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

Views of IRB members regarding phase 1 pediatric oncology trials

There is significant debate over whether phase 1 pediatric oncology trials are ethical and approvable. We thus surveyed IRB members to answer four questions. First, do IRB members think the potential medical benefits of average phase 1 pediatric oncology trials justify the risks? Second, do they think these trials are ethically appropriate? Third, do they think these trials are approvable? Fourth, how do the views of IRB members on the first two questions compare to the views of the US public? Of the 80 respondents who answered the test questions correctly, 18.8% stated that the potential medical benefits of average phase 1 pediatric oncology trials outweigh the risks, 32.5% stated that the potential medical benefits and risks are about equal, and 48.8% stated that the risks outweigh the potential medical benefits. Compared to the general public, IRB members were significantly more likely to think the risks outweigh the potential medical benefits (p = 0.01). Finally, 68.8% of IRB members indicated that average phase 1 pediatric oncology trials are approvable, and 56.3% indicated that these trials are appropriate in children. These findings suggest two-thirds of IRB members believe average phase 1 pediatric oncology trials are approvable. Yet, almost half regard the risks as outweighing the potential medical benefits and almost half think these trials are inappropriate. These findings raise important questions regarding why IRB members and the general public evaluate the same risk/benefit profile differently, and whether it is possible to reconcile the two perspectives.

Acceptable Risks in Pediatric Research: Views of the US Public

BACKGROUND AND OBJECTIVES

Critics argue that it is unethical to expose children to research risks for the benefit of others, whereas many regulations permit "net-risk" pediatric research but only when the risks are minimal. In the present survey, we assessed whether the US public agrees with these views and whether the US public's views regarding the acceptability of net-risk pediatric research are influenced by its social value.

METHODS

A 15-minute survey of a nationally representative sample of US adults. Participants were randomly assigned to 1 of 4 hypothetical scenarios involving procedures that pose increasing levels of risk. To assess whether respondents' views on the acceptability of the risks is influenced by the social value of the research, in each of the 4 scenarios we described the respective procedure being used in 3 studies with increasing levels of social value.

RESULTS

A total 1658 of the 2508 individuals who were sent the survey link participated (response rate = 66.1%). Approximately 91% approved of a research blood draw in minors, and ∼69% approved of a research bone marrow biopsy. The proportion who indicated that the respective procedure was acceptable increased as the study's social value increased. This effect was significantly stronger for studies which pose greater risks compared with studies with lower risks (P < .001).

CONCLUSIONS

The vast majority of the US public supports net-risk pediatric research that poses minimal risk, and a majority supports net-risk pediatric research that poses somewhat greater risks, provided it has high social value. These findings offer important information for assessing when it is acceptable to conduct net-risk pediatric research.

Do the Potential Medical Benefits of Phase 1 Pediatric Oncology Trials Justify the Risks? Views of the United States Public

OBJECTIVES

To assess the US public's views on whether the potential medical benefits of phase 1 pediatric oncology trials justify the risks.

STUDY DESIGN

Online survey of a nationally representative sample of US adults. Participants were presented with a hypothetical scenario in which they have a 10-year-old child with advanced cancer. They were then offered the option of giving their child supportive care or trying one more potential treatment, in the research or clinical care setting, which has the same risks and potential medical benefits as the average phase 1 pediatric oncology trial. We assessed what percentage of respondents thought the potential medical benefits justify the risks.

RESULTS

In total, 1658 of the 2508 individuals who were sent the survey participated (response rate = 66.1%). Of those who passed all 3 test questions indicating understanding, 67.1% in the research scenario and 58.5% in the clinical care scenario regarded the potential medical benefits of an average phase 1 pediatric oncology trial as equal to or greater than the risks. In addition, 53.4% of respondents in the research scenario thought it was appropriate for researchers to conduct a study in children with these risks and potential medical benefits, and 46.9% stated they would enroll their own child in such a trial.

CONCLUSIONS

A majority of the US public regards the potential medical benefits of average phase 1 pediatric oncology trials as justifying the risks. This finding suggests that these trials are ethically appropriate and approvable in patients who have no more effective treatment options. At the same time, a significant minority thought the potential medical benefits do not justify the risks, suggesting these trials should be approved only when they have significant social value. Moreover, approximately one-half of respondents regarded the trials as inappropriate and would not enroll their own child, underscoring the need for a rigorous informed consent process that accurately educates parents regarding the risks, potential medical benefits, and alternatives, so they can decide whether to enroll their child based on their own preferences and goals.

