Participant Recruitment From Low- and Middle-Income Countries for Pivotal Trials of Drugs Approved by the U.S. Food and Drug Administration : A Cross-Sectional Analysis

Globalization of clinical research in oncology: Status, challenges, and future directions

PURPOSE

Cancer is the second-leading cause of death worldwide, and its burden is increasing around the world, particularly in low- and middle-income countries (LMICs). Yet, cancer research has historically been conducted primarily in high-income countries (HICs).

METHODS

In this review, we describe the results of our literature search into the current state of international cancer trials, including the benefits, challenges, limitations, and ethical concerns regarding the international conduct of HIC-led trials. We also propose some possible means of addressing these challenges and overcoming these barriers to extend the benefits of cancer research to people around the world.

RESULTS

Over the last several decades, there has been a shift toward inclusion of investigators and participants from LMICs in pivotal cancer clinical trials.

CONCLUSIONS

While inclusion of LMIC countries has benefits, including increased diversity of participant populations, investment in research infrastructure in LMICs, and potential expansion of cancer treatment options around the world, the continued leadership of most trials by HICs presents ethical concerns, including potential exploitation of researchers and participants from LMICs, lack of focus on cancer types prevalent in all participating regions, and disparities in access to approved therapies once the trial is complete.

Use of suboptimal control arms in randomized clinical trials of investigational cancer drugs in China, 2016-2021: An observational study

BACKGROUND

The use of suboptimal controls in randomized trials of new cancer drugs can produce potentially unreliable clinical efficacy results over the current standard of care and expose patients to substandard therapy. We aim to investigate the proportion of randomized trials of investigational cancer drugs that used a suboptimal control arm and the number of trial participants at risk of exposure to suboptimal treatments in China. The association between the use of a suboptimal control and concluding statistical significance on the primary endpoint was also examined.

METHODS AND FINDINGS

This observational study included randomized controlled trials (RCTs) of cancer drugs that were authorized by specific Chinese institutional review boards between 2016 and 2021, supporting investigational new drug applications of these drugs in China. The proportion of trials that used a suboptimal control arm and the total number of trial participants at risk of exposure to suboptimal treatments were calculated. In a randomized trial for a specific condition, a comparator was deemed suboptimal if it was not recommended by clinical guidelines published in priori or if there existed a regimen with a higher level of recommendation for the indication. The final sample included 453 Phase II/III and Phase III randomized oncology trials. Overall, 60 trials (13.2%) adopted a suboptimal control arm. Among them, 58.3% (35/60) used comparators that were not recommended by a prior guideline for the indication. The cumulative number of trial participants at risk of exposure to suboptimal treatments totaled 18,610 by the end of 2021, contributing 15.1% to the total number of enrollees of all sampled RCTs in this study. After adjusting for the year of ethical approval, region of participant recruitment, line of therapy, and cancer site, second-line therapies (adjusted odds ratio [aOR] = 2.7, 95%CI [1.2, 5.9]), adjuvant therapies (aOR = 8.9, 95% CI [3.4, 23.1]), maintenance therapies (aOR = 5.2, 95% CI [1.6, 17.0]), and trials recruiting participants in China only (aOR = 4.1, 95% CI [2.1, 8.0]) were more likely to adopt a suboptimal control. For the 105 trials with publicly available results, no statistically significant difference was observed between the use of a suboptimal control and concluding positive on the primary endpoint (100.0% [12/12] versus 83.9% [78/93], p = 0.208). The main limitation of this study is its reliance on clinical guidelines that could vary across cancer types and time in assessing the quality of the control groups.

CONCLUSIONS

In this study, over one-eighth of randomized trials of cancer drugs registered to apply for regulatory approval in China used a suboptimal comparator. Our results highlight the necessity to refine the design of randomized trials to generate optimal clinical evidence for new cancer therapies.

Comparison of safety outcomes of anticancer drugs in Japanese and non-Japanese patients in multi-regional clinical trials: meta-analysis of safety profiles

No report has assessed the differences in adverse event (AE) profiles of anticancer drugs for all types of cancers in clinical trials involving Japanese patients. This study aimed to compare the safety outcomes of anticancer drugs in Japanese and non-Japanese patients in multi-regional clinical trials (MRCTs), regardless of the type of cancer or drug. All new approvals of oncology drugs in Japan from January 2009 to December 2018 were searched through the Pharmaceuticals and Medical Devices Agency website. The odds ratio (OR) for comparing the incidence of AEs between Japanese and non-Japanese patients was estimated using the Mantel-Haenszel method with a random effect model. Sixty-six multi-regional phase 3 trials were identified involving 43,712 patients. Severe AE, AE leading to dose reduction, and AE leading to dose interruption were significantly more frequent in Japanese patients than in non-Japanese (odds ratios [ORs] were 1.32 (95% confidence interval (CI): 1.13-1.53), 1.97 (95% CI: 1.66-2.31), and 1.63 (95% CI: 1.43-1.86), respectively). Serious AEs (SAEs) and AEs leading to death were significantly less frequent in Japanese patients (OR: 0.70 (95% CI: 0.62-0.77) vs. 0.56 (95% CI: 0.44-0.67), respectively). There were no differences in AEs leading to study withdrawal. The incidence of most AEs was significantly higher in Japanese patients. In Japanese patients, the incidence of SAEs and AEs leading to death was low, but severe AEs, AEs leading to dose reductions, AEs leading to dose interruption, and individual adverse events were high.