Phase Ib Trial of Cabazitaxel and Tasquinimod in Men With Heavily Pretreated Metastatic Castration Resistant Prostate Cancer (mCRPC): The CATCH Trial.

BACKGROUND: Tasquinimod is an immunomodulating and anti-antiangiogenic oral agent with anti-prostate cancer activity in preclinical studies and in clinical trials of men with metastatic castration resistant prostate cancer (mCRPC), including single agent activity and in combination with taxanes. We sought to identify the maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D) of tasquinimod in combination with cabazitaxel and prednisone in men with chemorefractory mCRPC. METHODS: Men with mCRPC who had failed prior docetaxel chemotherapy received cabazitaxel 25 mg/m2 every 3 weeks with oral tasquinimod at 1 of 3 escalating dose levels (0.25, 0.5, and 1.0 mg once daily) with prednisone and PEG-filgastrim support, using a 3 + 3 dose escalation design. Treatment continued until progressive disease or unacceptable toxicity. RESULTS: We enrolled 25 men with chemorefractory mCRPC. The RP2D was 0.5 mg tasquinimod based on excess DLTs (two of three men) observed at dose level 3 (1.0 mg) including grade 3 sensory neuropathy and grade 3 atrial fibrillation. Dose level 2 was expanded to 14 men, where 3 DLTs were observed: grade 3 fatigue, grade 4 febrile neutropenia, and grade 3 liver function abnormalities. The proportion of men with a ≥30% PSA decline was 63% and the median composite progression-free survival (PFS) was 8.5 months (95% CI 4.2-16.4 months) based on 12 PFS events. The median number of cycles of cabazitaxel was 6 (range 1-13), with six men receiving >10 cycles. Best overall RECIST responses (CR + PR) were observed in three men (12%), with stable disease in 12 (48%). No pharmacokinetic interactions were observed. CONCLUSIONS: We determined the RP2D of tasquinimod combined with cabazitaxel to be 0.5 mg daily following a 3 week lead-in of tasquinimod 0.25 mg with growth factor support. No unexpected toxicities occurred. Prostate 77: 385-395, 2017. © 2016 Wiley Periodicals, Inc.

Outcomes of patients with POEMS syndrome treated initially with radiation.

POEMS syndrome is a rare plasma cell dyscrasia presenting with polyneuropathy and other systemic findings. Patients with 1 to 3 bone lesions and negative bone marrows are often treated with involved field radiation therapy as the initial and potentially definitive therapy. Long-term outcomes of patients treated with this approach have not been systematically studied. Of the 146 patients with POEMS syndrome seen at the Mayo Clinic between January 1999 and September 2011, 38 (26%) were given targeted radiation as their initial primary therapy and are the ones studied here. The median number of bone lesions was 1 (range: 1-6). The median dose of radiation administered was 45 Gy (range: 35-54 Gy). Complete or partial hematologic, vascular endothelial growth factor, fluorodeoxyglucose-positron emission tomography, and clinical responses were documented in 31%, 14%, 22%, and 47%, respectively. With median follow-up of 43 months, the 4-year overall survival is 97% and event-free survival is 52%. Risk factors for needing salvage therapy included reduced pulmonary diffusing capacity of carbon monoxide and increased urinary total protein. The presence of 3 lesions compared with 1 or 2 did not increase risk for treatment failure. Among selected patients with POEMS syndrome, radiation produces durable, meaningful responses.

CYTOP® 366: A Tertiary Phosphine Inaccessible by Most Traditional Hydrophosphination Methods.

Homogenous catalysis is an essential tool within the commercial manufacture of bulk and fine chemicals. Within this, phosphine ligands, such as tricyclohexylphosphine, otherwise known as CYTOP® 366, are a crucial component. When designing a pathway to your ligand of choice, some key considerations include safety, yield and quality, but at commercial volumes we must also balance cost and consider the technologies readily available. Herein, we report the synthetic route that was chosen to manufacture tricyclohexylphosphine at commercial scale. We also consider, with the use of computational calculations, why traditional hydrophosphination methods failed, where the selected pathway succeeded.

