Citations

Abstract Breast cancer risks conferred by many germline missense variants in the BRCA1 and BRCA2 genes, often referred to as variants of uncertain significance (VUS), have not been established. In this study, associations between 19 BRCA1 and 33 BRCA2 missense substitution variants and breast cancer risk were investigated through a breast cancer case–control study using genotyping data from 38 studies of predominantly European ancestry (41,890 cases and 41,607 controls) and nine studies of Asian ancestry (6,269 cases and 6,624 controls). The BRCA2 c.9104A>C, p.Tyr3035Ser (OR = 2.52; P = 0.04), and BRCA1 c.5096G>A, p.Arg1699Gln (OR = 4.29; P = 0.009) variant were associated with moderately increased risks of breast cancer among Europeans, whereas BRCA2 c.7522G>A, p.Gly2508Ser (OR = 2.68; P = 0.004), and c.8187G>T, p.Lys2729Asn (OR = 1.4; P = 0.004) were associated with moderate and low risks of breast cancer among Asians. Functional characterization of the BRCA2 variants using four quantitative assays showed reduced BRCA2 activity for p.Tyr3035Ser compared with wild-type. Overall, our results show how BRCA2 missense variants that influence protein function can confer clinically relevant, moderately increased risks of breast cancer, with potential implications for risk management guidelines in women with these specific variants. Cancer Res; 77(11); 2789–99. ©2017 AACR.

467 Background: Regorafenib (REG) is an oral multikinase inhibitor that has recently demonstrated significant overall survival benefit vs placebo in the randomized phase III CORRECT study. We examined the time course of adverse events (AEs) in the CORRECT study. Methods: Regorafenib (REG) is an oral multikinase inhibitor that has recently demonstrated significant overall survival benefit vs placebo in the randomized phase III CORRECT study. We examined the time course of adverse events (AEs) in the CORRECT study. Results: The safety population comprised 753 patients (pts): REG n=500; placebo n=253. The mean treatment duration was 12.1 ± 9.7 weeks in the REG group and 7.8 ± 5.2 weeks in the placebo group. Treatment-emergent AEs occurred at any grade in 99.6% of REG pts and 96.8% of placebo pts, at grade 1/2 in 21.6% and 47.8%, respectively, at grade 3 in 56.0% and 26.5%, respectively, and at grade 4/5 in 22.0% and 22.5%, respectively. AEs occurring in ≥10% more REG than placebo pts were fatigue, hand–foot skin reaction (HFSR), anorexia, diarrhea, weight loss, voice changes, hypertension, rash/desquamation, oral mucositis, fever, hyperbilirubinemia, low platelet count. The most frequent AEs deemed to be regorafenib related were HFSR, fatigue, diarrhea, hypertension, and rash/desquamation. The frequency of these AEs over time is shown in the Table. The incidence of HFSR, fatigue, hypertension, and rash/desquamation peaked in cycle 1 and tapered to a relatively stable lower incidence over later cycles. The incidence of diarrhea remained relatively constant throughout treatment. AEs led to dose modification in 66.6% of pts in the REG group and 22.5% in the placebo group. Data on dose intensity across treatment cycles will be presented. Conclusions: In the CORRECT trial, the incidences of the most common AEs in the REG group peaked early during treatment. There appeared to be no evidence for cumulative toxicity of REG. Clinical trial information: NCT01103323. [Table: see text]

381 Background: In the CORRECT Ph3 trial, regorafenib demonstrated significant improvement in OS and PFS vs. placebo in subjects with metastatic colorectal cancer (mCRC) who had progressed on standard therapies. An exploratory biomarker substudy was conducted on samples collected from subjects enrolled in CORRECT. Methods: DNA was isolated from archival tumor tissue and fresh baseline plasma samples that were available from 239 (31%) and 503 (66%) subjects enrolled in CORRECT, respectively. Mutations in KRAS, PIK3CA and BRAF were evaluated via BEAMing technology. Results: Mutations were readily detected in DNA isolated from both tumor and plasma samples: KRAS: 59/69%; PIK3CA: 12/17% and BRAF: 1.5/3.4%. The frequency of KRAS mutation detected in tumor samples via BEAMing (59%) was identical to the frequency determined from pre-existing “historical” KRAS mutation data that was available from 96% of the subjects enrolled in the study. Concordance among the mutations detected via BEAMing in tumor vs. plasma was 76% (KRAS), 88% (PIK3CA), and 97% (BRAF). A subset of CRC which was found to be KRAS-wildtype in DNA from archival tumor, but KRAS-mutant in DNA from fresh plasma was identified and may represent subjects whose KRAS mutational status had changed during prior therapy. Correlative subgroup analyses demonstrated that regorafenib mediated a trend for clinical benefit vs. placebo in both KRAS wildtype and mutant subgroups identified by plasma BEAMing (OS: KRAS WT, HR: 0.67, 95% CI: 0.41–1.08; KRAS mutant, HR: 0.81, 95% CI: 0.61–1.09; interaction p=0.561). Similar results were noted for PIK3CA WT/mutant subgroups (OS: WT, HR: 0.75, 95% CI: 0.57–0.99; mutant, HR: 0.84, 95% CI: 0.47–1.50; interaction p=0.723). BRAF was not analysed due to the small number of BRAF-mutant samples. Conclusions: The mutational analysis of DNA isolated from fresh plasma is feasible and robust using the BEAMing platform and may better represent the mutational status of the tumor(s) that a mCRC patient harbors at the time of enrollment than does the mutational analysis of archival primary tumor tissue. Regorafenib was associated with clinical benefit (vs. placebo) in all mutational subgroups evaluated. Clinical trial information: NCT01103323.

