Evaluation of the absolute lymphocyte count as a biomarker for melanoma patients treated with the commercially available dose of ipilimumab (3mg/kg).
2012; Lippincott Williams & Wilkins; Volume: 30; Issue: 15_suppl Linguagem: Inglês
10.1200/jco.2012.30.15_suppl.8575
ISSN1527-7755
AutoresMichael A. Postow, Jianda Yuan, Katherine S. Panageas, Kita Bogatch, Margaret K. Callahan, Michael L. Cheng, Sebastian Edoardo Artur Schroeder, Ryan Kendle, James J. Harding, Mark A. Dickson, Sandra P. D’Angelo, Richard D. Carvajal, Gary K. Schwartz, Jedd D. Wolchok,
Tópico(s)Immunotherapy and Immune Responses
Resumo8575 Background: Ipilimumab (ipi) has demonstrated an overall survival (OS) benefit in 2 phase III trials. Only ~30% of patients (pts) achieve clinical benefit, and factors that determine which pts benefit are unclear. For pts treated with 10mg/kg of ipi, we previously reported that an absolute lymphocyte count (ALC) ≥1000/μL prior to dose 3 [week (wk) 7] was associated with improved OS. Since the mean increase in ALC during ipi treatment correlates with dose, we investigated if ALC is also associated with improved OS at 3mg/kg, the currently FDA approved, commercially available dose. Methods: In an IRB-approved analysis, we evaluated landmark survival data from 137 pts treated with 3mg/kg of ipi at Memorial Sloan-Kettering Cancer Center. 67 pts were treated on an expanded access protocol (CA 184-045). 70 pts were treated per FDA approval (commercial ipi) with 4 standard induction doses. These 2 groups were analyzed separately because some pts in CA 184-045 received re-induction ipi. ALC was determined at first ipi dose (baseline, wk 1) and at subsequent doses (wks 4, 7, and 10). Results: Pts treated with 3mg/kg on CA 184-045 with a wk 7 (prior to dose 3) ALC ≥1000/µL had significantly improved OS compared to pts with an ALC at wk 7 <1000/μL (Median OS: not reached vs. 4.24 mos, p<0.001). This OS difference was also seen for pts treated with commercial ipi (Median OS: not reached vs. 4.44 mos, p<0.01). This difference remained significant in a multivariable model accounting for Karnofsky performance score, LDH, M-stage, and number of prior therapies for pts in the CA 184-045 group and commercial ipi group (p=0.01 and p=0.05, respectively). Baseline ALC ≥1000/µL was associated with improved OS (p=0.02) for pts in the commercial ipi group, though follow-up is limited. Conclusions: At the FDA approved dose of ipi, 3mg/kg, ALC at wk 7 remains significantly associated with improved OS. Our preliminary finding of improved OS for pts treated with commercial ipi whose pre-treatment baseline ALC ≥1000/µL deserves confirmation with longer follow-up and prospective validation. Baseline or on treatment ALC may be a marker of overall prognosis, regardless of therapy.
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