Biomarkers of pembrolizumab efficacy in advanced anal squamous cell carcinoma: analysis of a phase II clinical trial and a cohort of long-term responders

BACKGROUND

Recent trials suggest that programmed cell death 1 (PD-1)-directed immunotherapy may be beneficial for some patients with anal squamous cell carcinoma and biomarkers predictive of response are greatly needed.

METHODS

This multicenter phase II clinical trial (NCT02919969) enrolled patients with metastatic or locally advanced incurable anal squamous cell carcinoma (n=32). Patients received pembrolizumab 200 mg every 3 weeks. The primary endpoint of the trial was objective response rate (ORR). Exploratory objectives included analysis of potential predictive biomarkers including assessment of tumor-associated immune cell populations with multichannel immunofluorescence and analysis of circulating tumor tissue modified viral-human papillomavirus DNA (TTMV-HPV DNA) using serially collected blood samples. To characterize the clinical features of long-term responders, we combined data from our prospective trial with a retrospective cohort of patients with anal cancer treated with anti-PD-1 immunotherapy (n=18).

RESULTS

In the phase II study, the ORR to pembrolizumab monotherapy was 9.4% and the median progression-free survival was 2.2 months. Despite the high level of HPV positivity observed with circulating TTMV-HPV DNA testing, the majority of patients had low levels of tumor-associated CD8+PD-1+ T cells on pretreatment biopsy. Patients who benefited from pembrolizumab had decreasing TTMV-HPV DNA scores and a complete responder's TTMV-HPV DNA became undetectable. Long-term pembrolizumab responses were observed in one patient from the trial (5.3 years) and three patients (2.5, 6, and 8 years) from the retrospective cohort. Long-term responders had HPV-positive tumors, lacked liver metastases, and achieved a radiological complete response.

CONCLUSIONS

Pembrolizumab has durable efficacy in a rare subset of anal cancers. However, despite persistence of HPV infection, indicated by circulating HPV DNA, most advanced anal cancers have low numbers of tumor-associated CD8+PD-1+ T cells and are resistant to pembrolizumab.

A Phase I Expansion Cohort Study Evaluating the Safety and Efficacy of the CHK1 Inhibitor LY2880070 with Low-dose Gemcitabine in Patients with Metastatic Pancreatic Adenocarcinoma

PURPOSE

Combining gemcitabine with CHK1 inhibition has shown promise in preclinical models of pancreatic ductal adenocarcinoma (PDAC). Here, we report the findings from a phase I expansion cohort study (NCT02632448) investigating low-dose gemcitabine combined with the CHK1 inhibitor LY2880070 in patients with previously treated advanced PDAC.

PATIENTS AND METHODS

Patients with metastatic PDAC were treated with gemcitabine intravenously at 100 mg/m2 on days 1, 8, and 15, and LY2880070 50 mg orally twice daily on days 2-6, 9-13, and 16-20 of each 21-day cycle. Pretreatment tumor biopsies were obtained from each patient for correlative studies and generation of organoid cultures for drug sensitivity testing and biomarker analyses.

RESULTS

Eleven patients with PDAC were enrolled in the expansion cohort between August 27, 2020 and July 30, 2021. Four patients (36%) experienced drug-related grade 3 adverse events. No objective radiologic responses were observed, and all patients discontinued the trial by 3.2 months. In contrast to the lack of efficacy observed in patients, organoid cultures derived from biopsies procured from two patients demonstrated strong sensitivity to the gemcitabine/LY2880070 combination and showed treatment-induced upregulation of replication stress and DNA damage biomarkers, including pKAP1, pRPA32, and γH2AX, as well as induction of replication fork instability.

CONCLUSIONS

No evidence of clinical activity was observed for combined low-dose gemcitabine and LY2880070 in this treatment-refractory PDAC cohort. However, the gemcitabine/LY2880070 combination showed in vitro efficacy, suggesting that drug sensitivity for this combination in organoid cultures may not predict clinical benefit in patients.

CT vs. MRI: Which is More Accurate in Grading Rectal Wall Infiltration after Hydrogel Spacer Placement for Prostate Cancer Patients?

PURPOSE/OBJECTIVE(S)

The purpose of this study was to evaluate the incidence and severity of rectal wall infiltration (RWI) in prostate cancer patients after rectal hydrogel spacer implantation, a commonly used procedure to minimize rectal radiation exposure during prostate radiotherapy. The study aimed to determine correlation of RWI using computed tomography (CT) scans and magnetic resonance imaging (MRI) scans in order to determine the optimal post-placement imaging modality.

MATERIALS/METHODS

This retrospective study was conducted on 370 patients diagnosed with localized prostate cancer who underwent rectal hydrogel spacer placement from 2020 to 2022. CT scans were performed on all patients, with a smaller subset also undergoing MRI scans. The images were independently evaluated by three radiation oncologists to grade RWI levels using a standardized scoring system based on CT and MRI images after hydrogel placement. The levels were categorized as 0 (no RWI), 1 (focal RWI), 2 (moderate RWI), and 3 (significant RWI).

RESULTS

Any grade of RWI was identified in 79.8% of men with the majority (41%) being RWI grade 1. The median time for CT scans was 9 days after hydrogel spacer placement and 14.5 days for MRI scans. For the subset of patients with both CT and MRI scans after spacer (mostly SpaceOAR Vue), RWI was detected in 58.33% of patients based on CT and 61.11% of patients based on MRI. Table 1 shows the mean percentage of patients with each score of RWI for each imaging modality. MRI was more likely to lead to a designation of RWI of any grade compared to CT and more often led to detection of RWI grades 2-3.

CONCLUSION

Our findings demonstrate that the incidence and severity of RWI may be higher than previously reported in clinical trials and that MRI may be a more sensitive imaging modality. Caution is needed in the utilization of rectal spacer gels given the potential for complications with misplacement prior to radiation therapy. Further study is warranted to determine the potential impact of low-grade RWI on the safety of subsequent treatment.

Highly Sensitive Circulating Tumor DNA Assay Aids Clinical Management of Radiographically Occult Isolated Peritoneal Metastases in Patients With GI Cancer

PURPOSE

GI cancers commonly spread to the peritoneal cavity, particularly from primary adenocarcinomas of the stomach and appendix. Peritoneal metastases are difficult to visualize on cross-sectional imaging and cause substantial morbidity and mortality. The purpose of this study was to determine whether serial highly sensitive tumor-informed circulating tumor DNA (ctDNA) measurements could longitudinally track changes in disease burden and inform clinical care.

METHODS

This was a retrospective case series of patients with gastric or appendiceal adenocarcinoma and isolated peritoneal disease that was radiographically occult. Patients underwent quantitative tumor-informed ctDNA testing (Signatera) as part of routine clinical care. No interventions were prespecified based on ctDNA results.

RESULTS

Of 13 patients studied, the median age was 65 (range, 45-75) years, with 7 (54%) women, 5 (38%) patients with gastric, and 8 (62%) patients with appendiceal adenocarcinoma. Eight (62%) patients had detectable ctDNA at baseline measurement, with median value 0.13 MTM/mL (range, 0.06-11.68), and assay was technically unsuccessful in two cases with appendiceal cancer because of limited tumor tissue. Five (100%) patients with gastric cancer and 3 (50%) patients with appendiceal cancer had detectable ctDNA at baseline. Although baseline levels of ctDNA were low, longitudinal assessment tracked with changes in disease burden among patients undergoing chemotherapy for metastatic disease. In two patients undergoing surveillance after definitive surgical management of gastric adenocarcinoma, detection of ctDNA prompted diagnosis of isolated peritoneal disease.

CONCLUSION

Quantitative tumor-informed serial ctDNA testing aids clinical management of patients with isolated peritoneal disease. Low levels of baseline ctDNA suggest a role for highly sensitive ctDNA approaches over panel-based testing. Further exploration of this approach should be considered in patients with isolated peritoneal malignant disease.

G-CSF rescue of FOLFIRINOX-induced neutropenia leads to systemic immune suppression in mice and humans

BACKGROUND

Recombinant granulocyte colony-stimulating factor (G-CSF) is routinely administered for prophylaxis or treatment of chemotherapy-induced neutropenia. Chronic myelopoiesis and granulopoiesis in patients with cancer has been shown to induce immature monocytes and neutrophils that contribute to both systemic and local immunosuppression in the tumor microenvironment. The effect of recombinant G-CSF (pegfilgrastim or filgrastim) on the production of myeloid-derived suppressive cells is unknown. Here we examined patients with pancreatic cancer, a disease known to induce myeloid-derived suppressor cells (MDSCs), and for which pegfilgrastim is routinely administered concurrently with FOLFIRINOX but not with gemcitabine-based chemotherapy regimens.

METHODS

Serial blood was collected from patients with pancreatic ductal adenocarcinoma newly starting on FOLFIRINOX or gemcitabine/n(ab)paclitaxel combination chemotherapy regimens. Neutrophil and monocyte frequencies were determined by flow cytometry from whole blood and peripheral blood mononuclear cell fractions. Serum cytokines were evaluated pretreatment and on-treatment. Patient serum was used in vitro to differentiate healthy donor monocytes to MDSCs as measured by downregulation of major histocompatibility complex II (HLA-DR) and the ability to suppress T-cell proliferation in vitro. C57BL/6 female mice with pancreatic tumors were treated with FOLFIRINOX with or without recombinant G-CSF to directly assess the role of G-CSF on induction of immunosuppressive neutrophils.

