Assessing patient risk, benefit, and outcomes in drug development: A decade of ramucirumab clinical trials.

OBJECTIVE: This study aims to evaluate published clinical trials of ramucirumab to assess the risk/benefit profile and burden over time for patients. BACKGROUND: The burden of oncologic drug development on patients paired with increasing clinical trial failure rates emphasizes the need for reform of drug development. Identifying and addressing patterns of excess burden can guide policy, ensure evidence-based protections for trial participants, and improve medical decision-making. METHODS: On May 25, 2023 a literature search was performed on Pubmed/MEDLINE, Embase, Cochrane CENTRAL, and ClinicalTrials.gov for clinical trials using ramucirumab as monotherapy or in combination with other interventions for cancer treatment. Authors screened titles and abstracts for potential inclusion in a masked, duplicate fashion. Following data screening, data was extracted in a masked, duplicate fashion. Trials were classified as positive when meeting their primary endpoint and safety, negative or indeterminate. RESULTS: Ramucirumab was initially approved for gastric cancer but has since been tested in 20 cancers outside of its FDA approved indications. In our analysis of ramucirumab trials, there were a total of 10,936 participants and 10,303 adverse events reported. Gains in overall survival and progression-free survival for patients were 1.5 and 1.2 months, respectively. FDA-approved indications have reported more positive outcomes in comparison to off-label indications. CONCLUSION: We found that FDA-approved indications for ramucirumab had better efficacy outcomes than non-approved indications. However, a concerning number of adverse events were observed across all trials assessed. Participants in ramucirumab randomized controlled trials saw meager gains in overall survival when evaluated against a comparison group. Clinicians should carefully weigh the risks associated with ramucirumab therapy given its toxicity burden and poor survival gains.

Long COVID clinics and services offered by top US hospitals: an empirical analysis of clinical options as of May 2023.

BACKGROUND: The economic and health burden of COVID-19 has transformed the healthcare system in the US. Hospitals have adapted to the heterogeneity in long COVID symptoms, and the sheer number of people affected by this condition, by building long COVID centers and programs. OBJECTIVE: We sought to describe characteristics, services, and clinical trials of long COVID centers at top US hospitals. DESIGN: Cross-sectional analysis. PARTICIPANTS: Long COVID treatment programs or centers at top US hospitals. EXPOSURES: Frequency of long COVID centers, eligibility for being treated, the services they provide, specialist to whom the patients may be referred, and the long COVID clinical trials in which these hospitals participate. FINDINGS: Most top hospitals in the US (n = 43/50; 86%) offer long COVID services. 65% (28/43) did not describe the services provided. 12 (28%) required a referral from a primary care physician. The most common services were meeting with a team member (n = 20; 47%), ordering lab and/or radiology services (n = 8; 18.6%), and administering a physical exam (n = 7; 16%). 7 (16%) centers/programs treated only adults; 5 (12%) treated both adults and children, and 31 (72%) did not specify. The most common specialists described were psychology (n = 25; 58%), neurology (n = 25; 58%), and pulmonary (n = 24; 56%). Sixty-three trials (of 134 long COVID clinical trials) had at least one top hospital listed as a study site. The median number of clinical trials that each hospital sponsored or was a study site was 2 (interquartile range: 1, 3). CONCLUSIONS AND RELEVANCE: We find that services offered at long COVID clinics at top hospitals in the US often include meeting with a team member and referrals to a wide range of specialists. The diversity in long COVID services offered parallels the diversity in long COVID symptoms, suggesting a need for better consensus in developing and delivering treatment.

Health-related quality of life in trials with high rates of early censoring: Caution advised.

Health-related quality-of-life (HRQoL) data are central to capturing the quality of patients' life, while endpoints like overall survival (OS) focus on the quantity of life. When analyzing HRQoL data gathered from patients in a randomized trial, a key consideration is the completion rate - indicating the proportion of patients remaining in the trial and with completed questionnaires. When completion rates are disproportionately low in one treatment arm, one likely explanation is that patients who did not complete questionnaires suffered more from toxicities, negatively impacting their HRQoL. This is likely the case when low completion rates occur in the more toxic arm within a randomized trial. If the HRQoL analysis is run as a complete-case analysis - only considering patients without missing data - a decrement in HRQoL can be missed. Conversely, when completion rates are high, the HRQoL data are thought to be more reliable, and informative censoring is less likely. We describe why this reasoning can be inadequate. In trials where high and imbalanced rates of early censoring affect progression-free survival or OS endpoints, the completion rates only apply to the fraction of patients remaining in the trial. In those, HRQoL results should be considered with caution, and reasons for censoring in the primary time-to-event analyses should be explored before making definite conclusions about HRQoL. This is even more relevant in trials with non-inferiority design, where a benefit in HRQoL could be used as a justification to modify practice.

