Increased PSMA-Targeted 18F-DCFPyL Uptake in Peripheral T-Cell Lymphoma

ABSTRACT

Peripheral T-cell lymphomas are a heterogenous group of lymphomas with a high rate of extranodal disease. We present a case of increased 18F-DCFPyL uptake in peripheral T-cell lymphoma of subcutaneous tissue and bone. Familiarity with the increased 18F-DCFPyL uptake and extranodal presentation of peripheral T-cell lymphomas can avoid misinterpretation for metastatic disease.

Ductal, intraductal, and cribriform carcinoma of the prostate: Molecular characteristics and clinical management

Prostatic acinar adenocarcinoma accounts for approximately 95% of prostate cancer (CaP) cases. The remaining 5% of histologic subtypes of CaP are known to be more aggressive and have recently garnered substantial attention. These histologic subtypes - namely, prostatic ductal adenocarcinoma (PDA), intraductal carcinoma of the prostate (IDC-P), and cribriform carcinoma of the prostate (CC-P) - typically exhibit distinct growth characteristics, genomic features, and unique oncologic outcomes. For example, PTEN mutations, which cause uncontrolled cell growth, are frequently present in IDC-P and CC-P. Germline mutations in homologous DNA recombination repair (HRR) genes (e.g., BRCA1, BRCA2, ATM, PALB2, and CHEK2) are discovered in 40% of patients with IDC-P, while only 9% of patients without ductal involvement had a germline mutation. CC-P is associated with deletions in common tumor suppressor genes, including PTEN, TP53, NKX3-1, MAP3K7, RB1, and CHD1. Evidence suggests abiraterone may be superior to docetaxel as a first-line treatment for patients with IDC-P. To address these and other critical pathological attributes, this review examines the molecular pathology, genetics, treatments, and oncologic outcomes associated with CC-P, PDA, and IDC-P with the objective of creating a comprehensive resource with a centralized repository of information on PDA, IDC-P, and CC-P.

Characterizing the Genomic Landscape of the Micropapillary Subtype of Urothelial Carcinoma of the Bladder Harboring Activating Extracellular Mutations of ERBB2

The micropapillary subtype of urothelial carcinoma (MPUC) of the bladder is a very aggressive histological variant of urothelial bladder cancer (UBC). A high frequency of MPUC contains activating mutations in the extracellular domain (ECD) of ERBB2. We sought to further characterize ERBB2 ECD-mutated MPUC to identify additional genomic alterations that have been associated with tumor progression and therapeutic response. In total, 5,485 cases of archived formalin-fixed, paraffin-embedded UBC underwent comprehensive genomic profiling to identify ERBB2 ECD-mutated MPUC and evaluate the frequencies of genomic co-alterations. We identified 219 cases of UBC with ERBB2 ECD mutations (74% S310F and 26% S310Y), of which 63 (28.8%) were MPUC. Genomic analysis revealed that TERT, TP53, and ARID1A were the most common co-altered genes in ERBB2-mutant MPUC (82.5%, 58.7%, and 39.7%, respectively) and did not differ from ERBB2-mutant non-MPUC (86.5%, 51.9%, and 35.3%). The main differences between ERBB2 ECD-mutated MPUC compared with non-MPUC were KMT2D, RB1, and MTAP alterations. KMT2D and RB1 are tumor-suppressor genes. KMT2D frequency was significantly decreased in ERBB2 ECD-mutated MPUC (6.3%) in contrast to non-MPUC (27.6%; P < .001). RB1 mutations were more frequent in ERBB2 ECD-mutated MPUC (33.3%) than in non-MPUC (17.3%; P = .012). Finally, MTAP loss, an emerging biomarker for new synthetic lethality-based anticancer drugs, was less frequent in ERBB2 ECD-mutated MPUC (11.1%) than in non-MPUC (26.9%; P = .018). Characterizing the genomic landscape of MPUC may not only improve our fundamental knowledge about this aggressive morphological variant of UBC but also has the potential to identify possible prognostic and predictive biomarkers that may drive tumor progression and dictate treatment response to therapeutic approaches.

Germline mutational profile in metastatic urothelial malignancy

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Background: 24% of patients with high-risk urothelial carcinoma have pathogenic germline mutations (Nassar, Genetics in Medicine 2020). In that study, demographics, metachronous/synchronous tumors, and family history did not differ between germline and sporadic cases of bladder cancer. We report herein the prevalence of actionable mutations and de novo metastatic disease in patients with germline mutations who developed metastatic urothelial carcinoma. Methods: We retrospectively analyzed a database of 90 patients with metastatic urothelial carcinoma (urethral, bladder, and upper tract disease) at our institution who had genetic testing performed on tumor specimens. T-student test was performed to calculate statistical significance for the distribution of age, while Chi-square test evaluated the frequency distribution of gender, actionable mutations, and de novo metastatic disease. Patients’ tumors were sequenced by a 700 gene panel for both somatic and germline mutations. Comprehensive chart review was performed to extract clinical data. Results: Out of the 90 patients reviewed, 11 (11.1%) had germline mutations. Of these patients, 5 had upper tract urothelial carcinoma, 5 had bladder cancer, and 1 had urethral cancer. Nine patients had pathogenic germline mutations: MUTYH, BRCA2 (each representing 1.8% of patients); APC, BRCA1, CDKN2A, FH, MSH2 (each representing 0.9% of patients). Two patients had germline mutations of unknown significance ( APC, CHEK2). Age (T-value 1.62053, p=1.08453), gender (Chi-square 0.0024, p=0.961037) or de novo metastatic presentation (Chi-square 0.5, p=0.4795) were not statistically significant between patients with germline and sporadic mutations. Somatic actionable mutations included ATR, BRCA2, BRAF, CDK12, ERBB2, FBXW7, FGFR3, HRAS, MTAP, and PIK3CA. Microsatellite instability high (MSI-H) status was only present in the patient with germline MSH2 mutation. PD-L1 expression was high (CPS ≥10) in 4 patients with germline mutations. Tumor mutational burden ranged from 1.1 to 28.4 mutations per Megabase. Conclusions: Our findings further define the clinical and genomic characteristics of patients with metastatic urothelial carcinoma and germline mutations in a tertiary center. Further investigation is warranted to validate these findings in national sequencing databases.

Where's My Doctor? The Impact of the Primary Oncologist's Visit with Their Hospitalized Patients

BACKGROUND

Continuity of care is a cornerstone of the patient-practitioner relationship. Previously, patient satisfaction has been related to perceived provider communication skills and competence. Our study assessed the relationship between the inpatient continuity visit (ICV), a face-to-face patient-provider interaction with the primary oncologist, and patient satisfaction.

METHODS

Subjects were adult inpatients on the oncology unit at The Miriam Hospital who had an oncologist at the hospital-based cancer center. A survey, given at discharge, included a 5-point Likert scale ranging from greatly worsened to greatly improved satisfaction to assess the impact of the ICV on patient satisfaction.

RESULTS

Of 75 participants, 43 (57.3%) reported a visit by their outpatient oncologist. Of these, 39 (90.7%) reported that this visit either greatly or somewhat improved satisfaction with their hospital stay. Of subjects who had a single ICV, 93.7% reported either greatly or somewhat improved satisfaction compared to 88.9% who had more than one visit. Of 32 (43.3%) subjects who did not receive a visit, 15.6% reported that the lack of visit either greatly or somewhat worsened their satisfaction during their hospital stay, while 84.4% reported no impact.