A phase 2 trial of avelumab in men with aggressive-variant or neuroendocrine prostate cancer.

BACKGROUND: Men with progressive neuroendocrine or aggressive-variant metastatic prostate cancer (NEPC/AVPC) have a poor prognosis and limited treatment options, and immunotherapy has not been tested in such patients. METHODS: We conducted an open label single center phase 2 trial (NCT03179410) of men with progressive NEPC/AVPC either defined by histology or AVPC criteria. Avelumab (10 mg/kg every 2 weeks) was administered until progression or unacceptable toxicity. The primary endpoint was overall response rate (ORR). Secondary endpoints included ORR, radiographic progression-free survival (rPFS), overall survival, and safety. Correlative studies included longitudinal peripheral blood immune phenotyping. The study was limited by the small number of patients enrolled and by the early termination due to COVID-19. RESULTS: A total of 15 men with AVPC/NEPC were enrolled. The median age was 71 (range 51-85 years), and men had received a median of two prior therapies (range 1-3). Median PSA was 54 ng/dl (range 0-393), and 73% of men had liver metastasis. The ORR with avelumab in this setting by iRECIST or RECIST 1.1 was 6.7%, including one patient (6.7%) with a complete remission (CR), 20% with stable disease, and 67% with progressive disease. The patient with the CR had an MSH2 somatic mutation and MSI-high NEPC with central nervous system metastases, and his CR remains durable off all therapy for 2 years. The median rPFS was 1.8 months (95% CI 1.6-3.6 months), and median overall survival was 7.4 months (85% CI 2.8-12.6 months). Safety was consistent with the known profile of avelumab. Phenotyping of peripheral immune subsets suggest enhanced CXCR2-dependent myeloid and T-cell responses in this extraordinary responder. CONCLUSIONS: While the study was terminated early due to slow enrollment at the onset of the COVID-19 pandemic and lower than anticipated objective response rate, PD-L1 inhibition with avelumab monotherapy showed poor efficacy in patients with microsatellite stable NEPC/AVPC. Immune profiling revealed enhanced CXCR2 positive immune cell activation in the one extraordinary responder, suggesting potential mechanisms for further immunotherapy development in this population.

Detecting solvent-driven transitions of poly(A) to double-stranded conformations by atomic force microscopy.

We report the results of direct measurements by atomic force microscopy of solvent-driven structural transitions within polyadenylic acid (poly(A)). Both atomic force microscopy imaging and pulling measurements reveal complex strand arrangements within poly(A) induced by acidic pH conditions, with a clear fraction of double-stranded molecules that increases as pH decreases. Among these complex structures, force spectroscopy identified molecules that, upon stretching, displayed two distinct plateau features in the force-extension curves. These plateaus exhibit transition forces similar to those previously observed in native double-stranded DNA (dsDNA). However, the width of the first plateau in the force-extension curves of poly(A) varies significantly, and on average is shorter than the canonical 70% of initial length corresponding to the B-S transition of dsDNA. Also, similar to findings in dsDNA, stretching and relaxing elasticity profiles of dspoly(A) at forces below the mechanical melting transition overlap but reveal hysteresis when the molecules are stretched above the mechanical melting transition. These results strongly suggest that under acidic pH conditions, poly(A) can form duplexes that are mechanically stable. We hypothesize that under acidic conditions, similar structures may be formed by the cellular poly(A) tails on mRNA.

Clinical utility of FoundationOne tissue molecular profiling in men with metastatic prostate cancer.

