Multiple Myeloma Therapy in Tawam Hospital. First Report from United Arab Emirates (UAE)

Introduction:

Plasma cell disorders are a heterogeneous group of disease ranging from Monocloncal gammopathy of unknown significance to Multiple myeloma (MM) and the highly lethal plasma cell leukemia. The prognosis and therapy of MM has been revolutionized in the past two decades with the introduction of proteasome inhibitors, immunomodulatory drugs (IMiDs) and the monoclonal antibodies. The standard of care for induction has been become a triplet regimen lately. Here we describe our experience with the management of MM patients.

Methods:

This is a retrospective analysis of Thirty-five patients who were seen with diagnosis with plasma cell disorders from January 1, 2016 till June 30th 2018 at our center in the UAE. Patients with solitary plasmacytoma and plasma cell leukemia were excluded from further analysis (N=3). Thirty-two patients were included in the analysis.

Results:

The median age was 58 years (range 26 to 94 years). Male to female ratio was 3:1. Biochemical classification showed ten patients with light chain disease only. Twelve patients had IgG kappa disease, eight had IgG lambda while there was one with IgA lambda disease and one was non-secretory with diffuse plasmacytomas.

ISS staging (based on albumin and Beta 2 microglobulin) showed ISS stage 1=7, ISS stage 2= 13, ISS stage 3=8 and data was not available for four patients (diagnosed elsewhere). Cytogenetic risk stratification was not possible due to lack of access to interphase FISH.

Seven patients did not receive any therapy either due to refusal for further investigation and therapy or poor performance status and comorbidities. Four of these seven have expired while the other three have been lost to follow-up.

Twenty-four patients were given induction therapy with a Bortezomib (V)-based regimen while one received IMIDs-based treatment. Regimens and patient numbers are as follows: RVd (Lenalidomide/V/dexamethasone) (N=16), PVd (pomalidomide instead of R due to renal insufficiency) (N=1), V/thalidomide (T) (N=1), VCd (N=2; one for secondary amyloidosis) and Vd (N=4) (poor performance status and/or comorbidities). All patients were given zoledronic acid as well as herpes zoster prophylaxis. Venous thromboembolism (VTE) prophylaxis was prescribed based on published guidelines.

Response evaluation was performed in patients receiving at least four cycles of therapy: CR(N=7); Very Good Partial Remission (VGPR) (N=6); Partial Response (PR) (N=5) and not evaluable for response due to lack of data (N=7). Five patients were documented to have received autologous stem cell transplant (autoSCT). Seven patients, lost to follow up after induction presumably received an autoSCT.

Conclusion:

This is the first report on the management of MM patients in UAE. With a median follow-up of 216 days (range 3 to 839 days) the response rate to induction therapy was 72% (CR+ VGPR). We are unable to report progression free survival due to short follow-up. This response rate of 72% (VGPR or better) is less than the reported in the literature. This may partly be due to lack of patient data regarding induction therapy elsewhere, the use of double over triplet regimens and the absence of autoSCT facilities. Outcome measurement is a difficult task due to tendency of local citizens to travel outside UAE for treatment and the transient nature of the large expatriate population (88% of the total population of approximately 5.4 million)

We are working on developing an infrastructure for consistent testing (CD138-selected FISH, consistent staging, use of PET-CT and bone marrow MRI as well as developing auto SCT facilities). We have formulated a uniform treatment plan based on weekly RVd based therapy for 16 weeks as induction followed by recommendation for Auto SCT. If auto SCT is not possible then patients will continue RVd therapy for a total of 12 cycles followed by maintenance lenalidomide till progression. The standardization of diagnosis, therapeutic approach and follow-up should optimize the care and outcomes of UAE MM patients.