An Evaluation of Ibrutinib and Ixazomib in Patients With Relapsed/Refractory Mantle Cell Lymphoma: PrE0404.

What was studied

This study tested ibrutinib plus ixazomib in relapsed or refractory mantle cell lymphoma (MCL). Bruton's tyrosine kinase (BTK) inhibitors have been used for more than 10 years. Finding a good combination partner has been hard. Ixazomib is a proteasome inhibitor. The trial was early-stage, phase 1/2. Phase 1 set the dose for the next stage. That dose was ixazomib 4 mg. It was given on days 1, 8, and 15. Each cycle lasted 28 days. Ibrutinib 560 mg was given daily. Treatment ran until progression or unacceptable toxicity. The phase 2 goal was the complete response (CR) rate. It was compared with the earlier single-agent CR rate of ibrutinib.

What they found

The phase 2 part enrolled 35 BTK-naive patients. Overall response rate was 77. The CR rate was 37. The 2-year progression-free survival (PFS) was 44. The duration of response was 47. Treatment-related adverse events were common. They led to stopping treatment in 37. All rates are shares of patients.

What it means for patients

The authors say PFS was not significantly better than past reports. They also cite the high rate of toxicity. They say the combination does not merit more study here. They say trials of newer BTK inhibitors and other partners are warranted.

Why it is not certain yet

The abstract does not give the number of phase 1 patients. The comparison was with historical reports, not a control group. The abstract does not give overall survival. Early-stage studies are small.

Source

An Evaluation of Ibrutinib and Ixazomib in Patients With Relapsed/Refractory Mantle Cell Lymphoma: PrE0404.

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