Revisiting Risk and Benefit in Early Oncology Trials in the Era of Precision Medicine: A Systematic Review and Meta-Analysis of Phase I Trials of Targeted Single-Agent Anticancer Therapies

PURPOSE

Phase I trials are a crucial step in the evaluation of new cancer therapies. Historically, low rates of response (5%) and comparably high rates of death from toxicities (0.5%) have contributed to debates on the ethics and orientation of these trials. With the introduction of novel targeted therapies, a contemporary estimate is needed.

METHODS

We systematically searched PubMed, Embase, and ClinicalTrials.gov for reports of phase I oncology trials of single-agent targeted immunomodulators, molecularly targeted therapies, and antiangiogenic agents, published between January 2015 and July 2018. Adult and pediatric trials of solid and hematological malignancies were eligible. Treatment-related adverse events (grades 3, 4, and 5) and response rates (objective, complete, and partial) were extracted and analyzed.

RESULTS

One hundred and fifty-eight trial reports, covering 6,707 patients, were included. The rate of treatment-related deaths was 0.0% (95% CI, 0.0 to 0.1), while 13.2% of patients (9.5 to 17.3) experienced a grade 3 or 4 treatment-related toxicity. The combined objective response rate was 6.4% (4.6 to 8.5). Among trials using tumor biomarkers as eligibility criteria, the objective response rate was higher (12.0% [7.3 to 17.6] compared to 4.9% [2.5 to 5.7], P value < .01). The same was true of trials focusing on a single tumor type (13.4% [8.2 to 19.4]) compared to multiple tumor types (3.8% [2.5 to 5.3], P value < .01).

CONCLUSION

Reduced grade 5 risk and improved benefit appears to exist in modern phase I oncology trials, particularly in trials that target single tumor types and integrate biomarkers as eligibility criteria. These findings provide information to support informed consent discussions, highlight the need for improved reporting of phase I oncology trials, and provide direction for optimizing their design.

Targeted drug delivery strategies for precision medicines

Progress in the field of precision medicine has changed the landscape of cancer therapy. Precision medicine is propelled by technologies that enable molecular profiling, genomic analysis, and optimized drug design to tailor treatments for individual patients. Although precision medicines have resulted in some clinical successes, the use of many potential therapeutics has been hindered by pharmacological issues, including toxicities and drug resistance. Drug delivery materials and approaches have now advanced to a point where they can enable the modulation of a drug's pharmacological parameters without compromising the desired effect on molecular targets. Specifically, they can modulate a drug's pharmacokinetics, stability, absorption, and exposure to tumours and healthy tissues, and facilitate the administration of synergistic drug combinations. This Review highlights recent progress in precision therapeutics and drug delivery, and identifies opportunities for strategies to improve the therapeutic index of cancer drugs, and consequently, clinical outcomes.

Realizing better doctor-patient dialogue about choices in palliative care and early phase clinical trial participation: towards an online value clarification tool (OnVaCT)

BACKGROUND

Patients with advanced cancer for whom standard systemic treatment is no longer available may be offered participation in early phase clinical trials. In the decision making process, both medical-technical information and patient values and preferences are important. Since patients report decisional conflict after deciding on participation in these trials, improving the decision making process is essential. We aim to develop and evaluate an Online Value Clarification Tool (OnVaCT) to assist patients in clarifying their values around this end-of-life decision. This improved sharing of values is hypothesized to support medical oncologists in tailoring their information to individual patients' needs and, consequently, to support patients in taking decisions in line with their values and reduce decisional conflict.

METHODS

In the first part, patients' values and preferences and medical oncologists' views hereupon will be explored in interviews and focus groups to build a first prototype OnVaCT using digital communication (serious gaming). Next, we will test feasibility during think aloud sessions, to deliver a ready-to-implement OnVaCT. In the second part, the OnVaCT, with accompanied training module, will be evaluated in a pre-test (12-18 months before implementation) post-test (12-18 months after implementation) study in three major Dutch cancer centres. We will include 276 patients (> 18 years) with advanced cancer for whom standard systemic therapy is no longer available, and who are referred for participation in early phase clinical trials. The first consultation will be recorded to analyse patient-physician communication regarding the discussion of patients' values and the decision making process. Three weeks afterwards, decisional conflict will be measured.