CONCLUSIONS

Our study suggests that an ICV improves satisfaction of care in cancer patients on a hospitalist service, and a lack of ICV negatively impacted satisfaction. There was no improvement in satisfaction for multiple versus single ICVs. While the practicality of this intervention should be reassessed with the emergence of more accessible telehealth modalities, the efficacy of a single visit to improve satisfaction is informative.

Clinical features of patients with MTAP-deleted bladder cancer

Advanced urothelial carcinoma continues to have a dismal prognosis despite several new therapies in the last 5 years. FGFR2 and FGFR3 mutations and fusions, PD-L1 expression, tumor mutational burden, and microsatellite instability are established predictive biomarkers in advanced urothelial carcinoma. Novel biomarkers can optimize the sequencing of available treatments and improve outcomes. We describe herein the clinical and pathologic features of patients with an emerging subtype of bladder cancer characterized by deletion of the gene MTAP encoding the enzyme S-Methyl-5'-thioadenosine phosphatase, a potential biomarker of response to pemetrexed. We performed a retrospective analysis of 61 patients with advanced urothelial carcinoma for whom demographics, pathologic specimens, next generation sequencing, and clinical outcomes were available. We compared the frequency of histology variants, upper tract location, pathogenic gene variants, tumor response, progression free survival (PFS) and overall survival (OS) between patients with tumors harboring MTAP deletion (MTAP-del) and wild type tumors (MTAP-WT). A propensity score matching of 5 covariates (age, gender, presence of variant histology, prior surgery, and prior non-muscle invasive bladder cancer) was calculated to compensate for disparity when comparing survival in these subgroups. Non-supervised clustering analysis of differentially expressed genes between MTAP-del and MTAP-WT urothelial carcinomas was performed. MTAP-del occurred in 19 patients (31%). Tumors with MTAP-del were characterized by higher prevalence of squamous differentiation (47.4 vs 11.9%), bone metastases (52.6 vs 23.5%) and lower frequency of upper urinary tract location (5.2% vs 26.1%). Pathway gene set enrichment analysis showed that among the genes upregulated in the MTAP-del cohort, at least 5 were linked to keratinization (FOXN1, KRT33A/B, KRT84, RPTN) possibly contributing to the higher prevalence of squamous differentiation. Alterations in the PIK3 and MAPK pathways were more frequent when MTAP was deleted. There was a trend to inferior response to chemotherapy among MTAP-del tumors, but no difference in the response to immune checkpoint inhibitors or enfortumab. Median progression free survival after first line therapy (PFS1) was 5.5 months for patients with MTAP-WT and 4.5 months for patients with MTAP-del (HR = 1.30; 95% CI, 0.64-2.63; P = 0.471). There was no difference in the time from metastatic diagnosis to death (P = 0.6346). Median OS from diagnosis of localized or de novo metastatic disease was 16 months (range 1.5-60, IQR 8-26) for patients with MTAP-del and 24.5 months (range 3-156, IQR 16-48) for patients with MTAP-WT (P = 0.0218), suggesting that time to progression to metastatic disease is shorter in MTAP-del patients. Covariates did not impact significantly overall survival on propensity score matching. In conclusion, MTAP -del occurs in approximately 30% of patients with advanced urothelial carcinoma and defines a subgroup of patients with aggressive features, such as squamous differentiation, frequent bone metastases, poor response to chemotherapy, and shorter time to progression to metastatic disease.

Genomic and immunologic profiles of concurrent RB1 and CDKN1A/p21(WAF1) truncating mutations (RW+) in bladder cancer

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Background: p53 target and cell cycle inhibitor CDKN1A/p21(WAF1) was initially not found to be mutated in cancer. TCGA analysis identified CDKN1A mutations are present but rare with frequencies of < 1%, but enrich in bladder cancer (̃8%). Truncating WAF1 mutations are associated with sensitivity to cisplatin and are associated with truncating Rb mutations in bladder cancer (RW+). We hypothesized RW+ bladder cancers may represent a unique subgroup with sensitivity to therapeutics. Methods: A total of 1104 urothelial tumors underwent molecular profiling at Caris Life Sciences (Phoenix, AZ) utilizing NGS of DNA (592 Gene Panel, NextSeq, or WES, NovaSeq) and RNA (NovaSeq, WTS). Wilcoxon, Fisher’s exact were used for statistical significance (p value without and q value with multi comparison correction). Immune cell fraction (QuanTIseq) and pathway analysis (ssGSEA) were assessed by mRNA analysis. Immune epitope prediction was performed using the NetMHCpan v4.0 method in the Immune Epitope Database. Results: Concurrent truncating mutation (frameshift, nonsense) for RB1 and WAF1 were detected in 47 tumors (RW+, 4.25%) and tumors with wild-type status for both RB1 and WAF1 genes were classified as RW- group (54.08%). Tumors harboring only one RB1 or WAF1 mutation were excluded for further analysis. When compared to RW- group, RW+ tumors showed lower mutation rate of TP53 (54.5% vs 80.9%, q < 0.05), ARID1A (23.5% vs 38.3%, p < 0.05), and PIK3CA (18.4% vs 31.9%, p < 0.05). Interestingly, RW+ was mutually exclusive with FGFR3 mutation (18.0% vs 0%, p < 0.05). We further evaluated RNA expression of DNA repair and checkpoint arrest pathways. Notably, E2F pathway (Normalized Enrichment Scores, NES: 0.89 vs 0.86, q < 0.01) and DNA G2M checkpoint (NES: 0.89 vs 0.86, q < 0.01) were found to be the most enriched in RW+ with respect to RW- group. In addition, mRNA levels of FANCC/A, CHEK1, WEE1, CDC25A/C, PALB2 and BRCA1/2 were found to be overexpressed in RW+ group (q < 0.05). RW+ tumors also displayed a distinct immunological profile: They were associated with higher PD-L1 status (63.8% vs 37.3%, q < 0.01), higher median TMB (11 mut/Mb vs 8 mut/Mb, q < 0.01) and with less frequent loss of heterozygosity for HLA-DPA1 (51.1% vs 66.7%, p < 0.05), with more high-binding-affinity neoantigen load (4.78 vs 3.89, p < 0.05) to MHC proteins, consistent with the significantly more myeloid dendritic cells in in RW+ group (0.3 vs 0.04, q < 0.001). Conclusions: Concurrent truncating mutation in RB1 and WAF1 (RW+) bladder carcinomas have fewer p53, ARID1A, and PIK3CA mutations but are enriched for E2F targets, G2/M checkpoint genes, FANCC/A, CHEK1, WEE1, CDC25A/C, PALB2 and BRCA1/2 and have a distinct immunological profile. The findings suggest therapeutic strategies for RW+ bladder cancers including Chk1/Wee1, PARP inhibitors, -/+ immunotherapy that may impact on clinical outcomes.

