AB0887 Designing a Phase 3b, Multicenter, Randomized, Double-blind, Placebo-controlled Study to Investigate the Effect of Guselkumab Dosing Interval in Psoriatic Arthritis Patients with Inadequate Response to Tumor Necrosis Factor Inhibition

Background

Tumor necrosis factor inhibitors (TNFi) are frequently chosen as the first biologic therapy for patients (pts) with psoriatic arthritis (PsA), though a sizeable proportion of pts have an inadequate response (IR), and some may also have intolerance. Guselkumab (GUS), a human mAb that targets the IL-23 p19 subunit, provides an alternative mechanism of action to treat PsA. In the Phase 3 (Ph3) DISCOVER-1 study of GUS in active PsA, GUS every 4 weeks (Q4W) and Q8W clinical response rates were generally consistent between TNFi-naïve (263 pts) and TNFi-experienced (118 pts) cohorts. In the TNFi-experienced cohort and the limited number of DISCOVER-1 pts with IR to their prior TNFi (N=44), American College of Rheumatology 50% improvement (ACR50) and ACR70 response rates at W24 were numerically higher in GUS Q4W- than Q8W-treated pts.1

Objectives

To further investigate whether GUS Q4W could provide incremental benefit to some TNFi-IR PsA pts by analyzing the existing DISCOVER-1 dataset to facilitate the design of a new clinical trial.

Methods

Study feasibility assessments included comparison of key efficacy endpoints by treatment group at W24 among TNFi-experienced pts receiving GUS Q8W and Q4W in DISCOVER-1. Results from the DISCOVER-1 study also informed sample size power calculations for a primary endpoint of ACR20 response at W24 in a future study in a TNFi-IR PsA pt population.

Results

Comparison of several efficacy endpoints (ACR70 response, minimal disease activity, Investigator’s Global Assessment [IGA] of psoriasis 0/1 response) across treatment groups in the TNFi-experienced DISCOVER-1 cohort supports a potential dose response, with more frequent GUS administration eliciting numerically higher response rates (Table 1). A similar trend was observed for ACR20/50/70 responses in the smaller TNFi-IR population1, though these findings should be interpreted with caution due to limited sample size. ACR20 response rates at W24 of DISCOVER-1 were employed to estimate sample size requirements for a new study. Assuming comparable rates of GUS treatment effect seen in DISCOVER-1, a sample size of 150 randomized pts per group for PBO, GUS Q8W, and GUS Q4W would provide >90% power to detect a significant difference between each GUS group and PBO for ACR20 response at W24. Based on these findings, a new Ph3b, multicenter, randomized, double-blind, PBO-controlled study, SOLSTICE, was designed to further evaluate the efficacy and safety of GUS in approximately 450 pts with active PsA who had IR to one prior TNFi, and to investigate the effect of GUS dosing interval in this important cohort of pts with PsA (Figure 1).

Table 1.

Clinical efficacy at W24 among DISCOVER-1 TNFi-experienced pts

PlaceboGUS Q8WGUS Q4WACR2017.9% (7/39)56.1% (23/41)57.9% (22/38)ACR505.1% (2/39)26.8% (11/41)34.2% (13/38)ACR702.6% (1/39)2.4% (1/41)21.1% (8/38)MDA2.6% (1/39)17.1% (7/41)26.3% (10/38)IGA 0/1a7.7% (2/26)48.3% (14/29)67.9% (19/28)

aIGA score of 0 (clear) or 1 (almost clear) among pts with ≥3% body surface area of psoriatic involvement and an IGA score ≥2 (mild-to-severe psoriasis) at baseline.

ACR20/50/70, American College of Rheumatology 20%/50%/70% improvement; GUS, guselkumab; IGA, Investigator’s Global Assessment; MDA, minimal disease activity; Q4W, every 4 weeks; Q8W, every 8 weeks; TNFi, tumor necrosis factor inhibitor; W, week

Conclusion

PsA pts with TNFi-IR are typically difficult to treat. Overall data from the pivotal DISCOVER-1 study of GUS in pts with active PsA showed consistent clinical response between doses and between TNFi-naïve and TNFi-experienced pts. Analyses based on limited numbers of TNFi-experienced pts from DISCOVER-1 demonstrated potential incremental benefit for achievement of higher response criteria with more frequent dosing in some TNFi-IR pts. SOLSTICE, a Ph3b, randomized, placebo-controlled study, will test this hypothesis.

References

[1]Deodhar A, et al. Lancet. 2020;395:1115-1125.

Figure 1.