DISCUSSION

This project aims to support the discussion of patient values when considering participation in early phase clinical trials. By including patients before their first appointment with the medical oncologist and recording that consultation, we are able to link decisional conflict to the decision making process, e.g. the communication during consultation. The study faces challenges such as timely including patients within the short period between referral and first consultation. Furthermore, with new treatments being developed rapidly, molecular stratification may affect the patient populations included in the pre-test and post-test periods.

TRIAL REGISTRATION

Netherlands Trial Registry number: NTR7551 (prospective; July 17, 2018).

Improved survival among patients enrolled in oncology phase 1 trials in recent decades

PURPOSE

This study aimed to compare the survival of patients enrolled in phase 1 trials in recent decades.

METHODS

The medical records of consecutive patients with advanced cancer who participated in single-agent oncology phase 1 trials from 1995 to 2015 at a single institution were retrospectively investigated.

RESULTS

A total of 267 (34.1%) patients participated in 1995-2004 and 516 (65.9%) participated in 2005-2015. The median follow-up period was 25.4 months (range 1.3-166.9). The response rate did not differ significantly between the two periods (3.9% vs. 6.2%, p = 0.17). The median survival times were 9.5 (95% confidence interval 8.4-11.2) months in 1995-2004 and 11.8 (95% confidence interval 10.9-13.3) months in 2005-2015 (p = 0.0009). The enrolment period was an independent prognostic factor of overall survival according to multivariate analysis (hazard ratio: 0.85, 95% confidence interval 0.72-0.99, p = 0.042).

CONCLUSIONS

In our single-centre, retrospective analysis, the trends in patients characteristic were consistent with those of Western countries, and the overall survival of cancer patients enrolled in oncology phase 1 trials tended to improve in recent decades, suggesting that patient selection, the population that benefits from investigational agents and treatment after phase 1 trials have improved.

Characterization and outcomes of patients enrolled to multiple phase I cancer trials

PURPOSE

Some patients who participate in early phase cancer trials enroll to more than one trial. Whether these patients have different characteristics or outcomes than patients who enroll to a single phase I trial is unknown.

METHODS

The study included all patients who participated in the solid tumor drug development program of the Princess Margaret Cancer Centre, a specialized academic cancer center, from July 2014 to January 2017. Patients sequentially enrolled to multiple phase I trials were compared to those enrolled in a single trial according to demographics, clinical characteristics, reported toxicities and prognosis.

RESULTS

The study cohort included 328 patients, including 61 (19%) enrolled to multiple phase I trials and 267 (81%) enrolled to a single phase I trial. Demographics, comorbidities, performance status, cancer site and time between initial diagnosis and initial enrollment to the phase I program were comparable between both groups. Patients enrolled to multiple phase I trials received more previous non-trial treatment lines (median 3 versus 2, p < 0.001) and had a higher average response rate on phase I trials (18% versus 10%, p = 0.03). Toxicity data, including number of any adverse events (AEs), grade 3/4 AEs, serious AEs and dose-limiting toxicities were comparable between both groups. Time to disease progression and time to last documented follow-up were also comparable between both groups.

CONCLUSIONS

Patients enrolled to multiple phase I trials and those enrolled to a single trial had similar toxicity and prognostic profiles. These patients do not introduce bias into early-phase cancer trials results.

An adaptive design for the identification of the optimal dose using joint modeling of continuous repeated biomarker measurements and time-to-toxicity in phase I/II clinical trials in oncology

We present a new adaptive dose-finding method, based on a joint modeling of longitudinal continuous biomarker activity measurements and time to first dose limiting toxicity, with a shared random effect. Estimation relies on likelihood that does not require approximation, an important property in the context of small sample sizes, typical of phase I/II trials. We address the important case of missing at random data that stem from unacceptable toxicity, lack of activity and rapid deterioration of phase I patients. The objective is to determine the lowest dose within a range of highly active doses, under the constraint of not exceeding the maximum tolerated dose. The maximum tolerated dose is associated to some cumulative risk of dose limiting toxicity over a predefined number of treatment cycles. Operating characteristics are explored via simulations in various scenarios.

