Citations

5544 Background: Pazopanib, an orally bioavailable multitargeted inhibitor of kinases including VEGF-R, demonstrated impressive activity in metastatic differentiated thyroid cancer (49% durable RECIST PRs) and promising preclinical activity in anaplastic thyroid cancer (ATC) models, prompting its evaluation also as a candidate therapeutic in advanced ATC. Methods: A multicenter single arm phase II trial of 800 mg pazopanib daily was undertaken with the primary endpoint of RECIST response rate. The trial was designed such that there would be a 90% chance of detecting a response rate of >20% at the 0.10 significance level when the true tumor response rate is >5%. A pre-specified stopping rule designated that enrollment would cease unless 1 or more RECIST PRs+CRs were observed in the first 14 of 33 potential patients. Eligibility required informed consent, >18 years of age, performance status ECOG 0-2, systolic blood pressure (BP) <140 mm Hg and diastolic BP <90 mm Hg at entry, QTc interval <480 msecs, and measurable disease by RECIST criteria. Anatomical imaging and toxicity evaluations were required every 4 weeks. Results: Sixteen patients were enrolled. One patient withdrew prior to therapy, leaving 15 evaluable patients – 33.3% were male, with a median age of 66 years (range 45-77); 11 of 15 patients had progressed through prior systemic therapy. Four patients required 1-2 dose reductions, with the most common severe toxicities (CTC-AE version 3.0 grades 3-5) hypertension (13%) and pharyngolaryngeal pain (13%). Reasons for treatment discontinuation included: disease progression (12 pts), death on study due to a vascular event possibly related to treatment (1 pt.), and intolerability (radiation recall tracheitis – 1 pt, and uncontrolled hypertension – 1 pt). Although transient disease regression was observed in several patients, there were no confirmed RECIST tumor responses, triggering study closure at time of interim analysis. Two patients are alive with disease 9.9 months and 2.9 years post-registration; the remaining 13 died of disease. The median time to progression was 62 days and the median survival time was 111 days. Conclusions: Pazopanib has poor single agent activity in advanced anaplastic thyroid cancer.

5076 Background: Advanced OVCA should be managed aggressively, and extensive surgery has been the most accepted initial treatment. Medically unfit patients or those with extensive disease, in which complete cytoreduction is unlikely, may not benefit from upfront radical surgery, and neoadjuvant chemotherapy might be an appropriate alternative. Thus, reliable preoperative indicators of surgical outcome are necessary for considering primary surgery vs. neoadjuvant chemotherapy. Our aim is to determine if C-reactive protein (CRP), IL-6, albumin and Glasgow Prognostic Score (GPS – score based on CRP and albumin) correlate with overall survival (OS), length of hospital stay (LOS), surgical morbidity, and suboptimal cytoreduction. Methods: We randomly selected 50 stages III/IV OVCA who underwent surgery as a primary treatment between July 2002 and June 2009 at Mayo Clinic with serum albumin levels and frozen serum available. CRP and IL-6 were measured in stored serum. Univariate and multivariate regression models were fit to evaluate associations with each of the outcomes. Results: Among the 50 patients, the mean age was 67.7 years. 34% had pretreatment albumin <3.5 g/ml, 22.4% had CRP level ≥10 mg/l, 26.5% had IL-6 ≥24 pg/ml and 45% had abnormal GPS score. At 1, 3 and 5 years following surgery, the OS was 75.6%, 49.8% and 36.9%, respectively. RD (0, <1, ≥1cm; p<0.001) was the only independent predictor of OS. Also, IL-6 (p=0.028) and stage (p=0.046) were independently associated with LOS, but no inflammatory or nutritional markers were significant associated with post surgical complications. Stage IV (p=0.019) and elevated CRP (p=0.044) were independent predictors of suboptimal surgery (RD ≥ 1cm). Conclusions: One-third of the patients in our series had low serum albumin at the time of the OVCA diagnosis, and at least one-fourth had elevated inflammatory markers. Advanced stage and elevated inflammatory markers (CRP and IL-6) were independent predictors of longer hospital stay and suboptimal debulking. These pilot data, if confirmed in a larger population, may help in the selection of candidates for neoadjuvant chemotherapy.