RESULTS

Patients receiving FOLFIRINOX with pegfilgrastim had increased serum G-CSF that correlated with an induction of granulocytic MDSCs. This increase was not observed in patients receiving gemcitabine/n(ab)paclitaxel without pegfilgrastim. Interleukin-18 also significantly increased in serum on FOLFIRINOX treatment. Patient serum could induce MDSCs as determined by in vitro functional assays, and this suppressive effect increased with on-treatment serum. Induction of MDSCs in vitro could be recapitulated by addition of recombinant G-CSF to healthy serum, indicating that G-CSF is sufficient for MDSC differentiation. In mice, neutrophils isolated from spleen of G-CSF-treated mice were significantly more capable of suppressing T-cell proliferation.

CONCLUSIONS

Pegfilgrastim use contributes to immune suppression in both humans and mice with pancreatic cancer. These results suggest that use of recombinant G-CSF as supportive care, while critically important for mitigating neutropenia, may complicate efforts to induce antitumor immunity.

Spontaneous tumor regression mediated by human T cells in a humanized immune system mouse model

Immunodeficient mice reconstituted with a human immune system (HIS mice) give rise to human T cells, which make them an attractive system to study human immune responses to tumors. However, such HIS mice typically exhibit sub-optimal responses to immune challenges as well as fail to develop antigen-specific B or T cell memory. Here we report HIS mice mediate spontaneous regression of human B cell lymphoma Raji. Tumor regression was dependent on CD4+ and CD8+ T cell responses and resulted in T cell memory. The T cell memory elicited was mainly Raji-specific, however some level of cross-protection was also elicited to a related B cell lymphoma cell line Ramos. Single-cell RNAseq analysis indicated activation of CD8+ T cells in regressing Raji tumors as well as clonal expansion of specific T cell receptors (TCRs). Cloning of TCRs from Raji-infiltrating T cells into a Jurkat reporter cell line showed reactivity specific for Raji tumor cells. Overall, we report a platform for studying in vivo human T cell tumor immunity by highlighting spontaneous Raji tumor regression, clonal TCR expansion, and T cell memory in HIS mice.

Programmatic Precision Oncology Decision Support for Patients With Gastrointestinal Cancer

PURPOSE

With the growing number of available targeted therapeutics and molecular biomarkers, the optimal care of patients with cancer now depends on a comprehensive understanding of the rapidly evolving landscape of precision oncology, which can be challenging for oncologists to navigate alone.

METHODS

We developed and implemented a precision oncology decision support system, GI TARGET, (Gastrointestinal Treatment Assistance Regarding Genomic Evaluation of Tumors) within the Gastrointestinal Cancer Center at the Dana-Farber Cancer Institute. With a multidisciplinary team, we systematically reviewed tumor molecular profiling for GI tumors and provided molecularly informed clinical recommendations, which included identifying appropriate clinical trials aided by the computational matching platform MatchMiner, suggesting targeted therapy options on or off the US Food and Drug Administration-approved label, and consideration of additional or orthogonal molecular testing.

RESULTS

We reviewed genomic data and provided clinical recommendations for 506 patients with GI cancer who underwent tumor molecular profiling between January and June 2019 and determined follow-up using the electronic health record. Summary reports were provided to 19 medical oncologists for patients with colorectal (n = 198, 39%), pancreatic (n = 124, 24%), esophagogastric (n = 67, 13%), biliary (n = 40, 8%), and other GI cancers. We recommended ≥ 1 precision medicine clinical trial for 80% (406 of 506) of patients, leading to 24 enrollments. We recommended on-label and off-label targeted therapies for 6% (28 of 506) and 25% (125 of 506) of patients, respectively. Recommendations for additional or orthogonal testing were made for 42% (211 of 506) of patients.

CONCLUSION

The integration of precision medicine in routine cancer care through a dedicated multidisciplinary molecular tumor board is scalable and sustainable, and implementation of precision oncology recommendations has clinical utility for patients with cancer.

Is Substantial Lymphovascular Space Invasion Prognostic for Clinical Outcomes in Type II Endometrial Cancer?

AIMS

Substantial lymphovascular space invasion (LVSI) compared with none or focal LVSI is predictive of lymph node involvement and worse clinical outcomes in endometrioid-type endometrial carcinoma. We aimed to quantify the incidence of substantial LVSI in type II (clear cell and serous) endometrial cancer and correlate the extent of LVSI with clinical outcomes.

MATERIALS AND METHODS

A retrospective review was conducted on type II endometrial cancer patients who underwent surgical management from July 2017 to December 2019 using the three-tier LVSI scoring system. Binary logistic regression and Cox regression were used to analyse predictors of lymph node involvement or survival outcomes, respectively. The Kaplan-Meier method and Log-rank test were used to analyse differences in locoregional disease-free survival (LR-DFS), distant metastasis disease-free survival (DM-DFS) and overall survival between patients with substantial versus none/focal LVSI.

RESULTS

In 79 patients with type II endometrial carcinoma, no LVSI, focal LVSI and substantial LVSI was present in 48.1%, 15.2% and 36.7% of patients, respectively. Lymph nodes were involved in 0.0% with no LVSI, 20.0% with focal LVSI and 60.0% with substantial LVSI (P < 0.001). The median follow-up was 22.2 months. In patients with none/focal versus substantial LVSI, the 2-year LR-DFS and DM-DFS rates were 91.5% versus 71.4% (P = 0.01) and 90.2% versus 63.8% (P = 0.005), respectively. On univariate analysis, myometrial invasion ≥50%, tumour size ≥3.6 cm, substantial versus none/focal LVSI, lymph node involvement and omission of adjuvant radiotherapy were significant predictors for worse LR-DFS and DM-DFS (P < 0.05).

DISCUSSION

Substantial LVSI has a high incidence in type II pathology at our institution and predicts for lymph node involvement and worse clinical outcomes.

Comprehensive genomic profiling in advanced/metastatic colorectal cancer: number needed to test and budget impact of expanded first line use

AIMS

Use of comprehensive genomic profiling (CGP) in metastatic colorectal cancer (mCRC) is limited. We estimated impacts of expanded 1 L CGP, using the Tempus xT test, on detection of actionable alterations and testing budgets in a modeled US health plan over two-years.

MATERIALS AND METHODS

A decision analytic model was developed to estimate the impact of replacing 20% of usual testing (a mix of CGP and non-CGP) with Tempus xT CGP. Actionable alterations for matched treatments or clinical trial included KRAS, NRAS, RAF, BRAF, deficient mismatch repair (dMMR)/microsatellite instability (MSI), NTRK, RET, EGFR, HER2, MET, PIK3CA and POLE1. Costs included initial and repeat testing, physician-associated and administrative costs.

RESULTS

In a hypothetical five-million-member plan, 50% Medicare and 50% commercial, 1,112 new cases of mCRC were expected per year. Of these, 566 (51%) would undergo 1 L molecular testing, with 55 re-tested upon progression. Based on current testing rates, there were an expected 521 missed opportunities for genomically informed treatment (47% of new cases), with 442 missed due to lack of testing and 79 due to testing without CGP. Replacing 20% of usual testing with Tempus xT CGP was associated with up to a $0.003 per member per month testing cost increase (net total cost of $202,102 for the five-million-member plan) and 15.5 additional patients with an opportunity for genomically informed care (12.7 patients for treatment and 2.8 for clinical trial). The testing total cost (initial test, repeat test, biopsy and physician services, and administrative cost) to put one additional patient with mCRC on matched therapy or matched clinical trial was estimated to be $13,005. Number needed to test to identify one actionable alteration with Tempus xT CGP versus usual testing was 7.8 patients.

LIMITATIONS

Conservative assumptions were made for inputs with limited evidence. Based on high concordance rates with dMMR/MSI status, tumor mutational burden (TMB) status was not calculated separately.

CONCLUSIONS

Replacing 20% of usual testing with Tempus xT CGP was associated with a small incremental testing cost and can identify meaningfully more actionable alterations.

Multicenter randomized phase II trial of atezolizumab with or without cobimetinib in biliary tract cancers

BACKGROUNDMEK inhibitors have limited activity in biliary tract cancers (BTCs) as monotherapy but are hypothesized to enhance responses to programmed death ligand 1 (PD-L1) inhibition.METHODSThis open-label phase II study randomized patients with BTC to atezolizumab (anti-PD-L1) as monotherapy or in combination with cobimetinib (MEK inhibitor). Eligible patients had unresectable BTC with 1 to 2 lines of prior therapy in the metastatic setting, measurable disease, and Eastern Cooperative Oncology Group (ECOG) performance status less than or equal to 1. The primary endpoint was progression-free survival (PFS).RESULTSSeventy-seven patients were randomized and received study therapy. The trial met its primary endpoint, with a median PFS of 3.65 months in the combination arm versus 1.87 months in the monotherapy arm (HR 0.58, 90% CI 0.35-0.93, 1-tail P = 0.027). One patient in the combination arm (3.3%) and 1 patient in the monotherapy arm (2.8%) had a partial response. Combination therapy was associated with more rash, gastrointestinal events, CPK elevations, and thrombocytopenia. Exploratory analysis of tumor biopsies revealed enhanced expression of antigen processing and presentation genes and an increase in CD8/FoxP3 ratios with combination treatment. Patients with higher baseline or lower fold changes in expression of certain inhibitory ligands (LAG3, BTLA, VISTA) on circulating T cells had evidence of greater clinical benefit from the combination.CONCLUSIONThe combination of atezolizumab plus cobimetinib prolonged PFS as compared with atezolizumab monotherapy, but the low response rate in both arms highlights the immune-resistant nature of BTCs.TRIAL REGISTRATIONClinicalTrials.gov NCT03201458.FUNDINGNational Cancer Institute (NCI) Experimental Therapeutics Clinical Trials Network (ETCTN); F. Hoffmann-La Roche, Ltd.; NCI, NIH (R01 CA228414-01 and UM1CA186691); NCI's Specialized Program of Research Excellence (SPORE) in Gastrointestinal Cancers (P50 CA062924); NIH Center Core Grant (P30 CA006973); and the Passano Foundation.