LBA385 Background: Regorafenib (BAY 73-4506) is an oral multikinase inhibitor of a broad range of angiogenic, oncogenic, and stromal kinases. The phase III CORRECT trial was conducted to evaluate efficacy and safety of regorafenib in pts with mCRC who had progressed after all approved standard therapies. Methods: Enrollment criteria included documented mCRC and progression during or ≤3 months after last standard therapy. Pts were randomized 2:1 to receive regorafenib (160 mg od po, 3 weeks on/1 week off) plus BSC, or placebo (PL) plus BSC. Pts continued on treatment until progression, death, or unacceptable toxicity. The primary endpoint was overall survival (OS). Secondary endpoints included progression-free survival (PFS), overall response rate (ORR), disease control rate (DCR), safety, and quality of life. Results: From May 2010 to March 2011, 760 pts were randomized (regorafenib: 505; PL: 255). Baseline characteristics were balanced between two arms. Preliminary results are available from a pre-planned formal interim analysis. The estimated hazard ratio (HR) for OS was 0.773 (95% CI: 0.635, 0.941; 1-sided p=0.0051). Median OS was 6.4 mos (95% CI: 5.9, 7.3) for regorafenib and 5.0 mos (95% CI: 4.4, 5.8) for PL. The estimated HR for PFS was 0.493 (95% CI: 0.418, 0.581; 1-sided p < 0.000001). Median PFS was 1.9 mos (95% CI: 1.88, 2.17) for regorafenib and 1.7 mos (95% CI: 1.68, 1.74) for PL. ORR was 1.6% for regorafenib and 0.4% for PL. DCR was 44% for regorafenib and 15% for PL (p < 0.000001). Since the prespecified OS efficacy boundary was crossed (nominal α: 0.0093), the Data Monitoring Committee recommended to unblind the study and pts on PL were allowed to cross over to regorafenib. The most frequent grade 3+ AEs in the regorafenib arm were hand-foot skin reaction (17%), fatigue (15%), diarrhea (8%), hyperbilirubinemia (8%), and hypertension (7%). Updated results will be presented. Conclusions: Statistically significant benefit in OS and PFS was observed for regorafenib over PL in pts with mCRC who have failed all approved standard therapies. No new or unexpected safety signal was found.

Key Points HSCT after PD-1 blockade is feasible, although may be associated with increased early immune toxicity. PD-1 blockade may cause persistent depletion of PD1+ T cells and alterations in T-cell differentiation impacting subsequent treatment.

Genome-wide association studies have identified >50 common variants associated with kidney function, but these variants do not fully explain the variation in eGFR. We performed a two-stage meta-analysis of associations between genotypes from the Illumina exome array and eGFR on the basis of serum creatinine (eGFRcrea) among participants of European ancestry from the CKDGen Consortium ( n Stage1 : 111,666; n Stage2 : 48,343). In single-variant analyses, we identified single nucleotide polymorphisms at seven new loci associated with eGFRcrea ( PPM1J , EDEM3, ACP1, SPEG, EYA4, CYP1A1 , and ATXN2L ; P Stage1 <3.7×10 −7 ), of which most were common and annotated as nonsynonymous variants. Gene-based analysis identified associations of functional rare variants in three genes with eGFRcrea, including a novel association with the SOS Ras/Rho guanine nucleotide exchange factor 2 gene, SOS2 ( P =5.4×10 −8 by sequence kernel association test). Experimental follow-up in zebrafish embryos revealed changes in glomerular gene expression and renal tubule morphology in the embryonic kidney of acp1- and sos2 -knockdowns. These developmental abnormalities associated with altered blood clearance rate and heightened prevalence of edema. This study expands the number of loci associated with kidney function and identifies novel genes with potential roles in kidney formation.

Background: Mitral valve (MV) repair is preferred over replacement in clinical guidelines and is an important determinant of the indication for surgery in degenerative mitral regurgitation. However, the level of evidence supporting current recommendations is low, and recent data cast doubts on its validity in the current era. Accordingly, the aim of the present study was to analyze very long-term outcome after MV repair and replacement for degenerative mitral regurgitation with a flail leaflet. Methods: MIDA (Mitral Regurgitation International Database) is a multicenter registry enrolling patients with degenerative mitral regurgitation with a flail leaflet in 6 tertiary European and US centers. We analyzed the outcome after MV repair (n=1709) and replacement (n=213) overall, by propensity score matching, and by inverse probability-of-treatment weighting. Results: At baseline, patients undergoing MV repair were younger, had more comorbidities, and were more likely to present with a posterior leaflet prolapse than those undergoing MV replacement. After propensity score matching and inverse probability-of-treatment weighting, the 2 treatments groups were balanced, and absolute standardized differences were usually <10%, indicating adequate match. Operative mortality (defined as a death occurring within 30 days from surgery or during the same hospitalization) was lower after MV repair than after replacement in both the entire population (1.3% versus 4.7%; P <0.001) and the propensity-matched population (0.2% versus 4.4%; P <0.001). During a mean follow-up of 9.2 years, 552 deaths were observed, of which 207 were of cardiovascular origin. Twenty-year survival was better after MV repair than after MV replacement in both the entire population (46% versus 23%; P <0.001) and the matched population (41% versus 24%; P <0.001). Similar superiority of MV repair was obtained in patient subsets on the basis of age, sex, or any stratification criteria (all P <0.001). MV repair was also associated with reduced incidence of reoperations and valve-related complications. Conclusions: Among patients with degenerative mitral regurgitation with a flail leaflet referred to mitral surgery, MV repair was associated with lower operative mortality, better long-term survival, and fewer valve-related complications compared with MV replacement.