An empirical analysis of overall survival in drug approvals by the US FDA (2006-2023).

BACKGROUND: The US Food and Drug Administration (FDA) has expanded the use of surrogate markers in drugs approved for oncology/hematology indications. This has likely resulted in a greater number of approvals and possibly drugs coming to market faster, but it is unknown whether these drugs also improve overall survival (OS) for patients taking them. METHODS: We sought to estimate the percentage of oncology drugs that have shown to improve OS in a cross-sectional analysis of US FDA oncology drug approvals (2006-2023). We searched for OS data in registration trials and the peer-reviewed literature. RESULTS: We found 392 oncology drug approvals. Eighty-seven (22%) drug approvals were based on OS, 147 drug approvals were later tested for OS benefit (38% of all approvals and 48% of drugs approved on a surrogate), and 130 (33%) have yet to be tested for OS benefit. Of the 147 drug approvals later tested for OS, 109 (28% of all approvals and 74% of drugs later tested for OS) have yet to show OS benefit, whereas 38 (10% of all approvals and 26% of drugs later tested for OS benefit) were later shown to have OS benefit. In total, 125 out of 392 (32%) drugs approved for any indication have been shown to improve OS benefit at some point, and 267 (68%) have yet to show approval. CONCLUSION: About 32% of all oncology drug approvals have evidence for an improvement in OS. Higher standards are needed in drug regulation to ensure that approved drugs are delivering better patient outcomes, specifically in regards to survival.

COVID-19 vaccines: history of the pandemic's great scientific success and flawed policy implementation.

The COVID-19 vaccine has been a miraculous, life-saving advance, offering staggering efficacy in adults, and was developed with astonishing speed. The time from sequencing the virus to authorizing the first COVID-19 vaccine was so brisk even the optimists appear close-minded. Yet, simultaneously, United States' COVID-19 vaccination roll-out and related policies have contained missed opportunities, errors, run counter to evidence-based medicine, and revealed limitations in the judgment of public policymakers. Misplaced utilization, contradictory messaging, and poor deployment in those who would benefit most-the elderly and high-risk-alongside unrealistic messaging, exaggeration, and coercion in those who benefit least-young, healthy Americans-is at the heart. It is important to consider the history of COVID-19 vaccines to identify where we succeeded and where we failed, and the effects that these errors may have more broadly on vaccination hesitancy and routine childhood immunization programs in the decades to come.

Justification for unequal allocation ratios in clinical trials: A scoping review.

OBJECTIVE: The objective of this review is to provide an overview of the justification reported for using unequal allocation ratios in randomized clinical trials (RCTs) testing a medical intervention. METHODS: Using the PICOS framework, we conducted a systematic search to find meta-studies within PubMed (a Medline database interface) that addressed the objective. RESULTS: The developed search strategy generated 525 results, of which, three studies met criteria for inclusion. These studies found that 22-43% of RCTs provided a justification for the use of unequal allocation based on publication alone, and between 38.7 and 66% after seeking input from trial authors. The most common reason given for this design was to gather increased safety data according to two reviews and to gain experience with an intervention according to the third review. CONCLUSION: Reporting of justification for RCTs designed with unequal allocation appears to occur less than half the time in the included studies. The reasons given for designing clinical trials with unequal participants encompass many domains, including ethical considerations. As such, this design feature should be implemented with intentionality to maximize the ethical features of clinical trials for participants. Coupling lack of justification with lack of adjusting for sample size estimations depicts an overall landscape in which there is significant room for improvement in methodological transparency within this area of RCTs.

Assessing Patient Risk, Benefit, and Outcomes in Drug Development: A Decade of Lenvatinib Clinical Trials: A Systematic Review.