Phase II study of pembrolizumab in refractory esophageal cancer with correlates of response and survival

BACKGROUND

Immune checkpoint inhibitors have revolutionized cancer treatment, but the benefits in refractory patients with esophageal cancer have been modest. Predictors of response as well as new targets for novel therapeutic combinations are needed. In this phase 2 clinical trial, we tested single-agent pembrolizumab in patients with advanced esophageal cancer, who received at least one prior line of therapy.

METHODS

Pembrolizumab 200 mg every 3 weeks was tested in 49 patients with refractory esophageal cancer: 39 with adenocarcinoma and 10 with esophageal squamous cell carcinoma. Major endpoints were radiological response by Immune-related Response Evaluation Criteria In Solid Tumors and survival. Tumor samples were evaluated for programmed cell death ligand 1 (PD-L1) expression, tumor mutational burden (TMB), and immune contexture by both NanoString mRNA expression analysis and flow cytometry. Peripheral blood mononuclear cells and a panel of circulating chemokines were also analyzed.

RESULTS

The overall response rate (ORR) was 8% (4 of 49 patients; 95% CI 2.3% to 19.6%). Median overall survival (OS) was 5.8 months (95% CI 4.0 to 9.5). ORR and OS were not associated with histology. For PD-L1-positive patients, ORR was 13.3% (95% CI 1.7% to 40.5%) and median OS was 7.9 months (95% CI 4.7 to 15.5). A trend toward improved OS was observed in seven patients with a TMB ≥10 mut/Mb (p=0.086). Tumors with a PD-L1 Combined Positive Score ≥1 showed enrichment of LAG3 (p=0.005) and IDO1 (p=0.04) gene expression. Baseline levels of circulating CXCL10, interleukin 2 (IL2) receptor α (IL2RA) and IL6 were associated with survival: CXCL10 favorably, (HR 0.37, p=0.002 (progression-free survival); HR 0.55, p=0.018 (OS)); IL2RA and IL6 unfavorably (HR 1.57, p=0.020 for IL6 (OS); HR 2.36, p=0.025 for IL2RA (OS)).

CONCLUSIONS

Pembrolizumab monotherapy was modestly effective in refractory esophageal cancer. Circulating CXCL10 at baseline appeared to be a robust predictor of response. Other T cell exhaustion markers are upregulated in PD-L1-positive patients, suggesting that immunotherapy combinations such as anti-LAG3/programmed cell death protein 1 (PD-1) or anti-IDO1/PD-1 may be of promise in refractory esophageal cancer.

Trifluridine/Tipiracil and Regorafenib in Patients with Metastatic Colorectal Cancer: A Retrospective Study at a Tertiary Oncology Center

BACKGROUND

Trifluridine/tipiracil (FTD/TPI) and regorafenib prolong survival for patients with refractory metastatic colorectal cancer (mCRC); limited comparative effectiveness data exist.

MATERIALS AND METHODS

A retrospective, longitudinal cohort study of patients with mCRC who initiated FTD/TPI or regorafenib (index therapy) between 2012 and 2017 at a U.S. tertiary oncology center, Dana-Farber Cancer Institute, was conducted. Using best tumor response assessments, real-world overall response rates (rwORR) and disease control rates (rwDCR) were described and analyzed using logistic regression. Survival rate was examined for each month after index therapy using Kaplan-Meier. Overall survival (OS) was assessed using Cox proportional hazards models. Subgroup analyses among patients with index therapy as second- or third-line were performed.

RESULTS

One hundred twenty-six and 95 patients were treated with FTD/TPI or regorafenib as index therapy, respectively. Patients treated with FTD/TPI versus regorafenib had a better response (rwORR 52.5% vs. 34.2%; adjusted odds ratio [OR] = 2.6; all p value <.05; rwDCR 64.2% vs. 46.1%; adjusted OR = 2.5; all p value <.05). Similar findings were observed for FTD/TPI versus regorafenib as second- or third-line therapy (rwORR 54.8% vs. 25.9%; adjusted OR = 4.1; all p value <.05; rwDCR 69.0% vs. 37.0%; adjusted OR = 4.9; all p value <.05). A greater proportion of patients treated with FTD/TPI versus regorafenib survived at 3 months (86.2% vs. 73.4%; p value = .016) and 4 months (79.6% vs. 65.8%; p value = .017). Adjusted OS hazard ratio for FTD/TPI versus regorafenib was 0.80, p value = .157.

CONCLUSION

Patients treated with FTD/TPI had better tumor response and disease control than patients treated with regorafenib. Subgroup analysis in second- or third-line suggests that early use of FTD/TPI may have clinical benefits.

IMPLICATIONS FOR PRACTICE

In this retrospective cohort study, patients with refractory metastatic colorectal cancer treated with trifluridine/tipiracil (FTD/TPI) were significantly less likely than those treated with regorafenib to have dose modifications and more likely to have higher real-world objective response rate (rwORR) and real-world disease control rate (rwDCR) while treated. Patients treated with FTD/TPI versus regorafenib had significantly higher odds of having rwORR or rwDCR in adjusted analyses. Monthly survival rates were higher overall in patients treated with FTD/TPI versus regorafenib in the first 6 months of follow-up, particularly at months 3 and 4. This study offers insight into patients' treatment experience in real-world clinical settings.

Comprehensive genomic profiling in advanced/metastatic colorectal cancer: Number needed to test and budget impact of expanded first-line use

e18834

Background: A growing number of genomic alterations inform treatment of advanced/metastatic colorectal cancer (mCRC). However, use of comprehensive genomic profiling (CGP) is limited in the first-line (1L) setting. Based on the Tempus xT next-generation sequencing assay, we estimated the impact of expanded 1L CGP on the detection of currently actionable alterations in mCRC and associated diagnostic testing costs in a modeled US health plan setting. Methods: A decision analytic model was used to compare testing scenarios over a two-year time horizon: current 1L testing with a mix of CGP and non-CGP diagnostics vs. replacing 20% of usual testing with Tempus CGP. The incidence of 1L mCRC, current testing rates, prevalence of actionable alterations, and test sensitivity were drawn from a literature review and clinical expert input. Currently actionable alterations included KRAS, NRAS, RAF, BRAF, dMMR/MSI, NTRK, RET, EGFR, HER2, MET, PIK3CA and POLE1. Cost components included initial and repeat testing, physician-associated and administrative costs. Opportunities for genomically-informed therapy or clinical trials were assessed under each testing scenario. A forward looking scenario, with additional informative alterations, was also explored. Results: In a hypothetical five million-member health plan, with 50% Medicare and 50% commercial insurance, 1,112 incident cases of mCRC (22 per 100,000 patients) are expected in a typical year. Among these cases, 566 (51%) are expected to undergo 1L molecular diagnostic testing, with 55 projected to undergo repeat testing upon progression within the next year. Based on current real-world testing rates, there are an expected 521 missed opportunities for genomically informed treatment (47% of the incident mCRC population), with 442 missed due to lack of testing and 79 due to testing without CGP. Replacing 20% of usual testing with Tempus CGP in the modeled scenario was associated with up to a $0.003 per member per month (PMPM) testing cost increase and an additional 15.5 patients with an opportunity for genomically-informed care (12.7 patients for guideline-recommended treatment and 2.8 for a clinical trial). The number needed to test (NNT) with Tempus CGP versus the usual mix of testing was 7.8 1L patients to identify one actionable alteration. Scenario analyses projecting the advent of additional genomically-informed treatments and clinical trials resulted in smaller numbers needed to test. Conclusions: Replacing 20% of usual testing with Tempus CGP is associated with a small incremental testing cost but can identify actionable alterations for a meaningful number of patients. For every eight 1L mCRC patients tested with Tempus CGP rather than the usual mix of molecular testing, one additional patient is expected to be identified as having currently actionable alterations.

FGFR2 Extracellular Domain In-Frame Deletions are Therapeutically Targetable Genomic Alterations that Function as Oncogenic Drivers in Cholangiocarcinoma

We conducted next generation DNA sequencing on 335 biliary tract cancers and characterized the genomic landscape by anatomic site within the biliary tree. In addition to frequent FGFR2 fusions among patients with intrahepatic cholangiocarcinoma (IHCC), we identified FGFR2 extracellular domain in-frame deletions (EIDs) in 5 of 178 (2.8%) patients with IHCC, including two patients with FGFR2 p.H167_N173del. Expression of this FGFR2 EID in NIH3T3 cells resulted in constitutive FGFR2 activation, oncogenic transformation, and sensitivity to FGFR inhibitors. Three patients with FGFR2 EIDs were treated with Debio 1347, an oral FGFR-1/2/3 inhibitor, and all showed partial responses. One patient developed an acquired L618F FGFR2 kinase domain mutation at disease progression and experienced a further partial response for 17 months to an irreversible FGFR2 inhibitor, futibatinib. Together, these findings reveal FGFR2 EIDs as an alternative mechanism of FGFR2 activation in IHCC that predict sensitivity to FGFR inhibitors in the clinic.

