Cancer Clinical Trials: The Rear-View Mirror and the Crystal Ball

Decision-making and autonomy among participants in early-phase cancer immunotherapy trials: a qualitative study

BACKGROUND

Participants considering early-phase cancer clinical trials (CTs) need to understand the unique risks and benefits prior to providing informed consent. This qualitative study explored the factors that influence patients' decisions about participating in early-phase cancer immunotherapy CTs through the ethical lens of relational autonomy.

METHODS

Using an interpretive descriptive design, interviews were conducted with 21 adult patients with advanced cancer who had enrolled in an early-phase CT. Data was analyzed using relational autonomy ethical theory and constant comparative analysis.

RESULTS

The extent to which participants perceived themselves as having a choice to participate in early-phase cancer immunotherapy CTs was a central construct. Perceptions of choice varied according to whether participants characterized their experience as an act of desperation or as an opportunity to receive a novel treatment. Intersecting psychosocial and structural factors influenced participants' decision making about participating in early-phase cancer immunotherapy trials. These relational factors included: (1) being provided with hope; (2) having trust; (3) having the ability to withdraw; and (4) timing constraints.

CONCLUSIONS

Findings highlight the continuum of perceived choice that exists among patients with cancer when considering participation in early-phase cancer immunotherapy CTs. All participants were interpreted as exhibiting some degree of relational autonomy within the psychosocial and structural context of early-phase CT decision making. This study offers insights into the intersection of cancer care delivery, personal beliefs and values, and established CT processes and structures that can inform future practices and policies associated with early-phase cancer immunotherapy CTs to better support patients in making informed decisions.

Biosimilar versus branded enoxaparin to prevent postoperative venous thromboembolism after surgery for digestive tract cancer: Randomized trial

Cancer and/or major surgery are two factors that predispose to post-operative thrombosis. The annual incidence of venous thromboembolic disease (VTED) in cancer patients was estimated at 0.5%-20%. Surgery increases the risk of VTED by 29% in the absence of thromboprophylaxis. Enoxaparin is a low molecular weight heparin that is safe and effective. Branded Enoxaparin and biosimilar Enoxaparin are two enoxaparin treatments. This study aimed to compare Branded Enoxaparin with biosimilar Enoxaparin in patients operated on for digestive cancer regarding the prevention of postoperative thrombosis event, to compare the tolerance of the two treatments and to identify independent predictive factors of thromboembolic incident. A randomized controlled trial conducted in a single-centre, surgical department B of Charles Nicolle Hospital, over a 5-year period from October 12th, 2015, to July 08th, 2020. We included all patients over 18 who had cancer of the digestive tract newly diagnosed, operable and whatever its nature, site, or stage, operated on in emergency or elective surgery. The primary endpoint was any asymptomatic thromboembolic event, demonstrated by systematic US Doppler of the lower limbs on postoperative day 7 to day 10. The sonographer was unaware of the prescribed treatment (Branded Enoxaparin [BE] or biosimilar Enoxaparin [BSE]). Of one hundred sixty-eight enrolled patients, six patients (4.1%) had subclinical venous thrombosis. Among those who had subclinical thrombosis, four patients (5.6%) were in the Branded Enoxaparin group and two patients (2.7%) in the Biosimilar Enoxaparin group without statistically significant difference (p = 0.435). Analysis of the difference in means using Student's t test demonstrated the equivalence of the two treatments. Our study allowed us to conclude that there was no statistically significant difference between Branded Enoxaparin and Biosimilar Enoxaparin regarding the occurrence of thromboembolic accidents postoperatively. BE and BSE are equivalent. Trial registration. Trial registration: The trial was registered on CLINICALTRIALS.GOV under the number NCT02444572.

A mathematical investigation of polyaneuploid cancer cell memory and cross-resistance in state-structured cancer populations

The polyaneuploid cancer cell (PACC) state promotes cancer lethality by contributing to survival in extreme conditions and metastasis. Recent experimental evidence suggests that post-therapy PACC-derived recurrent populations display cross-resistance to classes of therapies with independent mechanisms of action. We hypothesize that this can occur through PACC memory, whereby cancer cells that have undergone a polyaneuploid transition (PAT) reenter the PACC state more quickly or have higher levels of innate resistance. In this paper, we build on our prior mathematical models of the eco-evolutionary dynamics of cells in the 2N+ and PACC states to investigate these two hypotheses. We show that although an increase in innate resistance is more effective at promoting cross-resistance, this trend can also be produced via PACC memory. We also find that resensitization of cells that acquire increased innate resistance through the PAT have a considerable impact on eco-evolutionary dynamics and extinction probabilities. This study, though theoretical in nature, can help inspire future experimentation to tease apart hypotheses surrounding how cross-resistance in structured cancer populations arises.

