(P 102) EFFICACY AND SAFETY OF VIMSELTINIB IN TENOSYNOVIAL GIANT CELL TUMOUR: PHASE 2 EXPANSION

Author(s)

Jean-Yves Blay, MD, PhD (he/him/his)

Professor of Medicine,
Centre Léon Bérard and Université Claude Bernard, Lyon, France
Lyon, Auvergne, France

Co-Author(s)

Hans Gelderblom, MD, PhD

Professor medical oncology
Leiden University Medical Center, Leiden, Netherlands
Leiden, Zuid-Holland, Netherlands
Piotr Rutkowski, MD, PhD

Head of Department of Soft Tissue/Bone Sarcoma and Melanoma, Professor of Surgical Oncology
Department of Soft Tissue/Bone Sarcoma and Melanoma; Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland
Warsaw, Mazowieckie, Poland
Andrew J. Wagner, MD, PhD

Associate Professor, Medicine, Harvard Medical School
Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA, USA
Boston, Massachusetts, United States
Michiel van de Sande, MD, PhD (he/him/his)

Prof
Leiden University Medical Center, Leiden, Netherlands
Leiden, Zuid-Holland, Netherlands
Alejandro Falcón González, MD, PhD (he/him/his)

Medical Oncologist
Hospital Universitario Virgen del Rocío Sevilla and Instituto de BioMedicina de Sevilla
Seville, Andalucia, Spain
Silvia Stacchiotti (she/her/hers)

Medical Oncologist
Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
Milan, Lombardia, Italy
AL

Axel Le Cesne, MD

Department of Medicine, Gustave Roussy
Villejuif, Ile-de-France, France
Thierry Alcindor, MD MSc

Medical Oncologist
Dana-Farber Cancer Institute
Boston, Massachusetts, United States
César Serrano, MD, PhD

Head, Sarcoma Translational Research Program, Department of Medical Oncology
Vall D'hebron Institute of Oncology
Barcelona, Catalonia, Spain
Emanuela Palmerini, MD

Consultant, Medical Oncologist
IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
Bologna, Emilia-Romagna, Italy
VR

Vinod Ravi, MD

The University of Texas MD Anderson Cancer Center
Houston, Texas, United States
Antonio Casado Herraez, MD, PhD (he/him/his)

associate professor and senior consultant in medical oncologist, chief of the soft tissue and bone sarcoma unit and rare gynecological tumors
Hospital Universitario San Carlos
Madrid, Madrid, Spain
Beatrice Seddon, MBBS, MRCP, FRCR, PhD (she/her/hers)

Consultant Clinical Oncologist
University College London Hospitals, NHS Foundation Trust
London, England, United Kingdom
MV

Marc Vallee, MSc

Biostatistician
Deciphera Pharmaceuticals, LLC
Waltham, Massachusetts, United States
Rudresh Jarecha, MBBS, MD (he/him/his)

Medical Director, Clinical Development
Deciphera Pharmaceuticals, LLC
Waltham, Massachusetts, United States
MS

Maitreyi Sharma, MD (she/her/hers)

Vice President, Late Clinical Development
Deciphera Pharmaceuticals, LLC
Waltham, Massachusetts, United States
RR

Rodrigo Ruiz-Soto, N/A, MD

Deciphera Pharmaceuticals, LLC
Waltham, Massachusetts, United States
MS

Matthew L. Sherman, N/A, MD

Deciphera Pharmaceuticals, LLC
Waltham, Massachusetts, United States
William D. Tap, MD

Chief, Sarcoma Medical Oncology Service
Memorial Sloan Kettering Cancer Center and Weill Cornell Medical College, New York, NY, USA
New York, New York, United States

Objective: Tenosynovial giant cell tumour (TGCT) is a rare, locally aggressive neoplasm caused by upregulation of the colony-stimulating factor 1 (CSF1) gene, resulting in aberrant CSF1 expression and recruitment of CSF1 receptor (CSF1R)-dependent inflammatory macrophages. Vimseltinib is an oral switch control tyrosine kinase inhibitor specifically designed to selectively and potently inhibit CSF1R. We report safety, efficacy, and preliminary patient-reported outcome data for patients with TGCT treated with the recommended phase 2 dose (RP2D; 30 mg twice weekly; NCT03069469).

Methods: Patients with TGCT not amenable to surgery were treated in 2 cohorts: A (no prior anti-CSF1/CSF1R therapy except imatinib and/or nilotinib) and B (prior anti-CSF1/CSF1R therapy). Objectives were to evaluate efficacy and safety of RP2D. Pain was evaluated using brief pain inventory (BPI) worst and average numeric rating scale scores.

Results: As of Feb 18, 2022, 57 patients with TGCT were enrolled: 46 in A (enrollment complete) and 11 in B (enrollment ongoing). Median age was 45 years (range: 21–71) and the most common location was knee (56%). Objective response rates were 49% and 44% in Cohorts A and B, respectively (Table). Most non-laboratory treatment-emergent adverse events (TEAEs) were Grade 1/2; the only Grade 3/4 TEAE observed in >5% of patients was elevated creatine phosphokinase. One patient in Cohort B experienced treatment-related serious AEs of Grade 3 eczema and Grade 2 oedema peripheral. Overall, BPI score improvement was observed in >50% of patients at Week 25 (Table).

Conclusion: At RP2D, vimseltinib demonstrated encouraging antitumour activity with clinical benefit (partial response + stable disease) in 100% of patients. AEs were manageable in both cohorts. Patients reported symptomatic benefit (improved BPI scores). Results support continued evaluation of vimseltinib in the ongoing phase 3 MOTION trial (NCT05059262).

Previously presented at ESMO 2022, FPN: Pending, Blay, et al. Reused with permission.

DCR2205117b_CTOS 2022 Vimseltinib Phase 2 Encore Abstract_TABLE_22Jun2022.docx