An Interim Analysis of the Turkish Myeloma Registry Among the Patients Who Have Received up to Two Lines of Therapy
Authors: Sevindik Omur Gokmen , Ozkurt Zubeyde Nur , Boga Can , Besisik Sevgi Kalayoglu , Ipek Yildiz , Geduk Ayfer , Harmandali Aybuke , Salihoglu Ayse , Sahin Handan haydaroglu , Sönmez Mehmet , Vural Filiz , Akay Olga Meltem , Kurt Yuksel Meltem , Maral Senem , Ekinci Omer , Kirkizlar Onur Hakki , Tekinalp Atakan , Demir Nazli , Merter Mustafa , Saydam Guray , Alacacıoğlu İnci , Yegin Zeynep Arzu , Kasar Mutlu , Mastanzade Metban , Ozsan Guner Hayri 
Published: November 2021

Abstract
Introduction: To investigate the demographics and treatment details of the myeloma patients who were diagnosed and followed up in Turkey and received up to two lines of therapy.
Methods: Patients who were recorded on the database of Turkish Myeloma Registry project were included in this study if they had only received one or two lines of therapy. Demographics, patient, and disease related parameters both at the time of diagnosis and at the follow up and treatment outcomes were presented.
Results: A total of 532 patients were included in the study, and 44% of the patients were female. Median age at the time of diagnosis was 63 (30-106). 47.7% of the patients were diagnosed with IgG myeloma. According to the ISS risk stratification, 20.4% of patients had ISS 1, 34.7% of patients had ISS 2 and remaining 44.9% had ISS 3 disease. Defining high risk disease as harboring one or more of these following cytogenetic abnormalities; del 17p, t(4;14), t(14;16) or t(14;20); 7.1% of the patients were classified as having a high risk disease. Most commonly used frontline therapy approach was bortezomib cyclophosphamide dexamethasone combination (VCD) (76.5%) and followed by bortezomib dexamethasone (VD) (8.8%), and bortezomib lenalidomide and dexamethasone combination (VRd) (7.1%). Overall response rates (a better response than stable disease according to IMWG response assessment criteria) were 87.6% in VCD induced patients; 63.3% in VD induced patients and 92% in VRd induced patients. The PFS obtained by these frontline approaches was 17.8 months in patients who were able to proceed with high dose chemotherapy with ASCT support and 8.4 in patients who were not able to (p&lt;0.01), with an overall PFS of 15.3 months. With regard to the induction approach, PFS was 21.1 months for VRD, 15.3 months for VCD and 7.6 months for VD (p=0.08). Regarding maintenance, 23.6% of patients were maintained by lenalidomide alone, 62.7% of patients were maintained by a combination of lenalidomide and dexamethasone or bortezomib alone (2.7%). PFS after the first line of the treatment was 22.2 months in maintained patients and 12.2 in un-maintained patients (HR: 0.532, p=0.001, CI95% 0.359-0.790). Regarding the second line therapy Rd was the leading option (34.8%) and VRd (17.8%), Carfilzomib based (16.3%), VCD (8.1%) were the followings.
Conclusion: As the main concern of this study was to document the demographic features and clinical parameters of a Turkish Myeloma population and to give an idea about the treatment patterns and outcomes in frontline setting and first relapse an overall survival was not calculated. Progression free survival obtained after frontline therapy was relatively shorter than the ones which were presented by other real- world registries. Outcomes of second line therapy will be presented as follow up after 2nd line therapy exceeds a certain threshold. We hope, the results obtained from this study can have a role in the approval and re-imbursement of the current standard of care options.

Disclosures
No relevant conflicts of interest to declare.