Enhancing reporting quality and impact of early phase dose-finding clinical trials: CONSORT Dose-finding Extension (CONSORT-DEFINE) guidance

Pharmacokinetics, safety, and efficacy of an alternative dosing regimen of sasanlimab in participants with advanced NSCLC and other malignancies

Background

Sasanlimab (PF-06801591), a humanized immunoglobulin G4 monoclonal antibody, binds to programmed cell death protein-1 (PD-1), preventing ligand (PD-L1) interaction.

Objectives

To evaluate pharmacokinetics (PK), safety, tolerability, and efficacy of two subcutaneous sasanlimab dosing regimens.

Design

An open-label study consisting of phases Ib and II. Phase Ib: non-randomized, dose escalation, and expansion study in Asian participants with advanced malignancies.

Phase II

conducted globally in participants with non-small-cell lung cancer with PD-L1 positive or PD-L1 status unknown tumors; participants were randomized 1:2 to receive subcutaneous sasanlimab 300 mg once every 4 weeks (300 mg-Q4W) or 600 mg once every 6 weeks (600 mg-Q6W).

Methods

Primary endpoint in phase Ib: dose-limiting toxicity (DLT) occurring in first treatment cycle; in phase II: C trough and AUC.

Results

A total of 155 participants (phase Ib, n = 34; phase II, n = 121) received sasanlimab. Phase Ib: no DLT reported. Phase II: ratio of adjusted geometric mean for AUCtau was 231.2 (90% CI, 190.1-281.2) and C trough was 111.5 (90% CI, 86.3-144.0) following 600 mg-Q6W (test) versus 300 mg-Q4W (reference). Phase Ib: grade 3 treatment-related adverse events (TRAEs) occurred in 1/4 (25%) and 3/12 (25%) participants treated in 300 mg-Q4W dose escalation and expansion cohorts, respectively. Phase II: grade 3 TRAEs occurred in 3/41 (7.3%) and 3/80 (3.8%) participants treated with 300 mg-Q4W and 600 mg-Q6W, respectively; no grade 4/5 TRAEs. Phase II: confirmed objective response was observed in 11/41 (26.8% (95% CI, 14.2-42.9)) and 12/80 (15.0% (95% CI, 8.0-24.7)) participants treated with 300 mg-Q4W and 600 mg-Q6W, respectively.

Conclusions

Phase Ib regimens were considered safe with no DLTs reported. In phase II, 600 mg-Q6W regimen criteria were met for AUCtau and C trough metrics to support PK-based extrapolation of efficacy of alternative regimen. Regimens were well tolerated, showing anti-tumor activity in participants with advanced solid tumors. Administration of sasanlimab at a dose of 600 mg-Q6W subcutaneously may serve as a convenient alternative to 300 mg-Q4W administration.

Trial registration

NCT04181788 (ClinicalTrials.gov); 2019-003818-14 (EudraCT).

Addition of testosterone to endocrine care for transgender women: a dose-finding and feasibility trial

OBJECTIVE

Transgender women who underwent gonadectomy have lower serum testosterone concentrations than cisgender women. There is uncertainty regarding the dosing and side effects of supplementation of testosterone in transgender women. This study aimed to assess the feasibility of dosing testosterone to the cisgender female physiological range in transgender women. In addition, we explored changes in cardiovascular parameters, virilizing side effects, and clinical symptoms.

DESIGN

This is an open-label, single-arm feasibility study. Participants initially went through a dose-titration phase with 2-week intervals of 0.07-0.09-0.13 mL (277-318-403 μg bioavailable testosterone) testosterone 2% gel to establish a dose leading to serum testosterone concentrations between 1.5 and 2.5 nmol/L. This dose was then continued for 8 weeks.

METHODS

Participants applied daily transdermal testosterone 2% gel (Tostran®) at the prescribed dosage. Testosterone was measured every 2-4 weeks. Laboratory analyses, side effects, and clinical symptoms were evaluated.

RESULTS

In total, 12 participants were included. Most participants required a dose of 0.07 mL (277 μg bioavailable testosterone) or 0.09 mL (318 μg bioavailable testosterone) to reach serum testosterone concentrations of 1.5-2.5 nmol/L. Continuing this dose, testosterone concentrations remained stable throughout the study. Changes in clinical outcomes were in the desired direction, and side effects were mild.

CONCLUSIONS

The use of testosterone supplementation in transgender women seems feasible and safe in the short term. Although dosing requires personalized titration, stable testosterone levels can be established. A blinded, placebo-controlled, randomized clinical trial is needed to study the clinical benefit.