PURPOSE: Targeted inhibitors and immunotherapy have entered the treatment landscape of metastatic prostate cancer. Genomic testing may uncover which patients benefit most from these therapies. We report the clinical utility and benefits of FoundationOne testing in men with advanced prostate cancer. PATIENTS AND METHODS: We retrospectively identified all men with prostate cancer who received tissue FoundationOne testing at our institution between January 2010 and April 2017. Genomic alterations, treatment selection based on FoundationOne results, and clinical outcomes including response and duration of therapy following matched targeted therapy were analyzed. RESULTS: A total of 77 men with metastatic prostate cancer were referred for FoundationOne testing; 59 (77%) had sufficient tumor tissue for testing. Of these, 22% (17/77) of men had a targetable mutation and 9% (7/77) of men received matched off-label targeted therapy. Overall, 5% (4/77) of patients derived clinical benefit. One patient with a BRCA2 loss had a complete response on olaparib (>27 months) and 3 patients (ATM substitution, PALB2 frameshift, CDK12 frameshift) had stable disease with olaparib (10.3, 18.7, and 7.8 months, respectively). Three patients (BRCA2 frameshift, PDL1 + PDL2 amplification, PMS2 missense) had progressive disease despite targeted therapy. CONCLUSIONS: Tissue genomic testing can uncover patients who may benefit from targeted therapies such as poly(adenosine diphosphate-ribose) polymerase inhibitors or immunotherapy. In our limited single institution study, genomic testing led to clinical benefit in 5% of patients. Combined germline and circulating tumor DNA testing may be helpful to identify additional patients suitable for matched genomic therapies.

Platinum sensitivity in metastatic prostate cancer: does histology matter?

BACKGROUND: Platinum-based chemotherapy is effective in men with neuroendocrine prostate cancer (NEPC), but it is unclear whether histology (adenocarcinoma vs. non-adenocarcinoma NEPC variants) is predictive of platinum sensitivity. Given that NEPC exists as a spectrum, there may be men with adenocarcinoma who might benefit from platinum chemotherapy, particularly those men with DNA repair defects. METHODS: This was a retrospective study of all of the men seen at Duke University since 2005 who had metastatic castration-resistant prostate cancer (mCRPC) and were treated with a platinum agent. Data surrounding clinical features, histology, imaging, safety, and neuroendocrine transformation were collected. Scans were re-reviewed using RECIST v1.1 criteria to estimate responses as well as calculate radiographic progression-free survival (rPFS). RESULTS: A database search identified 73 men with mCRPC treated with cisplatin, carboplatin, or oxaliplatin. There were three men with primary NEPC and small cell prostate cancer, and 14 with a NEPC transformation. In the first-line setting, 10 (63%) men with NEPC had a partial response (PR) compared with 14 (29%) of the men with adenocarcinoma (p = 0.017), with a median rPFS of 5.1 mo (3.1-7.8) and 4.3 mo (3.0-5.2 mo), respectively. The median overall survival was 8.5 mo (6.4-20.1 mo) for men with NEPC compared to 10.0 mo (8.0-14.4) in men with adenocarcinoma. Prostate-specific antigen (PSA) declines meeting >30%, >50%, and >90% criteria from baseline were observed in 64/57/29% of NEPC patients (n = 14) treated with platinum chemotherapy vs. 48/30/14% of men with prostate adenocarcinoma (n = 50), respectively. CONCLUSIONS: This study suggests that NEPC histology enriches for platinum sensitivity, but that an important minority group (20-30%) of men with adenocarcinoma have a clinical benefit with platinum-based chemotherapy. Molecular predictors, such as germline or somatic mutations in DNA repair enzymes, should be evaluated for platinum responsiveness.

Risk Factors for Readmission in Patients With Cancer Comanaged by Hospitalists.

Little is known about which variables put patients with cancer at risk for 30-day hospital readmission. Comanagement of this often complex patient population by specialists and hospitalists has become increasingly common. This retrospective study examined inpatients with cancer comanaged by hospitalists, hematologists, and oncologists to determine the rate of readmission and factors associated with readmission. Patients in this cohort had a readmission rate of 23%. Patients who were discharged to a skilled nursing facility (odds ratio [OR] = 0.34) or hospice (OR = 0.11) were less likely to have 30-day readmissions, whereas patients who had surgery (OR = 3.16) during their index admission were more likely. Other factors, including patient demographics, cancer types, and hospitalization interventions and events, did not differ between patients who were readmitted and those who were not. These findings contribute to a growing body of literature identifying risk factors for readmission in medical oncology and hematology patients.