Disclosure of Interests

Alexis Ogdie Shareholder of: Her husband has received royalties from Novartis, Consultant of: AbbVie, Amgen, BMS, Celgene, Corrona, Gilead, Global Health Living Foundation, Janssen, Eli Lilly, Novartis, Pfizer, and UCB Pharma, Grant/research support from: Abbvie, Pfizer and Novartis/Amgen to the University of Pennsylvania, Joseph F. Merola Paid instructor for: AbbVie, Arena, Biogen, Bristol Myers Squibb, Dermavant, Lilly, Janssen, Novartis, Pfizer, Sun Pharma, and UCB Pharma, Consultant of: AbbVie, Arena, Biogen, Bristol Myers Squibb, Dermavant, Lilly, Janssen, Novartis, Pfizer, Sun Pharma, and UCB Pharma, Philip J Mease Speakers bureau: AbbVie, Aclaris, Amgen, BMS, Celgene, Eli Lilly, Galapagos, Gilead, GlaxoSmithKline, Inmagene, Janssen, Novartis, Pfizer, SUN Pharma, and UCB, Consultant of: AbbVie, Aclaris, Amgen, BMS, Celgene, Eli Lilly, Galapagos, Gilead, GlaxoSmithKline, Inmagene, Janssen, Novartis, Pfizer, SUN Pharma, and UCB, Grant/research support from: AbbVie, Aclaris, Amgen, BMS, Celgene, Eli Lilly, Galapagos, Gilead, GlaxoSmithKline, Inmagene, Janssen, Novartis, Pfizer, SUN Pharma, and UCB, Christopher T. Ritchlin Consultant of: UCB Pharma, Amgen, AbbVie, Lilly, Pfizer, Novartis, Gilead, and Janssen, Grant/research support from: UCB Pharma, AbbVie, and Amgen, Jose U. Scher Consultant of: Janssen, Novartis, Pfizer, Abbvie, Sanofi, Kaleido and UCB Pharma, Grant/research support from: Novartis, Pfizer and Janssen (for investigator-initiated studies), Daphne Chan Employee of: Janssen Scientific Affairs, LLC, and may own stock or stock options in Johnson & Johnson, Soumya D Chakravarty Employee of: Janssen Scientific Affairs, LLC, and may own stock or stock options in Johnson & Johnson, Wayne Langholff Employee of: Janssen Research & Development, LLC, and may own stock or stock options in Johnson & Johnson, Olivia Choi Employee of: Janssen Scientific Affairs, LLC, and may own stock or stock options in Johnson & Johnson, Yevgeniy Krol Employee of: Janssen Scientific Affairs, LLC, and may own stock or stock options in Johnson & Johnson, Katelyn Rowland Employee of: Janssen Scientific Affairs, LLC, and may own stock or stock options in Johnson & Johnson, Alice B Gottlieb Consultant of: AnaptsysBio, Avotres Therapeutics, Beiersdorf, Boehringer Ingelheim, Bristol-Myers Squibb Co., Incyte, GSK, Janssen, LEO Pharma, Eli Lilly, Novartis, Pfizer, Sun Pharmaceutical Industries, Inc., UCB Pharma, Dermavant, and Xbiotech, Grant/research support from: Boehringer Ingelheim, Incyte, Janssen, Novartis, UCB Pharma, Xbiotech, and Sun Pharma

Norrin mediates tumor-promoting and -suppressive effects in glioblastoma via Notch and Wnt

Glioblastoma multiforme (GBM) contains a subpopulation of cells, GBM stem cells (GSCs), that maintain the bulk tumor and represent a key therapeutic target. Norrin is a Wnt ligand that binds Frizzled class receptor 4 (FZD4) to activate canonical Wnt signaling. Although Norrin, encoded by NDP, has a well-described role in vascular development, its function in human tumorigenesis is largely unexplored. Here, we show that NDP expression is enriched in neurological cancers, including GBM, and its levels positively correlated with survival in a GBM subtype defined by low expression of ASCL1, a proneural factor. We investigated the function of Norrin and FZD4 in GSCs and found that it mediated opposing tumor-suppressive and -promoting effects on ASCL1lo and ASCL1hi GSCs. Consistent with a potential tumor-suppressive effect of Norrin suggested by the tumor outcome data, we found that Norrin signaling through FZD4 inhibited growth in ASCL1lo GSCs. In contrast, in ASCL1hi GSCs Norrin promoted Notch signaling, independently of WNT, to promote tumor progression. Forced ASCL1 expression reversed the tumor-suppressive effects of Norrin in ASCL1lo GSCs. Our results identify Norrin as a modulator of human brain cancer progression and reveal an unanticipated Notch-mediated function of Norrin in regulating cancer stem cell biology. This study identifies an unanticipated role of Norrin in human brain cancer progression. In addition, we provide preclinical evidence suggesting Norrin and canonical Wnt signaling as potential therapeutic targets for GBM subtype-restricted cancer stem cells.

Abstract 4671: Novel biological roles of the atypical WNT ligand, Norrin, on glioblastoma stem cells segregate with ASCL1 expression

Norrin is an atypical WNT ligand that binds the Frizzled-4 (FZD4) and Low-density lipoprotein receptor-related protein (LRP5/6) receptor complex to activate canonical WNT/ β-catenin signaling. Norrin/FZD4 signaling is involved in the regulation of vasculature in several tissues including the retina and for blood-brain barrier function. The role of Norrin in cancer is not very well characterized. Here, we show that NDP, the gene encoding for Norrin, is expressed in a wide range of cancer types, with a particular enrichment in glioblastoma (GBM) and lower grade glioma (LGG). Kaplan-Meier survival analysis of publicly available datasets revealed a significant correlation between NDP expression and survival in GBM, LGG and neuroblastoma. To investigate the function of NDP in GBM, we performed a set of NDP and FZD4 gain and loss of function experiments in patient-derived GBM stem cell (GNS) lines. Recently Achaete-scute homolog 1 (ASCL1) expression was shown to stratify GNS lines into two cohorts with different tumorigenic, proliferation and differentiation dynamics. Surprisingly, we found that NDP manipulation resulted in opposite effects in ASCL1hi versus ASCL1lo lines. NDP inhibited proliferation and sphere formation in ASCL1lo lines through the WNT/ β-catenin pathway, while it stimulated proliferation and sphere formation in ASCL1hi lines independently of the WNT/β-catenin pathway. The NDP/FZD4 effects on growth in both GNS subtypes were recapitulated in xenografts, confirming effects of this pathway on tumor progression in vivo. To gain insight into the cellular and molecular effects of NDP/FZD4 on GNS growth we performed immunocytochemistry (ICC) and RNA-Seq analyses in GNS cells with NDP knockdown. In parallel with our in vitro and in vivo observations, we found that NDP/FZD4 signaling affects GNS proliferation index and cell cycle kinetics and the expression of cell cycle regulatory genes in both GNS subtypes, but in opposite ways. RNA-Seq analysis identified cell cycle regulatory genes and gene sets that are commonly affected by NDP in both GNS types. Interestingly, the analysis also identified several genes and genesets unique to each GNS type, consistent with the divergence of NDP functions between GNS subtypes. Collectively, our results uncover novel functions of NDP in regulating GBM stem cell progression, and that NDP functions in GBM stem cells stratify with ASCL1 expression. Additionally, our results highlight the significance of precision medicine in targeting tumor subtypes based on the molecular signature.