IMPORTANCE: Chemotherapy agents are typically initially tested in their most promising indications; however, following initial US FDA approval, new clinical trials are often initiated in less promising indications where patients experience a worse burden-benefit ratio. The current literature on the burden-benefit profile of lenvatinib in non-FDA-approved indications is lacking. OBJECTIVE: This study aimed to evaluate published clinical trials of lenvatinib in order to determine the burden-benefit profile for patients over time. EVIDENCE REVIEW: On 25 May 2023, we searched the Pubmed/MEDLINE, Embase, Cochrane CENTRAL, and ClinicalTrials.gov databases for clinical trials of lenvatinib used to treat solid cancers. Eligible articles were clinical trials, containing adult participants, published in English, and involving solid tumors. Screening and data collection took place in a masked, duplicate fashion. For each eligible study, we collected adverse event data, trial characteristics, progression-free survival (PFS), overall survival (OS), and objective response rate (ORR). Trials were classified as positive when meeting their primary endpoint and safety, negative (not meeting either criteria), or indeterminate (lacking prespecified primary endpoint). FINDINGS: Expansion of clinical trial testing beyond lenvatinib's initial FDA indication demonstrated a consistent rise in cumulative adverse events, along with a decline in drug efficacy. Lenvatinib was tested in 16 cancer indications, receiving FDA approval in 4. A total of 5390 Grade 3-5 adverse events were experienced across 6225 clinical trial participants. Expanded indication testing further demonstrated widely variable ORR (11-69%), OS (6.2-32 months), and PFS (3.6-15.7 months) across all indications. After initial FDA approval, clinical trial results in expanded indications were less likely to meet their primary endpoints, particularly among non-randomized clinical trials. CONCLUSION AND RELEVANCE: Our paper evaluated the effectiveness of lenvatinib for its FDA-approved indications; however, expansion of clinical trials into novel indications was characterized by diminished efficacy, while patients experienced a high burden of adverse events consistent with lenvatinib's established safety profile. Furthermore, clinical trials testing in novel indications was marked by repeated phase I and II clinical trials along with a failure to progress to phase III clinical trials. Future clinical trials using lenvatinib as an intervention should carefully evaluate the potential benefits and burden patients may experience.

Cardiovascular/anti-inflammatory drugs repurposed for treating or preventing cancer: A systematic review and meta-analysis of randomized trials.

BACKGROUND: Due to encouraging pre-clinical data and supportive observational studies, there has been growing interest in applying cardiovascular drugs (including aspirin, angiotensin-converting enzyme [ACE] inhibitors, statins, and metformin) approved to treat diseases such as hypertension, hyperlipidemia, and diabetes mellitus to the field of oncology. Moreover, given growing costs with cancer care, these medications have offered a potentially more affordable avenue to treat or prevent recurrence of cancer. We sought to investigate the anti-cancer effects of drugs repurposed from cardiology or anti-inflammatories to treat cancer. We specifically evaluated the following drug classes: HMG-CoA reductase inhibitors (statins), cyclo-oxygenase inhibitors, aspirin, metformin, and both angiotensin receptor blockers (ARBs) and angiotensin-converting enzyme inhibitors. We also included non-steroidal anti-inflammatory drugs (NSAIDs) because they exert a similar mechanism to aspirin by blocking prostaglandins and reducing inflammation that is thought to promote the development of cancer. METHODS: We performed a systematic literature review using PubMed and Web of Science with search terms including "aspirin," "NSAID," "statin" (including specific statin drug names), "metformin," "ACE inhibitors," and "ARBs" (including specific anti-hypertensive drug names) in combination with "cancer." Searches were limited to human studies published between 2000 and 2023. MAIN OUTCOMES AND MEASURES: The number and percentage of studies reported positive results and pooled estimates of overall survival, progression-free survival, response, and disease-free survival. RESULTS: We reviewed 3094 titles and included 67 randomized clinical trials. The most common drugs that were tested were metformin (n = 21; 30.9%), celecoxib (n = 20; 29.4%), and simvastatin (n = 8; 11.8%). There was only one study that tested cardiac glycosides and none that studied ACE inhibitors. The most common tumor types were non-small-cell lung cancer (n = 19; 27.9%); breast (n = 8; 20.6%), colorectal (n = 7; 10.3%), and hepatocellular (n = 6; 8.8%). Most studies were conducted in a phase II trial (n = 38; 55.9%). Most studies were tested in metastatic cancers (n = 49; 72.1%) and in the first-line setting (n = 36; 521.9%). Four studies (5.9%) were stopped early because of difficulty with accrual. The majority of studies did not demonstrate an improvement in either progression-free survival (86.1% of studies testing progression-free survival) or in overall survival (94.3% of studies testing overall survival). Progression-free survival was improved in five studies (7.4%), and overall survival was improved in three studies (4.4%). Overall survival was significantly worse in two studies (3.8% of studies testing overall survival), and progression-free survival was worse in one study (2.8% of studies testing progression-free survival). CONCLUSIONS AND RELEVANCE: Despite promising pre-clinical and population-based data, cardiovascular drugs and anti-inflammatory medications have overall not demonstrated benefit in the treatment or preventing recurrence of cancer. These findings may help guide future potential clinical trials involving these medications when applied in oncology.