TPS8612 Background: Brentuximab vedotin, a CD30-targeted antibody-drug conjugate, has conditional approval in Europe for relapsed/refractory (RR) CD30-positive HL following autologous stem cell transplant (ASCT) or following ≥2 prior therapies when ASCT or multi-agent chemotherapy is not a treatment option. ABVD, a common front-line regimen for advanced HL, achieves complete response (CR) rates of 70–80%. However, 10–20% of patients (pts) are refractory to front-line treatment and up to 35% relapse after front-line multi-modality therapy. In pts with relapsed HL post-ASCT, single-agent brentuximab vedotin yields an objective response rate of 75% (CR, 33%; Chen ASH 2012). In a phase 1 study in treatment-naïve HL pts, A+AVD was associated with manageable toxicity and a CR rate of 96%; brentuximab vedotin + ABVD was contraindicated due to pulmonary toxicity (Ansell ASH 2012). We hypothesized that substituting bleomycin with brentuximab vedotin would eliminate bleomycin-associated pulmonary toxicity and improve progression-free survival (PFS) compared to a standard ABVD regimen. Methods: This ongoing, open-label, randomized, multicenter study (NCT01712490) will compare A+AVD vs ABVD in 1040 pts with stage III/IV classical HL. Primary endpoint: modified (m) PFS (death, progression, and receipt of chemotherapy or radiotherapy by pts not in CR after completing A+AVD or ABVD will count as progression event). Key secondary endpoint: overall survival. Key inclusion criteria: histologically-confirmed previously untreated stage III/IV classical HL. Pts will be stratified by region and International Prognostic Score, and will be randomized 1:1 to receive A+AVD (brentuximab vedotin 1.2 mg/kg with each dose of AVD) or ABVD administered intravenously on Days 1 and 15 of 28-day cycles, for up to 6 cycles. Disease status and survival will be evaluated regularly until study closure. Safety assessments: incidence and severity of adverse events, changes to physical and laboratory tests. Clinical trial information: NCT01712490.

3636 Background: In the CORRECT phase III trial, the multikinase inhibitor REG demonstrated significant improvement in overall survival (OS) and progression-free survival vs placebo (Pla) in patients (pts) with mCRC whose disease progressed on other standard therapies. The most frequent REG-related grade ≥3 adverse events (AEs) of interest were hand–foot skin reaction (HFSR), fatigue, diarrhea, hypertension, and rash/desquamation. We explored whether the impact of REG in pts aged ≥65 years differed from that in younger patients. Methods: Pts with mCRC progressing following all other available therapies were randomized 2:1 to receive REG 160 mg once daily (n=505) or Pla (n=255) for the first 3 weeks of each 4-week cycle. The dose could be modified to manage AEs. The primary endpoint was OS. We report efficacy, safety, and dosing data from REG recipients by age. Results: The REG treatment group included 309 pts <65 years (307 evaluable for safety) and 196 pts ≥65 years (193 evaluable for safety). The OS hazard ratio (REG/Pla) was 0.72 (95% confidence interval [CI] 0.56–0.91) in pts <65 years and 0.86 (95% CI 0.61–1.19) in pts ≥65 years (interaction p-value = 0.405). Median OS was 6.7 vs 5 months for REG vs Pla in pts <65 years, and 6.0 vs 5.6 months, respectively, in pts ≥65 years. Most pts experienced drug-related AEs (<65 years: 93.8%; ≥65 years: 91.7%). The rates of grade ≥3 REG-related AEs of interest and dose modifications are shown in the Table. In pts <65 years vs ≥65 years, median (interquartile range [IQR]) duration of REG was 7.6 weeks (6.6–15.4) vs 7.1 weeks (5.1–17.2), median (IQR) daily REG dose was 160.0 mg (134.6–160.0) vs 160.0 mg (137.5–160.0), and median (IQR) proportion of planned REG dose was 83.3% (65.7–100.0) vs 78.6% (66.7–100.0), respectively. Conclusions: In the CORRECT trial, REG demonstrated an OS benefit in pts <65 years and ≥65 years. Safety and tolerability of REG appeared to be similar in both age subgroups. Clinical trial information: NCT01103323. [Table: see text]