Citation Format: Ahmed A. Elsehemy, Hayden Selvadurai, Arturo Ortin-Martinez, Nenad Pokrajac, Yasin Mamatjan, Katherine Rowland, Kenneth Aldape, Peter Dirks, Valerie Wallace. Novel biological roles of the atypical WNT ligand, Norrin, on glioblastoma stem cells segregate with ASCL1 expression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4671.

Abstract 1117: Norrin signaling is protumorigenic in glioblastoma progression

Norrin signaling is protumorigenic in GBM progression

A-Introduction:

Norrin, a secreted factor encoded by the Norrie Disease Protein gene (NDP), is an atypical WNT ligand that specifically binds the FZD4 receptor and activates the canonical WNT signaling pathway in endothelial cells to regulate vascular development and barrier function in the brain. Recently, our group identified a novel tumor inhibitory function of NDP/FZD4 signaling in the endothelium in mouse models of medulloblastoma. Here we investigated the function of the NDP/FZD4 signaling axis in glioblastoma (GBM) progression.

B-Experimental approaches

GBM patients' survival data was obtained from TCGA and analyzed using the cBioportal server. Low passage mitogen expanded GBM cancer stem cell lines were established from primary tumors using standard conditions. NDP expression in experimental cell lines was modulated using lentiviral delivery of short hairpins or full length cDNA. Cell number was assessed by trypan blue cell counting, and sphere forming cell frequency was tested using extreme limited dilution assay (ELDA). For in vivo assessment of tumorigenesis, experimental and control cell lines were xenografted intracranially in NOD/SCID/Gamma (NSG) mice and symptomatic animals were euthanized and brains collected for histological analysis.

C-Results

Analysis of GBM data from TCGA showed that survival and NDP expression are negatively GBM. Gene expression analysis indicated variable expression levels of NDP/FZD4 signaling pathway components in a panel of 10 primary GBM stem cell lines. In vitro gain and loss of function studies showed that NDP promotes proliferation and sphere formation in GBM. Moreover, the effects of are recapitulated in xenografts. NDP appears to control GBM differentiation, as it affects the proportion of cycling (Ki67+) cells and the level of stemness (Sox2 levels). Finally, NDP function is independent of FZD4 and canonical Wnt signaling, indicating that it functions through an alternative pathway.

D-Conclusions Our in vitro and in vivo results indicate that Norrin might have an oncogeneic role in GBM. In addition, the effect of Norrin is FZD4- and WNT-independent. Our results indicate that targeting Norrin GBM might be a potential therapeutic approach.

Citation Format: Ahmed A. Elsehemy, Hayden Selvadurai, Katherine Rowland, Peter Dirks, Valerie Wallace. Norrin signaling is protumorigenic in glioblastoma progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1117.

Paraneoplastic cerebellar degeneration secondary to ovarian carcinosarcoma: a cerebellar conundrum

We present a case of an elderly female patient who presented with a 6-month history of progressive slurred speech, vertigo, unsteadiness and falls. She underwent an extensive battery of neurological and cardiovascular investigations, none of which demonstrated a diagnostic cause for her symptoms. She was referred to the stroke and neurology teams and was started on treatment for presumed anxiety. As her symptoms continued to progress, she was referred to the falls service. Following a multidisciplinary team discussion, she was reviewed by the consultant geriatrician who felt this may be due to a malignancy so the consultant geriatrician arranged blood testsand CT scan of her chest, abdomen and pelvis. These demonstrated a large left adnexal mass and a raised Ca-125 level. The patient was diagnosed with an ovarian tumour, which was treated surgically. A provisional diagnosis of paraneoplastic cerebellar degeneration, secondary to ovarian carcinosarcoma, was made.

Abstract B14: Wnt signaling circuits in glioblastoma multiforme

Glioblastoma multiforme (GBM) is the most common malignant tumour in the central nervous system with a prevalence of 2-3 cases per 100 000 people. Although the standard treatment of surgery, chemotherapy and radiotherapy improve survival, the median survival continues to remain at only 15 months with a 5-year survival rate of under 10%. Glioma neural stem-like (GNS) cells have been identified in GBM and have the capability of regenerating the tumour. Treatment strategies that target the majority of the tumour may be incapable of also targeting GNS cells and thus characterization of GNS cells may provide insight into additional treatment options. The Wnt signalling pathway has been linked to several cancers including GBM. Wnt signalling involves the secretion of Wnt ligand proteins that bind to specific Frizzled (FZD) receptor complexes on the cell surface of Wnt-responding cells to activate intracellular signalling cascades. The transcriptional and epigenetic regulation in GNS cells is the focus of several recent studies. The transcription factor ASCL1 was identified to be overexpressed and to lead to Wnt signalling activation by repressing Dickkopf (DKK1, Wnt inhibitor). Using microarray data we analyzed the expression of FZD receptors and Wnt target genes in over 50 primary GNS cell lines cultured in serum free conditions in order to maintain the GIC population and identified a subgroup of glioma lines with activated Wnt signalling. To determine the requirement of autocrine Wnt signalling for GNS cell renewal we inhibited Wnt secretion, using the porcupine inhibitor LGK974, and measured self-renewal using a limited dilution assay. There was a significant reduction in GNS cell frequency with LGK974 (1uM) treatment in four out of eight lines tested (G432NS, G472NS, G511NS and G523NS). Furthermore, a secondary sphere assay with G523NS cells also showed a significant reduction in GNS cell frequency. When G511NS and G523NS cells were treated with LGK974 (1uM) over a two week period, there was a significant increase in the percentage of GFAP (astrocytic marker) expressing cells whereas a two week treatment with Bio (1uM, Wnt activator), significantly increased the percentage of Tuj1 (neuronal marker) expressing cells. This finding suggest that these cells require a specific amount of Wnt signalling for self-renewal and Wnt inhibition or activation may lead to differentiation. RNAseq analysis comparing the four LGK974 responsive lines with the four LGK974 unresponsive lines identified ASCL1 to be highly expressed in the responsive lines. Gene set enrichment analysis identified four gene sets significantly enriched in the responsive group including the Glioblastoma Proneural gene set whereas genes from the Glioblastoma Mesenchymal gene set were significantly enriched in the unresponsive group. We have identified a subset of GNS cells that are dependent on Wnt secretion for self-renewal and RNAseq analysis suggests that GBMs that fall under the Proneural subtype may be sensitive to Wnt inhibition.

