Abstract: UGT1A1*28 polymorphism has been associated with decreased glucuronidation of SN38, the active metabolite of irinotecan. This could increase toxicity with this agent. Patients and Methods In a prospective study, 250 metastatic colorectal cancer patients were treated with irinotecan, fluorouracil, and leucovorin as first-line treatment. UGT1A1*28 polymorphism was investigated with respect to the distribution of hematologic and nonhematologic toxicity, objective response rate, and survival. Pharmacokinetics was investigated in a subgroup of patients (71 of 250) who had been analyzed with respect to toxicity and efficacy. Results UGT1A1*28 polymorphism was associated with a higher risk of grade 3 to 4 hematologic toxicity (odds ratio [OR], 8.63; 95% CI, 1.31 to 56.55), which was only relevant for the first cycle, and was not seen throughout the whole treatment period for patients with both variant alleles TA 7 /TA 7 compared with wild-type TA 6 /TA 6 . The response rate was also higher in TA 7 /TA 7 patients (OR, 0.32; 95% CI, 0.12 to 0.86) compared with TA 6 /TA 6 . A nonsignificant survival advantage was observed for TA 7 /TA 7 when compared with TA 6 /TA 6 patients (hazard ratio, 0.81; 95% CI, 0.45 to 1.44). Higher response rates were explained by a different pharmacokinetics with higher biliary index [irinotecan area under the curve (AUC)×(SN38 AUC/SN38G AUC)] and lower glucuronidation ratio (SN38G AUC/SN38 AUC) associated with the TA 7 /TA 7 genotype and a higher response rate, indicating that the polymorphism is functionally relevant. Conclusion The results indicate that UGT1A1*28 polymorphism is of some relevance to toxicity; however, it is less important than discussed in previous smaller trials. In particular, the possibility of a dose reduction for irinotecan in patients with a UGT1A1*28 polymorphism is not supported by the result of this analysis.

Abstract: Purpose: Irinotecan (CPT11) is a prodrug activated in humans mainly by carboxylesterase 2 (CES2) generating the SN38 metabolite responsible for the drug efficacy and toxicity. The interpatients variability in CPT11 activation step could cause unpredictable toxicity. To identify a predictive molecular marker for CPT11 activation in cancer patients, we investigated the CES2 mRNA expression in peripheral blood mononuclear cells (PBMC) and correlated it to CPT11 activation rate, toxic effects, and response. Experimental Design: Forty-five colorectal cancer patients were treated with a CPT11-including regimen (FOLFIRI). CES2 mRNA expression in PBMC was quantified by reverse transcription-PCR in real time. Plasma concentrations of CPT11, SN38, and SN38-glucuronide were determined by high-performance liquid chromatography and the pharmacokinetic variables calculated adopting the noncompartmental model. Toxicity was evaluated by the National Cancer Institute Common Toxicity Criteria scale and response by the WHO criteria. Results: A high interindividual variability in CES2 mRNA relative expression was observed (median, 1.45; range, 0.01-28.21). CES2 mRNA expression level was significantly associated with CPT11 activation ratio [(AUCSN38 + AUCSN38G)/AUCCPT11]. Patients with CES2 mRNA expression above the median cutoff value presented an activation ratio higher (median, 0.25; range, 0.15-0.42) than those with CES2 mRNA below the median (median, 0.20; range, 0.10-0.40; P = 0.013). This was associated with a nonsignificant trend of 1.34-fold increase of SN38 AUC in the group of patients with high CES2 mRNA expression (mean, 1.03 ± 0.62 versus 0.77 ± 0.32 μmol/L hour). Eight of 23 high CES2 mRNA–expressing patients (34.8%) developed grade 3 to 4 neutropenia or diarrhea compared with 2 of 22 (9.1%) in the low CES2-expressing group (P = 0.071). Conclusion: Our data support a predictive power of CES2 mRNA expression in PBMC for the activation rate of CPT11.