The importance of falsification endpoints in observational studies of vaccination to prevent severe disease: A critique of a harm-benefit analysis of BNT162b2 vaccination of 5- to 11-year-olds.

We explore one systematic review and meta-analysis of both observational and randomized studies examining COVID-19 vaccines in 5- to 11-year-olds, which reported substantial benefits associated with vaccinating this age group. We discuss the limitations of the individual studies that were used to estimate vaccination benefits. The review included five observational studies that evaluated vaccine effectiveness (VE) against COVID-19 severe disease or hospitalization. All five studies failed to adequately assess differences in underlying health between vaccination groups. In terms of vaccination harms, looking only at the randomized studies, a significantly higher odds of adverse events was identified among the vaccinated compared with the unvaccinated. Observational studies are at risk of overestimating the effectiveness of vaccines against severe disease if healthy vaccinee bias is present. Falsification endpoints can provide valuable information about underlying healthy vaccinee bias. Studies that have not adequately ruled out bias due to better health among the vaccinated or more vaccinated should be viewed as unreliable for estimating the VE of COVID-19 vaccination against severe disease and mortality. Existing systematic reviews that include observational studies of the COVID-19 vaccine in children may have overstated or falsely inferred vaccine benefits due to unidentified or undisclosed healthy vaccinee bias.

Financial conflicts of interest among presenters, panellists and moderators at haematology and oncology FDA workshops.

OBJECTIVE: To assess the characteristics and financial conflicts of interest of presenters, panellists and moderators at haematology and oncology workshops held jointly with or hosted by the US FDA. SETTING: We included information on all publicly available haematology or oncology FDA workshop agendas held between 1 January 2018 and 31 December 2022. EXPOSURE: General and research payments reported on Open Payments, industry funding to patient advocacy organizations reported on their webpages or 990 tax forms and employment in both pharmaceutical and regulatory settings. RESULTS: Among physicians eligible for payments, 78% received at least one payment from the industry between 2017 and 2021. The mean general payment amount was $82,170 for all years ($16,434 per year) and the median was $14,906 for all years ($2981 per year). Sixty-nine per cent of patient advocacy speakers were representing organizations that received financial support from the pharmaceutical industry. Among those representing regulatory agencies or pharmaceutical companies, 16% had worked in both settings during their careers. CONCLUSIONS AND RELEVANCE: Our findings in this cross-sectional study show a majority of US-based physician presenters at haematology and oncology workshops held jointly with members of the US FDA have some financial conflict of interest with the pharmaceutical industry. These findings support the need for clear disclosures and suggest that a more balanced selection of presenters with fewer conflicts may help to limit bias in discussions between multiple stakeholders.

Characteristics and outcomes of new molecular oncology drug approvals, in combination or monotherapy.

IMPORTANCE: Understanding the factors that are associated with new molecular entity (NME) cancer drug approvals as a single agent and in combination, and European Society for Medical Oncology (ESMO) scores, can aid in identifying suitable factors to consider in trial designs for future drugs. In addition, the association between the various outcomes can aid in determining benefit when surrogate outcomes are used in approval consideration. OBJECTIVE: This study aims to (1) use the measures used in evaluating clinical trials by ESMO scores to determine the differences in the characteristics of 2013-2022 Food and Drug Administration (FDA) oncology NME drug approvals for those approved for use in combination or as a monotherapy, and (2) analyze the association between survival outcomes and the response rate for monotherapy NME drugs and/or drugs approved in combination. DESIGN: Cross-sectional analysis. SETTING: US FDA Oncology Drug Approvals (2013-2022) PARTICIPANTS: US FDA Oncology Drug Approvals (2013-2022) EXPOSURES: Trial-level characteristics (tumor types, basis of approval, randomized or not, phase) and associations between overall survival (OS), progression-free survival (PFS), or overall response rate (ORR) and whether NME drugs were approved as monotherapy or in combination . RESULTS: Drugs approved for use as a monotherapy are less likely to be approved using a randomized study (p < 0.001) and more likely to be approved via the accelerated pathway (p = 0.012) and be open-label (p < 0.001). Drugs approved for use as a combination or monotherapy significantly differed on their approval basis (p = 0.002), phase of trial at the time of approval (p = 0.02), and ESMO scores (p = 0.02). There was low correlation between response rate and either PFS or OS metrics. However, nearly all of the drugs with large improvements in OS (> 5months) were drugs with robust ORR. CONCLUSIONS AND RELEVANCE: Drugs approved as monotherapy with a low response rate are likely to have marginal benefit in OS and PFS.