BrUOG360: A phase Ib/II study of copanlisib combined with rucaparib in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC)

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Background: mCRPC with alterations in genes associated with homologous recombination (HR) DNA repair (e.g., BRCA1/2) is sensitive to poly ADP-ribose polymerase inhibitors (PARPi). Preclinical studies showed that PI3K inhibitors (PI3Ki) impairs HR and sensitize cancer cells to PARPi even in the absence of HR gene mutations. These results support our hypothesis that dual PI3K and PARP inhibition may improve clinical outcomes in progressive mCRPC. We describe preliminary results of a phase Ib/II study investigating safety of the combination of copanlisib (pan-class I PI3Ki) and rucaparib (PARP-1, -2 and -3 inhibitor). Methods: Enrollment criteria included progressive mCRPC, prior androgen inhibitors (abiraterone, enzalutamide, and/or apalutamide); prior taxane chemotherapy was allowed. HR-deficiency was not required for the phase Ib. The phase I followed a standard 3+3 escalation design. Dose schema: rucaparib (continuous oral administration twice daily) 400mg (dose level [DL] -1, 1), 500mg (DL 2) or 600mg (DL 3,4) and intravenous copanlisib (45mg D1, D15 (DL -1, -2); 45mg, D1, D8, D15 (DL 1, 2, 3); 60mg, D1, D8, D15 (DL 4); 28-day cycle). Adverse events (AE) were graded by CTCAE v5.0. The primary aim of the phase I was to establish the MTD and the recommended phase II dose (RP2D) of copanlisib in combination with rucaparib. Results: Eleven pts were enrolled with a median age of 63 (55-78) and median PSA of 12 ng/mL (0.018–2,101). Seven pts (63%) received prior chemotherapy (docetaxel [7], cabazitaxel [3]). Pathogenic HR mutations included BRCA1 (1), BRCA2 (3), CDK12 (1), and FANCA (1). Treatment-related AE included grade 2 (G2) leukopenia (30%), G2 anemia (20%), G2 rash (20%). Two dose-limiting toxicities (DLTs) were observed in DL 1: G3 rash and G3 AST/ALT elevation attributed to both drugs. Six pts were treated at DL -1 without DLTs. The RP2D was rucaparib 400mg BID with copanlisib 45mg (D1, D15; 28-day cycle). There were 2 confirmed PSA50 responses among 7 evaluable pts (28%). One pt had BRCA2 loss and 1 had PALB2 VUS (ongoing PSA response for 14 mo). Three stable disease and 1 partial response were observed among 6 pts evaluable by RECIST 1.1. Conclusions: The combination of rucaparib and copanlisib is well tolerated. The RP2D was rucaparib 400mg BID with copanlisib 45mg (D1, D15; 28-day cycle) with signal of efficacy. Enrollment in a phase 2 expansion cohort in HR-mutated mCRPC is ongoing. Clinical trial information: NCT04253262.

Abstract 1205: Clinical and genomic features of advanced urothelial carcinoma with 9p21 deletion

Chromosome 9p21 deletion occurs in 25% of urothelial carcinomas (UC). 9p21 includes the MTAP gene that encodes methylthioadenosine phosphorylase, a critical enzyme in the alternate pathway of adenine synthesis. MTAP-deleted UC tumors are very sensitive to pemetrexed-induced blockage of purine synthesis. MTAP is commonly co-deleted with CDKN2A, an immediately adjacent gene associated with sensitivity to CDK4/6 inhibitors. We describe clinical and molecular features of a 9p21-deleted subgroup of UC to better inform targeted therapy approaches. We retrospectively analyzed 46 patients (pts) with UC treated at our institution. All tumor specimens were submitted to next-generation sequencing (NGS). Patient demographics, clinic-pathological and genomic features, and clinical outcomes were summarized with descriptive statistics. MTAP/CDKN2A co-deletion was defined as a surrogate for 9p21 deletion. Fifteen (32%) pts with 9p21-deleted UC were identified. The median age was 68 years-old (range 54-79), 80% of pts were former or active smokers. Fifty-three percent (8 of 15) of these tumors showed squamous differentiation. Other histology variants were papillary differentiation (6), micropapillary (1), and sarcomatoid (1). Sites of tumor specimens submitted to NGS included bladder (11), lymph node (1), abdominal wall (1), renal pelvis mass (1), and bone (1). All pts had metastatic disease involving bone (9), lung (8), lymph nodes (7), liver (3), abdominal wall (2), penis (2), peritoneum (1), and pararenal mass (1). Most pts (8) underwent curative surgery and later developed metastases; seven pts presented with de novo metastases. Among 9 pts with progression-free survival (PFS) data available, median PFS was 2 months (range 1-17). Median overall survival was 6 months (range 1-35). Median PD-L1 expression on tumor cells was 1% (range 1-20); 4 tumors were PD-L1 (-). All evaluable patients (14) had stable microsatellite tumors. The most common genomic alterations co-occurring with 9p21 deletion affected CDKN2B (100%), TERT (87%), KDM6A (60%), TP53 (40%), and FGFR3 (20%). The best response associated with immune checkpoint inhibitors among 7 patients with 9p21 deletion was a disease control rate of 28.5%. Our cohort with UC and 9p21 deletion had predominantly squamous cell differentiation. Thus, MTAP is always co-deleted with CDKN2A and is a potential biomarker for pemetrexed-based combinations. Molecular characterization of 9p21 deleted UC may in the future inform targeted therapeutic approaches.

Citation Format: Andre L. De Souza, Praveen Srinivasan, Luke B. Soliman, Dragan J. Golijanin, Ali Amin, Howard Safran, Anthony E. Mega, Wafik S. El-Deiry, Benedito A. Carneiro. Clinical and genomic features of advanced urothelial carcinoma with 9p21 deletion [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1205.

KEYNOTE-046 (Part B): Effects of ADXS-PSA in combination with pembrolizumab on survival in metastatic, castration-resistant prostate cancer patients with or without prior exposure to docetaxel

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Background: ADXS-PSA, an attenuated Listeria monocytogenes-based immunotherapy targeting prostate-specific antigen (PSA), is currently being evaluated in combination with pembrolizumab as a treatment for progressive metastatic castration-resistant prostate cancer (mCRPC) in the phase 1/2 KEYNOTE-046 trial (Part B). Methods: A total of 37 patients received 1x109 CFU + 200 mg pembro IV every 3 wks, for up to 2 yrs or until progression/toxicity. Results: At entry, patients were ~70 yrs with median a Gleason score of 9, and bone predominant disease (70%). MSI-High was negative in 36 pts who were able to be tested. Eighteen (48.6%) patients had received prior docetaxel, 15 pts of whom (83.3%) had also received 1-2 next generation hormonal agents (NGHAs). Nineteen (51.3%) had not received prior docetaxel and 16 of these pts (84.2%) had received 1-2 NGHAs. Overall, 16 out of 37 pts (43%) had a decreased PSA post-BL with 6/37 (16%) pts achieving a confirmed PSA reduction ≥50% from baseline. The median OS (months) for the whole group (37 pts) was 33.6 m (95% CI, range 15.4-33.6 months). The mOS for pts with and without prior exposure to docetaxel was 16 m (5.9 -33.6) and NR at 30 months of follow-up (15.4-NR), respectively. Prolonged survival was observed in pts regardless of prior therapies, microsatellite stable (MSS) status or PSA delta <50% or ≥50%. Conclusions: Results with ADXS-PSA in combination with pembrolizumab in mCRPC, with or without prior docetaxel, show promising clinical activity to be further assessed in randomized studies. Clinical trial information: NCT02325557.

