Dose optimisation and scarce resource allocation: two sides of the same coin

Optimizing the doses of cancer drugs after usual dose finding

Since the middle of the 20th century, oncology's dose-finding paradigm has been oriented toward identifying a drug's maximum tolerated dose, which is then carried forward into phase 2 and 3 trials and clinical practice. For most modern precision medicines, however, maximum tolerated dose is far greater than the minimum dose needed to achieve maximal benefit, leading to unnecessary side effects. Regulatory change may decrease maximum tolerated dose's predominance by enforcing dose optimization of new drugs. Dozens of already approved cancer drugs require re-evaluation, however, introducing a new methodologic and ethical challenge in cancer clinical trials. In this article, we assess the history and current landscape of cancer drug dose finding. We provide a set of strategic priorities for postapproval dose optimization trials of the future. We discuss ethical considerations for postapproval dose optimization trial design and review three major design strategies for these unique trials that would both adhere to ethical standards and benefit patients and funders. We close with a discussion of financial and reporting considerations in the realm of dose optimization. Taken together, we provide a comprehensive, bird's eye view of the postapproval dose optimization trial landscape and offer our thoughts on the next steps required of methodologies and regulatory and funding regimes.

Targeted randomization dose optimization trials enable fractional dosing of scarce drugs

Administering drug at a dose lower than that used in pivotal clinical trials, known as fractional dosing, can stretch scarce resources. Implementing fractional dosing with confidence requires understanding a drug's dose-response relationship. Clinical trials aimed at describing dose-response in scarce, efficacious drugs risk underdosing, leading dose-finding trials to not be pursued despite their obvious potential benefit. We developed a new set of response-adaptive randomized dose-finding trials and demonstrate, in a series of simulated trials across diverse dose-response curves, these designs' efficiency in identifying the minimum dose that achieves satisfactory efficacy. Compared to conventional designs, these trials have higher probabilities of identifying lower doses while reducing the risks of both population- and subject-level underdosing. We strongly recommend that, upon demonstration of a drug's efficacy, pandemic drug development swiftly proceeds with response-adaptive dose-finding trials. This unified strategy ensures that scarce effective drugs produce maximum social benefits.

Socially optimal dosing for scarce vaccines: Ethical analysis through the principlism framework

RATIONALE, AIMS, AND OBJECTIVES

Under conditions of vaccine scarcity, the socially optimal dosing (SOD) strategy administers a lower dose of vaccine to a larger number of people than the individually optimal dosing (IOD) strategy, which administers a higher dose of vaccine to a smaller number of people. In the context of vaccines that generate diminishing returns of effectiveness with each additional dose beyond the first, SOD therefore generates a greater total amount of vaccine-induced protection than IOD and, as such, constitutes the socially optimal strategy. While the clinical and public health arguments in favour of SOD have previously been outlined, this article conducts an ethical analysis of SOD for scarce vaccines through the ethical framework of principlism.

METHODS

SOD is examined with regard to each principle within the principlism framework-nonmaleficence, beneficence, autonomy, and justice.

RESULTS

SOD is found to satisfy each of the ethical requirements under examination. Regarding nonmaleficence, SOD induces less iatrogenic harm than IOD since the dose of vaccine administered to each individual is lower in the former than the latter. Furthermore, both the good and bad effects of SOD are foreseen while only the good effects are intended, meaning this strategy simultaneously satisfies the doctrine of double effect. Regarding autonomy, SOD makes vaccine-induced protection available to a greater number of individuals who wish to receive it, thereby respecting their capacity for self-determination and to make independent decisions. Regarding beneficence, SOD renders the good-namely the protection of health-more widely available to the individuals that constitute the population in question. Finally, SOD promotes theories of justice that treat individuals equally and is unlikely to reduce the effectiveness of other distribution policies that allocate scarce vaccines in a just manner.

CONCLUSION

In conditions of vaccine scarcity, SOD favourably satisfies the ethical framework of principlism.

Alternative Trastuzumab Dosing Schedules Are Associated With Reductions in Health Care Greenhouse Gas Emissions

PURPOSE

Cancer care-related greenhouse gas (GHG) emissions harm human health. Many cancer drugs are administered at greater-than-necessary doses, frequencies, and durations. Alternative dosing strategies may enable reductions in cancer care GHG emissions without compromising patient outcomes.

MATERIALS AND METHODS

We used streamlined life-cycle analysis in a case-control simulation to estimate the relative reductions in GHG emissions that would be expected to result from using each of three alternative dosing strategies of trastuzumab (6-month adjuvant treatment duration, once every 4-week dosing, and both) in human epidermal growth factor receptor 2 (HER2)+ breast cancer. Using primary data and conversion factors from the environmental science literature, we estimated per-patient relative reduction in GHG emissions and, using SEER data, health impacts (in terms of disability-adjusted life-years [DALYs] and excess mortality per kg CO2) on bystanders for each alternative dosing strategy.

RESULTS

Compared with the trastuzumab dosing strategy commonly used at baseline (12-month duration of adjuvant therapy and once every 3-week dosing in all settings), adoption of both 6-month adjuvant trastuzumab and once every 4-week trastuzumab dosing would reduce GHG emissions by 4.5%, 18.7%, and 14.6% in the neoadjuvant, adjuvant, and metastatic settings, respectively. We estimate that US-based adoption of alternative trastuzumab dosing would reduce annual DALYs and excess lives lost due to environmental impact of US-based trastuzumab therapy for HER2+ breast cancer by 1.5 and 0.9, respectively.

CONCLUSION

Alternative dosing strategies may materially reduce the population health impacts of cancer care by reducing environmental impact. Regulatory decision making and health technology assessments should consider a treatment's environmental and population health impacts. Clinical trials of alternative dosing strategies are justified on the basis of environmental and population health impacts.