Prostate-specific antigen response in black and white patients treated with abiraterone acetate for metastatic castrate-resistant prostate cancer.

PURPOSE: Evidence suggests differences in androgen receptor AR signaling between black (B) and white (W) patients with prostate cancer, but pivotal trials of abiraterone acetate (AA) for patients with metastatic castration-resistant prostate cancer (mCRPC) enrolled few black patients, a population with a higher mortality from prostate cancer. Our primary objective was to determine differences in response to AA between B and W patients. METHODS: We performed a retrospective case-control study of B vs. W patients treated with AA between May 1, 2008 and June 16, 2015 at Duke University Medical Center. Patients were identified (W control patients were matched 2:1 to B patients stratified based on previous docetaxel exposure) through pharmacy records and were eligible if treated with AA for metastatic castration-resistant prostate cancer. Patients with previous enzalutamide use were excluded. The primary objective was to compare the rate of≥90% prostate-specific antigen (PSA) decline from baseline between B vs. W patients. Secondary outcomes included comparing time on therapy, time to PSA progression, and overall survival among groups. RESULTS: Baseline characteristics among patients (n = 45 B, n = 90 W) were identified; these included Karnofsky performance status, PSA, Gleason score, alkaline phosphatase, albumin, hemoglobin, lactate dehydrogenase, opiate use for pain, and metastatic sites. Baseline characteristics among groups were similar except for median hemoglobin (B = 11.4g/dl, W = 12.3g/dl). The proportion of B patients achieving a≥90% PSA level decline was 37.8% vs. 28.9% for W patients (P = 0.296). Statistically significant differences were found in the proportion of patients achieving a≥50% PSA level decline (B = 68.9%, W = 48.9% [P = 0.028]) and≥30% PSA level decline (B = 77.8%, W = 54.4% [P = 0.008]). Rates of primary abiraterone-refractory disease (PSA increase as best response) trended higher in W (31.1%) than in B (15.6%) patients (P = 0.052). Median treatment duration (B = 9.4 mo, W = 8.3 mo) did not differ (Wilcoxon P = 0.444). Median overall survival (B = 27.3 mo [95% CI: 13.9, not estimable], W = 24.8 mo [95% CI: 19, 31.6] [P = 0.669]) and median time to PSA progression (B = 11.0 mo [95% CI: 4.3, 18.0], W = 9.4 mo [95% CI: 6.2, 13.0] [P = 0.917]) did not differ. CONCLUSIONS: Black patients may have a higher PSA response to AA than white patients. An ongoing prospective clinical study (NCT01940276) is evaluating outcomes between black and white patients treated with AA.

Spontaneous complete remission of angioimmunoblastic T-cell lymphoma.

Angioimmunoblastic T-cell lymphoma (AITL) is a rare hematologic neoplasm that typically presents with B symptoms, anemia, and lymphadenopathy. Its overall prognosis is poor, with a 5-year survival rate of 30%. We present a case of AITL that went into spontaneous remission, an uncommon occurrence.

Direct measurements of base stacking interactions in DNA by single-molecule atomic-force spectroscopy.

We investigate the elasticity of two types of single-stranded synthetic DNA homopolydeoxynucletides, poly(dA) and poly(dT), by AFM-based single-molecule force spectroscopy. We find that poly(dT) exhibits the expected entropic elasticity behavior, while poly(dA) unexpectedly displays two overstretching transitions in the force-extension relationship. We suggest that these transitions, which occur at approximately 23 pN and approximately 113 pN, directly capture, for the first time, the mechanical signature of base-stacking interactions among adenines in DNA, in the absence of base pairing.