serum vitamin d levels and peripheral neuropathy among multiple myeloma patients

Conditions: Multiple Myeloma; Peripheral Neuropathy

Summary: this is a prospective study investigating the relationship between vitamin d and peripheral neuropathy (pn) among multiple myeloma (mm) patients treated with either bortezomib or thalidomide. the study consists of a screening period of up to 14 days, followed by a single assessment visit to evaluate vitamin d levels, incidence and severity of pn, neuropathic pain, and markers of depression. patient charts will also be utilized to assess the frequency of skeletal-related events.

approximately 10% of myeloma patients present at diagnosis with clinical neuropathy although studies reveal as many as 1/3 may have abnormal electrophysiological examinations. baseline neuropathic abnormal findings are exacerbated by many myeloma treatments, especially bortezomib, thalidomide, and to a lesser extent lenalidomide. several studies suggest that vitamin d supplementation may help reduce the symptoms of neuropathy.in this prospective study, we will investigate the relationship between vitamin d and pn among mm patients treated with either bortezomib or thalidomide. the study consists of a screening period of up to 14 days, followed by a single assessment visit to evaluate vitamin d levels, incidence and severity of pn, neuropathic pain, and markers of depression. patient charts will also be utilized to assess the frequency of skeletal-related events.

Eligibility criteria:
inclusion criteria: * voluntary written informed consent before performance of any study-related procedure not part of normal medical care, with the understanding that consent may be withdrawn by the subject at any time without prejudice to future medical care. * prior diagnosis of multiple myeloma based on standard criteria (durie 1986) * received consecutive, prior treatment for mm with a regimen consisting of at least 16 consecutive weeks of bortezomib or 16 consecutive weeks of thalidomide prior to the day of assessment * the 16 weeks of consecutive treatment must have included at least one of the following doses and schedules: * bortezomib: ≥ 1.0 mg/m² dosed 3 or more times per each 4-week period * thalidomide: ≥ 50 mg/day dosed daily * the qualifying regimen may include both bortezomib and thalidomide. however, the above inclusion requirements need only be satisfied by either one of the agents. * age ≥18 years at the time of signing the informed consent form * able to adhere to the study visit schedule and other protocol requirements exclusion criteria: * plasma cell dyscrasia with polyneuropathy, organomegaly, endocrinopathy, monoclonal protein (m-protein) and skin changes (poems) syndrome (bardwick 1980) * plasma cell leukemia * primary amyloidosis * vitamin d level assessment occurring within the 12 months preceding the day of assessment * vitamin d non-dietary oral supplementation \> 1200 iu per day for \> 30 total days within the 12 month period preceding the day of assessment * serious medical or psychiatric illness likely to interfere with participation in this clinical study. * any serious medical condition, laboratory abnormality, or psychiatric illness that would prevent the subject from signing the informed consent form * any condition, including the presence of laboratory abnormalities, which places the subject at unacceptable risk if he/she were to participate in the study or confounds the ability to interpret data from the study.