Purpose The CYP17A1 inhibitor abiraterone markedly reduces androgen precursors and is thereby effective in castration-resistant prostate cancer (CRPC). However, abiraterone increases progesterone, which can activate certain mutant androgen receptors (ARs) identified previously in flutamide-resistant tumors. Therefore, we sought to determine if CYP17A1 inhibitor treatment selects for progesterone activated mutant ARs. Experimental Design AR was examined by targeted sequencing in metastatic tumor biopsies from 18 CRPC patients who were progressing on a CYP17A1 inhibitor (17 on abiraterone, 1 on ketoconazole), alone or in combination with dutasteride, and by whole exome sequencing in residual tumor in one patient treated with neoadjuvant leuprolide plus abiraterone. Results The progesterone-activated T878A mutant AR was present at high allele frequency in 3 of the 18 CRPC cases. It was also present in one focus of resistant tumor in the neoadjuvant treated patient, but not in a second clonally related resistant focus which instead had lost one copy of PTEN and both copies of CHD1. The T878A mutation appeared to be less common in the subset of CRPC patients treated with abiraterone plus dutasteride, and transfection studies showed that dutasteride was a more potent direct antagonist of the T878A versus the wildtype AR. Conclusions These findings indicate that selection for tumor cells expressing progesterone-activated mutant ARs is a mechanism of resistance to CYP17A1 inhibition.

Embedding an oncologist in the ED of an academic medical center did not significantly reduce hospital admissions. Novel approaches are needed to strengthen outpatient acute care for patients with cancer.

No abstract

2071 Background: Publication of clinical trial results in peer reviewed literature is essential to inform clinicians regarding the use of new anti-cancer treatments, which often have a low therapeutic ratio and require careful assessment of risks and benefits. Publication of registration trials should precede FDA approval to facilitate evaluation and implementation of new therapies. The timing of trial publication relative to FDA drug approvals has not been systematically investigated. Methods: We collected all FDA drug approvals for a cancer indication between 2000-19. Trials were identified using FDA labels as well as drugs and publications indexed on HemOnc.org. Approvals for generics/biosimilars, non-oncology indications and label revisions without supportive evidence were excluded. Dates of approval, the approval pathway, approval type (new vs expansion), and the first full publication related to the registration were recorded. Trials and approvals were matched using available metadata. We calculated the proportion of drugs approved prior to publication overall and for those receiving accelerated approval (AA). We used logistic regression to compare rates of pre-publication approval by approval pathway and by new vs expanded approval. Results: Among a total of 378 drug approvals, 139 (37%) had pre-publication approval. Of these, the median overall time from approval to publication was 140 days (IQR 64-281 days). For those with approval after publication, median time from publication to approval was 157 days (IQR 72-359 days). The number of drugs approved pre-publication rose by 27% between the first and last quarters of the study period, though, the proportion decreased as more anti-cancer drugs have been approved in recent years (Table). More drugs were approved pre-publication through AA than regular approval (46% vs 34%, OR 1.66 [95% CI 1.03-2.70], p=0.04) and as new approvals vs. expanded approvals (45% vs 32%, OR 1.76 [95% CI 1.15-2.70], p=0.01). Conclusions: A substantial minority of FDA approvals occur before trial results are published, with the odds being higher for drugs receiving AA and for new approvals. Since clinicians rely upon published results to inform risk/benefit decisions, efforts are needed to ensure trial results are published by the time of FDA approval of new cancer drugs and indications. [Table: see text]

No abstract

Clinical trials establish the standard of cancer care, yet the evolution and characteristics of the social dynamics between the people conducting this work remain understudied. We performed a social network analysis of authors publishing chemotherapy-based prospective trials from 1946 to 2018 to understand how social influences, including the role of gender, have influenced the growth and development of this network, which has expanded exponentially from fewer than 50 authors in 1946 to 29,197 in 2018. While 99.4% of authors were directly or indirectly connected by 2018, our results indicate a tendency to predominantly connect with others in the same or similar fields, as well as an increasing disparity in author impact and number of connections. Scale-free effects were evident, with small numbers of individuals having disproportionate impact. Women were under-represented and likelier to have lower impact, shorter productive periods (P < 0.001 for both comparisons), less centrality, and a greater proportion of co-authors in their same subspecialty. The past 30 years were characterized by a trend towards increased authorship by women, with new author parity anticipated in 2032. The network of cancer clinical trialists is best characterized as strategic or mixed-motive, with cooperative and competitive elements influencing its appearance. Network effects such as low centrality, which may limit access to high-profile individuals, likely contribute to the observed disparities.

Background: Clinical trials establish the standard of care for cancer and other diseases. While social network analysis has been applied to basic sciences, the social component of clinical trial research is not well characterized. We examined the social network of cancer clinical trialists and its dynamic development over more than 70 years, including the roles of subspecialization and gender in relation to traditional and network-based metrics of productivity. Methods: We conducted a social network analysis of authors publishing chemotherapy-based prospective trials from 1946-2018, based on the curated knowledge base HemOnc.org, examining: 1) network density; 2) modularity; 3) assortativity; 4) betweenness centrality; 5) PageRank; and 6) the proportion of co-authors sharing the same primary cancer subspecialty designation. Individual author impact and productive period were analyzed as a function of gender and subspecialty. Findings: From 1946-2018, the network grew to 29,197 authors and 697,084 co-authors. While 99.4% of authors were directly or indirectly connected as of 2018, the network had very few connections and was very siloed by cancer subspecialty. Small numbers of individuals were highly connected and had disproportionate impact (scale-free effects). Women were under-represented and likelier to have lower impact, shorter productive periods (P<0.001 for both comparisons), less centrality, and a greater proportion of co-authors in their same subspecialty. The past 30 years were characterized by a trend towards increased authorship by women, with new author parity anticipated in 2032. However, women remain a distinct minority of first/last authors, with parity not anticipated for 50+ years. Interpretation: The network of cancer clinical trialists is best characterized as a strategic or "mixed-motive" network, with cooperative and competitive elements influencing its appearance. Network effects e.g., low centrality, which may limit access to high-profile individuals, likely contribute to ongoing disparities. Funding: Vanderbilt Initiative for Interdisciplinary Research; National Institutes of Health; National Science Foundation

<p>Supplementary Figure S4. AR antagonist activities of dutasteride versus bicalutamide in LAPC4 cells.</p>