Patient-derived cancer models: Valuable platforms for anticancer drug testing

Molecularly targeted treatments and immunotherapy are cornerstones in oncology, with demonstrated efficacy across different tumor types. Nevertheless, the overwhelming majority metastatic disease is incurable due to the onset of drug resistance. Preclinical models including genetically engineered mouse models, patient-derived xenografts and two- and three-dimensional cell cultures have emerged as a useful resource to study mechanisms of cancer progression and predict efficacy of anticancer drugs. However, variables including tumor heterogeneity and the complexities of the microenvironment can impair the faithfulness of these platforms. Here, we will discuss advantages and limitations of these preclinical models, their applicability for drug testing and in co-clinical trials and potential strategies to increase their reliability in predicting responsiveness to anticancer medications.

Innovative highlights of clinical drug trial design

Clinical trials serve as the gold standard to evaluate the efficacy and safety of tested drugs prior to marketing authorization. Nevertheless, there have been a few challenging issues well noted in traditional clinical trials such as tedious processing duration and escalating high costs among others. To improve the efficiency of clinical studies, a spectrum of expedited clinical trial modes has been designed, and selectively implemented in contemporary drug developing landscape. Herein this article presents an update on the innovated human trial designs that are corroborated through coming up with approval of notable therapeutic compounds for clinical utilization including delivery of several blockbuster products. It is intended to inspire clinical investigators and pharmaceutical development not only timely communicating with the regulatory agencies, but also insightful translating from cutting-edge scientific discoveries.

Enhancing global access to cancer medicines

Globally, cancer is the second leading cause of death, with numbers greatly exceeding those for human immunodeficiency virus/acquired immunodeficiency syndrome, tuberculosis, and malaria combined. Limited access to timely diagnosis, to affordable, effective treatment, and to high-quality care are just some of the factors that lead to disparities in cancer survival between countries and within countries. In this article, the authors consider various factors that prevent access to cancer medicines (particularly access to essential cancer medicines). Even if an essential cancer medicine is included on a national medicines list, cost might preclude its use, it might be prescribed or used inappropriately, weak infrastructure might prevent it being accessed by those who could benefit, or quality might not be guaranteed. Potential strategies to address the access problems are discussed, including universal health coverage for essential cancer medicines, fairer methods for pricing cancer medicines, reducing development costs, optimizing regulation, and improving reliability in the global supply chain. Optimizing schedules for cancer therapy could reduce not only costs, but also adverse events, and improve access. More and better biomarkers are required to target patients who are most likely to benefit from cancer medicines. The optimum use of cancer medicines depends on the effective delivery of several services allied to oncology (including laboratory, imaging, surgery, and radiotherapy). Investment is necessary in all aspects of cancer care, from these supportive services to technologies, and the training of health care workers and other staff.

The Emerging Potential for Network Analysis to Inform Precision Cancer Medicine

Precision cancer medicine promises to tailor clinical decisions to patients using genomic information. Indeed, successes of drugs targeting genetic alterations in tumors, such as imatinib that targets BCR-ABL in chronic myelogenous leukemia, have demonstrated the power of this approach. However, biological systems are complex, and patients may differ not only by the specific genetic alterations in their tumor, but also by more subtle interactions among such alterations. Systems biology and more specifically, network analysis, provides a framework for advancing precision medicine beyond clinical actionability of individual mutations. Here we discuss applications of network analysis to study tumor biology, early methods for N-of-1 tumor genome analysis, and the path for such tools to the clinic.

