Pivotal Considerations for Optimal Deployment of Healthy Volunteers in Oncology Drug Development

Pharmacokinetics, pharmacodynamics and safety of oral formulation (CG-750) of ivaltinostat, a histone deacetylase inhibitor, compared to IV formulation (CG-745)

AIMS

CG-750 is an oral formulation of ivaltinostat, a newly developing histone deacetylase (HDAC) inhibitor. This study aimed to evaluate the pharmacokinetics (PK), pharmacodynamics (PD) and safety of an oral formulation (CG-750) of ivaltinostat compared to an intravenous (IV) formulation (CG-745).

METHODS

A randomized, double-blind, placebo-controlled study was conducted in three cohorts. Subjects received either CG-745 (Cohorts 1 and 3: 125 mg; Cohort 2: 250 mg) or placebo followed by CG-750 (Cohort 1: 125 mg; Cohort 2: 375 mg; Cohort 3: 750 mg) or placebo. Blood samples for PK and PD assessment were collected up to 72 h post-dose. Histone H3 acetylation at sites K9, K9/K14 and K27 was assessed for area under the % acetylation induction versus time curve (AUEC).

RESULTS

A total of 25 subjects were randomized, and 23 subjects completed the study (Cohort 1, n = 6; Cohort 2, n = 6; Cohort 3, n = 6; placebo, n = 5). The mean bioavailability of CG-750 was 10.6% (range: 4.18%-21.33%) and displayed linear PK in the dose range of 125-750 mg. The comparison of AUEC between formulations and the evaluation of the dose-AUEC relationship were inconclusive, due to the small sample sizes and significant variability observed in PD markers. All adverse events (AEs) were transient and of mild or moderate intensity.

CONCLUSIONS

The oral formulation of ivaltinostat (CG-750) was generally well tolerated after a single dose. CG-750 displayed a mean bioavailability of 10.6%.

Phase I crossover study of DNA-protein kinase inhibitor peposertib in healthy volunteers: Effect of food and pharmacokinetics of an oral suspension

Peposertib is an orally administered inhibitor of DNA-dependent protein kinase. We evaluated the effect of food on its pharmacokinetics, and examined the pharmacokinetics of an oral suspension (OS) of disintegrated tablets, in a phase I, open-label, crossover three-period study (NCT04702698). Twelve healthy volunteers were randomized to one of six treatment sequences. They received a single dose of peposertib 100 mg as film-coated tablets under fasted or fed conditions ("tablet fasted" or "tablet fed") or as an OS under fasted conditions ("OS fasted"), with washout between treatments. Using healthy volunteers was possible because, despite its mechanism of action being suppression of DNA repair, peposertib has shown no genotoxic effect in animals. A mild food effect was observed with peposertib tablets. Fed-to-fasted ratios were: area under the curve from time 0 to time t (AUC0-t ), 123.81% (90% confidence interval [CI]: 108.04, 141.87%); AUC from zero to infinity (AUC0-∞ ), 110.28% (90% CI 100.71, 120.77%); and maximum concentration (Cmax ) 104.47% (90% CI: 79.15, 137.90%). Cmax was delayed under fed conditions (median time to maximum concentration [Tmax ] was 3.5 h [tablet fed] vs. 1 h [tablet fasted]). OS-to-tablet (fasted) ratios were: AUC0-t , 124.83% (90% CI: 111.50%, 139.76%); AUC0-∞ , 119.05% (90% CI: 104.47, 135.67%); and Cmax 173.29% (90% CI: 135.78, 221.16%). Median Tmax was 0.5 h (OS fasted) versus 1 h (tablet). All treatments were well-tolerated in healthy volunteers. Peposertib tablets can be taken with or without food; if combined with chemotherapy or radiotherapy, the delay in Cmax must be considered to optimize the chemo- or radiosensitizing effect. The peposertib OS form represents an alternative route of administration in patients with specific cancers causing dysphagia. However, the OS form should be part of future dose optimization strategies in relevant settings.

Asia-Inclusive Clinical Research and Development Enabled by Translational Science and Quantitative Clinical Pharmacology: Toward a Culture That Challenges the Status Quo

Access lag to innovative therapies in Asian populations continues to present a challenge to global health. Recent progressive changes in the global regulatory landscape, including newer guidelines, are enabling simultaneous global drug development and near-simultaneous global drug registration. The International Conference on Harmonization (ICH) E17 guideline outlines general principles for the design and analysis of multiregional clinical trials (MRCTs). We posit that translational research and quantitative clinical pharmacology tools are core enablers for Asia-inclusive global drug development aligned with ICH E17 principles. Assessment of ethnic sensitivity should be initiated early in the development lifecycle to inform the need for, and extent of, Asian phase I ethno-bridging data. Relevant ethno-bridging data may be generated as standalone Asian phase I trials, as part of Western First-In-Human trials, or under accelerated development settings as a lead-in phase in an MRCT. Quantitative understanding of human clearance mechanisms and pharmacogenetic factors is vital to forecasting ethnic sensitivity in drug exposure using physiologically-based pharmacokinetic models. Stratification factors to control heterogeneity in MRCTs can be identified by reverse translational research incorporating pharmacometric disease models and model-based meta-analyses. Because epidemiological variations can extend to the molecular level, quantitative systems pharmacology models may be useful in forecasting how molecular variation in therapeutic targets or pathway proteins across populations might impact treatment outcomes. Through prospective evaluation of conservation in drug- and disease-related intrinsic and extrinsic factors, a pooled East Asian region can be implemented in Asia-inclusive MRCTs to maximize efficiency in substantiating evidence of benefit-risk for the region at-large with a Totality of Evidence approach.

