Adding Imbruvica to a standard-of-care chemotherapy-immunotherapy treatment regimen was associated with a significant improvement in survival in older patients with newly diagnosed mantle cell lymphoma.
Adding Imbruvica (ibrutinib) to a treatment regimen of the chemotherapy bendamustine in combination with the immunotherapy Rituxan (rituximab) improved progression-free survival (time during and after treatment when the patient lives without disease progression) outcomes by 50% in older patients with mantel cell lymphoma, when compared with placebo plus the chemoimmunotherapy combination.
The results of the phase 3 SHINE trial — which were presented at the 2022 American Society of Clinical Oncology (ASCO) Annual Meeting — demonstrated that patients who received the Imbruvica-based combination achieved a median progression-free survival of 6.7 years compared with 4.4 years in the patients who were administered placebo plus bendamustine and Rituxan.
The lead study author, Dr. Michael Wang, a professor in the Department of Lymphoma and Myeloma at The University of Texas MD Anderson Cancer Center in Houston, noted that these results are both statistically significant and clinically meaningful for this patient population.
“Indeed, this is very meaningful,” he explained during the presentation. “Imagine a patient is diagnosed with a life-threatening mantle cell lymphoma (and) in this regimen we achieved 6.7 years without any disease. This is truly meaningful and a really remarkable achievement in the field (and) for these patients.”
He also noted that these findings mark the highest progression-free survival rate ever reported for this hard-to-treat patient population with mantle cell lymphoma.
For instance, some lymphoma treatments, such as intensive chemotherapy may be associated with excessive side effects that are often not well tolerated by older patients with mantle cell lymphoma. And even though older patients with mantle cell lymphoma need a better effective treatment option, they are often underrepresented in clinical trials.
In this study, Wang and colleagues analyzed the safety and efficacy of adding Imbruvica to the standard-of-care regimen of bendamustine and Rituxan followed by Rituxan maintenance in previously untreated patients aged 65 years and older with mantle cell lymphoma.
Patients were randomized to either the Imbruvica treatment group or placebo treatment group. Of note, patients within the placebo group were treated with the chemoimmunotherapy combination of bendamustine and Rituxan. They did not, however, receive Imbruvica. In total, 261 patients received the Imbruvica-based treatment regimen, and 262 patients were given the standard-of-care treatment plus placebo.
The study results also demonstrated that treatment with the Imbruvica-based regimen elicited a complete response rate (or the disappearance of cancer as a response to treatment) of 65.5% versus 57.6% with the placebo-based treatment. Of note, there was no difference in overall survival data between the two patient groups.
The Imbruvica-based treatment group also had a higher time to next treatment, which means more time lapsed before their disease stopped responding to treatment and they had to receive additional treatment. Fifty-two of the patients in the Imbruvica group had to receive subsequent anti-lymphoma therapies compared with 106 of the patients who received the placebo-based regimen.
Severe or potentially life-threatening side effects occurred in 81.5% and 77.3% of patients in the Imbruvica and placebo groups, respectively. Notably, atrial fibrillation (irregular heartbeat) was reported in 13.9% and 6.5% of patients in each group, respectively. Other side effects noted by Wang included neutropenia, rash and pneumonia. Rates of major hemorrhage, hypertension, arthralgia (joint stiffness) and second primary malignancies were similar in both treatment groups.
Wang noted that these side effects were “no surprise” to the study investigators and were consistent with what they have seen in daily practice with Imbruvica.
“We believe this phase 3 clinical trial set a new benchmark for patients with a newly diagnosed (MCL) and the elderly and for those patients who are not eligible for autologous stem cell transplantation,” he concluded.
“Results from this trial bring new hope to newly diagnosed, older patients with this rare cancer who have had too few treatment options,” Dr. Julie R. Gralow, ASCO’s chief medical officer and executive vice president, said of the findings in a press release.
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