Key Points• Independent prognostic impact of biological markers, notably TP53 and SF3B1 mutations, in CLL patients requiring therapy.• NOTCH1 mutation as a predictive factor for reduced benefit from the addition of rituximab to FC chemotherapy.Mutations in TP53, NOTCH1, and SF3B1 were analyzed in the CLL8 study evaluating firstline therapy with fludarabine and cyclophosphamide (FC) or FC with rituximab (FCR) among patients with untreated chronic lymphocytic leukemia (CLL). TP53, NOTCH1, and SF3B1 were mutated in 11.5%, 10.0%, and 18.4% of patients, respectively. NOTCH1 mut and SF3B1 mut virtually showed mutual exclusivity (0.6% concurrence), but TP53 mut was frequently found in NOTCH1 mut (16.1%) and in SF3B1 mut (14.0%) patients. There were few significant associations with clinical and laboratory characteristics, but genetic markers had a strong influence on response and survival. In multivariable analyses, an independent prognostic impact was found for FCR, thymidine kinase (TK) ‡10 U/L, unmutated IGHV, 11q deletion, 17p deletion, TP53 mut , and SF3B1 mut on progression-free survival; and for FCR, age ‡65 years, Eastern Cooperative Oncology Group performance status ‡1, b2-microglobulin ‡3.5 mg/L, TK ‡10 U/L, unmutated IGHV, 17p deletion, and TP53 mut on overall survival. Notably, predictive marker analysis identified an interaction of NOTCH1 mutational status and treatment in that rituximab failed to improve response and survival in patients with NOTCH1 mut . In conclusion, TP53 and SF3B1 mutations appear among the strongest prognostic markers in CLL patients receiving current-standard first-line therapy. NOTCH1 mut was identified as a predictive marker for decreased benefit from the addition of rituximab to FC. This study is registered at www.clinicaltrials.gov as #NCT00281918. (Blood. 2014;123(21):3247-3254)

The poor prognosis of chronic lymphocytic leukemia (CLL) patients with del (17p) is well established. We analyzed whether mutation of TP53 on the remaining allele adds to the poor prognosis or whether even TP53 mutation alone may be an adverse prognostic factor. We analyzed TP53 mutations in 193 CLL patients by denaturing high performance liquid chromatography in combination with direct DNA sequencing and a TP53 resequencing research microarray. Mutations were correlated to chromosomal aberrations defined by interphase fluorescent in situ hybridization and chromosome banding analyses and to the clinical course of patients. TP53 mutations were detected in 13.5% (26 of 193) of samples, whereas the incidence of del (17p) was 9.3% (18 of 193). TP53 mutations were significantly associated with del (17p) (concordance 94%, P<0.001) and complex cytogenetic abnormalities (concordance 50%, P<0.001). Among 147 patients whose clinical data were available, patients with TP53 abnormalities (n=20) had a significantly decreased time to treatment compared to patients without TP53 aberration (P<0.001). Median time to treatment was short in patients with isolated TP53 mutation (n=6, 2.0 months) and in those with del (17p) (n=14, 21.3 months) as compared to patients without TP53 aberration (n=127, 64.9 months, P<0.001). In multivariate Cox regression analysis, VH status, TP53 mutations and also isolated TP53 mutations independently predicted rapid disease progression.