An Analysis of Studies Pertaining to Masks in Morbidity and Mortality Weekly Report: Characteristics and Quality of Studies through 2023.

BACKGROUND: The purpose of this study was to describe and evaluate the nature and methodology of reports and appropriateness of conclusions in The Morbidity and Mortality Weekly Report (MMWR) pertaining to masks. Because MMWR has substantial influence on United States health policy and is not externally peer-reviewed, it is critical to understand the scientific process within the journal. Mask policies have been highly influenced by data published in the MMWR. METHODS: Retrospective cross-sectional study of MMWR publications pertaining to masks through 2023. Outcomes included study design, whether the study was able to assess mask effectiveness, if results were statistically significant, if masks were concluded to be effective, if randomized evidence or conflicting data were mentioned or cited, and appropriateness of causal statements. RESULTS: There were 77 studies, all published after 2019, that met our inclusion criteria. The most common study design was observational without a comparator group: 22/77 (28.6%); 0/77 were randomized; 23/77 (29.9%) assessed mask effectiveness; 11/77 (14.3%) were statistically significant, but 58/77 (75.3%) stated that masks were effective. Of these, 41/58 (70.7%) used causal language. One mannequin study used causal language appropriately (1.3%). None cited randomized data; 1/77 (1.3%) cited conflicting evidence. CONCLUSIONS: MMWR publications pertaining to masks drew positive conclusions about mask effectiveness >75% of the time despite only 30% testing masks and <15% having statistically significant results. No studies were randomized, yet over half drew causal conclusions. The level of evidence generated was low and the conclusions were most often unsupported by the data. Our findings raise concern about the reliability of the journal for informing health policy.

Systematic Review and Meta-Analysis of Randomized Trials Testing Interventions to Reduce Physician Burnout.

BACKGROUND: Physicians deal with intense professional pressures, which may contribute to increasing burnout. We sought to evaluate the efficacy of interventions designed to reduce burnout in physicians, physicians-in-training, and other health care professionals. METHODS: We searched PubMed and Embase (through January 6, 2023) and reference lists. We included all randomized studies assessing an intervention designed to reduce professional burnout in physicians and other health care personnel. We adhered to the PRISMA reporting guidelines. We abstracted data on study and participant characteristics, study outcomes, and study quality. We used a random-effects model to pool mean differences in burnout change (pre- and post-intervention) between intervention and control arms. RESULTS: Thirty-one of the 38 eligible studies (81.6%) used the Maslach Burnout Inventory (MBI) questionnaire to assess burnout. When comparing the intervention and control groups, the mean difference in the emotional exhaustion component of the MBI was -1.11 (95% confidence interval [CI], -2.14 to -0.09; I2: 74.5%; 20 studies); the mean difference in the depersonalization component of the MBI was -0.32 (95% CI, -0.63 to -0.01; I2: 54.2%; 17 studies); and the mean difference in the personal accomplishment component of the MBI was 1.11 (95% CI, -0.21 to 2.43; I2: 94.3%; 16 studies). CONCLUSIONS: Studies testing interventions to decrease physician burnout led to significant numerical improvements in some domains of burnout, but it is unlikely that these changes result in meaningful changes in clinical burnout. Further, the limited follow-up time, biased assessments, and heterogeneity in intervention efficacy suggest that a more nuanced understanding of the causes of burnout is needed to develop more effective interventions.

Assessing patient burden and benefit: A decade of cabozantinib clinical trials.