9-Arylimino noscapinoids as potent tubulin binding anticancer agent: chemical synthesis and cellular evaluation against breast tumour cells

A library of 9-arylimino derivatives of noscapine was developed by coupling of Schiff base containing imine groups. Virtual screening using molecular docking with tubulin revealed three molecules, 12-14 that bind with high affinity. An improved predicted free energy of binding (FEB) of -5.390, -6.506 and -6.679 kcal/mol for the molecules 12-14 was found compared to noscapine (-5.135 kcal/mol). Furthermore, molecular dynamics simulation in combination with Molecular Mechanics Poisson-Boltzmann Surface Area (MM-PBSA) revealed robust binding free energy of -166.03, -169.75 and -170.63 kcal/mol for the molecules 12, 13 and 14, respectively. These derivatives were strategically synthesized and experimentally validated for their anticancer activity. Tubulin binding assay revealed substantial binding of molecules 12-14 with purified tubulin. Further, their anticancer activity was demonstrated using two cancer cell lines (MCF-7 and MDAMB-231) and a panel of primary breast tumour cells. All these derivatives inhibited cellular proliferation in all the cancer cells that ranged between 30.1 and 5.8 µM, which is 1.7 to 7.52 fold lower than that of noscapine. Further, these novel derivatives arrest cell cycle in the G2/M-phase followed by induction of apoptosis. Thus, 9-arylimino noscapinoids 12-14 have a great potential to be a novel therapeutic agent for breast cancers.

Early outcomes after definitive chemoradiation therapy with Vienna/Venezia hybrid high-dose rate brachytherapy applicators for cervical cancer: A single-institution experience

PURPOSE

The Vienna and Venezia (Elekta) are hybrid intracavitary/interstitial brachytherapy (BT) applicators for cervical cancers unsuitable for intracavitary BT alone to improve target coverage or reduce critical organ dose. There is limited outcome data with the use of these applicators outside published experience of the EMBRACE group. We report feasibility and early outcomes with the use of these hybrid applicators at our institution.

METHODS AND MATERIALS

Hybrid applicators were used to treat 61 patients with cervical cancer from November 2011 to December 2019. Indications for hybrid applicator use were involvement of the vagina in 10 patients (16%), residual central or parametrial disease in 46 patients (75%), and a narrow introitus in 5 patients (9%). Toxicities were graded using the CTCAE v4.0. Outcomes were assessed with the Kaplan-Meier method.

RESULTS

Median follow-up was 16 months (IQR 9-32 mos). Median HRCTV volume was 31.6 cm³ (IQR 25-48 cm³). Median HRCTV D90 was 86.1 Gy (IQR 84.3-88.0 Gy). In 54 patients with follow-up PET/CT at 3 months, complete initial imaging response locally was seen in 46 patients.Estimated 12-month Kaplan-Meier overall survival, locoregional control, distant control, and recurrence-free survival estimates were 86.9%, 80.6%, 73.8%, and 65.9%, respectively. The 12-month incidence of Grade 3+ GI/GU chronic toxicities was 5.7%, consisting of vesicovaginal fistula, rectovaginal fistula, and ureterovesical fistula.

CONCLUSIONS

Our single-institution data support the use of the hybrid applicators, as an alternative to traditional BT applicators when clinically warranted. Use of hybrid applicators is feasible with adequate coverage of disease in the vagina and parametrium.

Abstract 1097: FGFR2 in-frame indels: A novel targetable alteration in intrahepatic cholangiocarcinoma

Biliary cancers include intrahepatic cholangiocarcinoma (IHCC), extrahepatic cholangiocarcinoma (EHCC), and gallbladder cancer (GBC). These cancers are clinically, pathologically, and biologically heterogeneous, but are all aggressive with poor prognosis and few available therapies. Potentially actionable genomic alterations described to date include IDH1 mutations, FGFR2 fusions, BRAF V600E mutations, HER2 amplification/mutation, and BRCA1/2 mutations. FGFR inhibitors have demonstrated encouraging efficacy in patients with FGFR2 oncogenic fusions; however, the efficacy of these inhibitors in patients with other types of FGFR alterations is less clear.

We analyzed somatic alterations in 272 patients with biliary cancers (135 IHCCs, 34 EHCCs, and 59 GBCs) that underwent targeted OncoPanel sequencing at Dana-Farber Cancer Institute. The identified oncogenic alterations were similar to those previously reported in cholangiocarcinoma genomic landscapes. Mutational signature analyses found genomic features of microsatellite instability in 5 cases, APOBEC in 4 cases, and homologous recombination repair deficiency in 7 cases. Clinicopathological and outcome data for these patients are being collected to evaluate for associations with genomic findings.

16 FGFR2 translocations involving intron 17 were identified in the IHCC cohort (14% of evaluable IHCCs). Surprisingly, 5 IHCCs (4% of evaluable cases) harbored extracellular domain FGFR2 indels, of which p.W290_I291delinsC was previously reported to show oncogenic activity in vitro. Two cases harbored an identical FGFR2 p.H167_N173del. In vitro expression of this deletion resulted in oncogenic transformation, and that this growth could be inhibited by FGFR inhibitors. The two patients with FGFR2 p.H167_N173del were treated with an FGFR-1/2/3 inhibitor (Debio-1347), and both achieved durable partial response (PR) of over 11 months. We followed the first patient with tumor sequencing at five timepoints during her care and found that at resistance to Debio-1347, she developed an FGFR2 kinase domain mutation (p.L617F) that was subsequently demonstrated to confer resistance to Debio-1347 in vitro. This patient was then treated with a second FGFR inhibitor and experienced a PR lasting 17 months. At resistance to this second FGFR inhibitor, the tumor was biopsied and found to harbor a previously undetected BRAF p.L597Q mutation. The second patient remains on active treatment.

Our data show that extracellular domain FGFR2 in-frame indels are rare but targetable novel oncogenic alterations in IHCC. An expanded search of AACR Project GENIE data found 18 extracellular FGFR2 in-frame indels in diverse tumor types, supporting further functional evaluation and clinical targeting of these indels across tumor types.

Citation Format: Yvonne Y. Li, James M. Cleary, Srivatsan Raghavan, Liam F. Spurr, Qibiao Wu, Lei Shi, Lauren K. Brais, Maureen Loftus, Lipika Goyal, Anuj K. Patel, Atul B. Shinagare, Thomas E. Clancy, Geoffrey Shapiro, Ethan Cerami, William R. Sellers, William C. Hahn, Matthew Meyerson, Nabeel Bardeesy, Andrew D. Cherniack, Brian M. Wolpin. FGFR2 in-frame indels: A novel targetable alteration in intrahepatic cholangiocarcinoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1097.

Therapeutic targeting of extracellular FGFR2 activating deletions in intrahepatic cholangiocarcinoma

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Background: Fibroblast growth factor receptor (FGFR) pathway alterations have been identified in approximately 20% of patients (pts) with intrahepatic cholangiocarcinoma (IHCC), most commonly by FGFR2 fusions. Early phase clinical trials have demonstrated encouraging efficacy of FGFR inhibitors in pts with FGFR2-translocated cholangiocarcinoma, but efficacy in pts with other FGFR2 activating alterations is less clear. Methods: Pts with cholangiocarcinoma underwent CLIA-certified next generation DNA sequencing (NGS) to identify actionable alterations. FGFR2 fusions and other FGFR2 genomic events were assessed, with genomic characterization performed before and after treatment with FGFR inhibitors in appropriate pts. Novel extracellular domain in-frame deletions (INDELs) of FGFR2 and apparent resistance mutations were investigated for oncogenic activity and inhibitor resistance in vitro and in vivo. Results: Cholangiocarcinomas from 284 pts (136 male, 148 female; median age, 64 [20-89], including 139 IHCCs, were sequenced. Among the IHCCs, 16 (11.5%) had FGFR2 fusions, with 9 different gene partners. Surprisingly, 5 (3.6%) IHCCs harbored extracellular domain FGFR2 INDELs. Two of these IHCCs harbored an exon 5 deletion FGFR2 p.H167_N173del. Expression of FGFR2 p.H167_N173del in 3T3 cells resulted in oncogenic transformation. In the clinic, two pts with FGFR2 p.H167_N173del were treated with Debio1347, an oral FGFR-1/2/3 inhibitor. Both patients achieved a durable partial response (PR) of 11 months, with one of the pts still on active treatment with Debio-1347. The patient who developed acquired resistance underwent repeat biopsy, and NGS identified a secondary mutation ( FGFR2 p. L617F) in the kinase domain. In vitro studies demonstrated that this mutation confers resistance to Debio1347. This patient was subsequently treated with another FGFR inhibitor and again experienced a PR lasting 17 months. A third biopsy after disease progression demonstrated a previously undetected L597Q BRAF mutation. Conclusions: Extracellular domain FGFR2 in-frame deletions are a novel genomic alteration in IHCC that are transforming and predict clinical sensitivity to FGFR inhibitors.

