Study highlights need for induction strategy in elderly, frail MM patients
ATLANTA—Initial results of the phase 2 HOVON-126 trial in newly diagnosed multiple myeloma (MM) patients have highlighted the need for an induction strategy in elderly and frail patients.
The trial showed high overall response rates (ORRs) after induction with ixazomib, thalidomide, and low-dose dexamethasone.
However, 62% of patients older than 75 and 60% of frail patients discontinued therapy prior to starting maintenance.
HOVON-126 was designed to determine the ORR of induction therapy with ixazomib, thalidomide, and dexamethasone but also compare progression-free survival in patients who received ixazomib maintenance and those who received placebo.
Sonja Zweegman, MD, of VUmc in Amsterdam, The Netherlands, presented induction results from HOVON-126 at the 2017 ASH Annual Meeting (abstract 433).
The study was supported by Takeda and the Dutch Cancer Society. Dr Zweegman disclosed research funding from, and advisory board participation for, Takeda.
Study design
Investigators enrolled patients with previously untreated, symptomatic MM who were not eligible for stem cell transplant. Patients had to have measurable disease and a WHO performance status of 0 to 3 for patients younger than 75 and 0 to 2 for patients 75 or older.
Patients were not eligible if they had grade 3 neuropathy or grade 2 with pain. They were also ineligible if their creatinine clearance was less than 30 mL/minute.
All patients received ixazomib at 4 mg on days 1, 8, and 15; thalidomide at 100 mg on days 1 to 28; and dexamethasone at 40 mg on days 1, 8, 15, and 22 for nine 28-day cycles.
They could then be randomized to ixazomib maintenance (on the aforementioned schedule) or placebo for 28-day cycles until progression.
Investigators performed subgroup analyses based on cytogenetic risk and frailty.
They defined frailty according to the modified IMWG frailty index, which takes into account age, the Charlson Comorbidity Index, and the WHO performance scale as a proxy for Activities of Daily Living.
They defined high-risk cytogenetics as del17p, t(4;14), or t(14;16).
Investigators planned to enroll 142 patients and expected 94 patients to be randomized.
Patient demographics
The first 120 patients enrolled had a median age of 74 (range, 64–90). Thirty percent (n=38) were older than 75, and 8% (n=10) were older than 80.
More than two-thirds had an ISS score of I or II, and three-quarters had a WHO performance status of 0 or 1. Twenty-four percent had a performance status of 2, and 1% had a performance status of 3.
Eighty percent had lytic bone disease.
One hundred thirteen patients (94%) had FISH analysis performed. Of those, 10% had del17p, 7% had t(4;14), and 1% had t(14;16).
Eighty-one percent of patients fell into the standard-risk category and 19% into the high-risk category.
Almost half of patients (47%) were considered frail, 28% unfit, 21% fit, and 4% unknown.
Response
The ORR for induction was 81%. Ten percent of patients achieved a complete response (CR), 34% had a very good partial response (VGPR), and 37% had a partial response (PR).
The median time to response was 1.1 months, and the median time to maximum response was 4.7 months.
The response rate was independent of cytogenetic risk. Standard-risk patients achieved an ORR of 84%, a VGPR rate of 48%, and a CR rate of 10%. High-risk patients had an ORR of 79%, VGPR of 42%, and CR of 11%.
The response rate was also independent of frailty. Fit patients had an ORR of 88%, unfit patients 85%, and frail patients 75%. The VGPR rate was 36% for fit, 53% for unfit, and 43% for frail patients. The CR rate was 16% for fit, 9% for unfit, and 9% for frail patients.
