Multiple myeloma (MM) is an incurable disease, and clinical trials with newer agents have shown improved patient outcomes. There is a need for effective and tolerable treatment for patients with relapsed/refractory MM (RRMM). Proteasome inhibitors (bortezomib, carfilzomib, ixazomib) remain an integral part of regimens used in RRMM or newly diagnosed (ND) MM. This meta-analysis aims to assess the efficacy and safety of ixazomib (Ixa) based regimens in RRMM.


A comprehensive literature search was performed on PubMed, Cochrane, Embase, Web of Science, and We used MeSH and Emtree terms, "ixazomib" AND "multiple myeloma" from the inception of literature till 06/01/2020. We screened 1529 articles and included 3 randomized clinical trials (RCT, N=907) and 8 non-randomized clinical trials (NRCT, N=321). We excluded case reports, case series, review articles, meta-analysis, observational studies, and clinical trials that didn't provide data about the efficacy and safety of Ixa in RRMM. We used the R programming language (version 4.0.2) to conduct a meta-analysis.


In 11 clinical trials (N=1228), the age range of patients was 30-91 years. In Phase III RCTs (N=837) comparing Ixa + Lenalidomide (Len) + dexamethasone (Dex) vs. placebo + Len + Dex, risk ratio of overall response rate (ORR), complete response (CR), and very good partial response (VGPR) were 1.14 (95% CI=1.05-1.24, I2=80%), 1.87 (95% CI=1.17-2.99, I2=0), and 1.15 (95% CI=0.95-1.40, I2=0), respectively in favor of Ixa + Len + Dex. (Fig 1-3) Grade 3 or higher treatment-related adverse events (TRAEs) thrombocytopenia, diarrhea, and rash were reported in 20%, 5.7% and 6.4% of the patients in the Ixa group vs. 10%, 2.1%, and 2.8% in the placebo group, respectively. In a Phase II RCT by Kumar et al (N=70) comparing the Ixa dosage, 4 mg Ixa + Dex yielded an ORR of 31%, CR 2.8%, and VGPR 17.1%, while 5.5 mg Ixa yielded improved ORR of 54%, CR 2.8%, and VGPR 25.7%.

In a NRCT by Costello et al. (N=6), Ixa + daratumumab (Dara) + Pom + Dex yielded 100% ORR, CR 5% (95% CI=0.17-0.83), and VGPR 50% (95% CI=0.17-0.83). ≥Grade 3 TRAEs were hypertension (16%), and hematological (33%). Among 417 patients from two RCT in single arm who received Ixa + Len + Dex, pooled ORR was 70% (95% CI=0.53-0.82, I2=84%), pooled CR 11% (95% CI=0.8-0.14, I2=0), and pooled VGPR was 29% (95% CI=0.18-0.43, I2=66%). In a NRCT by Dhakal et al. (N=19), Ixa + bendamustine + Dex yielded an ORR 58% (95% CI=0.36-0.77), CR 0, and VGPR 11% (95% CI =0.03-0.34). ≥Grade 3 TRAEs were neutropenia 31%, thrombocytopenia 52%, and diarrhea 10%. In 2 NRCT (N=106), Ixa + cyclophosphamide (Cyc) + Dex yielded a pooled ORR 52% (95% CI=0.42-0.61, I2=0), CR 4% (95% CI=0.01-0.10, I2=0), and VGPR 17% (95% CI=0.11-0.25, I2=0). ≥Grade 3 TRAEs were thrombocytopenia (15%), and upper abdominal pain (4%). In a NRCT by Ludwig et al. (N=90), Ixa + thalidomide (Thal) + Dex yielded an ORR 51% (95% CI=0.41-0.61), CR 9% (95% CI=0.5-0.17), and VGPR 14% (95% CI=0.09-0.23). ≥Grade 3 TRAEs were anemia (17.8%), and infections (16.1%). In a NRCT by Krishnan et al. (N=31), Ixa + Pomalidomide (Pom) + Dex yielded an ORR 48% (95% CI=0.32-0.65) and VGPR 16% (95% CI=0.07-0.33). (Fig 4-6) ≥Grade 3 TRAEs were neutropenia (10%), and lymphopenia (35%).

In 2 NRCT by Kumar et al. (N=70) of two drugs combination, Ixa + Dex yielded a pooled ORR 43% (95% CI=0.28-0.59, I2=47%), pooled CR 1% (95% CI=0-0.09, I2=0), and pooled VGPR 24% (95% CI=0.16-0.36, I2=0). ≥Grade 3 TRAEs were hematological (28%), and non-hematological (22.8%). In 2 NRCT of Ixa monotherapy (N=69), pooled ORR was 17% (95% CI=0.10-0.28, I2=0), and pooled CR 6% (95% CI=0.2-0.22, I2=0). (Fig 4-6) ≥Grade 3 TRAEs were anemia (11%), thrombocytopenia (5.4%), and neutropenia (2.7%).


Our study provides useful insight into relative efficacy of various Ixa regimens for the treatment of RRMM. The pooled analysis of RCT showed that the combination of Ixa + Len + Dex yielded better response as compared to placebo. In the pooled analysis of outcomes in single arm NRCT, Ixa + Dara + Pom + Dex and Ixa + Len + Dex showed better efficacy outcomes as compared to Ixa + Dex in combination with Thal, Cyc, or Bendamustin. Three drugs Ixa combination regimens had better efficacy as compared to two drugs combination of Ixa + Dex and Ixa monotherapy. Ixa was well tolerated with acceptable safety profile. Additional multicenter, double-blind clinical trials are needed to confirm these results.


Anwer:Incyte, Seattle Genetics, Acetylon Pharmaceuticals, AbbVie Pharma, Astellas Pharma, Celegene, Millennium Pharmaceuticals.: Honoraria, Research Funding, Speakers Bureau.

Author notes


Asterisk with author names denotes non-ASH members.