Feasibility of pharmacist co-management for patients prescribed oral anticancer therapy for gastrointestinal cancers

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Background: There is an increased use of oral anti-cancer therapies (OACTs) for treatment of gastrointestinal (GI) cancers. While OACTs provide convenience compared to IV agents, they carry similar risks for drug-drug interactions (DDI), toxicities, and unique challenges like adherence and drug access. Patients on OACTs have fewer touch-points with clinicians, requiring more patient ownership of treatment. Pharmacist co-management of pts has been shown to be successful in teaching and monitoring of IV therapy. We sought to assess feasibility of pharmacist co-management for pts prescribed OACTs for treatment of GI cancers. Methods: In 2019, the Dana-Farber GI Cancer Center (GCC) had an embedded pharmacist 8 hrs/week to help with co-management of pts on OACTs. The pharmacist provided (1) in-person and telephone teaching; (2) comprehensive medication reconciliation; (3) DDI review; and (4) supportive care recommendations. Patients were identified by reviewing provider schedules and through provider referrals. The initial teach visit was one-on-one with each patient before initiation, with joint visits with providers thereafter for monitoring and adherence checks. Data were collected to quantify the types of support/recommendation provided by pharmacist and the impact on clinical workflow. Results: After 4 months in the GCC clinic, the pharmacist has co-managed 26 new pts, 61% seen in-person. In initial visits, the pharmacist identified 3 DDI, updated 15 medication lists, and assisted 11 pts/or providers with drug access and drug information. The pharmacist saw 10 of 26 pts for follow up, totaling 21 encounters. The pharmacist assisted in 17 of the 21 encounters with drug access and drug information. Pharmacist spent 20 min/pt on teaching. For follow-up visits, the pharmacist did not additional incur clinic resources as patients were seen with providers. Conclusions: Pharmacist co-management of patients on OACTs is feasible and offers an added safety resource to pts and providers from initial teaching to monitoring. Future research will focus on the impacts of co-management on clinical outcomes, such as the use of emergency/hospital visits, the duration of therapy, and adherence.

Real-World Adherence in Patients with Metastatic Colorectal Cancer Treated with Trifluridine plus Tipiracil or Regorafenib

BACKGROUND

Trifluridine and tipiracil (FTD + TPI) and regorafenib (REG) are approved treatments for the treatment of refractory metastatic colorectal cancer (mCRC). This study assesses adherence and duration of therapy with FTD + TPI versus REG and explores the effect of sequencing on adherence.

MATERIALS AND METHODS

Adults diagnosed with mCRC were identified in the IQVIA Real-World Data Adjudicated Claims: U.S. database (October 2014-July 2017). The observation period spanned from the index date (first dispensing of FTD + TPI or REG) to the earliest of a switch to another mCRC agent, the end of continuous enrollment, or the end of data availability. Medication possession ratio (MPR), proportion of days covered (PDC), and persistence and time to discontinuation (gap ≥45 days) were compared between FTD + TPI and REG users and among switchers (FTD + TPI-to-REG vs. REG-to-FTD + TPI).

RESULTS

A total of 469 FTD + TPI and 311 REG users were identified. FTD + TPI users had higher compliance with an MPR ≥80% (odds ratio [OR], 2.47; p < .001) and PDC ≥80% (OR, 2.77; p < .001). FTD + TPI users had better persistence (82.8% vs. 68.0%; p < .001) and lower risk of discontinuation (hazard ratio [HR], 0.76; p = .006). Among switchers (96 FTD + TPI-to-REG; 83 REG-to-FTD + TPI), those switching from FTD + TPI to REG were more likely to have an MPR ≥80% (OR, 2.91; p < .001) and PDC ≥80% (OR, 4.60; p < .001) compared with REG-to-FTD + TPI switchers while treated with these drugs. Additionally, FTD + TPI-to-REG switchers had a lower risk of first treatment discontinuation (HR, 0.66; p = .009).

CONCLUSION

FTD + TPI users had significantly higher adherence and persistence, and patients who were treated with FTD + TPI before switching to REG also had higher adherence and persistence outcomes.

IMPLICATIONS FOR PRACTICE

Trifluridine plus tipiracil (FTD + TPI) and regorafenib (REG) prolong survival in refractory metastatic colorectal cancer (mCRC) but have different tolerability profiles. This study assessed real-world adherence to treatment with FTD + TPI versus REG and compared outcomes among patients who switched from FTD + TPI to REG and vice versa. FTD + TPI was associated with significantly higher medication adherence and longer time to discontinuation than REG. Patients treated with FTD + TPI prior to switching to REG also showed higher adherence outcomes. Findings could help inform decision making regarding the choice and sequencing of treatment with FTD + TPI versus REG in patients with mCRC.

Trifluridine/tipiracil (FTD/TPI) and regorafenib (REG) in patients with metastatic colorectal cancer (mCRC): A single institution retrospective study

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Background: FTD/TPI and REG have both demonstrated prolonged survival in refractory mCRC patients (pts) when compared to placebo but limited comparative effectiveness data are available. This study aims to compare outcomes following initiation of FTD/TPI or REG for mCRC at a single academic cancer center. Methods: Retrospective chart reviews were conducted in all pts with mCRC who initiated FTD/TPI or REG between 2012-2017. Analyses of time from index therapy initiation to discontinuation for any reason (TTD), real-world response rates (rwRR) and disease control rates (rwDCR) were performed. Cox proportional hazards models adjusting for demographic and clinical characteristics were performed for overall survival (OS). Results: 126 FTD/TPI and 95 REG pts were included. Baseline characteristics were similar in both groups, though more pts treated with FTD/TPI had right-sided primary tumors compared to REG (30.4% vs. 25.5%, p = 0.43). Treatment patterns pre- and post-index therapy were comparable in both groups. Median observation duration for FTD/TPI and REG was 7.1 and 6.3 months, respectively. Mean TTD was 88.4 days for FTD/TPI pts and 84.2 days for REG pts (p = 0.42). Fewer pts treated with FTD/TPI discontinued due to toxicities than pts treated with REG (8.2% vs. 24.2%, p = 0.001). A higher proportion of FTD/TPI pts had no dose modifications vs. REG pts (84.0% vs. 64.1%, p < 0.001). OS was similar between the two groups (adjusted hazard ratio [HR] FTD/TPI vs. REG: 0.79, p = 0.13). FTD/TPI pts had higher rwRR (52.5% vs. 34.2%, p = 0.01) and rwDCR (64.2% vs. 46.1%, p = 0.01) than REG pts. In the subgroup of pts ≥ 65 years, mean TTD was higher in FTD/TPI pts (105.9 vs. 77.6 days, p = 0.004). Pts ≥ 65 years receiving FTD/TPI had better OS than REG pts (HR: 0.51, p = 0.03). Conclusions: In this single institution study, TTD and OS were similar between pts treated with FTD/TPI and REG. Fewer pts treated with FTD/TPI than REG discontinued due to toxicities or required dose modification. Reported responses rates were higher in FTD/TPI pts. Older pts (≥ 65 years) on FTD/TPI remained on treatment longer and had better OS than REG pts.

Real-world adherence in patients with metastatic colorectal cancer (mCRC) treated with trifluridine/tipiracil (FTD/TPI) or regorafenib (REG)

11

Background: Adherence to oral chemotherapies is a critical but difficult to measure factor in the care of patients with advanced cancer. FTD/TPI and REG have both demonstrated prolonged survival in patients with refractory mCRC, but with notably different side effect profiles. This study utilizes real-world data to assess adherence and discontinuation of patients treated with FTD/TPI or REG and explore the effect of sequencing on adherence. Methods: Adults diagnosed with mCRC were identified using the nationally representative IQVIA Real-World Data Adjudicated Claims – US database (10/2014–07/2017). The first dispensing date of FTD/TPI or REG (if after FTD/TPI approval [10/2015]) was defined as the index date and the 3 months before as the baseline period. The observation period spanned from the index to the earliest date of a switch to another mCRC agent, end of continuous enrollment, or end of data availability. Medication possession ratio (MPR), proportion of days covered (PDC) at 3 months, and discontinuation (i.e., allowable gap≥45 days) were compared. Logistic (odds ratio [OR]) and Cox proportional hazards (hazard ratio [HR]) regressions, adjusting for baseline characteristics, were used to compare adherence and discontinuation, respectively. A subgroup analysis was conducted among switchers (FTD/TPI to REG vs REG to FTD/TPI). Results: A total of 469 FTD/TPI and 311 REG users were identified. FTD/TPI users had higher compliance with an MPR ≥ 80% (OR = 2.47; p < 0.001) and PDC ≥ 80% (OR = 2.77; p < 0.001). FTD/TPI users had lower risk of discontinuation (HR = 0.76; p = 0.006). Among switchers (96 FTD/TPI to REG; 83 REG to FTD/TPI), those switching from FTD/TPI to REG were more likely to have an MPR ≥ 80% (OR = 2.91; p < 0.001) and PDC ≥ 80% (OR = 4.60; p < 0.001) compared to REG to FTD/TPI switchers. Additionally, FTD/TPI to REG switchers had a lower risk of first treatment discontinuation (HR = 0.66; p = 0.009). Conclusions: In this study, FTD/TPI users had significantly higher compliance, lower discontinuation rate, and switchers treated first with FTD/TPI had better compliance, demonstrating that claims data can provide insight into oral chemotherapy adherence patterns in mCRC.

Real-time Genomic Characterization of Advanced Pancreatic Cancer to Enable Precision Medicine

Clinically relevant subtypes exist for pancreatic ductal adenocarcinoma (PDAC), but molecular characterization is not yet standard in clinical care. We implemented a biopsy protocol to perform time-sensitive whole-exome sequencing and RNA sequencing for patients with advanced PDAC. Therapeutically relevant genomic alterations were identified in 48% (34/71) and pathogenic/likely pathogenic germline alterations in 18% (13/71) of patients. Overall, 30% (21/71) of enrolled patients experienced a change in clinical management as a result of genomic data. Twenty-six patients had germline and/or somatic alterations in DNA-damage repair genes, and 5 additional patients had mutational signatures of homologous recombination deficiency but no identified causal genomic alteration. Two patients had oncogenic in-frame BRAF deletions, and we report the first clinical evidence that this alteration confers sensitivity to MAPK pathway inhibition. Moreover, we identified tumor/stroma gene expression signatures with clinical relevance. Collectively, these data demonstrate the feasibility and value of real-time genomic characterization of advanced PDAC.Significance: Molecular analyses of metastatic PDAC tumors are challenging due to the heterogeneous cellular composition of biopsy specimens and rapid progression of the disease. Using an integrated multidisciplinary biopsy program, we demonstrate that real-time genomic characterization of advanced PDAC can identify clinically relevant alterations that inform management of this difficult disease. Cancer Discov; 8(9); 1096-111. ©2018 AACR.See related commentary by Collisson, p. 1062This article is highlighted in the In This Issue feature, p. 1047.