Abstract: Abstract 3888 Chronic lymphocytic leukemia (CLL) is a heterogeneous leukemia with a very variable outcome. The occurrence of a second malignancy (SM) or of a disease transformation (DT) may complicate the course of the disease. An aggressive diffuse large B-cell lymphoma (DLBCL) and, less frequently, a Hodgkin's lymphoma (HL) are the most commonly observed forms of DT, defined as Richter's syndrome (RS). Since the presence of enlarged “bulky nodes”, as well as the observation of extra-nodal lesions, can lead both to the suspicion of a CLL progression and to the possibility of a DT or of a SM, a biopsy of the involved tissue is the only appropriate approach for a correct diagnosis. Positron emission tomography/computed tomography (PET/CT) is currently used for the initial staging and restaging of HL and DLBCL, as well as for the identification of other malignancies. In a previous report by Bruzzi et al. (JNM, 2006), PET/CT showed a high predictive value in demonstrating or excluding DT. The same finding has been observed in single case reports, where in patients with CLL a high 18F-FDG uptake was associated with the presence of a DLBCL. With the aim of discriminating the presence of a DT or a SM malignancy, between June 2008 and June 2012, a PET/CT exam followed by the biopsy of the involved tissue was performed in CLL patients from 4 Italian centers. Patients included in this study showed disease progression requiring treatment according to the 2008 revised IWCLL criteria and clinical signs suggestive of the presence of a more aggressive disease, such as rapidly enlarging or bulky lymph nodes (diameter ≥5 cm) and/or extra-nodal lesions associated with at least one additional sign including B systemic symptoms, increased serum lactate dehydrogenase (LDH), increased β2 microglobulin (B2M). The 18F-FDG uptake was correlated with the histologic findings and, for the purpose of this study, a maximum standardized uptake value (SUVmax) ≥5 was considered highly suggestive of a more aggressive disease. Data on 64 CLL patients (median age, 66 years, range, 35–85) were retrospectively analyzed. At the time of PET/CT, the median follow-up from CLL diagnosis was 73 months (range, 3– 227 months) and a Binet C stage was observed in 16 cases (25%). Twenty-three (36%) patients were treatment-naïve and 41 (64%) had been previously treated (median number of prior treatments, 2; range, 1–4), including 14 (22%) refractory cases. Systemic symptoms were recorded in 25% of cases, LDH was increased in 41% and B2M in 72%. The majority of patients (61%) were IGVH unmutated, 45% CD38 positive and 56% ZAP-70 positive. Bulky lymph nodes (diameter ≥5 cm) and/or marked splenomegaly (longitudinal diameter ≥17 cm) were observed in 30 cases (47%). Evidence of extra-nodal disease was recorded in 8 cases (12.5%): thyroid, 2 cases; uterine fundus, 1; gastric,1; bone, 1; nasopharynx, 1; skin infiltrates, 2. The biopsy confirmed a SLL/CLL diagnosis in 44 cases, a DT in 15 (DLBCL, 10; HL, 5) and SM in 5 (thyroid cancer + SLL/CLL, 2 cases; lymph node metastasis of carcynoid + SLL/CLL, 1; lymph-node metastasis of a squamous cancer, 1; lejomioma of the uterine fundus,1). Sites of abnormal 18F-FDG uptake having a SUVmax ≥5 were recorded in a total number of 30 cases, in 13/44 cases (30%) with a SLL/CLL histology, in 13/15 with DT (87%), including 9/10 (90%) cases of DLBCL and 4/5 (80%) HL. An abnormal uptake was recorded also in 4/5 patients with SM. Based on these results, for the diagnosis of a DT or SM, PET/CTPET/CT showed an overall sensitivity, specificity, positive and negative predictive values of 85% 70%, 57% and 91%, respectively, while for the diagnosis of a DT (DLBCL+HL) the sensitivity, specificity, positive and negative predictive values were 87%, 65%, 43% and 94%, respectively. The cases with a SLL/CLL histology having a SUVmax ≥5 were characterized by a higher Ki-67% expression (p=0.0001) suggesting a high rate of cell turnover. Our results show that a PET/CT performed in CLL patients at the time of disease progression can detect cases with a high likelihood of DT or SM, representing therefore a very helpful imaging technique in guiding the appropriate site that should be considered for biopsy. Disclosures: No relevant conflicts of interest to declare.