Outcomes of patients with pancreatic-only oligometastatic renal cell carcinoma (RCC)

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Background: Patients (pts) with RCC and oligometastatic pancreas metastases are treated with pancreatectomy, stereotactic body radiation therapy (SBRT), or systemic therapy. The optimal approach is not clear. We aimed to evaluate the comparative efficacy of the modalities in terms of progression-free survival (PFS) and overall survival (OS). Methods: This IRB-approved, multi-institutional, retrospective study evaluated pts with pancreatic-only RCC metastasis without concurrent metastases elsewhere. Data on pt demographics, tumor characteristics, treatment, and outcomes were collected. PFS and OS in pts treated with pancreatectomy vs. systemic therapy were compared by log rank tests. Results: Fifty-one pts from 9 institutions were included. All had clear cell RCC; 50 pts had nephrectomy; 30 pts (58.8%) and 18 pts (35.3%) had IMDC favorable and intermediate risk, respectively. Median time from RCC diagnosis to oligometastatic disease was 120 months (mo) (range: 0, 175). As initial treatment, 23 (45%) pts had pancreatectomy (mostly partial); 25 (49%) had systemic therapy (VEGFR TKI and/or immunotherapy); 1 had SBRT; 2 had other treatments. Too few pts had SBRT for comparison. With a median follow-up of 25 mo (2, 68), median PFS for the population was 25 mo (17, 42 95% CI). Median PFS was 36 mo (8, 43 95% CI) for surgery pts and 22 mo (17, NR 95% CI) for systemic therapy pts; this was not statistically significant (NS), p = 0.3. Median OS for the population was 121 mo (100, NR 95% CI). With a median follow-up of 51 mo (2, 217), OS was 121 mo (100, NR 95% CI) for surgery pts and not reached (64, NR 95% CI) for systemic therapy pts; NS, p = 0.52. Conclusions: In this retrospective series, RCC pts with oligometastatic pancreatic-only disease had similar PFS and OS outcomes from initial pancreatectomy or systemic therapy. RCC pts with pancreas-only metastases represent a unique patient population and studies informing the underlying biology are needed to optimize clinical management.

PSMA ADC monotherapy in patients with progressive metastatic castration-resistant prostate cancer following abiraterone and/or enzalutamide: Efficacy and safety in open-label single-arm phase 2 study

BACKGROUND

Prostate-specific membrane antigen (PSMA) is a well-established therapeutic and diagnostic target overexpressed in both primary and metastatic prostate cancers. PSMA antibody-drug conjugate (PSMA ADC) is a fully human immunoglobulin G1 anti-PSMA monoclonal antibody conjugated to monomethylauristatin E, which binds to PSMA-positive cells and induces cytotoxicity. In a phase 1 study, PSMA ADC was well tolerated and demonstrated activity as measured by reductions in serum prostate-specific antigen (PSA) and circulating tumor cells (CTCs). To further assess PSMA ADC, we conducted a phase 2 trial in metastatic castration-resistant prostate cancer (mCRPC) subjects who progressed following abiraterone/enzalutamide (abi/enz) therapy.

METHODS

A total of 119 (84 chemotherapy-experienced and 35 chemotherapy-naïve) subjects were administered PSMA ADC 2.5 or 2.3 mg/kg IV q3w for up to eight cycles. Antitumor activity (best percentage declines in PSA and CTCs from baseline and tumor responses through radiological imaging), exploratory biomarkers, and safety (monitoring of adverse events [AEs], clinical laboratory tests, and Eastern Cooperative Oncology Group performance status) were assessed.

RESULTS

PSA declines ≥50% occurred in 14% of all treated (n = 113) and 21% of chemotherapy-naïve subjects (n = 34). CTC declines ≥50% were seen in 78% of all treated (n = 77; number of subjects with ≥5 CTCs at baseline and a posttreatment result) and 89% of chemotherapy-naïve subjects (n = 19); 47% of all treated and 53% of chemotherapy-naïve subjects had a transition from ≥5 to less than 5 CTCs/7.5 mL blood at some point during the study. PSA and CTC reductions were associated with high PSMA expression (CTCs or tumor tissue) and low neuroendocrine serum markers. In the chemotherapy-experienced group, the best overall radiologic response to PSMA ADC treatment was stable disease in 51 (60.7%) subjects; 5.7% of subjects in the chemotherapy-naïve group had partial responses. The most common treatment-related AEs ≥Common Terminology Criteria for AE (CTCAE) grade 3 were neutropenia, fatigue, electrolyte imbalance, anemia, and neuropathy. The most common serious AEs were dehydration, hyponatremia, febrile neutropenia, and constipation. Two subjects who received 2.5 mg/kg died of sepsis.

CONCLUSIONS

PSMA ADC demonstrated some activity with respect to PSA declines, CTC conversions/reductions, and radiologic assessments in abi/enz treated mCRPC subjects. Clinically significant treatment-related AEs included neutropenia and neuropathy.

Where’s my doctor? the impact of the primary oncologist’s visit with their hospitalized patients

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Background: Continuity of care is a cornerstone of the patient-practitioner relationship and patient satisfaction. The inpatient continuity visit (ICV), a face-to-face patient-provider interaction, involves a discussion regarding hospital course and care goals and decisions. We theorize that the ICV influences patient satisfaction. Previously, patient satisfaction has been related to patient perception of physician conduct, including communication skills. Currently, there are no studies investigating the impact of an ICV on inpatient oncology patients on a hospitalist service. Objectives: To assess the relationship between the ICV and patient satisfaction. We hypothesized that one or more visits by the outpatient oncologist would enhance satisfaction of oncology inpatients. Methods: Subjects (N=82) were comprised of adult inpatients on the oncology unit at Miriam Hospital, a teaching hospital of the Alpert Medical School of Brown University. All participants had an oncologist at the hospital based cancer center. A survey, given at discharge, included a 5-point Likert scale ranging from greatly worsened to greatly improved to assess the impact of the ICV on patient satisfaction. Results: Of 82 participants, 46 reported a visit by their outpatient oncologist. Forty-two (91.3%) reported that this visit either greatly or somewhat improved satisfaction with their hospital stay, while 8.7% reported no impact. Of patients whose oncologist visited once, 94.4% reported either greatly or somewhat improved satisfaction compared to 89.3% who had more than one visit. Out of 36 subjects who did not receive a visit, 16.7% reported that the lack of visit either greatly or somewhat worsened their hospital stay, while 83.3% reported no impact. Conclusions: Our study suggests that an ICV improves satisfaction of care in cancer patients on a hospitalist service. Furthermore, one of every six subjects who did not receive an ICV reported a negative impact on satisfaction. Results highlight a possible intervention to the discontinuity of care that may be perceived by patients. While the practicality of this intervention requires evaluation, the efficacy of a single continuity visit to improve satisfaction is reassuring.

Cabozantinib in advanced non-clear-cell renal cell carcinoma: a multicentre, retrospective, cohort study

BACKGROUND

Cabozantinib is approved for patients with metastatic renal cell carcinoma on the basis of studies done in clear-cell histology. The activity of cabozantinib in patients with non-clear-cell renal cell carcinoma is poorly characterised. We sought to analyse the antitumour activity and toxicity of cabozantinib in advanced non-clear-cell renal cell carcinoma.

