Effect of Low Dose Bortezomib on Bone Formation in Smoldering Myeloma Patients
Smoldering multiple myeloma (SMM) is usually followed expectantly without therapy. The
overall risk of progression to active multiple myeloma has been estimated up to 20% in the
first year from diagnosis (Kyle et al, 2007). An angiogenic switch has been postulated as a
pivotal event in the progression from MGUS to smoldering myeloma. Two trials for advanced
and refractory MM patients tested this hypothesis using Thalidomide as antiangiogenic agent
in association with biphosphonates showing and effect on disease progression (Barlogie et
al, 2008).
The ubiquitin-proteasome pathway, which has been shown to be an essential cellular
degradative system in myeloma cells, also regulates bone formation though effects on
osteoblast differentiation (Pennisi et al., 2008).
Retrospective analysis of ALP variation in 2 large Bortezomib trials in the refractory
setting confirmed the finding. In the SUMMIT trial (Zangari, et al., 2005), 77 patients
were evaluated. The media increment ALP in levels of responding patients (patients with
>50% decrease in paraprotein) upon completion of 3 cycles of therapy was statistically
higher of those individuals with less than partial response (week 8, P=0.0015; responder
range, 62-837 mL/L). In the APEX trial (Zangari et al. 2005), 422 patients were analyzed;
217 patients were randomized to bortezomib, 205 to dexamethasone. Within the bortezomib
arm, the increment in serum ALP levels in responder patients (>CR) was statistically higher
at week 3 (P=0.014), week 6 (P=0.002; responder rage, 31-272 mL/L) and week 9 (P=0.036).
Comparing only responders patients in both arms of the study, we observed a significantly
higher median ALP increase in the bortezomib compared to the dexamethasone arm (P<0.01;
responder ran, 31-272 mL/L) (Zangari et al., 2007). A 25% increase in ALP (N=105) at week 6
was also the strongest indicator associated with quality of response (P<0.0001) and also
with the time to progression (206 vs. 169 days) relative to patients with less than a 25%
increase in ALP (N=228; P=0.01) (Zangari et al., 2007). We will now test the bone anabolic
effect of bortezomib in a cohort of smoldering multiple myeloma patients.
Study rationale and selection of drug doses VELCADE has been shown to produce an anabolic
bone effect (increase bone ALP and osteocalcin) in relapsed/refractory patients. This study
will examine the bone anabolic effect in patients with smoldering myeloma who, with a median
age of 67 years, have frequent evidence of osteopenia not associated with lytic bone
disease. Risk of disease progression is estimated at 10% per year in this patient
population. The primary aim of this trial is to determine the effect of a short course
(i.e. 9 cycles) of low-dose Bortezomib on bone remodeling and on disease progression. The
dose of bortezomib used in this trial of 0.7 mg/m2 is the lowest dose which has shown
efficacy in the 3 largest monotherapy trials with bortezomib. Seventeen percent of patients
in the APEX 9% of patients in CREST and 24% in SUMMIT trials were treated with 0.7 mg/m2
dosages. Bortezomib will be given on days 1, 8, 15, 22 over 42 days to reduce the incidence
of possible drug related side effects.
Interventional
Endpoint Classification: Safety/Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Prevention
To evaluate the bone anabolic effect of bortezomib in patients with smoldering myeloma.
September 2012
No
Maurizio Zangari, MD
Principal Investigator
University of Utah
United States: Institutional Review Board
HCI33979
NCT00983346
September 2009
December 2013
Name | Location |
---|---|
Huntsman Cancer Institute | Salt Lake City, Utah 84112 |