3576 Background: BRAF encodes a serine-threonine kinase that is a downstream effector of activated RAS. A point mutation (V600E) in BRAF occurs in a subset of colorectal cancers (CRCs) and is associated with adverse outcome and may predict non response to anti-EGFR antibodies. Detection of a BRAFV600E mutation in a CRC with microsatellite instability indicates a sporadic origin and excludes Lynch Syndrome. While BRAFV600E mutation status is determined using a DNA-based assay, antibodies against the BRAFV600E protein have recently been developed. We examined mutant BRAFV600E protein expression and its concordance with mutation status. Methods: Primary stage III colon carcinomas (50 BRAFV600E mutation carriers and 25 wild-type cases) were studied from a completed phase III adjuvant trial comparing FOLFOX +/- cetuximab (NCCTG N0147). In archival resection specimens, immunohistochemistry (IHC) was performed using a pan-BRAF antibody and a V600E mutation-specific antibody raised against an immunogenic synthetic peptide derived from the internal region of the BRAFV600E protein. BRAFV600E mutations in codon 15 were analyzed in extracted DNA using a multiplex, allele specific PCR–based assay. BRAF staining was scored independently by two pathologists blinded to mutation status. Results: In primary colon carcinomas stained with a pan-BRAF antibody, diffuse cytoplasmic staining for BRAF proteins was detected in 74 of 75 carcinomas with one case deemed non-evaluable. Using the mutation-specific BRAFV600E antibody, diffuse cytoplasmic staining was detected in 49 of 74 tumors without appreciable heterogeneity of expression. Among these 49 tumors expressing mutant BRAFV600E proteins, all (100%) were found to carry a BRAFV600E mutation according to a DNA-based assay. In contrast, absent BRAFV600E staining was observed in all 25 tumors that were found to have wild-type copies of BRAFV600E detected using a PCR-based assay. Conclusions: For the detection of mutant BRAFV600E, complete concordance was found between IHC and a DNA-based method in colon carcinomas. This finding supports the use of IHC as a simplified strategy to screen CRCs for mutant BRAFV600E proteins in routine clinical practice to inform clinical decision-making.

5004 Background: Since 1999, patients with low-risk endometrial cancer (EC) as defined by the Mayo criteria have preferably not undergone lymphadenectomy (LND) at our institution. We assess survival, sites of recurrence, morbidity, and cost per up-staged case in this low-risk cohort. Methods: Consecutive patients with Mayo-defined low-risk EC managed without (non-LND) and with LND were compared. Cause-specific survival (CSS) was estimated using the Kaplan-Meier method and compared using the log-rank test. 30-day cost analyses were equated to 2010 Medicare dollars. Results: Among 1,393 consecutive surgically managed EC cases, 385 (27.6%) met the Mayo low-risk criteria, accounting for 34.1% of type I EC. The 5-year CSS of the low-risk cases was 98.6 %. There were 80 LND cases (median # nodes, 29) and 305 non-LND cases. Complications within 30 days occurred in 37.5% and 19.3% of LND and non-LND cases, respectively (P<0.001). Nodal metastasis was identified in a single LND case (1.3%). There were 11 recurrences, 6 of which were vaginal. Not a single recurrence was detected in the pelvic or paraaortic nodal areas in these 385 patients, with a median follow-up of 5.4 years. The estimated prevalence (combining surgery and surveillance) of lymph node metastasis was 0.3%. The 5-year CSS in LND and non-LND cases was 97.3% and 99.0%, respectively (P=0.32). Patients were more than seven times as likely to die of co-morbidities than from EC. The 30-day median cost of care was $15,678 for LND cases compared to $11,028 for non-LND cases (P<0.001). The estimated cost per up-staged low-risk case was $439,990 if performed via endoscopy and $327,866 via laparotomy. If the 305 non-LND cases had been subjected to LND, an estimated additional $1,418,189 would have been expended. Conclusions: For patients with low-risk EC as defined by the Mayo criteria, lymphadenectomy dramatically increases morbidity and 30-day cost of care without discernible short- or long-term benefits: CSS was 99% with a 0.3% rate of nodal metastasis. In these low-risk patients, hysterectomy with salpingo-oophorectomy alone is appropriate surgical management and should be standard of care.

3502 Background: Regorafenib (REG) is an oral multi-kinase inhibitor. The CORRECT trial was conducted to evaluate REG in patients (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 best supportive care plus either REG (160 mg od po, 3 wks on/1 wk off) or placebo (PL). The primary endpoint was overall survival (OS). Secondary endpoints included progression-free survival (PFS), overall response rate, disease control rate, safety and quality of life (QoL). Efficacy analyses across prespecified subgroups were evaluated using univariate Cox regression. Results: 760 pts were randomized (REG: 505; PL: 255). The OS primary endpoint was met at a preplanned interim analysis. OS and PFS were significantly improved in REG arm compared to PL arm: hazard ratio (HR) for OS 0.77 (95% CI 0.64-0.94, 1-sided p=0.0052), median OS 6.4 vs 5.0 mos; HR for PFS 0.49 (95% CI 0.42-0.58, 1-sided p<0.000001), median PFS 1.9 vs 1.7 mos. Comparable OS and PFS benefits were observed in exploratory subgroup analyses by region, age, time from diagnosis of mCRC to randomization, prior lines of treatment, and KRAS status (shown in table). The most common grade 3+ AEs related to REG were hand-foot skin reaction (16.6%), fatigue (9.6%), hypertension (7.2%), diarrhea (7.2%) and rash/desquamation (5.8%). QoL data will be presented. Conclusions: REG demonstrated statistically significant improvement in OS and PFS over PL, as well as comparable efficacy benefits across pt subgroups analyzed. [Table: see text]

