Glasgow – Patients with relapsed or refractory multiple myeloma (RRMM) who were treated with a combination of the oral protease inhibitor ixazomib with lenalidomide and dexamethasone (IRd) in routine clinical practice had similar responses to clinical trial patients, according to a global observational study.
Will Pass/MDedge News
Dr. Gordon Cook
Real-world progression-free survival (PFS) and overall response (OR) rates closely approximated data from the TOURMALINE‑MM1 trial, reported lead author Gordon Cook, MB ChB, PhD, clinical director of hematology at the University of Leeds (England).
Tolerability appeared slightly higher in routine clinical practice, and in agreement with previous real-world studies for RRMM, patients who received IRd in earlier lines of therapy had better outcomes than did those who received IRd in later lines of therapy. “The translation of clinical trial data into the real world is really important because we practice in the real world,” Dr. Cook said at the annual meeting of the British Society for Haematology. “We know that trials are really important for establishing efficacy and safety of drugs so they can get licensed and market access, but [clinical trials] often don’t tell us about the true effectiveness of the drugs and tolerability because the populations in trials are often different from [patients in] the real world.”
This situation leads to an evidence gap, which the present trial, dubbed INSIGHT MM aims to fill. INSIGHT is the largest global, prospective, observational trial for multiple myeloma conducted to date, with ongoing enrollment of about 4,200 patients from 15 countries with newly diagnosed or refractory/relapsed multiple myeloma. Dr. Cook estimated that recruitment would be complete by June of 2019.
“The aim of [INSIGHT MM] is to evaluate real-world treatment and outcomes [in multiple myeloma] over 5 years and beyond,” Dr. Cook said.
In combination with interim data from INSIGHT MM (n = 50), Dr. Cook reported patient outcomes from the Czech Registry of Monoclonal Gammopathies (n = 113), a similar database. Unlike INSIGHT MM, which includes patients treated with between one and three prior lines of therapy, the Czech registry does not cap the number of prior therapies. Overall, in the data presented by Dr. Cook, nine countries were represented; about 90% of which were European, although approximately 10% of patients were treated in the United States and about 1% were treated in Taiwan.
The median age of diagnosis was 67 years, with about 14% of patients over the age of 75 years. Median time from diagnosis to initiation of IRd was about 3.5 years (42.6 months), at which point 71% of patients had an Eastern Cooperative Oncology Group performance status of at least 1.
About two-thirds of the patients (65%) had IgG multiple myeloma, and 14% had extramedullary disease. The most common prior therapy was bortezomib (89%), followed by transplant (61%), thalidomide (42%), lenalidomide (21%), carfilzomib (11%), daratumumab (3%), and pomalidomide (2%).
Half of the patients received IRd as second-line therapy, while the other half received the treatment third-line (30%), or fourth-line or later (20%). Median duration of therapy was just over 1 year (14 months), with 62% of patients still receiving therapy at data cutoff.
Dr. Cook cautioned that with a median follow-up of 9.3 months, data are still immature. However, the results so far suggest strong similarities in tolerability and efficacy when comparing real-world and clinical trial administration of IRd.
Routine clinical use was associated with an overall response rate of 74%, compared with 78% in the TOURMALINE‑MM1 trial. Again, showing high similarity, median PFS rates were 20.9 months and 20.6 months for the present data set and the TOURMALINE‑MM1 trial, respectively.
Just 4% of patients permanently discontinued ixazomib in the real-world study, compared with 17% in the clinical trial, suggesting that IRd may be better tolerated in routine clinical practice than the trial data indicated.
“IRd is effective in this setting,” Dr. Cook said. “Bear in mind that patients in the real-world database were further down the line in terms of the treatment pathway, they had prior heavier exposure to bortezomib and lenalidomide, and their performance status was slightly less impressive than it was in [TOURMALINE‑MM1]; therefore, to see this level of response in the real world is very pleasing.”
When asked by an attendee if clinical trials should push for inclusion of patients more representative of real-world populations, Dr. Cook said no. “I think the way we conduct phase 3 clinical trials, in particular, has to be the way it is in order for us to ensure that we can actually get the absolute efficacy and the safety, and that has to be done by a refined population, I’m afraid,” he said.
However, Dr. Cook supported efforts to improve reliability of data for clinicians at the time of drug licensing.
“We should be running real-world exposure in parallel with phase 3 studies, which is harder to do but just requires a bit of imagination,” Dr. Cook said.
The study was funded by Takeda. The investigators reported financial relationships with Takeda and other companies.
SOURCE: Cook G et al. BSH 2019, Abstract OR-018.