Phase 1b Study of Weekly Carfilzomib in Combination With Lenalidomide and Dexamethasone in Subjects With Multiple Myeloma

Safety and tolerability were evaluated according to the type, incidence, and severity of adverse events.

An AE is defined as any untoward medical occurrence in a clinical trial subject. The event does not necessarily have a causal relationship with study treatment.

A serious adverse event is defined as an AE that meets at least 1 of the following serious criteria:

• fatal
• life threatening
• requires in-patient hospitalization or prolongation of existing hospitalization
• results in persistent or significant disability/incapacity
• congenital anomaly/birth defect
• other medically important serious event

The severity of each AE was assessed according to the National Cancer Institute Common Terminology Criteria for Adverse Events, version 4.03 where Grade 1 = Mild, Grade 2 = Moderate, Grade 3 = Severe, Grade 4 = Life-threatening, and Grade 5 = Death.

Response was determined by the investigator based on the International Myeloma Working Group Uniform Response Criteria (IMWG URC). ORR was defined as the percentage of participants who achieved a best response of stringent complete response (sCR), complete response (CR), very good partial response (VGPR) or partial response (PR). Responses must have been confirmed in 2 consecutive assessments at any time prior to initiation of any new therapy.

Disease assessments included serum protein electrophoresis (SPEP) with immunofixation, urine protein electrophoresis (UPEP; 24-hour assessment) with immunofixation, serum free light chain (SFLC), quantitative immunoglobulins, bone marrow aspirates to determine percent plasma cell involvement, and skeletal imaging for plasmacytoma evaluation.

Complete Response Rate (CRR) is defined as the percentage of participants who achieved a best overall response of either stringent complete response (sCR) or complete response (CR) in accordance with International Myeloma Working Group-Uniform Response Criteria (IMWG-URC).

sCR: As for CR, and absence of clonal plasma cells in bone marrow (BM) CR: Negative serum and urine immunofixation, disappearance of any soft tissue plasmacytomas, < 5% plasma cells in BM, and normal SFLC ratio in participants with measurable disease only by SFLC.

PFS is defined as the time from the first day of study treatment to the earlier of disease progression or death due to any cause.

Disease progression was determined by the investigator according to IMWG-URC. Progressive Disease (PD): Increase of 25% from lowest value in serum M-component (absolute increase ≥ 0.5 g/dL), urine M-component (absolute increase ≥ 200 mg per 24 hours) and/or the difference between involved and uninvolved FLC levels (absolute increase >10 mg/dL) in patients without measurable serum and urine M-protein levels, and/or any new or increase in size of bone lesions or soft tissue plasmacytomas, or development of hypercalcemia.

PFS was analyzed using Kaplan-Meier methods. Participants who were alive with no documented PD, started new anticancer therapy before documentation of PD or death, had death or PD immediately after > 1 consecutively missed assessment visit, were lost to follow-up or withdrew consent were censored at the date of last disease assessment.

Duration of response (DOR) was calculated for participants who achieved a confirmed PR or better based on Investigator assessment and according to the IMWG URC. Duration of overall response is defined as the time from first documentation of response to disease progression or death due to any cause. DOR was analyzed using Kaplan-Meier methods. Participants who were alive with no documented PD, started new anticancer therapy before documentation of PD or death, had death or PD immediately after > 1 consecutively missed disease assessment visit, were lost to follow-up, or withdrew consent were censored at the date of last disease assessment.