Citation Format: Nishani Rajakulendran, Hayden Selvadurai, Katherine Rowland, Nicole Park, Nizar Batada, Peter Dirks, Stephane Angers. Wnt signaling circuits in glioblastoma multiforme. [abstract]. In: Proceedings of the AACR Special Conference: Developmental Biology and Cancer; Nov 30-Dec 3, 2015; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(4_Suppl):Abstract nr B14.

Improved time to treatment failure with an intermittent oxaliplatin strategy: results of CONcePT

BACKGROUND

Oxaliplatin is an integral component of colorectal cancer treatment, but its use is limited by neurotoxicity. The Combined Oxaliplatin Neurotoxicity Prevention Trial (CONcePT) tested intermittent oxaliplatin (IO) administration and the use of concurrent calcium and magnesium salts (Ca/Mg), two modifications intended to reduce neurotoxicity and extend the duration of treatment.

PATIENTS AND METHODS

In this trial involving double randomization, 140 patients were randomized to receive modified FOLFOX7 plus bevacizumab with IO (eight-cycle blocks of oxaliplatin treatment) versus continuous oxaliplatin (CO); and Ca/Mg versus placebo (pre- and postoxaliplatin infusion). The primary end point was time-to-treatment failure (TTF).

RESULTS

One hundred thirty-nine patients were entered and treated up to the point of early study termination due to concerns by the data-monitoring committee (DMC) that Ca/Mg adversely affected tumor response. Tumor response was not a study end point. Given DMC concerns, an additional independent, blinded radiology review of all images showed no adverse effect of treatment schedule or Ca/Mg on response by Response Evaluation Criteria In Solid Tumors. The IO schedule was superior to CO [hazard ratio (HR) = 0.581, P = 0.0026] for both TTF and time-to-tumor progression (TTP) (HR = 0.533, P = 0.047).

CONCLUSIONS

An IO dosing schedule had a significant benefit on both TTF and TTP versus CO dosing in this trial despite the very attenuated sample. There was no effect of Ca/Mg on response.

N0539 phase II trial of fulvestrant and bevacizumab in patients with metastatic breast cancer previously treated with an aromatase inhibitor: a North Central Cancer Treatment Group (now Alliance) trial

BACKGROUND

Based on preclinical studies, the vascular endothelial pathway is an important mechanism for estrogen receptor resistance. We conducted a phase II study of fulvestrant and bevacizumab in patients with aromatase inhibitor pretreated metastatic breast cancer.

PATIENTS AND METHODS

A single-stage phase II study was conducted with these objectives: 6-month progression-free survival (PFS), tumor response, toxic effect, and overall survival. Regimen: 250 mg fulvestrant days 1 and 15 (cycle 1) then day 1 (cycle 2 and beyond) and 10 mg/kg bevacizumab days 1 and 15 of each 4-week cycle.

RESULTS

At interim analysis, 20 eligible patients initiated treatment, 11 were progression free and on treatment at 3 months, not meeting the protocol-specified efficacy requirements (at least 12 of 20). Accrual remained open during interim analysis with 36 patients enrolling before final study closure. Among the 33 eligible patients, the median PFS was 6.2 months [95% confidence interval (CI) 3.6-10.1 months]. Of the 18 with measurable disease, 4 (22%) patients (95% CI 6% to 48%) had a confirmed tumor response (1 complete, 3 partial). The most common grade 3/4 adverse events were hypertension 3 (9%) and headache 3 (9%).

CONCLUSIONS

The fulvestrant/bevacizumab combination is safe and tolerable; however, it did not meet its statistical end point.

N0539 Phase II Trial of Fulvstrant and Bevacizumab in Patients with Metastatic Breast Cancer Previously Treated with an Aromatase Inhibitor: A North Central Cancer Treatment Group Trial