METHODS

We did a multicentre, international, retrospective cohort study of patients with metastatic non-clear-cell renal cell carcinoma treated with oral cabozantinib during any treatment line at 22 centres: 21 in the USA and one in Belgium. Eligibility required patients with histologically confirmed non-clear-cell renal cell carcinoma who received cabozantinib for metastatic disease during any treatment line roughly between 2015 and 2018. Mixed tumours with a clear-cell histology component were excluded. No other restrictive inclusion criteria were applied. Data were obtained from retrospective chart review by investigators at each institution. Demographic, surgical, pathological, and systemic therapy data were captured with uniform database templates to ensure consistent data collection. The main objectives were to estimate the proportion of patients who achieved an objective response, time to treatment failure, and overall survival after treatment.

FINDINGS

Of 112 identified patients with non-clear-cell renal cell carcinoma treated at the participating centres, 66 (59%) had papillary histology, 17 (15%) had Xp11.2 translocation histology, 15 (13%) had unclassified histology, ten (9%) had chromophobe histology, and four (4%) had collecting duct histology. The proportion of patients who achieved an objective response across all histologies was 30 (27%, 95% CI 19-36) of 112 patients. At a median follow-up of 11 months (IQR 6-18), median time to treatment failure was 6·7 months (95% CI 5·5-8·6), median progression-free survival was 7·0 months (5·7-9·0), and median overall survival was 12·0 months (9·2-17·0). The most common adverse events of any grade were fatigue (58 [52%]), and diarrhoea (38 [34%]). The most common grade 3 events were skin toxicity (rash and palmar-plantar erythrodysesthesia; five [4%]) and hypertension (four [4%]). No treatment-related deaths were observed. Across 54 patients with available next-generation sequencing data, the most frequently altered somatic genes were CDKN2A (12 [22%]) and MET (11 [20%]) with responses seen irrespective of mutational status.

INTERPRETATION

While we await results from prospective studies, this real-world study provides evidence supporting the antitumour activity and safety of cabozantinib across non-clear-cell renal cell carcinomas. Continued support of international collaborations and prospective ongoing studies targeting non-clear-cell renal cell carcinoma subtypes and specific molecular alterations are warranted to improve outcomes across these rare diseases with few evidence-based treatment options.

FUNDING

None.

Androgen receptor-independent prostate cancer: an emerging clinical entity

Androgen deprivation therapy remains the backbone of prostate cancer treatment given its pivotal role in the pathogenesis of prostate cancer. The growing knowledge of androgen receptor-independent (i.e. AR-null) prostate cancer cells, however, might advance the treatment paradigm of prostate cancer. Here, we examined the results of two recent studies, published in Cancer Cell by Bluemn and Shukla et al., and their impact in the future management of castration-resistant prostate cancer.

Strategies to embed palliative care into a culture of cancer care

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Background: In 2012, the 3 hospital Lifespan Health System launched a palliative care initiative. The hospitals and medical oncologists knew this was critical for patient centered and value-based cancer care, but recognized many barriers: physician practice patterns, lack of dedicated resources and systems, patient and family education gaps, and limited return on investment in the current environment. A multi-level inpatient and outpatient strategy was implemented and tracked over four years. Methods: External benchmarking data from a Medicare claims analysis of Vizient (academic health system consortium) member organizations and from ASCO QOPI data were used in the analysis. Internal data analysis included a study on symptom management for lung cancer patients, hospital reports on palliative care service utilization, ED visits and hospital admission trends for cancer patients. Multi-level interventions were employed: hospital investment in staff and systems, partnership with a community-based hospice and palliative care provider, a medical oncology physician champion with Board certification in palliative care, a palliative care inpatient consult service and daily ICU rounds, an oncology medical home, medical oncologist Saturday hours, electronic prompts for consults, and a cancer call triage center. Results: A Medicare claims analysis for 2012 to 2014 on cancer decedents with ICU stays in the last 30 days in the Vizient national study of health systems showed that Lifespan was at the 11th percentile, making them the 4th lowest (days in ICU) in performance (pre/post data requested). QOPI data on appropriate referrals to hospice or palliative care prior to death improved from 58% in 2010, which was below the QOPI benchmark of 61%, to 94% in 2016 which is above the QOPI benchmark of 74%. Other QOPI and hospital data will be included in the presentation. Conclusions: Palliative care, a crucial tool for the delivery of future cancer care, is challenging to implement effectively. This study shows that a hospital/medical oncology partnership can drive change to embed palliative care into the culture of cancer care and these strategies offer a roadmap for others to follow as they strive to offer patient centered and value-based cancer care.

Avelumab, an Anti-Programmed Death-Ligand 1 Antibody, In Patients With Refractory Metastatic Urothelial Carcinoma: Results From a Multicenter, Phase Ib Study

Purpose

We assessed the safety and antitumor activity of avelumab, a fully human anti–programmed death-ligand 1 (PD-L1) IgG1 antibody, in patients with refractory metastatic urothelial carcinoma.

Methods

In this phase Ib, multicenter, expansion cohort, patients with urothelial carcinoma progressing after platinum-based chemotherapy and unselected for PD-L1 expression received avelumab 10 mg/kg intravenously every 2 weeks. The primary objectives were safety and tolerability. Secondary objectives included confirmed objective response rate (Response Evaluation Criteria in Solid Tumors [RECIST] version 1.1), progression-free survival, overall survival (OS), and PD-L1–associated clinical activity. PD-L1 positivity was defined as expression by immunohistochemistry on ≥ 5% of tumor cells.

Results

Forty-four patients were treated with avelumab and followed for a median of 16.5 months (interquartile range, 15.8 to 16.7 months). The data cutoff was March 19, 2016. The most frequent treatment-related adverse events of any grade were fatigue/asthenia (31.8%), infusion-related reaction (20.5%), and nausea (11.4%). Grades 3 to 4 treatment-related adverse events occurred in three patients (6.8%) and included asthenia, AST elevation, creatine phosphokinase elevation, and decreased appetite. The confirmed objective response rate by independent central review was 18.2% (95% CI, 8.2% to 32.7%; five complete responses and three partial responses). The median duration of response was not reached (95% CI, 12.1 weeks to not estimable), and responses were ongoing in six patients (75.0%), including four of five complete responses. Seven of eight responding patients had PD-L1–positive tumors. The median progression-free survival was 11.6 weeks (95% CI, 6.1 to 17.4 weeks); the median OS was 13.7 months (95% CI, 8.5 months to not estimable), with a 12-month OS rate of 54.3% (95% CI, 37.9% to 68.1%).

Conclusion

Avelumab was well tolerated and associated with durable responses and prolonged survival in patients with refractory metastatic UC.