Abstract: 562 Background: Dosing based on UGT1A1*28 genotyping has been demonstrated to reduce irinotecan-related adverse events. Previous data (Toffoli et al. JCO, 2010) showed that mCRC pts treated with first-line FOLFIRI tolerated higher doses (310 mg/m 2 for *1/*28; 370 mg/m 2 for *1/*1) of irinotecan than the standard 180 mg/m 2 . The aims of this study (NCT01183494; supported by Eudract 2009-012227-28) were to define the maximally-tolerated dose (MTD) of irinotecan in FOLFIRI plus BEV as first-line therapy in mCRC pts and to determine whether BEV alters irinotecan pharmacokinetics (PK). Methods: Pts were accrued at 3 sites: Chicago (USA), Aviano (Italy), Rome (Italy). In *1/*28 and *1/*1 pts (*28/*28 pts were excluded), irinotecan was administered at an initial dose of 260 mg/m 2 IV every 2 weeks. The dose was escalated to 310 and 370 mg/m 2 if 0/3, 〈 2/6, or 〈 3/10 pts had a DLT (grade 3-4 non-hematologic or grade 4 hematologic toxicity during the first 28-day cycle). MTD was defined as the highest dose at which 〈 4/10 pts had a DLT. 5-FU was administered as a 400 mg/m 2 IV bolus followed by 2400 mg/m 2 IV over 46 hours, plus 200 mg/m 2 leucovorin. BEV was administered at 5 mg/kg IV on day 3 (2 days after irinotecan) and on day 15 (before irinotecan), then every 2 weeks. Irinotecan PK were collected on days 1-3 (in absence of BEV) and on days 15-17 (in presence of BEV). Results: 44 pts (23 *1/*28; 21 *1/*1) were enrolled and 43 were evaluable for DLTs during cycle 1 (Table). Neutropenia and diarrhea were the most common DLTs and were each observed in 5 of 11 (45%) pts with DLTs. The MTD is 260 mg/m 2 in the *1/*28 cohort and at least 310 mg/m 2 in the *1/*1 cohort. In a preliminary analysis of 22 pts, BEV decreased the AUC of SN-38, the active metabolite of irinotecan (p = 0.026 by Wilcoxon matched pairs signed rank test). Conclusions: In first-line therapy of mCRC with FOLFIRI plus BEV, irinotecan doses higher than the standard dose can be safely administered based on UGT1A1 genotype. The impact of this genotype-guided dosing approach on survival will be established in future trials. Clinical trial information: NCT01183494. [Table: see text]

Abstract: Introduction. Observational studies from patients treated outside controlled clinical trials offer real life information and are relevant to understand whether data derived from prospective trials are reproducible in the clinical practice. A retrospective observational study was carried out by the GIMEMA (Gruppo Italiano Malattie EMatologiche dell'Adulto) group in order to evaluate the clinical characteristics and outcome of patients with chronic lymphocytic leukemia (CLL) treated with ibrutinib in Italy within a Named Patient Program (NPP). The NPP was intended to offer free and early drug access to CLL patients until ibrutinib became available on the Italian market. Methods. Patients included in the NPP program had refractory or relapsed (R/R) disease with progression within 24 months after prior chemo-immunotherapy, and/or 17p deletion/TP53 mutations. Patients were also required to have an ECOG performance status ≤2; serum creatinine ≤2 times, liver enzymes ≤3 times and total bilirubin ≤1.5 times the upper limit of normal. Key exclusion criteria were: the need of a concomitant treatment with a strong CYP3A inhibitor or warfarin, an allogeneic stem cell transplantation within the past 6 months or an ongoing active infection. All patients included in the program received ibrutinib orally as a single agent at the standard dose of 420 mg daily. Clinical data of 110 patients included in the NPP program between January 2014 and November 2014 have so far been collected and analyzed using the Research Electronic Data Capture (REDCap) system. Patients were managed at 20 Italian