Background: Treatment of aromatase refractory metastatic breast cancer (MBC) is difficult and challenging. Estrogen receptor (ER) resistance causes enhanced expression of the vascular endothelial growth factor (VEGF).Several studies have shown that the ER interacts with the VEGF pathway and is an important mechanism of resistance. Therefore we embarked on a phase II study of fulvestrant, a complete ER suppressor and bevacizumab, a well studied VEGF monoclonal antibody in aromatase refractory MBC patients. Methods: A single stage phase II study with an interim analysis of fulvestrant and bevacizumab was conducted with these objectives: 6 month progression-free survival rate (PFS), tumor response, toxicity, and overall survival. Regimen: fulvestrant 250 mg day1 and 15 (cycle 1) then day 1 (cycle 2 and beyond) and bevacizumab 10mg/kg days 1 and 15 of each 4 weeks is a cycle. Results: At the time of interim analysis, 11/20 evaluable patients achieved 3-month progression-free survival status while remaining on treatment for at least 3 months, not meeting the protocol specified efficacy requirements and thus halting accrual. 36 patients were enrolled from September 2007-December 2008; 33 patients were evaluable. Number of prior metastatic chemotherapy regimens: 0 in 26 patients and 1 in 7 patients. 22 (67%) patients received prior hormonal therapy in the metastatic setting. 18 (55%) had measurable disease. A median of 6 cycles (range 1-19) were administered. 12/33 evaluable patients (95% CI:20-55%) achieved 6-month progression-free survival status while remaining on treatment for a least 6 months. Among 18 patients with measurable disease, 2 (11%) patients CI:1.4-35%) had a confirmed tumor reponse (both PR). Additionally, 2 patients had stable disease for greater than 6 months, for a clinical benefit rate of 22%. Median follow up was 8.5 months (range 1.7-17.5 months). Median progression-free survival was 6.2 months (95% CI:5.4-10.1 months). The 6 -month overall survival rate was 84.8% (95% CI 73.5-98%). The median dose level administered was 250 mg for fulvestrant and 10 mg/kg for bevacizumab for cycles 1-19. The most common grade 3/4 adverse events (AEs) were hypertension 2 (6%), headache pain 2 (6%), and confusion 2 (6%). There was 1 grade 5 central nervous system hemorrhage. 13 (39%) patients experienced a grade 3 non-hematologic AE and 4 (12%) experience a grade 4+ non-hematologic AE. Conclusion: Fulvestrant/bevacizumab is safe and tolerable. Although this regimen did not meet its statistical endpoint, 22% of evaluable patients with aromatase refractory diesease achieved clinical benefit with minimal toxicity.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4096.

Paclitaxel-Related Peripheral Neuropathy Associated with Improved Outcome of Patients with Early Stage HER2+ Breast Cancer Who Did Not Receive Trastuzumab in the N9831 Clinical Trial

Background: Microtubules are crucial for spindle formation during mitosis and for cellular proliferation. The antineoplastic effect of paclitaxel is mainly related to its ability to bind the beta subunit of tubulin, thus preventing tubulin chain depolarization and inducing apoptosis. Tubulins are expressed in human peripheral nerves and the binding of paclitaxel to tubulin may lead to neuropathy. Peripheral neuropathy is a common dose limiting toxicity of paclitaxel. We hypothesized that the occurrence of peripheral neuropathy may correlate with outcome (disease-free survival; DFS).Methods: This analysis sought to describe incidence of peripheral neuropathy following paclitaxel and its association to outcome (DFS) in patients who received paclitaxel (weekly x 12) in the adjuvant HER2+ intergroup trial N9831. Only eligible pts who initiated paclitaxel and did not have peripheral neuropathy at initiation of paclitaxel that were randomized to arms A (955 pts; chemotherapy alone) and C (889 pts; chemotherapy plus concurrent trastuzumab) of N9831 were included. Cox regression analysis stratified by ER/PR status and nodal status was used to compare DFS within arm between patients with and without peripheral neuropathy.Results: Out of 1844 eligible pts, 379 developed neuropathy (20.5%). For pts in arm A, those who developed neuropathy had better DFS than pts who did not (3 yr DFS: 86.2% vs 81.8%; HR 0.65; p=0.01), despite lower doses of paclitaxel in the pts with neuropathy. Grade of neuropathy did not appear to impact DFS. No statistical difference was noted for pts treated in the trastuzumab-containing arm (3 yr DFS: 92.8% vs 91.1% for pts with neuropathy vs not; HR 0.79; p=0.34). There were no differences in paclitaxel dose intensity between arms A and C.Conclusion: Patients with early stage HER2+ breast cancer who received adjuvant paclitaxel-containing chemotherapy in arm A and developed peripheral neuropathy had a better DFS than pts who did not develop neuropathy. This effect was possibly abrogated by the use of trastuzumab in Arm C. This side effect may represent effective bindings of paclitaxel to the target tubulin, lack of point mutations in tubulin at the paclitaxel binding site and/or lack of selective overexpression of β-III tubulin. This is a hypothesis generating study and additional analysis needs to be conducted from other large taxane-based trials.Partial support from Genentech and the Breast Cancer Research Foundation

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2100.

Salvage chemotherapy with rituximab, oxaliplatin, cytosine arabinoside, and dexamethasone (ROAD) in patients with relapsed CD20+ aggressive B-cell lymphoma

8556

Background: In the original PARMA trial it was demonstrated that salvage chemotherapy with DHAP followed by autologous bone marrow transplant resulted in increased overall survival over salvage chemotherapy with DHAP alone in patients with aggressive lymphomas. The current study was designed to assess safety and feasibility of ROAD as a salvage chemotherapy regimen which could be administered as an inpatient or outpatient. Methods: Patients received immunochemotherapy on the following schedule: rituximab 375 mg/m2 weekly × 4, oxaliplatin 130 mg/m2 on day 2, Ara C 2000mg/m2 x 2 doses on day 2 and dexamethasone 40 mg on days 2–5, with OAD repeated at 3 week intervals (up to 6 cycles). Patients were considered for autologous stem cell transplantation after 2 cycles if eligible. Eligible histologies included diffuse large B cell lymphoma, mantle cell lymphoma and transformed lymphoma in first relapse. Results: 50 patients were accrued from Aug 2006 through Jul 2008: 5 patients were deemed ineligible after central pathology review. Baseline characteristics of eligible patients included median age 69 (range 23 - 77), 53% were male, 53% had advanced stage at relapse, LDH was elevated in 58% and all patients had an ECOG PS of 2 or less. Patients received a median of 2 cycles of therapy (range 1–6) with 39/45 receiving treatment in cycle 2, with 12 patients continuing beyond 2 cycles. 31 patients experienced grade III/IV hematologic toxicity and 22 patients had grade III/IV non-hematologic toxicity, primarily febrile neutropenia. One patient developed grade III nephrotoxicity due to disease progression. Twenty patients received their treatments exclusively as outpatients. 26 responses were seen in the 45 eligible patients (58%, 95% CI: 44–74%), with 20 responding patients proceeding to autologous SCT. Conclusions: ROAD is a safe and effective salvage chemotherapy regimen for relapsed aggressive lymphoma, including as a preparatory regimen prior to stem cell transplant. It appears to have similar response rates to R-DHAP in a similar patient population, but without the potential nephrotoxicity (data from prior published study from NCCTG). ROAD can be safely administered as an inpatient or outpatient.