Background: Tumoral melanosis clinically resembles metastatic melanoma, occurs in the context of regressed disease, and requires evaluation to rule out underlying melanoma and metastatic disease. Histopathology demonstrates a nodular infiltrate of melanophages in the dermis, subcutaneous tissue, deep soft tissue, or lymph nodes in the absence of viable melanocytes. Recent limited reports of tumoral melanosis in the context of immunotherapy with ipilimumab (monoclonal antibody targeting CTLA-4) as well as nivolumab and pembrolizumab (humanized monoclonal antibodies against programmed death 1 receptor) highlight a unique presentation representative of treatment-related tumor regression and an association with a favorable clinical response. Objective: To describe our experience with tumoral melanosis in the setting of immunotherapy for metastatic melanoma and elucidate the clinical and histopathological features. Methods: Retrospective case series from a single tertiary care institution. Results: We describe 10 cases of patients with metastatic melanoma who received treatment with immunotherapy before the development of tumoral melanosis. Length of time between the initiation of therapy and the onset of tumoral melanosis ranged from 2 to 20 months with a mean time of 10 months. At the end of the follow-up period, 8 patients were classified as having a complete or partial response to treatment with immunotherapy. One patient had progression of visceral and cutaneous disease on ipilimumab despite developing tumoral melanosis, and 1 patient had yet to undergo repeat imaging. Furthermore, at the end of follow-up, 3 patients were alive with no evidence of active disease, 5 patients were alive with disease, and 1 patient was deceased, although this patient died of a cardiovascular event unrelated to his underlying melanoma. Of the patients who were classified as alive with disease, 2 patients had minimal remaining disease, and 2 patients had an almost complete response on immunotherapy with recurrence of visceral metastases after immunotherapy was discontinued. One patient developed new peritoneal and cutaneous metastases on pembrolizumab despite development of tumoral melanosis. Conclusions: The underlying biologic mechanisms and prognostic implications of tumoral melanosis in the setting of immunotherapy remain to be elucidated. Further prospective studies with a larger cohort and prolonged follow-up are necessary to better understand the incidence, prevalence, and oncologic outcomes in patients with tumoral melanosis who receive immunotherapy.

OBJECTIVELoss to follow-up has been shown to bias outcomes assessment among studies utilizing clinical registries. Here, the authors analyzed patients enrolled in a national surgical registry and compared the baseline characteristics of patients captured with those lost to follow-up at 2 years.METHODSThe authors queried the Quality Outcomes Database for patients with grade I lumbar degenerative spondylolisthesis undergoing a surgical intervention between July 2014 and June 2016. Only those patients enrolled in a multisite study investigating the impact of fusion on clinical and patient-reported outcomes (PROs) among patients with grade I spondylolisthesis were evaluated.RESULTSOf the 608 patients enrolled in the study undergoing 1- or 2-level decompression (23.0%, n = 140) or 1-level fusion (77.0%, n = 468), 14.5% (n = 88) were lost to follow-up at 2 years. Patients who were lost to follow-up were more likely to be younger (59.6 ± 13.5 vs 62.6 ± 11.7 years, p = 0.031), be employed (unemployment rate: 53.3% [n = 277] for successful follow-up vs 40.9% [n = 36] for those lost to follow-up, p = 0.017), have anxiety (26.1% [n = 23] vs 16.3% [n = 85], p = 0.026), have higher back pain scores (7.4 ± 2.9 vs 6.6 ± 2.8, p = 0.010), have higher leg pain scores (7.4 ± 2.5 vs 6.4 ± 2.9, p = 0.003), have higher Oswestry Disability Index scores (50.8 ± 18.7 vs 46 ± 16.8, p = 0.018), and have lower EQ-5D scores (0.481 ± 0.2 vs 0.547 ± 0.2, p = 0.012) at baseline.CONCLUSIONSTo execute future, high-quality studies, it is important to identify patients undergoing surgery for spondylolisthesis who might be lost to follow-up. In a large, prospective registry, the authors found that those lost to follow-up were more likely to be younger, be employed, have anxiety disorder, and have worse PRO scores.

Plazomicin was tested against 697 recently acquired carbapenem-resistant Klebsiella pneumoniae isolates from the Great Lakes region of the United States. Plazomicin MIC 50 and MIC 90 values were 0.25 and 1 mg/liter, respectively; 680 isolates (97.6%) were susceptible (MICs of ≤2 mg/liter), 9 (1.3%) intermediate (MICs of 4 mg/liter), and 8 (1.1%) resistant (MICs of >32 mg/liter). Resistance was associated with rmtF -, rmtB -, or armA -encoded 16S rRNA methyltransferases in all except 1 isolate.