centers and received at least one dose of ibrutinib. Clinical data were reported by the treating physicians. Results. The median age of patients was 69.9 years (range 49.8-83.3); 53% were in Rai stage III-IV, 32% in stage II and 15% in stage 0-I. Sixty-two percent of patients had relapsed disease, 38% were refractory to prior treatment. The presence of a 17p deletion and/or TP53 mutations was recorded in 51 R/R patients. Eighty-six percent of patients had an unmutated IGHV gene profile. The median number of prior treatments was 3 and included allogeneic stem cell transplantation in 4 cases. Two or more comorbidities were reported in 57 patients (52%) and included atrial fibrillation (AF) in 10 (9.1%) and hypertension in 40 (36.4%). After a median follow-up of 12.1 months (range, 1.6-24.6), 87 patients (79%) were still on ibrutinib. A response to ibrutinib was reported in 98/110 patients (89.1%). The best recorded response was a CR/CRi in 19 patients (17.3%), while a PR was reported in 79 patients (72%; PR-L 21.1%). Similar response rates were observed in patients with unmutated IGHV genes (91.9%) and in those with 17p deletion/TP53 mutations (90.3%). At 12 months, the progression-free survival (PFS) and overall survival (OS) were 92.9% (95%CI: 87.9-98.2) and 95.2% (95%CI: 91.1-99.4), respectively. PFS at 12 months of patients who achieved a response was 96.3%, 98.9% in unmutated IGHV patients, 90.7% in those with 17p deletion/TP53 mutations. Five patients (4.5%) died during the NPP program (1 patient each for sepsis, heart failure, ileus perforation, cancer, unknown cause). Adverse events (AE) were recorded in 75 patients (68.2%); in 47 (42.7%) they were grade ≥3. Any grade AEs recorded in ≥5% of patients were: infections (35%; grade ≥3, 22%), granulocytopenia (18.8%; grade ≥3, 17.2%), bleeding (15.5%; grade ≥3, 2.7%), fever of unknown origin or febrile neutropenia (12%; grade ≥3, 5.4%), AF (10.9%; grade ≥3, 4.5%), diarrhoea (8.3; grade ≥3, 2%), hypertension (7.2%; grade ≥3, 5.4%). A new event of AF occurred in 1/10 patients with a prior history of AF. Warfarin was required in 1 patient with AF and this was the reason for ibrutinib discontinuation. Conclusions. The results of the first interim analysis of this retrospective, real life study confirms that ibrutinib, as a single agent, is an effective treatment for patients with poor-prognosis CLL. Our data also suggest that ibrutinib given to unselected patients, in a compassionate-use program, shows a clinical activity and a safety profile comparable to those reported in prospective trials. Data collection is ongoing in order to complete the analysis of this large NPP cohort in Italy. Disclosures Marasca: Roche: Honoraria; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria. Coscia:Karyopharm: Research Funding; ROCHE: Honoraria, Other: Advisory board; Janssen: Honoraria; Gilead: Honoraria; Mundipharma: Honoraria. Zinzani:Abbvie: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; MorphoSys: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Celegene: Membership on an entity's Board of Directors or advisory committees. Molica:Jansen: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Roche Italy: Membership on an entity's Board of Directors or advisory committees; Gilead Sciences: Speakers Bureau. Orlandi:Ariad: Honoraria; BMS: Honoraria; Novartis: Honoraria. Ghia:Gilead: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Abbvie: Consultancy, Honoraria; Adaptive Biotechnology: Consultancy; Roche: Honoraria, Research Funding. Foà:Amgen: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; Roche: Consultancy, Speakers Bureau; Gilead: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau; BMS: Consultancy; Genentech: Consultancy; Pfizer: Speakers Bureau; Ariad: Speakers Bureau.