433 Novel gene mutations have been found in CLL by next generation sequencing including mutations of NOTCH1 and SF3B1 in 5–20% of cases. In initial studies, both have been associated with advanced disease and poor outcome. We assessed the incidence and impact of gene mutations in the CLL8 trial (1st line FC vs. FCR, n=817). TP53 (exons 2–11) was analyzed by a re-sequencing chip (Amplichip, Roche Molecular Systems) with confirmatory Sanger sequencing. NOTCH1 was analyzed by Sanger sequencing exon 34, chr9:139,390,619–139,391,290 (PEST domain). SF3B1 (exons 13–16) was analyzed by DHPLC (WAVE® 3500HT, Transgenomic Inc.) with subsequent Sanger sequencing. Baseline samples were available for analysis of genetic markers in 619 (75.8%) to 645 (78.9%) patients. All markers were available for 573 (70.1%) patients and this cohort was representative of the full trial population. Mutations (mut) were found in TP53, NOTCH1, and SF3B1 in 11.5%, 10.0%, and 18.4%, respectively. At least one mutation was identified in 35.2% patients, while 30.6% had one, 4.4% had two and 0.2% had three mutations. Concurrent NOTCH1mut and SF3B1mut were found in only 0.5% patients. TP53mut was observed in 16.7% of NOTCH1mut cases (p=.528) and in 14.5% of SF3B1mut patients (p=.472). Regarding baseline characteristics, there were significant associations of TP53mut with CIRS>1, unmutated IGHV and 17p-; of NOTCH1mut with Binet A/B, no B-symptoms, unmutated IGHV, and 17p-; and of SF3B1mut with TK>10, and no +12. Regarding response to therapy, TP53mut was significantly associated with refractory disease in both arms (FCR: 25.0% vs. 1.8%, p<.001, FC: 48.4% vs. 7.8%, p<.001,); while NOTCH1mut showed only a trend in the FCR arm (FCR: 10.9% vs. 3.4%, p=.109, FC: 11.9% vs. 12.9%, p=.775); and SF3B1mut did not impact response to therapy (FCR: 3.6% vs. 3.7%, p=1.00, FC: 12.3% vs. 10.9%, p=1.00). At extended follow-up (median 69.97 months), FCR resulted into significantly improved PFS (HR 0.586, p<.001) and OS (HR 0.678, p=.001). TP53mut was associated in both treatment arms with significantly decreased PFS (FC: HR 4.295, p<.001; FCR: HR 3.173 p<.001) and OS (FC: HR 4.642 p<.001; FCR: HR 4.447, p<.001). In contrast, NOTCH1mut was only in the FCR arm associated with significantly decreased PFS (FC: HR 0.931, p=.741; FCR: HR 1.718, p=.013) and a trend to inferior OS (FC: HR 0.854, p=.605; FCR: HR 1.610, p=.112). SF3B1mut was associated in both treatment arms with significantly decreased PFS (FC: HR 1.520, p=.009; FCR: HR 1.463, p=.033) and a trend to inferior OS (FC: HR 1.338, p=.178; FCR: HR 1.305, p=.301). To evaluate the independent prognostic impact, we performed multivariable analyses by Cox regression for PFS and OS including the following variables: treatment, age, sex, stage, ECOG status, B-symptoms, WBC, TK, β2-MG, 11q-, +12, 13q-, 17p-, IGHV, TP53, NOTCH1 and SF3B1. Regarding PFS, the following independent prognostic factors were identified: FCR (HR 0.510, p<.001), TK>10 (HR 1.367, p=.019), IGHV<98% (HR 1.727, p<.001), 11q- (HR 1.536, p<.001), 17p- (HR 2.949 p<.001), TP53mut (HR 2.113 p<.001), and SF3B1mut (HR 1.348, p=.024). Regarding OS, the following independent prognostic factors were identified: FCR (HR 0.701, p=.049), ECOG>0 (HR 2.202, p<.001), TK>10 (HR 2.707, p<.001), IGHV<98% (HR 1.547, p=.055), 17p- (HR 3.546 p<.001) and TP53mut (HR 3.032 p<.001). To identify a predictive impact of gene mutations for a specific treatment effect by the addition of rituximab, we performed multivariable analyses including the treatment arms, the gene mutations and the interaction of both. Regarding PFS, FCR (HR 0.544, p<.001), TP53mut (HR 3.607, p<.001), SF3B1mut (HR 1.355, p=.012) and NOTCH1mut interaction with FCR (HR 1.652, p=.022) were identified as independent factors. Regarding OS, FCR (HR 0.654, p=.002) and TP53mut (HR 4.470, p<.001) were identified as independent factors while NOTCH1mut interaction with FCR (HR 1.331, p=.344) showed a trend. The interaction between NOTCH1mut and FCR treatment is illustrated in univariate PFS analysis, in which the addition of rituximab led to a benefit only among patients without NOTCH1mut (Figure). In conclusion, gene mutations show independent prognostic value for PFS (TP53, SF3B1) and OS (TP53) in patients receiving 1st line FC and FCR treatment. Of note, NOTCH1mut appears to identify a subset of CLL patients that does not benefit from the addition of rituximab to FC. Disclosures: Stilgenbauer: Roche: Consultancy, Honoraria, Research Funding. Patten:Roche: Employment. Wenger:Roche: Employment. Mendila:Roche: Employment. Hallek:Roche: Consultancy, Honoraria, Research Funding.

The TP53 mutation profile in chronic lymphocytic leukemia (CLL) and the correlation of TP53 mutations with allele status or associated molecular genetics are currently unknown. We performed a large mutation analysis of TP53 at four centers and characterized the pattern of TP53 mutations in CLL. We report on 268 mutations in 254 patients with CLL. Missense mutations appeared in 74% of cases compared with deletions and insertions (20%), nonsense (4%) and splice site (2%) mutations. The majority (243 of 268) of mutations were located in the DNA-binding domain. Transitions were found in 131 of 268 mutations, with only 41 occurring at methylated CpG sites (15%), suggesting that transitions at CpGs are uncommon. The codons most frequently mutated were at positions 175, 179, 248 and 273; in addition, we detected a common 2-nt deletion in the codon 209. Most mutations (199 of 259) were accompanied by deletion of the other allele (17p-). Interestingly, trisomy 12 (without 17p-) was only found in one of 60 cases with TP53 mutation (without 17p-) compared with 60 of 16 in the cohort without mutation (P ¼ 0.006). The mutational profile was not different in the cohorts with and without previous therapy, suggesting that the mechanism underlying the development of mutations may be similar, independent of treatment.

Chemotherapy (CT) resistance in ovarian cancer is related to multiple factors, and assessment of these factors is necessary for the development of new drugs and therapeutic regimens. In an effort to identify such determinants, we evaluated the expression of approximately 21,000 genes using DNA microarray screening in paired tumor samples taken prior to and after CT treatment from 6 patients with predominantly advanced stage, high-grade epithelial ovarian cancer. A subset of differentially expressed genes was selected from all microarray data by initial filtering on confidence at p=0.05, followed by filtering on expression level (≥2-fold). Using these selection criteria, we found 121 genes to be commonly up-regulated and 54 genes to be down-regulated in the post-CT tumors, compared to primary tumors. Upregulated genes in post-CT tumors included substantial number of genes with previously known implication in mechanisms of chemoresistance (

We show that evaluation of both the p53 gene and protein statuses provides information in assessing the clinical recurrence risk in bladder cancer and that the specific mutation site may be important in assessing recurrence risk. These findings may substantially impact the assessment of p53 alterations and the management of bladder cancer.

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