Integration of healthy volunteers in early phase clinical trials with immuno-oncological compounds

Aim

Traditionally, early phase clinical trials in oncology have been performed in patients based on safety risk-benefit assessment. Therapeutic transition to immuno-oncology may open new opportunities for studies in healthy volunteers, which are conducted faster and are less susceptible to confounders. Aim of this study was to investigate to what extent this approach is utilized and whether pharmacodynamic endpoints are evaluated in these early phase trials. We conducted a comprehensive review of clinical trials with healthy volunteers using immunotherapies potentially relevant for oncology.

Methods

Literature searches according to PRISMA guidelines and after registration in PROSPERO were conducted in PubMed, Embase, Web of Science and Cochrane databases with the cut-off date 20 October 2020, using search terms of relevant targets in immuno-oncology. Articles describing clinical trials with immunotherapeutics in healthy volunteers with a mechanism relevant for oncology were included. “Immunotherapeutic” was defined as compounds exhibiting effects through immunological targets. Data including study design and endpoints were extracted, with specific attention to pharmacodynamic endpoints and safety.

Results

In total, we found 38 relevant immunotherapeutic compounds tested in HVs, with 86% of studies investigating safety, 82% investigating the pharmacokinetics (PK) and 57% including at least one pharmacodynamic (PD) endpoint. Most of the observed adverse events (AEs) were Grade 1 and 2, consisting mostly of gastrointestinal, cutaneous and flu-like symptoms. Severe AEs were leukopenia, asthenia, syncope, headache, flu-like reaction and liver enzymes increase. PD endpoints investigated comprised of cytokines, immune and inflammatory biomarkers, cell counts, phenotyping circulating immune cells and ex vivo challenge assays.

Discussion

Healthy volunteer studies with immuno-oncology compounds have been performed, although not to a large extent. The integration of healthy volunteers in well-designed proof-of-mechanism oriented drug development programs has advantages and could be pursued more in the future, since integrative clinical trial protocols may facilitate early dose selection and prevent cancer patients to be exposed to non-therapeutic dosing regimens.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=210861, identifier CRD42020210861

Healthy Volunteer Studies in the Development of Anticancer Drugs with Genotoxic Findings

Background

Recent scientific advances in cancer research have led to the development of immunomodulatory and molecularly targeted drugs with better safety profiles than chemotherapeutics, which makes it possible to include healthy volunteers (HVs) in clinical trials. In this study, we aimed to identify the number of marketing authorization applications (MAAs) that enrolled HVs in a clinical trial and to identify the number of anticancer drugs that were given to HVs despite a positive genotoxic finding. In addition, we evaluated the dose of anticancer drugs administered to HVs and the justification for proceeding with HV studies despite a positive genotoxic finding.

Methods

Publicly available information from the European Medicines Agency (EMA) website was used for this study. Anticancer drugs were identified using the human medicines highlights published by EMA between January 2010 and December 2019. EPARs were used to collect general information of the anticancer drugs, details on genotoxicity studies, and the enrollment of HVs in clinical trials.

Results

We identified 71 MAAs for small molecule anticancer drugs with a positive or negative CHMP opinion in the EU. Forty-eight anticancer drugs were studied in HVs, of which 12 anticancer drugs were administered to HVs despite positive genotoxic findings in the standard battery. Systematic and extensive genetic toxicology screening demonstrated the absence of genotoxic risks to the cell system.

Conclusion

We showed that despite a positive genotoxic finding, comprehensive genetic toxicology testing demonstrated the absence of risks to the cell system at the human exposure dose. Therefore, these anticancer drugs posed no harm to HVs.

Single-Dose Pharmacokinetics and Tolerability of the Oral Epidermal Growth Factor Receptor Inhibitor Mobocertinib (TAK-788) in Healthy Volunteers: Low-Fat Meal Effect and Relative Bioavailability of 2 Capsule Products

Mobocertinib (TAK‐788) is a tyrosine kinase inhibitor under investigation for treatment of non–small cell lung cancer with activating EGFR exon 20 insertions. This study examined the safety; tolerability; pharmacokinetics (PK), including food effects; and bioavailability of mobocertinib in healthy volunteers. In part 1, fasted volunteers were randomized to placebo or mobocertinib in single‐ascending‐dose cohorts (20‐160 mg). In part 2, mobocertinib (120/160 mg) was administered on day 1 of periods 1 and 2 under fasted or low‐fat meal conditions (2‐period, 2‐sequence crossover design). In part 3, fasted volunteers received mobocertinib 160 mg in 1 of 2 capsule products on day 1 of periods 1 and 2 with 7‐day washout. Safety and PK parameters were assessed. Sixty‐nine volunteers were enrolled (mean age, 29 years; 75% male). The most common adverse events (AEs; ≥10% of volunteers) were gastrointestinal AEs (25%‐50%) and headache (8%‐31%). No serious AEs were reported. A low‐fat meal did not affect the PK of mobocertinib or its active metabolites. The geometric mean terminal disposition phase half‐life (20 hours) supported once‐daily dosing. The 2 capsule products were bioequivalent. These data guided dosing and supported administration of mobocertinib without regard to low‐fat meal intake in ongoing and planned clinical studies.