Safety, clinical activity, and PD-L1 expression of avelumab (MSB0010718C), an anti-PD-L1 antibody, in patients with metastatic urothelial carcinoma from the JAVELIN Solid Tumor phase Ib trial

367

Background: Avelumab* (MSB0010718C) is a fully human anti-PD-L1 IgG1 antibody being investigated in multiple clinical trials. We report safety and clinical activity of avelumab as a second-line therapy in patients (pts) with metastatic urothelial carcinoma (mUC) based on level of PD-L1 expression (NCT01772004). Methods: Pts with mUC unselected for PD-L1 expression received avelumab at 10 mg/kg Q2W by IV infusion until confirmed progression, unacceptable toxicity, or any criterion for withdrawal occurred. Tumors were assessed every 6 wks (RECIST 1.1). Best overall response rate (ORR) and progression-free survival (PFS) were evaluated. Adverse events (AEs) were graded by NCI-CTCAE v4.0. PD-L1 expression was assessed by immunohistochemistry. Results: As of 19 Mar 2015, 44 pts (30 men, 14 women) with mUC were treated with avelumab (median 13 wks [range 2-28]) and followed for a median of 3.5 mo (range 3.0-5.0). Median age was 68y (range 30-84), ECOG performance status was 0 (43.2%) or 1 (56.8%), and pts had received a median of 2 prior therapies (range 1- ≥ 4). Treatment-related treatment-emergent AEs (TR-TEAEs) of any grade occurred in 26 pts (59.1%); those occurring ≥ 10% were grade 1/2 infusion-related reactions (8 [18.2%]) and fatigue (7 [15.9%]). One pt had grade 3 asthenia. There were no treatment-related deaths. ORR was 15.9% (7 pts; 95% CI: 6.6, 30.1) with 1 CR and 6 PRs; 6 responses were ongoing at data cutoff. Stable disease (SD) was observed in 19 pts (42.3%) and disease-control rate (CR+PR+SD) was 59.1%. PD-L1 expression was evaluable in 32 pts. Using a ≥ 5% cutoff (10/32 [31.3%] were PD-L1+), ORR was 40.0% in PD-L1+ pts (4/10) vs 9.1% in PD-L1– pts (2/22; p= 0.060). PFS rate at 12 wks was 70.0% (95% CI: 32.9, 89.2) in PD-L1+ pts vs 45.5% (95% CI 22.7, 65.8) in PD-L1− pts. Conclusions: Avelumabshowed an acceptable safety profile and had clinical activity in pts with mUC. There was a trend towards higher ORR and prolonged PFS rate at 12 wks in pts with PD-L1+ mUC. Further analyses of PD-L1 expression and clinical activity of avelumab in UC are ongoing. *Proposed INN. Clinical trial information: NCT01772004.

A phase 2 study of prostate specific membrane antigen antibody drug conjugate (PSMA ADC) in patients (pts) with progressive metastatic castration-resistant prostate cancer (mCRPC) following abiraterone and/or enzalutamide (abi/enz)

144

Background: PSMA is a validated target that is overexpressed selectively on prostate cancer cells. PSMA ADC is a fully human IgG1 antibody conjugated to the microtubule disrupting agent MMAE which binds to PSMA-positive cells, inducing cytotoxicity. A phase 1 study showed activity and tolerability at doses from 1.8-2.5 mg/kg. We have enrolled 119 mCRPC pts who progressed following abi/enz in a phase 2 trial of PSMA ADC. Methods: mCRPC pts (83 taxane experienced (TE) and 36 chemo-naïve (CN)) were administered PSMA ADC 2.5 or 2.3 mg/kg IV Q3 wk for up to 8 cycles. 95% of pts received prior abi and/or enz treatment. Safety, antitumor activity (including PSA, CTCs, and tumor imaging) and exploratory biomarkers were assessed. Results: In all treated pts, PSA declines of ≥30% and ≥50% were 30% and 14%, respectively (n=113); CTC counts showed a decline of ≥50% in 78% of pts and conversion from ≥5 to <5 cells/7.5 ml blood in 47% (n=77) at any time during the study. For 2.3 mg/kg pts (n=82), corresponding PSA declines were 35% and 17%; CTC declines of ≥50% were seen in 81% and conversions in 46% (n=54). For CN pts, PSA declines of ≥30% and ≥50% were 31% and 20% (n=35); CTC declines of ≥50% were seen in 89% and conversion in 53% (n=19). Radiologic response by RECIST in 31 pts with measurable target lesions: PR in 4 pts, SD in 19 pts, and PD in 8 pts. Efficacy responses were associated with: low neuroendocrine serum markers (low CgA, low NSE, and high PSA), high PSMA expression (CTCs or tumor tissue). The most common treatment-related AEs ≥CTCAE grade 3 were neutropenia (TE: 25%; CN: 22%), fatigue (20%; 8%), electrolyte imbalance (16%; 11%), anemia (10%; 8%), and neuropathy (8%; 8%). Grade 1-2 neuropathy occurred in 40% (TE) and 50% (CN) of pts. Two 2.5 mg/kg pts (n=34) and one 2.3 mg/kg pt (n=85) died of sepsis. 2.3 mg/kg was better tolerated than 2.5 mg/kg. Conclusions: PSMA ADC was active in abi/enz refractory mCRPC pts. Clinically significant AEs included neutropenia and neuropathy. CTC conversions/reductions, PSA declines, and radiologic evidence of antitumor activity were seen in CN as well as heavily pretreated pts. Clinical trial information: NCT01695044.

Prostate-specific membrane antigen antibody drug conjugate (PSMA ADC): A phase I trial in metastatic castration-resistant prostate cancer (mCRPC) previously treated with a taxane

5018

Background: The abundant expression of prostate specific membrane antigen (PSMA) on prostate cancer cells provides a rationale for antibody therapy. PSMA ADC is a fully human antibody to PSMA linked to the microtubule disrupting agent monomethyl auristatin E (MMAE). It binds PSMA and is internalized within the cancer cell where cleavage by lysosomal enzymes release free MMAE, causing cell cycle arrest and apoptosis. A phase 1 dose escalation study of PSMA ADC in taxane-refractory mCRPC has been completed. Methods: Patients with progressive mCRPC following taxane-containing chemotherapy and ECOG status of 0 or 1 were eligible. PSMA ADC was administered by IV infusion Q3W for up to 4 cycles. Safety, pharmacokinetics, PSA, circulating tumor cells (CTC), immunogenicity and clinical progression were assessed. Serum PSMA ADC and total anti-PSMA ADC antibodies were measured by ELISA, and free MMAE was measured by LC/MS/MS.The dosing cohorts ranged from 0.4 mg/kg to 2.8 mg/kg. Subjects who benefitted from PSMA ADC were eligible for treatment in an extension study. Results: 52 subjects were dosed in 9 dose levels. All subjects received prior docetaxel, 6 also received cabazitaxel and 3 subjects also received paclitaxel. PSMA ADC was generally well tolerated with the most commonly seen adverse events being anorexia and fatigue. 16 patients reported peripheral neuropathies, including 3 with grade 3. Dose limiting toxicities (DLT) seen at 2.8 mg/kg were neutropenia (one death) and reversible elevations in liver function tests (LFTs). Antitumor activity was manifested as reductions either in PSA or in CTCs in approximately 50% of patients at ≥ 1.8 mg/kg PSMA ADC. Exposure to PSMA ADC increased with dose and was ~1,000-fold greater than MMAE exposure. There was no accumulation. Conclusion: PSMA ADC in this study was generally well tolerated in subjects with progressive mCRPC, previously treated with taxane. Antitumor activity was seen at doses ≥ 1.8 mg/kg. DLTs were neutropenia and reversible LFT abnormalities. The maximum tolerated dose was determined to be 2.5 mg/kg. A phase 2 trial of PSMA ADC in taxane refractory mCRPC has been initiated at 2.5 mg/kg. Clinical trial information: NCT01414283.