Drug development is complex and costly. Clinical trial participants take on risks, making it essential to maximize trial efficiency and maintain participant safety. Identifying periods of excessive burden during drug development can inform trial design, ensure patient benefit and prevent harm. This study aims to examine all published clinical trials for cabozantinib to assess patient benefit and burden over time. We conducted a retrospective cross-sectional review of interventional clinical trials of cabozantinib for solid cancer treatment. We searched PubMed/MEDLINE, Embase, Cochrane (CENTRAL) and ClinicalTrials.gov. We extracted adverse event rates, median progression-free survival (PFS), median overall survival and objective response rate (ORR) for each included trial. We calculated frequencies of trial characteristics, cumulative grade 3-5 adverse event rates and cumulative ORRs. Out of 1735 studies, 54 publications were included that involved 6372 participants and 21 cancers. Of the 54 studies in our sample, 31 (57.41%) were single-arm trials and 23 (42.60%) had negative results. Trials among and within various indications had conflicting results over time. Cumulative risk to participants increased over time, and clinical benefit decreased. The findings suggest that the risk profile of cabozantinib increased from 2011 to 2016 and has remained elevated but stable while benefit has decreased over time. The use of non-randomized and single-arm trials is concerning, and more methodologically rigorous trials are needed. The results of trials for different indications are inconsistent, and empirical administration may reduce the drug's efficacy.

Cancer Drug Price and Novelty in Mechanism of Action.

Importance: Many economic theories point to regulatory issues and subsidization of research and development costs as the primary factor in the high cancer drug prices in the US. Even so, the association between the median annual cost and novelty of cancer drugs approved in the US remains unclear. Objective: To evaluate the association between the median annual cost and novelty of cancer drugs approved in the US over a 6-year period. Design, Setting, and Participants: This cross-sectional study included all cancer drugs approved by the US Food and Drug Administration (FDA) from January 1, 2015, to December 31, 2020. Drug names, indications, manufacturer, dosage, and measures of activity/efficacy were extracted from the FDA announcement. The search was performed in December 2021. Data were analyzed from January 2022 until April 2022. Main Outcomes and Measures: Annual cost of treatment was calculated based on average wholesale price collected from the 2021 Micromedex Red Book database. Mechanism of action was inferred from trial publication or its references. Results: There were 224 cancer drug approvals across 119 individual drugs, with a median annual cost of $196 000 (IQR, $170 000-$277 000). Gene and viral therapies were the most expensive (median, $448 000 [IQR, $448 000-$479 000]), followed by small molecule therapy (median, $244 000 [IQR, $203 000-$321 000), and biologics (median, $185 000 [IQR, $148 000-$195 000]). There was no significant difference in cost between first-in-class, next-in-class, and subsequent approvals of an already approved drug. Conclusions and Relevance: Findings of this study indicate that the median annual price of anticancer drugs in the US is not associated with the novelty of their mechanism of action.

Eligibility for Human Leukocyte Antigen-Based Therapeutics by Race and Ethnicity.

Importance: The development of therapeutics for patients who are positive for specific human leukocyte antigen (HLA) subtypes evokes the question of whether certain racial and ethnic groups are more or less likely to be eligible for novel products. Objective: To determine whether racial and ethnic inequities were present with regard to trial eligibility in trials investigating a therapeutic restricted to patients with specific HLA subtypes. Design, Setting, and Participants: This cross-sectional study included all clinical trials registered in ClinicalTrials.gov through March 18, 2022, that investigated an interventional study of a therapeutic strategy and restricted participants to those with at least 1 HLA subtype. Data were analyzed from May 8 to July 1, 2022. Main Outcomes and Measures: The type of therapeutics used in trials, the condition under study, the HLA subtypes used, and the likelihood of being enrolled in such a trial according to race and ethnicity. Results: Of 2135 trials identified, 263 met inclusion criteria. Overall, the estimated likelihood of being eligible for an HLA-based trial was 50.3%. Individuals of African American descent had the lowest likelihood of eligibility (33.0%), while being an individual of European descent conferred the highest (53.0%; 1.6 times more likely than African American individuals). Most trials studied anticancer therapeutics (258 [98.1%; 95% CI, 96.4%-99.7%]), and most were a therapeutic vaccine (179 [68.1%; 95% CI, 62.4%-73.7%]). The HLA-A*02:01 allele and the HLA-A2 serotype were the most frequent HLA subtypes for trial eligibility. The frequency of the HLA-A*02:01 allele in the population varied, with 11.9% (95% CI, 11.8%-12.0%) in African or African American individuals and 27.1% (95% CI, 27.1%-27.1%) in individuals of European descent. Conclusions and Relevance: The findings of this cross-sectional study suggest that enrollment restrictions for clinical trials investigating novel HLA therapeutics may be associated with racial and ethnic inequities with regard to trial eligibility. Overcoming these restrictions poses biological challenges, but solutions must be implemented to provide equal access to innovative strategies regardless of race or ethnicity.