No significant financial relationships to disclose.

A randomized controlled trial evaluating a topical treatment for chemotherapy-induced neuropathy: NCCTG trial N06CA

9531

Background: Chemotherapy induced peripheral neuropathy (CIPN) is a prevalent dose limiting toxicity for several important cancer treatment agents. CIPN can impair function and cause distress. There are no proven pharmacologic treatments for established CIPN currently. This double blind randomized placebo controlled trial evaluated a compounded topical gel for this problem. The novelty of this treatment is that it might incorporate several agents with different mechanisms of action to provide relief locally without negative systemic effects. Methods: Patients with CIPN (rated ≥4 out of 10) for at least one month, related to previous and/or concurrent exposure to neurotoxic agents, were randomized to baclofen 10 mg, amitriptyline HCL 40 mg and ketamine 20 mg in a pluronic lecithin organogel (BAK-PLO) vs placebo (PLO) to determine its effect on numbness, tingling, pain, and motor function. Exclusion criteria included other causes and/or current treatment for peripheral neuropathy. The primary endpoint was the baseline adjusted sensory subscale of the EORTC QLQ-CIPN20, at 4 weeks. Results: Between February and May 2008, 208 patients were enrolled onto this trial. Four week data are shown in the table below, higher numbers being better. The percentage of patients that had improvements of at least 10, on a 100 point scale, in the motor subscale was statistically significantly higher in the BAK-PLO arm, p=.04. There were no unwanted toxicities associated with the BAK-PLO that were significantly different from placebo and no evidence of CNS or systemic toxicity. Conclusions: Topical treatment with BAK-PLO appears to moderately improve symptoms of CIPN. This topical gel was well tolerated without systemic side effects.

[Table: see text]

No significant financial relationships to disclose.

Does tetracycline prevent/palliate epidermal growth factor receptor (EGFR) inhibitor-induced rash? A phase III trial from the North Central Cancer Treatment Group (N03CB)

LBA9006

Purpose: Many patients who receive EGFR inhibitors develop an acneiform rash, and anecdotal reports suggest tetracycline is effective in treating it. To our knowledge, however, no rigorous trials have ever been published to substantiate this approach. This double- blinded, placebo-controlled trial was conducted to assess the role of tetracycline in preventing EGFR inhibitor-induced rash and/or reducing its severity. Methods: 61 patients were randomly assigned to tetracycline 500 mg orally twice a day×4 weeks versus an identical, similarly prescribed placebo. Eligibility criteria required all patients to have begun an EGFR inhibitor </= 7 days prior with no rash at study entry. Patients were to be followed for 8 weeks. Physician assessments of rash incidence, severity, and adverse events, occurred at 4 and 8 weeks. Patients completed a weekly rash diary, quality of life questionnaire (SKINDEX-16), and EGFR inhibitor compliance questionnaire. Thirty patients per group provides 90% power to detect a difference in rash incidence (the primary endpoint) of 40% between groups and of rejecting the null hypothesis of equal proportions with a type I error of 5% (2-sided). Results: Treatment arms were balanced on baseline characteristics, drop out rates, and rates of discontinuation of the EGFR inhibitor. Rash incidence was comparable across arms. Physicians reported that 16 tetracycline-treated patients (70%) and 22 placebo-exposed patients (76%) developed a rash (p=0.61). However, tetracycline appears to have lessened rash severity. By week 4, physician-reported grade 2 rash occurred in 17% of tetracycline-treated patients (n=4) and 55% of placebo- exposed patients (n=16); (p=0.04). Tetracycline-treated patients reported better scores on certain quality of life parameters (SKINDEX-16), such as skin burning or stinging, skin irritation, and being bothered by a persistence/recurrence of a skin condition. Adverse events were comparable across arms. Conclusion: Tetracycline did not prevent EGFR inhibitor-induced rashes. However, diminished rash severity and improved quality of life suggest this antibiotic merits further study.

No significant financial relationships to disclose.

Correlation between mouse potency and in vitro relative potency for human papillomavirus Type 16 virus-like particles and Gardasil vaccine samples

An in vitro relative potency (IVRP) assay has been developed as an alternative to the mouse potency assay used to release Merck's human papillomavirus (HPV) vaccine, Gardasil, for early phase clinical trials. The mouse potency assay is a classical, in vivo assay, which requires 4-6 weeks to complete and exhibits variability on the order of 40% relative standard deviation (RSD). The IVRP assay is a sandwich-type immunoassay that is used to measure relative antigenicity of the vaccine product. The IVRP assay can be completed in three days, has a variability of approximately 10% RSD and does not require the sacrifice of live animals. Because antigen detection is achieved using H16.V5, a neutralizing monoclonal antibody, which binds to a clinically-relevant epitope, the relative antigenicity measured by the IVRP assay is believed to be a good predictor of in vivo potency. In this study, the relationship between immunogenicity, as measured by the mouse potency assay and antigenicity as measured by the IVRP assay, is demonstrated. Freshly manufactured and aged samples produced using two different manufacturing processes were tested using both methods. The results demonstrate that there is an inverse correlation between the IVRP and mouse potency assays. Additionally, clinical results indicate IVRP is predictive of human immunogenicity. Thus, antigenicity, as defined by the H16.V5 epitope, can be used as a surrogate for immunogenicity and the IVRP assay is suitable for use as the sole potency test for Gardasil samples.