Assessment of the effectiveness of a chemotherapy education program: A Brown University Oncology Research Group study

6574

Background: Patients about to begin chemotherapy often have questions about their treatment along with significant anxiety. This study evaluated whether pre-chemotherapy teaching sessions improved patient knowledge and anxiety. Methods: After meeting with their oncologist to discuss planned chemotherapy treatment, subjects completed a 10-question survey which assessed their knowledge of anticipated side effects and treatment schedule on a 1-4 rating scale (1=no knowledge, 2=minimally informed, 3=reasonably informed, 4=well informed) as well as anxiety about initiating chemotherapy (1=no anxiety, 2=minimal anxiety, 3=moderate anxiety, 4=severe anxiety). Subjects then completed a structured nurse-led chemotherapy education session. The survey was repeated on the first day of cycle 1. Mantel-Haentzel Chi-square tests were used to evaluate for changes across the surveys. Subgroup analysis by Wilcoxon signed-rank test was performed to assess differences in anxiety based on age. Results: At the time of analysis, 142 subjects had completed the education session. Improvement was seen in knowledge of treatment schedule (mean score increase from 2.5 to 3.4, p<0.001), side effects (mean score increase from 2.3 to 3.4, p<0.001), and how to use medications designed to prevent and treat nausea (mean score increase from 1.8 to 3.2, p<0.001). There was significant reduction in patient anxiety about starting treatment (mean score decrease from 2.3 to 2, p<0.001) and anxiety related to treatment side effects (mean score decrease from 2.3 to 2, p<0.001). Analysis of anxiety by age showed that those age <65 had higher baseline anxiety scores with a reduction in anxiety after the education session while those age ≥65 had lower baseline anxiety scores with a rise in anxiety after the education session (Table). Conclusions: A pre-chemotherapy teaching session improves patient knowledge about the planned treatment along with reduction in anxiety. Change in anxiety differs between patients 65 years of age and older as compared to those less than 65. [Table: see text]

Prostate-specific membrane antigen antibody drug conjugate (PSMA ADC): A phase I trial in metastatic castration-resistant prostate cancer (mCRPC) previously treated with a taxane

119

Background: The abundant expression of prostate specific membrane antigen (PSMA) on prostate cancer cells provides a rationale for antibody therapy. PSMA ADC, a fully human antibody to PSMA linked to the microtubule disrupting agent monomethyl auristatin E (MMAE), binds PSMA and is internalized within the prostate cancer cell where cleavage by lysosomal enzymes release free MMAE, causing cell cycle arrest and apoptosis. We have completed a phase 1 dose escalation study of PSMA ADC in subjects with taxane-refractory mCRPC. Methods: Eligibility requirements include progressive mCRPC following taxane-containing chemotherapy and ECOG status of 0 or 1. PSMA ADC was administered by IV infusion Q3W for up to 4 cycles. Safety, pharmacokinetics (PK), PSA, circulating tumor cells (CTC), clinical disease progression and immunogenicity to PSMA ADC were assessed. Serum PSMA ADC and total antibody were measured by ELISA, and free MMAE was measured by LC/MS/MS.The dosing cohorts ranged from 0.4 mg/kg to 2.8 mg/kg. Results: 52 subjects with mCRPC were dosed in nine dose levels. All subjects received prior docetaxel, 5 also received cabazitaxel and 3 subjects also received paclitaxel. PSMA ADC was generally well tolerated with the most commonly seen adverse events being anorexia and fatigue. Peripheral neuropathy was reported by 7 subjects after repeated doses. Two were grade 3. Dose limiting toxicities (DLT) seen at 2.8 mg/kg were neutropenia (one death) and reversible liver function tests (LFTs) elevations. Antitumor activity was manifested as reductions either in PSA or CTCs at ≥ 1.8 mg/kg PSMA ADC in approximately 50% of patients. Exposure to PSMA ADC increased with dose and was ~1,000-fold greater than MMAE exposure and no accumulation was observed. Conclusions: PSMA ADC in this study was generally well tolerated in doses up to 2.8 mg/kg every three weeks in subjects with mCRPC, previously treated with taxane. Antitumor activity was seen at higher dose levels. DLTs were neutropenia and reversible LFT abnormalities. The maximum tolerated dose of PSMA ADC was determined to be 2.5 mg/kg. A phase 2 trial in taxane refractory mCRPC has been initiated. Clinical trial information: NCT01414283.

Assessment of the effectiveness of a prechemotherapy teaching session: A Brown University Oncology Group study

260

Background: Pre-chemotherapy teaching sessions, often coordinated by nursing personnel, are an opportunity to educate patients on treatment side effects, schedule, medications for toxicities such as nausea, and how to contact the oncology team if adverse events develop. Our institution provides a structured 60-minute nurse-coordinated pre-chemotherapy teaching session. The aims of this study were to evaluate whether pre-chemotherapy teaching sessions improve patient knowledge, preparedness, and anxiety in relation to chemotherapy. Methods: Patients were offered the opportunity to participate in the study after their medical oncologist had reviewed their treatment regimen. After informed consent was obtained, participants were administered a 10-question survey assessing knowledge of treatment adverse effects, treatment schedule, management of complications, accessing their medical team, and patient anxiety. Subjects then participated in a pre-chemotherapy teaching session with an oncology nurse. The survey was readministered when patients returned on day 1, cycle 1 of treatment and on day 1, cycle 2. The questionnaire used a 1 to 4 rating scale (1=no knowledge, 2= minimally informed, 3= reasonably informed, 4= well informed). A pre-defined mean change of 1 on the rating scale was considered to be clinically significant. Paired one-sided t-tests were performed to evaluate the mean change in groups between each of the three surveys. p values <0.05 were considered statistically significant. Results: At the time of analysis, 78 patients had completed a pre-chemotherapy teaching session and all three surveys. After participating in a teaching session, there was an increase in patient’s perceived knowledge of side effects (mean score 2.3 vs. 3.5, p<0.001), knowledge of the treatment schedule (mean score 2.4 vs. 3.5, p<0.001) and medications to prevent nausea (mean score of 1.4 vs. 3.1, p <0.001). There was also a statistically significant reduction in patient anxiety in relation to treatment, p< 0.001. Conclusions: These results show that a nurse-coordinated, pre-chemotherapy teaching session increases patient knowledge and reduces anxiety regarding their upcoming treatment.