Induction of cell cycle arrest and apoptosis by copper complex Cu(SBCM)2 towards oestrogen-receptor positive MCF-7 breast cancer cells

Copper complexes have the potential to be developed as targeted therapy for cancer because cancer cells take up larger amounts of copper than normal cells. Copper complex Cu(SBCM)₂ has been reported to induce cell cycle arrest and apoptosis towards triple-negative breast cancer cells. Nevertheless, its effect towards other breast cancer subtypes has not been explored. Therefore, the present study was conducted to investigate the effect of Cu(SBCM)₂ towards oestrogen-receptor positive MCF-7 breast cancer cells. Growth inhibition of Cu(SBCM)₂ towards MCF-7 and human non-cancerous MCF-10A breast cells was determined by MTT assay. Morphological changes of Cu(SBCM)₂-treated-MCF-7 cells were observed under an inverted microscope. Annexin V/PI apoptosis assay and cell cycle analysis were evaluated by flow cytometry. The expression of wild-type p53 protein was evaluated by Western blot analysis. The intracellular ROS levels of MCF-7 treated with Cu(SBCM)₂ were detected using DCFH-DA under a fluorescence microscope. The cells were then co-treated with Cu(SBCM)₂ and antioxidants to evaluate the involvement of ROS in the cytotoxicity of Cu(SBCM)₂. Docking studies of Cu(SBCM)₂ with DNA, DNA topoisomerase I, and human ribonucleotide reductase were also performed. The growth of MCF-7 cells was inhibited by Cu(SBCM)₂ in a dose-dependent manner with less toxicity towards MCF-10A cells. It was found that Cu(SBCM)₂ induced G₂/M cell cycle arrest and apoptosis in MCF-7 cells, possibly via a p53 pathway. Induction of intracellular ROS was not detected in MCF-7 cells. Interestingly, antioxidants enhance the cytotoxicity of Cu(SBCM)₂ towards MCF-7 cells. DNA topoisomerase I may be the most likely target that accounts for the cytotoxicity of Cu(SBCM)₂.

Cu(SBCM)₂ binds to DNA topoisomerase I, which, in turn, induces cell cycle arrest and apoptosis in MCF-7 breast cancer cells, possibly via p53 signalling pathway.

Copper complex derived from S-benzyldithiocarbazate and 3-acetylcoumarin induced apoptosis in breast cancer cell

Copper complexes have been widely studied for the anti-tumour application as cancer cells are reported to take up greater amounts of copper than normal cells. Preliminary study revealed that the newly synthesised copper complex [Cu(SBCM)₂] displayed marked anti-proliferative towards triple-negative MDA-MB-231 breast cancer cells. Therefore, Cu(SBCM)₂ has great potential to be developed as an agent for the management of breast cancer. The present study was carried out to investigate the mode of cell death induced by Cu(SBCM)₂ towards MDA-MB-231 breast cancer cells. The inhibitory and morphological changes of MDA-MB-231 cells treated with Cu(SBCM)₂ was determined by using MTT assay and inverted light microscope, respectively. The safety profile of Cu(SBCM)₂ was also evaluated towards human dermal fibroblast (HDF) normal cells. Confirmation of apoptosis and cell cycle arrest were determined by flow cytometry analysis. The expression of p53, Bax, Bcl-2 and MMP2 protein were detected with western blot analysis. Cu(SBCM)₂ significantly inhibited the growth of MDA-MB-231 cells in a dose-dependent manner with GI₅₀ 18.7 ± 3.06 µM. Indeed, Cu(SBCM)₂ was less toxic towards HDF normal cells with GI₅₀ 31.8 ± 4.0 µM. Morphological study revealed that Cu(SBCM)₂-treated MDA-MB-231 cells experienced cellular shrinkage, membrane blebbing, chromatin condensation and formation of apoptotic bodies, suggesting that Cu(SBCM)₂ induced apoptosis in the cells, which was confirmed by Annexin-V/PI flow cytometry analysis. It was also found that Cu(SBCM)₂ induced G₂/M phase cell cycle arrest towards MDA-MB-231 cells. The induction of apoptosis and cell cycle arrest in the present study is possibly due to the down-regulation of the mutant p53 and MMP2 protein. In conclusion, Cu(SBCM)₂ can be developed as a targeted therapy for the treatment of triple-negative breast cancer.

