O’Brien SM, et al. - The intention of the authors was to scrutinize the baseline factors which speculate complete response (CR) in chronic lymphocytic leukemia/small lymphocytic lymphoma patients treated with ibrutinib. Those individuals receiving ibrutinib as a first-line therapy for chronic lymphocytic leukemia and those without bulky disease demonstrated a better likelihood of CR to treatment. Data unveiled higher CR rate with continued longer-term ibrutinib treatment when compared to previous reports.

Methods

• With the aid of univariate and multivariate analyses from 2 clinical trials, researchers contemplated the prognostic value of baseline factors associated with CR.
• The study cohort consisted of 327 patients from the PCYC-1102 and PCYC-1112 studies treated with single-agent ibrutinib.
• The follow-up took place in academic and community medical centers in the United States, the United Kingdom, Australia, France, Italy, Ireland, Poland, Spain, and Austria.
• Odds ratio (OR) of CR rate served as the primary outcome measure.

Results

• Subjects had a median age of 67 years (range, 30-86 years) and 227 (69.4%) were male.
• A total of 185 candidates (56.6%) had bulky disease (lymph node ≥5 cm), 184 (56.3%) had advanced-stage disease, and 182 (55.7%) had an Eastern Cooperative Oncology Group performance status of 1 or higher at baseline.
• In the first-line setting, 31 subjects (9.5%) were included; 38 (11.6%) had undergone 1 previous therapy, 81 (24.8%) had undergone 2, and 177 (54.1%) had undergone 3 or more.
• It was noted that individuals with relapsed/refractory disease had undergone a median of 3 (range, 0-12) previous therapies.
• Median time on study was discovered to be 26.4 months (range, 0.3-55.6 months).
• Findings revealed that 32 of the 327 patients (9.8%) treated with ibrutinib had a CR (PCYC-1102: Relapsed/refractory, 12 of 101 [11.9%]; treatment-naive, 8 of 31 [25.8%]; and PCYC-1112: 12 of 195 [6.2%]).
• For these candidates, the median time to CR was 14.7 months (range, 4.6-47.1 months).
• Bulky disease, clinical stage, number of previous therapies, and β2-microglobulin concentration exerted a prominent effect on the odds of CR, as demonstrated via univariate analysis of baseline factors.
• In final multivariate model, subjects with no previous therapy vs patients with at least 1 previous therapy (OR, 2.65; 95% CI, 1.01-6.95; P=.047) and individuals without bulky disease (lymph node <5 cm) vs those with bulky disease (lymph node ≥5 cm [OR, 4.97; 95% CI, 1.91-12.91; P=.001]) displayed an increased tendency for CR.