Randomized phase III trial comparing cisplatin-etoposide to carboplatin-paclitaxel in advanced or metastatic non-small cell lung cancer

BACKGROUND

The present study was designed to evaluate the efficacy and safety of the regimen of carboplatin plus paclitaxel (investigational arm) versus the reference regimen of cisplatin plus etoposide for the treatment of advanced or metastatic non-small-cell lung cancer.

PATIENTS AND METHODS

A total of 369 patients were enrolled, 179 on arm A (cisplatin 75 mg/m2 and etoposide 100 mg/m2) and 190 on arm B (carboplatin AUC=6 mg/ml min and paclitaxel 225 mg/m2), with cycles repeated every 3 weeks. The arms were well balanced with respect to age, performance status, weight loss, stage of disease and disease measurability. However, significantly more women were randomized to arm A than to arm B (P=0.039).

RESULTS

The objective response rate (ORR) was 15% on arm A compared with 23% on arm B (P=0.061). Median survival time, time to progression and 1-year survival rates for arms A and B were 274 days and 233 days (P=0.086), 111 days and 121 days (P=0.877), and 37% and 32%, respectively. The most prevalent toxicities were neutropenia and leukopenia and they occurred at a higher rate in arm A than in arm B.

CONCLUSION

There was no statistically significant survival advantage for carboplatin-paclitaxel compared with cisplatin-etoposide. However, there was an overall benefit in quality of life with the carboplatin-paclitaxel regimen.

Gynecologic cancer treatment and the impact of cancer-related infertility

OBJECTIVE

The objective of this study was to empirically assess the emotional and sexual impact of cancer-related infertility in women with a history of gynecologic cancer.

METHOD

Women with a history of gynecologic cancer were approached during their gynecologic oncology clinic appointment; they were provided a description of the study and asked to participate. All participants completed a one-time self-report survey. We present data acquired via the following methods: Center for Epidemiologic Studies-Depression Scale (CES-D), Impact of Events Scale (IES), Modified Inventory of Traumatic Grief (M-ITG), Female Sexual Function Index (FSFI), and the Menopausal Symptom Checklist.

RESULTS

The study sample consisted of 20 women, ages 27 to 49 years (mean, approximately 40 years), who had undergone treatment for cervical (40%), ovarian (20%), or uterine (40%) cancer. Forty percent of the sample reported depressive symptoms as measured by the CES-D, with 35% of the women experiencing moderate to severe levels of distress as measured by the IES. The women in this sample experienced dissatisfaction with their overall sex lives (67%), pain during vaginal penetration (62%), and low levels of sexual desire (56%).

CONCLUSIONS

The preliminary findings of this study indicated that feelings of depression, grief, stress, and sexual dysfunction are being experienced by women with a history of gynecologic cancer who have lost their fertility as a result of their cancer treatment.

Pulmonary nocardiosis re-visited: experience of 35 patients at diagnosis

Pulmonary infection by Nocardia is an uncommon opportunistic infection in humans. Thirty-five patients with pulmonary nocardiosis were identified in two tertiary referral hospitals. A retrospective review of the patient characteristics, clinical and laboratory features including antimicrobial susceptibility at diagnosis was carried out. Radiological features derived from chest radiographs and CT scans were also documented. In our population, the predominant risk factors were immuno-compromised state, corticosteroid therapy, and underlying pulmonary pathology. The presenting features were similar to those previously described but disseminated infection was not common. The radiological changes were diverse and non-specific. Nocardia asteroides was the commonest species. Most Nocardia isolates were susceptible to imipenem, ceftriaxone, amikacin, and cotrimoxazole. Co-existing microbial agents are common and reflect the underlying complex disorders.

Maintenance of caspase-3 proenzyme dormancy by an intrinsic "safety catch" regulatory tripeptide

Caspase-3 is synthesized as a dormant proenzyme and is maintained in an inactive conformation by an Asp-Asp-Asp "safety-catch" regulatory tripeptide contained within a flexible loop near the large-subunit/small-subunit junction. Removal of this "safety catch" results in substantially enhanced autocatalytic maturation as well as increased vulnerability to proteolytic activation by upstream proteases in the apoptotic pathway such as caspase-9 and granzyme B. The safety catch functions through multiple ionic interactions that are disrupted by acidification, which occurs in the cytosol of cells during the early stages of apoptosis. We propose that the caspase-3 safety catch is a key regulatory checkpoint in the apoptotic cascade that regulates terminal events in the caspase cascade by modulating the triggering of caspase-3 activation.

Rotavirus encephalopathy: pathogenesis reviewed

Two cases of rotavirus gastroenteritis associated with neurological involvement, one with encephalitis (defined by abnormal neurological signs, cerebrospinal fluid (CSF) pleocytosis and detection of rotavirus genomic nucleic acid in the CSF) and one with a non-inflammatory encephalopathy (defined by abnormal neurological signs, an entirely normal CSF and detection of rotavirus genomic nucleic acid in the CSF), are presented and used as a basis to review and explore potential pathogenetic mechanisms, including direct viral replication within neurons and indirect effects of the newly described rotavirus 'enterotoxin'.

In vitro metabolism of 6-mercaptopurine by human liver cytosol

1. The aim of this study was to investigate 6-mercaptopurine (6MP) metabolism by human liver cytosol in vitro. 2. Cytosol was prepared from seven human livers (A-G). A single cytosol (C) was used to optimize incubation conditions. 3. Cytosols A-G were incubated with 6MP at 2, 10 and 500 microM for two fixed times (5 and 48 h). Parent drug, thiopurine and thionucleotide metabolites were quantitated by high performance liquid chromatography at all time points. 4. At 5 and 48 h the 2 microM and 10 microM 6MP incubations contained both 6MP and its initial nucleotide metabolite, thioinosine 5'-monophosphate (TIMP). In addition, the 10 microM 6MP 48 h incubates contained small amounts of 6-thioguanine (6TG, median 0.12 microM). At 500 microM 6MP all seven liver incubates produced a range of metabolites. At 48 h these included thiouric acid, 8-hydroxy-6-mercaptopurine and 6-methylmercaptopurine (median 31, 19.5 and 8.8 microM respectively), with TIMP, 6TG, thioxanthine and thioxanthine nucleotide at median concentrations of 61, 0.79, 2.11 and 0.80 microM respectively. Thioguanine nucleotides, major metabolites measured in vivo, were not detected. 5. These results indicate that the human liver 6MP metabolic profile is dependent upon drug concentration.

