time periods and DCR improved, suggesting that the benefit-risk balance for patients participating in early-phase trials remains acceptable.