Comparison of the real-world adherence and compliance patterns with trifluridine/tipiracil (FTD/TPI) and regorafenib (REG) for the treatment of metastatic colorectal cancer (mCRC)

666

Background: FTD/TPI and REG both prolong survival in refractory mCRC and have similar indications with different side effect profiles. This study compares real-world treatment patterns with FTD/TPI and REG for mCRC in a large, representative US claims database. Methods: Retrospective data from 10/2014 to 7/2016 from the US Symphony Health Solutions’ Integrated Dataverse (IDV®) database were analyzed for patients receiving FTD/TPI or REG. The index date was the date of first FTD/TPI or REG prescription. Patients were included if: 1) age ≥18 years old, 2) ≥1 CRC diagnosis, 3) no diagnosis of gastric cancer or gastrointestinal stromal tumor, and 4) continuous clinical activity for ≥3 months before and after index date. The observation period spanned from index date to end of data, end of continuous clinical activity, or switch to another mCRC treatment. Adherence was assessed using medication possession ratio (MPR) ≥0.80 and proportion of days covered (PDC) ≥0.80 at 3 months. Compliance was assessed using time to discontinuation over the observation period using allowable gaps of 45, 60, or 90 days. Patients who never discontinued therapy were censored at the end of the observation period. Outcomes were compared between FTD/TPI and REG using multivariate logistic regression and Cox proportional hazards models, adjusting for demographic and clinical baseline characteristics. Results: A total of 1,630 FTD/TPI patients and 1,425 REG patients were identified. Mean ± standard deviation (SD) age of FTD/TPI patients was 61.0 ± 11.0 compared to 62.8 ± 10.9 for REG patients (p < 0.001). FTD/TPI patients were 80% more likely to have a MPR ≥0.80 compared to those on REG (Odds Ratio [OR] = 1.80, p < 0.001) and more than twice as likely to have a PDC ≥0.80 (OR = 2.66, p < 0.001) at 3 months. FTD/TPI patients were 37% less likely to discontinue their treatment compared to those on REG when using gaps of 60 days (Hazard Ratio = 0.63, p < 0.001). Similar results were found with 45 and 90 days. Conclusions: In this retrospective study of mCRC patients, patients on FTD/TPI were significantly more likely to adhere and comply with therapy compared to those on REG.

A phase 2 trial of regorafenib as a single agent in patients with chemotherapy refractory advanced and metastatic biliary adenocarcinoma/cholangiocarcinoma

4081

Background: Biliary adenocarcinoma/cholangiocarcinoma is a rare but aggressive neoplasm. Most patients present with unresectable or metastatic disease with 5-year survival rate ~5%. No second-line regimen has demonstrated clinical benefit in this disease. Regorafenib is an oral multi-kinase inhibitor with potent antitumor activity. This single arm phase II study evaluates the efficacy and safety of regorafenib as a single agent in advanced or metastatic biliary carcinoma/cholangiocarcinoma pts who failed systemic chemotherapy. Methods: Patients with ECOG PS 0-1and adequate liver, kidney and bone marrow function were given regorafenib orally once daily, 21 days on and 7 days off in a 28-day cycle. The initial dose of 160 mg was given to the first 3 patients. After toxicity assessment, the dose was reduced to 120 mg for the subsequent pts. The primary endpoint is PFS with the null hypotheses of 2.0 months, and median PFS ≥3.5 months as evidence of the study drug activity (α = 0.10, 80% power). Secondary objectives include OS, RR, and DCR. Results: Thirty-seven patients received at least one dose of regorafenib, of whom 28 were evaluable for efficacy. All had previous gemcitabine/cisplatin treatment. The mean age was 62.5 (34.5-82.8) with 17 (46%) females. PR was achieved in 3 (10.7%), SD in 18 (64.3%, with DCR of 75%), and PD in 7 (25%). For all 37 patients, median PFS was 3.55 months (95% CI = 2.1- 5.72) and mOS was 5.55 months (95% CI = 4.04 -NA) with survival rate of 42 % at 12 months, and 38% at 18 months. Medan PFS and OS of 30 patients who had ≥1 cycle were 3.91 months (95% CI = 3.55-9.79) and 13.4 months (95% CI = 5.06 - NA), respectively. The overall toxicity profile was as expected, with G3/4 AE’s of 40.5%. The most common toxicities were HTN, hypophosphatemia, hand-foot skin reaction, and increased serum bilirubin. Dose modification was required in 11 (30.6%) patients. Tumor samples were collected in 80% of patients, with planned correlative studies underway. Conclusions: This study showed promising efficacy of regorafenib in chemotherapy refractory advanced/metastatic cholangiocarcinoma. Further studies to confirm the clinic efficacy are recommended. Clinical trial information: NCT02053376.

Real-world adherence and treatment discontinuation with trifluridine/tipiracil (FTD-TPI) compared with regorafenib (REG) for the treatment of metastatic colorectal cancer (mCRC)

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Background: FTD-TPI and REG both prolong survival in refractory mCRC. Both agents have the benefit of oral administration but with distinct side effect profiles. This study aims to compare real-world treatment patterns following initiation of FTD-TPI or REG for mCRC in a large, nationally representative US claims database. Methods: Retrospective data from 10/2014 to 7/2016 from the US Symphony Health Solutions’ Integrated Dataverse (IDV®) database were analyzed for patients (pts) receiving FTD-TPI or REG. The index date was the date of first FTD-TPI or REG prescription. Pts were included if: 1) age ≥18 years old, 2) ≥1 CRC diagnosis, 3) no diagnosis of gastric cancer or gastrointestinal stromal tumor, and 4) continuous clinical activity for ≥3 months before and after index date. The observation period spanned from index date to end of data, end of continuous clinical activity, or switch to another mCRC treatment. Medication adherence was assessed by medication possession ratio (MPR), with MPR ≥80% as the defined threshold for adherence, as well as by proportion of days covered (PDC) at 3 months. Between treatment groups, binary endpoints were compared using Chi-square tests and mean and median time to treatment discontinuation (TTD) were compared using t-test and Wilcoxon test, respectively. Results: The study population consisted of 1,630 FTD-TPI pts and 1,425 REG pts. Mean ± standard deviation (SD) age of FTD-TPI pts was 61 ± 11 and REG pts was 63 ± 11 (p < 0.01). Mean ± SD length of observation period in days was 161 ± 59 for FTD-TPI pts and REG pts was 212 ± 113 (p < 0.01). 84% of FTD-TPI and 74% of REG pts reached MPR ≥80% (p < 0.01). FTD-TPI pts had higher mean PDC (71% vs 59%, p < 0.01) than REG pts. Mean and median TTD were significantly longer for FTD-TPI than REG pts (mean: 101 vs. 88 days, p < 0.01; median: 97 vs. 69 days, p < 0.01). Conclusions: In this analysis of real-world medication utilization for mCRC pts, those pts started on FTD-TPI had significantly higher medication adherence and longer TTD than those on REG.

Transcriptomic comparison of primary bovine horn core carcinoma culture and parental tissue at early stage

Aim:

Squamous cell carcinoma or SCC of horn in bovines (bovine horn core carcinoma) frequently observed in Bos indicus affecting almost 1% of cattle population. Freshly isolated primary epithelial cells may be closely related to the malignant epithelial cells of the tumor. Comparison of gene expression in between horn’s SCC tissue and its early passage primary culture using next generation sequencing was the aim of this study.

Materials and Methods:

Whole transcriptome sequencing of horn’s SCC tissue and its early passage cells using Ion Torrent PGM were done. Comparative expression and analysis of different genes and pathways related to cancer and biological processes associated with malignancy, proliferating capacity, differentiation, apoptosis, senescence, adhesion, cohesion, migration, invasion, angiogenesis, and metabolic pathways were identified.

Results:

Up-regulated genes in SCC of horn’s early passage cells were involved in transporter activity, catalytic activity, nucleic acid binding transcription factor activity, biogenesis, cellular processes, biological regulation and localization and the down-regulated genes mainly were involved in focal adhesion, extracellular matrix receptor interaction and spliceosome activity.

Conclusion:

The experiment revealed similar transcriptomic nature of horn’s SCC tissue and its early passage cells.

Incidence and species distribution of candidaemia in Asia: a laboratory-based surveillance study

The epidemiology of candidaemia varies between hospitals and geographic regions. Although there are many studies from Asia, a large-scale cross-sectional study across Asia has not been performed. We conducted a 12-month, laboratory-based surveillance of candidaemia at 25 hospitals from China, Hong Kong, India, Singapore, Taiwan and Thailand. The incidence and species distribution of candidaemia were determined. There were 1601 episodes of candidaemia among 1.2 million discharges. The overall incidence was 1.22 episodes per 1000 discharges and varied among the hospitals (range 0.16-4.53 per 1000 discharges) and countries (range 0.25-2.93 per 1000 discharges). The number of Candida blood isolates and the total number of fungal isolates were highly correlated among the six countries (R² = 0.87) and 25 hospitals (R² = 0.77). There was a moderate correlation between incidence of candidaemia and the intensive care unit (ICU)/total bed ratio (R² = 0.47), although ICUs contributed to only 23% of candidaemia cases. Of 1910 blood isolates evaluated, Candida albicans was most frequently isolated (41.3%), followed by Candida tropicalis (25.4%), Candida glabrata (13.9%) and Candida parapsilosis (12.1%). The proportion of C. tropicalis among blood isolates was higher in haemato-oncology wards than others wards (33.7% versus 24.5%, p 0.0058) and was more likely to be isolated from tropical countries than other Asian countries (46.2% versus 18.9%, p 0.04). In conclusion, the ICU settings contribute, at least in part, to the incidence variation among hospitals. The species distribution is different from Western countries. Both geographic and healthcare factors contribute to the variation of species distribution.

