Forvisirvat showed no QTcF prolongation risk, and ECG assay sensitivity was confirmed via meal-induced QTcF shortening, supporting regulatory acceptance of a thorough QT study waiver by the Japanese Pharmaceuticals and Medical Devices Agency.
Key Findings
Results
The two-sided 90% confidence interval for the model-predicted ΔΔQTcF was below 10 ms up to the maximum observed plasma concentration of 703 ng/mL for forvisirvat.
A prespecified linear mixed-effects model was used to assess the impact of forvisirvat on baseline- and placebo-adjusted QT interval corrected by the Fridericia method (ΔΔQTcF).
The study was a double-blind, randomized, placebo-controlled, single ascending dose design.
Single oral doses up to 80 mg were evaluated in 32 healthy adults.
The maximum observed plasma concentration reached was 703 ng/mL.
The 10 ms threshold is the regulatory standard for defining clinically relevant QTc prolongation risk.
Results
ECG assay sensitivity was successfully demonstrated through prospectively evaluated postprandial QTcF shortening.
Meal-induced QTcF shortening was -6.38 ms at 4 hours after the standardized lunch.
The 95% confidence interval for meal-induced QTcF shortening was -8.51 to -4.26 ms, with the two-sided 95% CI entirely below 0.
This approach was used as an alternative to a positive control drug (e.g., moxifloxacin) to establish ECG assay sensitivity.
The meal effect is described as a 'well-described' phenomenon used to validate ECG measurement sensitivity.
Prospective evaluation of postprandial QTcF shortening was prespecified in the study design.
Background
Concentration-QTc analysis was used as an alternative to a traditional thorough QT (TQT) study to evaluate QTc prolongation risk of forvisirvat.
According to International Conference on Harmonization (ICH) E14 documents, concentration-QTc analyses should include exposures at twice the highest clinically relevant exposure instead of a positive control.
Achieving twice the highest clinically relevant exposure may be challenging when the highest dose in Phase 1 studies is restricted for various reasons.
The study used time-matched plasma forvisirvat concentrations and 12-lead ECG data collected from Phase 1 studies.
The results supported regulatory acceptance of a TQT study waiver by the Japanese Pharmaceuticals and Medical Devices Agency (PMDA).
Methods
The study design was a double-blind, randomized, placebo-controlled, single ascending dose study evaluating forvisirvat in 32 healthy adults.
Single oral doses up to 80 mg of forvisirvat were evaluated.
Time-matched plasma forvisirvat concentrations and 12-lead ECG data were collected.
A prespecified linear mixed-effects model was used for primary analysis.
The study population consisted of healthy adults.
Conclusions
The findings of no QTcF prolongation and confirmed ECG assay sensitivity via the meal effect resulted in regulatory acceptance of a TQT study waiver.
The Japanese Pharmaceuticals and Medical Devices Agency (PMDA) accepted the TQT study waiver based on these results.
This demonstrates that the meal effect can serve as a viable method to establish ECG assay sensitivity when a traditional positive control or supratherapeutic exposures are not feasible.
The approach is consistent with ICH E14 guidance for concentration-QTc analyses as an alternative to TQT studies.
What This Means
This research evaluated whether forvisirvat, a drug being developed, poses any risk of causing dangerous heart rhythm changes — specifically, prolongation of a heart electrical measurement called the QT interval. Rather than conducting a traditional 'thorough QT study,' which typically requires giving participants a positive control drug to verify that the heart monitoring equipment is working correctly, the researchers used an innovative approach: they leveraged the well-known fact that eating a meal causes a small but measurable shortening of the QT interval. By showing they could reliably detect this meal-induced change, they confirmed their ECG measurements were sensitive enough to detect meaningful effects. The study enrolled 32 healthy adults who received single oral doses of forvisirvat up to 80 mg.
The results showed that forvisirvat did not meaningfully prolong the QT interval at any tested dose — the statistical confidence interval for QT changes stayed below the 10-millisecond threshold considered clinically significant. Importantly, the researchers successfully detected the expected QT shortening after a standardized lunch meal (-6.38 ms, four hours after eating), confirming that their heart monitoring was sensitive enough to detect real effects if they had existed. This meal-effect approach provided an alternative way to validate the measurement system when achieving very high drug exposures (twice the maximum clinical dose) was not feasible.
This research matters because it demonstrates a practical pathway for drug developers to establish heart safety without conducting a dedicated thorough QT study, which is resource-intensive. The Japanese drug regulatory agency (PMDA) accepted these results and granted a waiver for the traditional thorough QT study. The use of the meal effect as a sensitivity control could be informative for other drug development programs facing similar challenges in demonstrating cardiac safety monitoring reliability.
Kashihara Y, Igawa Y, Okita K, Sasaki M, Ohara T, Kotsuma M, et al.. (2026). Concentration-QTc Analysis Supporting Thorough QT Study Waiver for Forvisirvat: Electrocardiogram Assay Sensitivity Demonstrated via Meal Effect.. Journal of clinical pharmacology. https://doi.org/10.1002/jcph.70312