Hedgehog blockade in steroid-refractory sclerotic chronic graft-versus-host disease

Targeting Hedgehog Signaling with Glasdegib in Patients with Refractory Sclerotic Chronic GVHD: A Report of Two Phase I/II Trials

PURPOSE

Sclerotic chronic GVHD (scGVHD) is characterized by progressive skin fibrosis and frequent refractoriness to available therapies. Aberrant activation of Hedgehog signaling in dermal fibroblasts has been implicated in scGVHD. Here, we report the results of two phase I/II studies (NCT03415867, GETH-TC; NCT04111497, FHD) that evaluated glasdegib, a smoothened antagonist, as a novel therapeutic agent in refractory scGVHD.

PATIENTS AND METHODS

Adult patients with active scGVHD after ≥1 (FHD) or ≥2 (GETH-TC) lines of therapy were enrolled. Primary endpoints were dose-limiting toxicity (DLT) and MTD in the GETH-TC trial, and safety and tolerability measures in the FHD trial. Glasdegib was administered once daily in 28-day cycles. Responses were scored per 2014 NIH cGVHD criteria. Correlative studies were performed to evaluate the role of fibroblast-independent immune mechanisms on clinical activity.

RESULTS

Twenty (GETH-TC) and 15 (FHD) patients were recruited. Treatment-emergent grade (G) ≥2 adverse events (AE) in the GETH-TC trial included muscle cramps (85%), alopecia (50%), and dysgeusia (35%). Two patients experienced a DLT (G3 muscle cramps), and the MTD was established at 50 mg. G3 muscle cramps were the most frequently reported AE (33%) in the FHD trial. At 12-months, the skin/joint scGVHD overall response rate was 65% (all partial responses) in the GETH-TC trial and 47% (6 partial responses, 1 complete response) in the FHD cohort. No immune correlates of response were identified.

CONCLUSIONS

Glasdegib demonstrated promising responses in patients with refractory scGVHD, but tolerability was limited by muscle cramping.

Chronic graft-versus-recipient disease: Systematic review of joint and fascial involvement

BACKGROUND AND OBJECTIVE

Chronic graft-versus-host disease (cGVRD) is a systemic immune-mediated complication that occurs in approximately half of the patients undergoing allogeneic haematopoietic stem cell transplantation (allo-HCT) and, although it is associated with beneficial graft versus tumour effects and lower relapse rates, it remains the leading cause of late morbidity and mortality in these patients. The aim of this systematic review of the literature is to provide a current overview on the diagnostic musculoskeletal manifestations of cGVRD, its clinical evaluation, and therapeutic possibilities.

METHODS

We ran a systematic search in PubMed, Embase, and Cochrane Library. Studies from the last 20 years were included. Priority was given to cross-sectional studies to evaluate diagnostic methods and to clinical trials in the case of articles referring to treatment. The search was limited to humans and articles published in English or Spanish.

RESULTS

We identified 6423 studies, of which we selected 86 (37 on clinical and diagnostic evaluation and 49 on treatments). Specific studies on fascial and joint complications are scarce and of low quality, including only isolated clinical cases or case series. Fasciitis is the most relevant musculoskeletal manifestation, and isolated joint involvement is low, sometimes unnoticed and underdiagnosed, if a thorough exploration of joint motion is not performed. Early detection of cGVRD with fascial and/or joint involvement requires careful and repeated evaluation.

CONCLUSIONS

The search for new biomarkers or advanced imaging techniques that allow early diagnosis is necessary. Physiotherapy is essential to improve functionality and prevent disease progression. Controlled studies are needed to establish recommendations on second lines of treatment. Because of its multisystemic nature, cGVRD requires a multidisciplinary approach.