Prostate-specific membrane antigen antibody drug conjugate (PSMA ADC): A phase I trial in metastatic castration-resistant prostate cancer (mCRPC) previously treated with a taxane

4662

Background: The abundant expression of prostate specific membrane antigen (PSMA) type II transmembrane glycoprotein on prostate cancer cells provides a rationale for antibody therapy. PSMA ADC, a fully humanized antibody to PSMA linked to the potent antitubulin agent monomethyl auristatin E (MMAE), binds PSMA and is internalized within the prostate cancer cell where cleavage by lysosomal enzymes and releases free MMAE, causing cell cycle arrest and apoptosis. We report results from an ongoing phase 1 dose escalation study of PSMA ADC in subjects with taxane-refractory mCRPC. Methods: Eligibility requirements include progressive mCRPC following taxane-containing chemotherapy and ECOG status of 0 or 1. PSMA ADC was administered by IV infusion Q3W for up to 4 cycles. Adverse events, pharmacokinetics (PK), PSA, circulating tumor cells, clinical disease progression and immunogenic response to PSMA ADC were assessed. Serum PSMA ADC and total antibody were measured by ELISA, and free MMAE was measured by LC/MS/MS.The dosing cohorts range from 0.4 mg/kg to 2.8 mg/kg, with dose escalation continuing. Results: 40 subjects have been dosed in nine dose levels (0.4, 0.7, 1.1, 1.6, 1.8, 2.0, 2.2, 2.5, 2.8 mg/kg). To date, PSMA ADC has been well tolerated with the most commonly seen adverse events being anorexia and nausea, and the most common laboratory abnormalities being reversible hematologic parameters and liver function tests. Antitumor activity has been manifested as reductions either in PSA or circulating tumor cells in the higher dose cohorts. Exposure to PSMA ADC increased with dose and was ~1,000-fold greater than MMAE exposure. Similar PK metrics were observed after the first and third doses. Dosing at the 2.8 mg/kg cohort is continuing and an MTD has not yet been reached. Conclusions: PSMA ADC is generally well tolerated in subjects with mCRPC, previously treated with taxane in doses up to 2.8 mg/kg. Antitumor activity at higher dose levels has been observed. The MTD has not yet been reached and enrollment is ongoing at higher dose levels.

The impact of neoadjuvant weekly ixabepilone for high-risk prostate cancer: A phase I/II clinical trial

158

Background: Potential benefits of neoadjuvant chemotherapy are tumor downstaging and treatment of micrometastatic disease. A prior study using docetaxel yielded no pathologic complete responses and concerns for increased operative morbidity. In Phase II studies, ixabepilone has promising activity in metastatic prostate cancer. Our study is a Phase I/II clinical trial evaluating neoadjuvant, weekly ixabepilone in men with high-risk prostate cancer opting for radical prostatectomy.

Methods: Men with high risk prostate cancer defined as either Gleason 8-10, cT3 disease, high volume Gleason 4+3 and a palpable nodule or a PSA>20 ng/ml were eligible. Men received weekly ixabepilone 16-20/m2 for 12-16 weeks prior to surgery. Fifteen men underwent robotic prostatectomy; one patient who had an open prostatectomy. Initial PSA response, post-operative PSA values, pathology, and evaluation of adverse events were recorded.

Results: We enrolled 16 men with a mean follow-up of 15.25 months at time of review. All had pretreatment Gleason scores of 4+3 or higher. With neoadjuvant treatment, PSA values decreased in 14/16 men (mean 46.8%); increased in 2/16 men. None reached an undetectable pre-operative PSA. Nine men experienced an adverse event requiring dose modification or cessation of chemotherapy (neuropathy or allergic reaction). Only 5/16 men completed planned treatment. Mean operative time, EBL, and hospital stay were 189 minutes, 184mL, and1.5 days, respectively; all consistent with institutional and national norms. Post surgery 15/16 (94%) had pT3 disease, 8/16 (50%) had a positive surgical margin and 2/16 (12.5%) had positive regional lymph nodes. There were no pathologic complete responses. Only 1/16 (6.25%) had a biochemical relapse.

Conclusions: While a PSA response is achieved, there is substantial toxicity with neoadjuvant weekly ixabepilone. Men were able to undergo prostatectomy without increased morbidity after neoadjuvant therapy. Extracapsular extension and positive surgical margins remained common in this population with high-risk disease. Assessment of biochemical recurrence rates and time to treatment failure will require longer, planned follow-up.

Prostate-specific membrane antigen antibody drug conjugate (PSMA ADC): A phase I trial in men with prostate cancer previously treated with taxane

107

Background: The abundant expression of prostate specific membrane antigen (PSMA) type II transmembrane glycoprotein on prostate cancer cells provides a rationale for antibody therapy. PSMA ADC, a fully humanized antibody to PSMA linked to the potent antitubulin agent monomethyl auristatin E (MMAE), binds PSMA and is internalized within the prostate cancer cell where cleavage and release of free MMAE occur, causing cell cycle arrest and apoptosis. We report results from an ongoing phase 1 dose escalation study of PSMA ADC in patients (pts) with taxane-refractory metastatic castration-resistant prostate cancer (metCRPC).

Methods: Eligibility requirements include metCRPC after taxane-containing regimen and ECOG status of 0 or 1. PSMA ADC was administered by IV infusion Q3W for up to 4 cycles. Adverse events, PK, PSA, circulating tumor cells, clinical disease progression and immunogenic response to PSMA ADC were assessed. Serum PSMA ADC and total antibody were measured by ELISA, and free MMAE was measured by LC/MS/MS. Dosing cohorts have ranged from 0.4 mg/kg to 2.2 mg/kg.

Results: 26 pts have enrolled in six dosing cohorts (0.4, 0.7, 1.1, 1.6, 1.8, 2.0 mg/kg). Treatment has to date been generally well tolerated with the most commonly seen adverse event being fatigue and the most common laboratory abnormalities being reversible changes in liver and hematological parameters. Antitumor activity manifested as reductions in PSA, circulating tumor cells and/or bone pain has been observed in the higher dose cohorts and appears to be dose-related. Exposure to PSMA ADC increased with dose and was ∼1,000-fold greater than MMAE exposure. Similar PK metrics were observed after the first and third doses. Dosing at the 2.2 mg/kg cohort is continuing and an MTD has not yet been reached.

Conclusions: In pts with metCRPC previously treated with taxane PSMA ADC has exhibited dose-related antitumor activity. The MTD has not yet been reached and enrollment is ongoing at higher dose levels.

Lack of bleeding in patients with severe factor VII deficiency

Factor VII deficiency, although rare, is now recognized as the most common autosomal recessive inherited factor deficiency. It is usually considered to be associated with bleeding only in the severely affected subject and heterozygotes (>10%) are not considered at risk. The general recommendation for surgery is to achieve a FVII level in excess of 15% (0.15 1U/mL). We present three cases of severe factor VII deficiency, each of whom appeared hemostatically competent based on clinical history. Subject 1 is a 33 year-old African-American female with a baseline FVII of <1%, who had a fractured tibia requiring open reduction with internal fixation without any FVII replacement and subsequently underwent successful laparoscopic knee surgery with a factor VII level measured at 6%. Subject 2 is a 58 year-old African-American female with a factor VII level of 9% who underwent an elective left total hip replacement without any factor replacement and had no excessive bleeding, but who sustained a pulmonary embolism postoperatively. Subject 3 is a 19-year-old African-American male with a baseline FVII of 1% with a history of active participation in football without noticeable injury and who underwent an emergent appendectomy without bleeding. These three cases represent individuals with the severe form of FVII deficiency who did not exhibit excessive bleeding when challenged with surgical procedures. The clinical history would appear the most valuable tool in predicting the likelihood of bleeding in these patients, and we suggest that the presumption that all patients with severe FVII deficiency should receive replacement therapy before surgical procedures may not be valid in all cases.

Aortitis as a manifestation of myelodysplastic syndrome

Aortitis is the inflammation of the wall of the aorta and can occur from an infection or autoimmune disease. Myelodysplastic syndrome (MDS) is characterised by abnormal haematopoiesis and a dysfunctional immune system. Autoimmune manifestations have been described in MDS. Here a case of a patient with aortitis and MDS is presented and discussed. All possible aetiologies were ruled out. The patient's symptoms resolved after she received steroids.