Investigational Multiple Myeloma Drug Combo Shows Promise

Oral drug combination effective in treating newly diagnosed multiple myeloma.

An experimental treatment for early stage multiple myeloma exhibited promising results in recent clinical trials.

Researchers evaluated the investigational drug ixazomib taken orally in combination with lenalidomide and dexamethasone in patients with newly diagnosed multiple myeloma for a phase 1/2 study published in the journal Lancet Oncology.

The treatment was found to be active and well tolerated in patients newly diagnosed with the disease.

"Ixazomib is an investigational, oral proteasome inhibitor with promising anti-myeloma effects and low rates of peripheral neuropathy," lead author Shaji Kumar, MD, said in a press release. "While it is well known that a combination of bortezomib, lenalidomide, and dexamethasone is highly effective in treating newly diagnosed multiple myeloma, we wanted to study the safety, tolerability and activity of ixazomib in combination with lenalidomide and dexamethasone in newly diagnosed multiple myeloma."

The trials enrolled a total of 65 patients (15 in phase 1 and 50 in phase 2) between November 2010 and February 2012. Patients were treated with 2.97 mg/m2 as the maximum tolerated dose of ixazomib followed by a recommended phase 2 dose of 2.23 mg/m2, which was converted to a 4.0 mg fixed dose as a result of population pharmacokinetic tests.

There were a reported 41 grade 3 or higher adverse events from the combination, including skin and subcutaneous tissue disorders neutropenia and thrombocytopenia and drug-related peripheral neuropathy, the authors wrote. A total of 5 patients discontinued therapy due to the adverse events.

Of 64 response-evaluable patients, 59 exhibited a partial response, with 37 who showed a very good partial response or better.

"The all-oral combination of weekly ixazomib plus lenalidomide and dexamethasone was generally well tolerated and appeared active in patients with newly diagnosed multiple myeloma," Dr. Kumar said. "Our results support the development of a phase 3 trial studying this combination for multiple myeloma."