A first-in-human phase I study to determine the maximum tolerated dose of the oral Src/ABL inhibitor AZD0424

BACKGROUND

Src is involved in cancer invasion and metastasis. AZD0424, an oral inhibitor of Src and ABL1, has shown evidence of anti-tumour activity in pre-clinical studies.

METHODS

A phase Ia, dose escalation study was performed to assess the safety of continuous oral dosing with AZD0424 in advanced solid tumours. Secondary objectives included investigation of AZD0424 pharmacokinetics, effect on Src activity using markers of bone turnover, and anti-tumour activity.

RESULTS

41 patients were treated; 34 received AZD0424 once-daily at doses ranging from 5 mg to 150 mg, and 7 received 40 mg bi-daily 41.5% of patients experienced at least one AZD0424-related adverse event that was Grade 3-5 in severity, with patients treated at doses above 60 mg per day experiencing multiple treatment-related toxicities. The most commonly observed AZD0424-related adverse events were nausea, fatigue, anorexia and alopecia. Cmax and AUC increased linearly with dose and the mean±standard deviation t1/2 was 8.4±2.8 h. Clear evidence of Src target inhibition was seen at doses ⩾20 mg per day. No responses were observed and 7 patients (17.1%) achieved stable disease lasting 6 weeks or more.

CONCLUSIONS

AZD0424 displayed no evidence of efficacy as monotherapy despite a clear pharmacodynamic effect. Further evaluation of AZD0424 monotherapy in patients with solid tumours is not recommended.

Risk and surrogate benefit for pediatric Phase I trials in oncology: A systematic review with meta-analysis

BACKGROUND

Pediatric Phase I cancer trials are critical for establishing the safety and dosing of anti-cancer treatments in children. Their implementation, however, must contend with the rarity of many pediatric cancers and limits on allowable risk in minors. The aim of this study is to describe the risk and benefit for pediatric cancer Phase I trials.

METHODS AND FINDINGS

Our protocol was prospectively registered in PROSPERO (CRD42015015961). We systematically searched Embase and PubMed for solid and hematological malignancy Phase I pediatric trials published between 1 January 2004 and 1 March 2015. We included pediatric cancer Phase I studies, defined as "small sample size, non‑randomized, dose escalation studies that defined the recommended dose for subsequent study of a new drug in each schedule tested." We measured risk using grade 3, 4, and 5 (fatal) drug-related adverse events (AEs) and benefit using objective response rates. When possible, data were meta-analyzed. We identified 170 studies meeting our eligibility criteria, accounting for 4,604 patients. The pooled overall objective response rate was 10.29% (95% CI 8.33% to 12.25%), and was lower in solid tumors, 3.17% (95% CI 2.62% to 3.72%), compared with hematological malignancies, 27.90% (95% CI 20.53% to 35.27%); p < 0.001. The overall fatal (grade 5) AE rate was 2.09% (95% CI 1.45% to 2.72%). Across the 4,604 evaluated patients, there were 4,675 grade 3 and 4 drug-related AEs, with an average grade 3/4 AE rate per person equal to 1.32. Our study had the following limitations: trials included in our review were heterogeneous (to minimize heterogeneity, we separated types of therapy and cancer types), and we relied on published data only and encountered challenges with the quality of reporting.

CONCLUSIONS

Our meta-analysis suggests that, on the whole, AE and response rates in pediatric Phase I trials are similar to those in adult Phase I trials. Our findings provide an empirical basis for the refinement and review of pediatric Phase I trials, and for communication about their risk and benefit.

Burdensome Research Procedures in Trials: Why Less Is More

A large volume of trials involve invasive, nontherapeutic research procedures, like organ biopsy or sham surgeries, that can pose risks comparable with the experimental treatment itself but that have no direct benefit for volunteers. Though such procedures can enhance the value of clinical investigations, recent studies suggest that many studies involving invasive, nontherapeutic research procedures are not well planned and reported; some studies suggest that their results are often not utilized in the planning of new investigations. This commentary offers recommendations for how investigators, sponsors, and ethics committees might improve evaluation and implementation of studies involving invasive nontherapeutic procedures. We conclude by urging more demanding scientific standards for the rationale, design, and reporting of burdensome, nontherapeutic research procedures-particularly where they involve risk of serious complications.