Are Gujarati Asian Indians 'older' for their 'vascular age' as compared to their 'Chronological age'?

BACKGROUND

South Asians are known to carry higher burden of cardiovascular diseases when compared with their Caucasian counterparts.

AIM

This study was designed to evaluate whether vascular age is advanced for Gujarati Asian Indians as matched to their chronological age in apparently healthy, asymptomatic population. We have also assessed the contributing risk factors for premature vascular ageing.

DESIGN

It was cross-sectional study of 2483 individuals of Gujarat state in Western India having no past or present history of major illness including cardiovascular diseases.

METHOD

The vascular age of the population was calculated using Framingham vascular age calculator. A relationship between risk factor prevalence and vascular ageing was evaluated using univariate analysis of variance.

RESULTS

The mean chronological age of the study population was 46.8 (±10.35) years whereas mean vascular age was 53.34 (±16.05) years, and the difference (6.54±9.5) between both was statistically significant (P < 0.0001). Contributory risk factors for advanced vascular age apart from chronological age (75.4%) and male gender (66.2%) were the presence of dyslipidemia (60.4%) hypertension (57.34%) and increased waist circumference (WC) (male 39.7%, female 29%). Results of regression analysis showed that vascular age progression was highly associated with blood pressure (19.9, 95% CI: 14.34-27.63), followed by smoking (15.23, 95% CI: 8.4-27.59), and blood sugar (12.97, 95% CI: 3.48-48.25).

CONCLUSION

The Gujarati Asian Indians are subjected to premature vascular ageing and henceforth routine screening for vascular age and risk factors prevalence is strongly advocated in this ethnic group.

Qualitative and quantitative assessment of Theileria annulata in cattle and buffaloes Polymerase Chain Reaction

Bovine tropical theileriosis caused by Theileria annulata is a tick-borne disease associated with high morbidity and mortality in the livestock. The conventional method of diagnosis is by the demonstration of the parasite stages by microscopic examination. This method suffers from low sensitivity, making it even more difficult to detect piroplasms in the carriers. PCR based assays are known to be more sensitive. The present study was undertaken to detect and quantify T. annulata in the blood of clinically infected and carrier animals using a quantitative PCR protocol targeting the gene encoding the major merozoite piroplasm surface antigen Tams 1. A total of 116 samples were collected from infected as well as apparently healthy cattle and buffaloes. Of these, 74 samples (63.79%) were positive for T. annulata by real-time PCR, including the 15 samples that were positive by Giemsa staining. The parasite load ranged from 1.39 x 10(6) to 3.35 x 10(9) and 0.35 x 10(6) to 2.83 x 10(7) ml(-1) of blood in cattle and buffalo samples, respectively by qPCR. Our study suggests that real-time PCR assay can be used to detect and quantify the load of T. annulata in the blood of cattle and buffaloes. It also serves as a support to clinical diagnosis and assessment of carrier status in apparently healthy animals.

Association of psychiatric co-morbidities and quality of life with severity of chronic obstructive pulmonary disease

OBJECTIVE

This was a single-centre, cross-sectional, observational study performed at a tertiary care hospital in India to study the association of psychiatric co-morbidities and quality of life with severity of chronic obstructive pulmonary disease (COPD).

METHODS

A total of 59 clinically stable patients with COPD were assessed for disease severity, as per the updated Global Initiative for Chronic Obstructive Lung Disease (GOLD) guideline (2013). Psychiatric co-morbidities like anxiety disorders and depression were diagnosed by clinician-administered interview (as per the DSM-V criteria). Insomnia, anxiety disorders and depression, as well as quality of life were also assessed by self-rating scales including Insomnia Severity Index (ISI), Hospital Anxiety and Depression Scale, and St. George's Respiratory Questionnaire, respectively.

RESULTS

Depression was the commonest psychiatric co-morbidity affecting 32.2% of individuals. Patients with depression and anxiety disorders had higher score in COPD assessment test (p = 0.02 and p = 0.004, respectively), ISI (p < 0.001 and p = 0.01, respectively), and poorer quality of life (p < 0.001 and p = 0.02, respectively) compared with those without these conditions. Patients with severe symptoms of COPD were more likely to suffer from anxiety (p = 0.001), depression (p = 0.01), insomnia (p = 0.01), and have poor quality of life (p < 0.001). Patients in the GOLD-D (i.e. those at high risk and with more symptoms) group had poorer quality of life (p = 0.004) when compared with GOLD-A (low risk and less symptoms) and GOLD-C (high risk and less symptoms) groups.

CONCLUSIONS

Patients with psychiatric co-morbidities have severe symptoms of COPD and poor quality of life.

Microbial profiles of liquid and solid fraction associated biomaterial in buffalo rumen fed green and dry roughage diets by tagged 16S rRNA gene pyrosequencing

The microbiome of buffalo rumen plays an important role in animal health and productivity. The rumen bacterial composition of both liquid and solid fraction was surveyed using pyrosequencing of the 16S rRNA gene. Sequences were analyzed using taxonomy-dependent clustering methods and revealed that the dominant ruminal bacteria shared by samples belonged to phyla Bacteroidetes, Firmicutes, Fibrobacteres and Proteobacteria. The core rumen microbiome of the rumen consisted of 10 phyla, 19 classes, 22 orders and 25 families. However, the relative abundance of these bacterial groups was markedly affected by diet composition as well as in type of biomaterial. In animals fed with a green and dry roughage diet, the cellulolytic bacteria, Ruminococcaceae, and Fibrobacteraceae was found in highest abundance in all biomaterials which reflected the need for enhanced fiber-digesting capacity in buffalo. The polysaccharide-degrading Prevotellaceae bacteria were most abundant in buffalo rumen. In taxonomic comparison of rumen bacteria, about 26 genera were differentially abundant among liquid and solid fraction of ruminal fluid. These results highlight the buffalo ruminal microbiome's ability to adapt to feed with different composition.

Chemically diverse polymer microarrays and high throughput surface characterisation: a method for discovery of materials for stem cell culture†Electronic supplementary information (ESI) available. See DOI: 10.1039/c4bm00054dClick here for additional data file

Chemically diverse polymer microarrays as a powerful screening tool for the discovery of new materials for a variety of applications.

Materials discovery provides the opportunity to identify novel materials that are tailored to complex biological environments by using combinatorial mixing of monomers to form large libraries of polymers as micro arrays. The materials discovery approach is predicated on the use of the largest chemical diversity possible, yet previous studies into human pluripotent stem cell (hPSC) response to polymer microarrays have been limited to 20 or so different monomer identities in each study. Here we show that it is possible to print and assess cell adhesion of 141 different monomers in a microarray format. This provides access to the largest chemical space to date, allowing us to meet the regenerative medicine challenge to provide scalable synthetic culture ware. This study identifies new materials suitable for hPSC expansion that could not have been predicted from previous knowledge of cell-material interactions.

Metagenomic analysis of buffalo rumen microbiome: Effect of roughage diet on Dormancy and Sporulation genes

Buffalo rumen microbiome experiences a variety of diet stress and represents reservoir of Dormancy and Sporulation genes. However, the information on genomic responses to such conditions is very limited. The Ion Torrent PGM next generation sequencing technology was used to characterize general microbial diversity and the repertoire of microbial genes present, including genes associated with Dormancy and Sporulation in Mehsani buffalo rumen metagenome. The research findings revealed the abundance of bacteria at the domain level and presence of Dormancy and Sporulation genes which were predominantly associated with the Clostridia and Bacilli taxa belonging to the phyla Firmicutes. Genes associated with Sporulation cluster and Sporulation orphans were increased from 50% to 100% roughage treatment, thereby promoting sporulation all along the treatments. The spore germination is observed to be the highest in the 75% roughage treatment both in the liquid and solid rumen fraction samples with respect to the decrease in the values of the genes associated with spore core dehydration, thereby facilitating spore core hydration which is necessary for spore germination.

Comprehensive transcriptome profiling of squamous cell carcinoma of horn in Bos indicus

Squamous cell carcinoma (SCC) of horn is frequently observed in Bos indicus affecting 1% of cattle population and accounting 83.34% of total tumours found. The transcriptome profile of horn cancer (HC) tissue and the matched normal (HN) tissue were analysed by RNA-seq using Roche 454 sequencing. A total of 1 504 900 reads comprising of 612 MB data were used to identify differentially expressed genes using CLC Genomic Workbench. These include up-regulation of KRT6A, KRT6B, KRT6C, KRT14, SFN, KRT84, PI3, COL17A1, ANLN, SERPINB5 and down-regulation of BOLA, SCGB1A1, CXCL17, KRT19, BPIFB1, NR4A1 and TFF3 in HC, which are involved in regulation of gene transcription, cell proliferation, apoptosis, cell survival and metabolic pathways. The qPCR analysis of several targets suggested concordance of gene expression profile with RNA-seq analysis. The present findings would provide basis for further screening of genes and identification of markers for early diagnosis and therapeutic intervention of HC.