Targeting the cell cycle in breast cancer: towards the next phase

Deregulation of the cell cycle is a hallmark of cancer that enables limitless cell division. To support this malignant phenotype, cells acquire molecular alterations that abrogate or bypass control mechanisms in signaling pathways and cellular checkpoints that normally function to prevent genomic instability and uncontrolled cell proliferation. Consequently, therapeutic targeting of the cell cycle has long been viewed as a promising anti-cancer strategy. Until recently, attempts to target the cell cycle for cancer therapy using selective inhibitors have proven unsuccessful due to intolerable toxicities and a lack of target specificity. However, improvements in our understanding of malignant cell-specific vulnerabilities has revealed a therapeutic window for preferential targeting of the cell cycle in cancer cells, and has led to the development of agents now in the clinic. In this review, we discuss the latest generation of cell cycle targeting anti-cancer agents for breast cancer, including approved CDK4/6 inhibitors, and investigational TTK and PLK4 inhibitors that are currently in clinical trials. In recognition of the emerging population of ER+ breast cancers with acquired resistance to CDK4/6 inhibitors we suggest new therapeutic avenues to treat these patients. We also offer our perspective on the direction of future research to address the problem of drug resistance, and discuss the mechanistic insights required for the successful implementation of these strategies.

Postmarketing Modifications of Drug Labels for Cancer Drugs Approved by the US Food and Drug Administration Between 2006 and 2016 With and Without Supporting Randomized Controlled Trials

Purpose

Modifications in cancer drug indications, dosing, and related toxicities after Food and Drug Administration approval are common. It is unclear whether drug approval without a supporting randomized controlled trial (RCT) influences the probability of such modifications.

Methods

We searched the Drugs@FDA Web site for new drug indications for solid tumors approved between January 2006 and December 2016. Study characteristics, regulatory pathways, and label modifications from approval to October 2017 were collected from drug labels. Label modifications were considered to be major if defined as such in the drug label. Indications approved with and without supporting RCTs were compared using logistic regression. The Benjamini-Hochberg false discovery rate method was used to adjust for multiplicity.

Results

We identified 59 individual drugs for 109 solid tumor indications. Of these, 17 indications (15.6%) were not supported by an RCT, with no change over time. Indications not supported by RCTs were more likely to require companion diagnostic tests (odds ratio [OR], 3.90; P = .02), to include surrogate end points as primary outcomes (OR, 7.88; P < .001), and to receive breakthrough therapy designation (OR, 7.62; P = .006) or accelerated approval (OR, 17.67; P < .001). Indications not supported by RCTs were associated with significantly higher odds of postapproval modifications in common adverse events (71% v 29%; OR, 5.78; P = .002). A nonsignificantly higher odds of postapproval major modifications in warnings and precautions was also observed (88% v 62%; OR, 4.61; P = .051). Postapproval major modifications in indication and usage, dosing and administration, boxed warnings, and contraindications were comparable in the two groups.

Conclusion

Cancer drug indications not supported initially by RCTs are associated with more postmarketing safety-related label modifications. Health care professionals should be vigilant for unrecognized adverse effects when prescribing drugs approved without a supporting RCT.

Disruption of the anaphase-promoting complex confers resistance to TTK inhibitors in triple-negative breast cancer

TTK protein kinase (TTK), also known as Monopolar spindle 1 (MPS1), is a key regulator of the spindle assembly checkpoint (SAC), which functions to maintain genomic integrity. TTK has emerged as a promising therapeutic target in human cancers, including triple-negative breast cancer (TNBC). Several TTK inhibitors (TTKis) are being evaluated in clinical trials, and an understanding of the mechanisms mediating TTKi sensitivity and resistance could inform the successful development of this class of agents. We evaluated the cellular effects of the potent clinical TTKi CFI-402257 in TNBC models. CFI-402257 induced apoptosis and potentiated aneuploidy in TNBC lines by accelerating progression through mitosis and inducing mitotic segregation errors. We used genome-wide CRISPR/Cas9 screens in multiple TNBC cell lines to identify mechanisms of resistance to CFI-402257. Our functional genomic screens identified members of the anaphase-promoting complex/cyclosome (APC/C) complex, which promotes mitotic progression following inactivation of the SAC. Several screen candidates were validated to confer resistance to CFI-402257 and other TTKis using CRISPR/Cas9 and siRNA methods. These findings extend the observation that impairment of the APC/C enables cells to tolerate genomic instability caused by SAC inactivation, and support the notion that a measure of APC/C function could predict the response to TTK inhibition. Indeed, an APC/C gene expression signature is significantly associated with CFI-402257 response in breast and lung adenocarcinoma cell line panels. This expression signature, along with somatic alterations in genes involved in mitotic progression, represent potential biomarkers that could be evaluated in ongoing clinical trials of CFI-402257 or other TTKis.