Final Analysis of a Multicenter, Randomised Study Comparing Zoledronate vs Observation in Patients with Asymptomatic Myeloma.
Authors: Musto Pellegrino , Petrucci Maria Teresa , Bringhen Sara , Guglielmelli Tommasina , Caravita Tommaso , Balleari Enrico , Andriani Alessandro , D’Arena Giovanni , Bongarzoni Velia , Guariglia Roberto , Pietrantuono Giuseppe , Villani Oreste , Martorelli Maria Carmen , D’Auria Fiorella , Niscola Pasquale , Falcone Antonietta , Sanpaolo Grazia , Palumbo Antonio 
Published: October 2019

Abstract
In vitro evidences suggest that bisphosponates (BP) may exert some anti-myeloma activities. Indeed, the use of BP has been associated with better survival in selected subgroups of myeloma patients. We have previously reported that pamidronate, a second generation BP, is not useful to prevent or to delay the need of chemo-radiotherapy in patients with early stage or smouldering myeloma, who do not require specific treatments at diagnosis, although such a therapy may reduce skeletal events at the time of disease progression (Musto et al, Leuk Lymphoma2003; 44: 1545). Based on this limited evidence, the recently updated ASCO guidelines still not recommend the use of BP in this specific setting of patients (Kyle et al, J Clin Oncol2007; 25: 2464). On June, 2001, we started a randomised clinical trial comparing zoledronate (ZOL), a third generation, more potent BP, vs simple observation in patients with monoclonal gammopathy fulfilling the diagnostic criteria of stage IA, IIA or smouldering myeloma, not requiring further treatments. These criteria substantially correspond to the current definition of “asymptomatic myeloma”, recently suggested by the International Myeloma Working Group (IMWG, Br J Haematol2003; 121: 749). Accrual was completed on June, 2004. One-hundred-sixty patients were enrolled and randomised (1:1) to receive (n. 80) or not (n. 80) ZOL (Zometa, Novartis Pharmaceuticals. Origgio, Italy) for one year, on an out-patient basis, at the dose of 4 mg as 15′ i.v. single monthly infusion. The two groups were comparable at baseline for time from diagnosis, levels and type of M-component and percentage of bone marrow plasma cells. The most frequent adverse effects observed in ZOL-treated patients were moderate, not clinically relevant hypocalcemia (15 patients: all received oral substitutive therapy and continued the treatment) and fever (7 patients, one of whom stopped drug administration after two cycles). One patient developed reversible osteonecrosis of the jaw, none evidenced renal failure under ZOL therapy. Eight patients (two in the ZOL-treated group and six within controls) died due to unrelated reasons or were lost at follow-up after 6–26 months. No significant reduction of M-component (> 25%) was observed throughout the study in both groups. After a median follow-up of 55 months (range 36–72), there were 35 (46%) progressions to “symptomatic” myeloma in the ZOL group and 37 (50%) within the controls (p n.s.). Median time-to-progression was 42.2 and 40.7 months, respectively (p n.s.). Bone lesions and/or hypercalcemia at the time of progression were significantly lower (17/35, 48.5%) in ZOL-treated patients than in controls (30/37, 81%) (p < 0.02). These mature data suggest that the monthly use of ZOL for one year in patients with early-stage, asymptomatic myeloma is safe, reduces the development of skeletal events at progression, but does not decrease the number of evolutions and does not prolong the time to transformation into “overt” myeloma.