Detection of theileriosis in cattle and buffaloes by polymerase chain reaction

Bovine tropical theileriosis caused by Theileria annulata is a tick-borne disease of great economic importance in tropical and subtropical regions of the world. The present study was undertaken to detect theilerosis in cattle and buffaloes by polymerase chain reaction (PCR). The diagnosis of theileriosis is usually carried out by blood smear staining technique, which is not sufficiently sensitive to detect the piroplasms in the carrier animals. In this study, a total of 116 samples were collected from infected as well as apparently healthy cattle and buffaloes. Screening of blood smears by Giemsa staining detected 15 samples (12.93 %) positive for Theileria piroplasms out of 116 samples. However, the PCR based screening using the specific primers from the major merozoite-piroplasm surface antigen sequence of T. annulata (Tams1) gene detected 74 samples (63.79 %) positive for T. annulata which included 59 samples found negative by Giemsa staining. Our study suggests that the PCR based screening is more sensitive and accurate method for diagnosis of tropical theileriosis in cattle and buffaloes.

Botulinum toxin injection therapy in the management of lower urinary tract dysfunction

We have great pleasure in introducing this supplement containing a collection of articles reviewing the contemporary clinical management of functional disorders of the lower urinary tract (LUT) with particular emphasis on the potential role of botulinum toxin injection therapy. Detrusor sphincter dyssynergia (DSD), detrusor overactivity (DO), painful bladder syndrome (PBS) and LUT symptoms consequent on bladder outflow obstruction (LUTS/BPH) have all been treated by the injection of botulinum toxin. This treatment can be administered as a minimally invasive, outpatient procedure which on the initial trials for DO (particularly of neurogenic aetiology) shows a remarkable efficacy with effects lasting up to a year after a single treatment with few significant side effects. Success has been reported with the management of detrusor sphincter dyssynergia and preliminary series report positive outcomes in the management of PBS and LUTS/BPH. However, most of the studies to date include small numbers and have a recruitment bias with few randomised controlled trials having been reported. The answers to some of the key questions are addressed with reference to our contemporary knowledge. It is clear that considerable work both clinical and basic science still needs to be performed to answer the many remaining questions with regard to this treatment modality but undoubtedly it will be a major future treatment option in those with intractable symptoms or those unable to tolerate medications. Currently, all botulinum toxin use for urological conditions is off-label and unlicensed, therefore caution should be exercised until future large randomised studies are reported.

The emerging role of intravesical botulinum toxin therapy in idiopathic detrusor overactivity

Recently there has been considerable original research into the use of the botulinum neurotoxins in idiopathic detrusor overactivity (DO). This common condition underlies the overactive bladder syndrome in a significant proportion of cases and was previously known as idiopathic detrusor instability. Failure of initial pharmacotherapy in this condition leaves few effective conservative/medical treatment options. Early reports of botulinum toxin (BoNT) therapy have been extremely promising, and the therapy appears to bridge the gap in such patients, before resorting to invasive surgical procedures. Approximately 30 studies have been reported often with widely differing techniques and some clinicians are beginning to administer BoNT for this unlicensed indication. This has led to the urgent need to critically review all available evidence to assess efficacy, safety and technique. In addition to performing a systematic Medline review, all abstracts presented to urological, urogynaecological and incontinence meetings that reported BoNT usage in idiopathic DO were analysed. Remarkable efficacy has been demonstrated in the vast majority of reported series and the treatment has also been used safely in paediatric and elderly populations. Side effects in all populations appear to be minimal and short lived. However, all the series are small and there remains a considerable number of fundamental questions to be answered. Hopefully large-scale robust randomised controlled trials will provide the necessary answers to facilitate the widespread adoption of this technique. Until then caution must be exercised in this unlicensed indication.

Nevirapine versus efavirenz based antiretroviral treatment in naive Indian patients: comparison of effectiveness in clinical cohort

OBJECTIVE

Our objective was to compare immunologic effectiveness of nevirapine and efavirenz based antiretroviral therapy in antiretroviral naïve HIV-1 infected Indian patients.

DESIGN AND METHODS

Study was an observational, non-randomized, longitudinal cohort. Antiretroviral naive HIV-1 infected patients receiving efavirenz + 2NRTI (n=254) and nevirapine + 2 NRTI (n=857) from April 2000 were followed up at two tertiary care HIV clinics at Ahmedabad and Pune. Patients were followed up clinically monthly and CD4 was carried out every 3 monthly. All patients were examined for various side effects as well as development of various OIs. Data were analyzed using standard statistical methods.

RESULTS

Baseline characteristics for both the groups (NVP and EFV) were comparable. In the random effects model, there was an increase of 40.97 (p < 0.05) units of CD4 cell counts with an unit increase in time in the NVP arm as against a 44.75 (p < 0.05) units of increase in CD4 cell counts in the EFV group with a unit increase in time, which is significant for both groups. However, at any given point of time there was no difference in the rate of increase of CD4 count between the two treatment arms (p = 0.58). Hypersensitivity reaction (6.6% in NVP vs. 2.32% in EFV, p = 0.0146) and hepatitis (3.2% in NVP vs. 0% in EFV, p = 0.0085) were more common with nevirapine, while neurologic disturbances (0.93% in NVP vs. 20.15% in EFV, p = 0.0001) were more common with efavirenz. Incidence of distal sensory neuropathy and lipid abnormalities was similar in both the groups.

CONCLUSION

Use of NVP and EFV based HAART in antiretroviral naive Indian patients led to significant and durable rise in CD4 cell count. Although observational and non-randomized, our study showed equivalent immunological response amongst NVP and EFV based HAART which is in line with the results of the 2NN study.

API consensus guidelines for use of antiretroviral therapy in adults (API-ART guidelines). Endorsed by the AIDS Society of India

With rational use of antiretroviral therapy (ART), human immunodeficiency virus (HIV) infection has been transformed into a chronic manageable illness like diabetes and hypertension. These guidelines provide information on state of art, evidence based approach for use of ART in Indian context. When to initiate ART? Antiretroviral therapy is indicated for all symptomatic HIV infected persons regardless of CD4 counts and plasma viral load (PVL) levels. In asymptomatic patients, ART should be offered when the CD4 counts < 200/mm3 and should be considered in patients with CD4 counts between 200-250/mm3. Therapy is not recommended for patients with CD4 count more than 350/ mm3. Involvement of patient in all treatment decisions and assessing readiness is critical before initiating ART. What to start with? A non-nucleoside reverse transcriptase inhibitor (NNRTI) based regimen is recommended for antiretroviral naïve patients. The choice between nevirapine and efavirenz is based on differences in adverse events profiles; cost and availability of convenient fixed dose combinations and need for concomitant use of rifampicin. A backbone of 2-nucleoside reverse transcriptase inhibitors (NRTIs) is combined with the NNRTI. Various combinations and ART strategies not to be used in clinical practice has been enlisted. How to follow up? Recommendations have been made for baseline evaluation and monitoring of patients on ART. These include guidelines on laboratory and clinical evaluation. A plasma viral load at 6 months after initiation of first-line ART is strongly recommended. Yearly estimation of lipid profile has been recommended. How to identify and manage ART failure? The guidelines recognize the issue of identifying ART failure late if only CD4 counts are used for monitoring. In the absence of resistance testing various second-line regimens have been enlisted. A boosted protease inhibitor based regimen is recommended in this situation to be combined with 2-NRTIs. Special situations Recommendations have been made for use of ART in HIV-TB, HIV-HBV, and HIV-HCV co-infected patients. In patients with active TB and a CD4 count < 200/mm3, initiation of ART is recommended as soon as the anti-TB treatment is tolerated. Efavirenz is the only ARV drug, which can be safely used with rifampicin. In pregnancy use of single dose nevirapine for reducing risk of mother to child transmission of HIV is not recommended, because of the risk of development of resistance. For post-exposure prophylaxis taking ART treatment history of the source patient is crucial in designing an effective regimen.

Lactic acidosis in HIV-I infected patients receiving antiretroviral therapy

Highly active antiretroviral therapy (HAART) has resulted in dramatic declines in morbidity and mortality in HIV-I infected patients in the developed world. However, with the availability of generic antiretroviral treatments (ART) in India, a large number of patients now receive ART. Increase in experience with ART has led to the detection of drug-related toxicities. We report herein potentially fatal side effects associated with the use of nucleoside analogues in HIV treatment--hyperlactatemia and lactic acidosis/hepatic steatosis.

Compatibility of the thioamide functional group with beta-sheet secondary structure: incorporation of a thioamide linkage into a beta-hairpin peptide

[structure: see text]. We report the incorporation of a thioamide linkage between the i + 2 and i + 3 residues of the type II' beta-turn of a peptide known to fold into a beta-hairpin conformation. Two-dimensional NMR spectroscopy and circular dichroism spectroscopy indicate that the thioxo peptide adopts a hairpin conformation similar to that of the oxo peptide and that the hairpin conformation persists at elevated temperatures. The results show that a thioamide linkage is compatible with beta-sheet secondary structure.

Autoamputation of the tongue

Autoamputation is an uncommon phenomenon that has been reported for the fingers, toes, appendix, ovary, spleen, etc. Autoamputation of the tongue has never been reported. An elderly man with carcinoma of lateral pharyngeal wall and tonsil presented with an autoamputated tongue that was attached to the oral cavity with a thin band. The patient required detachment of the tongue and tracheostomy followed by radiotherapy for the primary tumour.