2. Progressive disease. For non-secretory multiple myeloma, progressive disease is defined as bone marrow biopsy with > 25% increase in plasma cells or an absolute increase of at least 10% over prior known level. Alternatively, development of new or worsening of existing lytic bone lesions or soft tissue plasmacytomas, or hypercalcemia (serum calcium >11.5 mg/dL), or relapse from CR.