Insertion, efficacy, and removal of a nonendoscopically removable percutaneous endoscopic gastrostomy (PEG) tube

BACKGROUND

Externally removable PEG tubes require an internal bumper that can collapse to a size that is small enough to allow for its removal through the abdominal wall by external traction. Adequate force must be maintained to avoid accidental dislodgement of the tube prior to its desired removal.

METHODS

A nonendoscopically removable PEG (Inverta-PEG, Ross Products Division, Abbott Laboratories, Columbus, OH, USA) was evaluated in a nonmasked, prospective clinical study involving 131 patients enrolled by 25 physicians. The over-the-wire (Sacks-Vine) technique was used for all placements. After insertion, patients were followed weekly for 8 weeks. During week 9, the PEGs were removed percutaneously (nonendoscopically). Insertion, efficacy, and removal performance were evaluated.

RESULTS

Complication rate during insertion was 1.5% and removal was 1.2%. Qualitatively, investigators rated ease of insertion and removal as very easy, easy, average, difficult, or very difficult. Investigators rated 98.5% of insertions as very easy, easy, or average; 95.4% of removals were rated as very easy, easy, or average. Some patients exited the study prematurely due to leakage around the stoma (2.3%) and inadvertent tube removal (5.3%). These complication rates were consistent with earlier reports of other PEG studies.

CONCLUSIONS

These results demonstrate that Inverta-PEG is a safe and effective tube that can be removed nonendoscopically with ease in 95% of the cases.

Laparoscopic gastrostomy and jejunostomy: safety and cost with local vs general anesthesia

BACKGROUND AND HYPOTHESIS

General anesthesia is used for laparoscopic enteral access because pneumoperitoneum requires relaxation of the abdominal muscles. We wanted to determine whether these procedures could be performed with similar results and cost under local anesthesia.

DESIGN

Randomized controlled study with 30-day follow-up including a cost-benefit analysis.

SETTING

University-affiliated hospitals.

PATIENTS

Forty-eight patients (32 men, 16 women; mean age, 67 years) undergoing laparoscopic gastrostomies (n = 32) and jejunostomies (n = 16).

INTERVENTION

Twenty-four patients underwent laparoscopic gastrostomy (n = 15) and jejunostomy (n = 9) under local anesthesia with intravenous conscious sedation and monitored anesthesia care. Twenty-four patients had general anesthesia.

MAIN OUTCOME MEASURES

Conversion to general anesthesia, complications, and cost.

RESULTS

Ten patients under local anesthesia had periods of deep sedation and 1 required conversion to general anesthesia. One patient under general anesthesia required conversion to open gastrostomy. No patients had intraoperative aspiration; however, 4 aspirated after the procedure. One patient died of myocardial infarction during the 30-day follow-up. We found no significant difference in the total mean cost and actual procedure time. The surgeon's fee accounted for 31% of the total cost.

CONCLUSIONS

Some patients undergoing laparoscopic enteral access may require deep sedation and a rare patient may require general anesthesia. Clinical conditions and surgeon preference, therefore, should determine whether local anesthesia is suitable for laparoscopic gastrostomies and jejunostomies, and in what setting, since there is no difference in success rate or complications when compared with general anesthesia. Potential savings are possible from the operating room (26% of total cost) or anesthesiologist (12% of total cost) if these procedures are performed in an endoscopy suite without monitored anesthesia care.

Thioguanine versus mercaptopurine for therapy of childhood lymphoblastic leukaemia: a comparison of haematological toxicity and drug metabolite concentrations

As a prelude to a nationwide randomized trial of thioguanine (TG) versus mercaptopurine (MP) for childhood lymphoblastic leukaemia we compared a pilot group of 23 children taking TG with a matched group taking MP. We assessed drug tolerance based on haematological toxicity and measured erythrocyte (RBC) concentrations of thioguanine nucleotides (TGN). The median tolerated dose of TG was 30 mg/m2 compared to 55 mg/m2 for MP. There was no difference in the pattern of anaemia or neutropenia between the two groups, but dose-limiting thrombocytopenia was more evident in the TG children (P< 0.001), four of whom had a decrease in platelet count to <20 x 10(9)/l compared to only one on MP. The median RBC TGN concentration for those on 40 mg/m2 TG was 1726 pmol/8 x 10(8) RBCs compared with 308 pmol/8 x 10(8) RBCs for those on 75 mg/m2 MP (P< 0.0001). There was an inverse correlation between RBC TGNs and neutrophil count in the MP group but not in those on TG. No correlation between metabolite concentration and thrombocytopenia was found in either group. These results provide further evidence that TG has a selective effect on platelets. They also showed that RBC TGN were, on average, 5-fold higher in those taking TG but did not obviously relate to myelotoxicity as found in children on MP. The higher concentrations seen may partly reflect the erythrocyte's ability to metabolize TG directly to TGN by pathways not open to MP.

High-performance liquid chromatographic assay of methylthioguanine nucleotide

This paper describes a specific and sensitive reversed-phase HPLC assay for the measurement of 6-methylthioguanine (methyl-TG) and methyl-TG nucleotides (methyl-TGNs) in red blood cells (RBCs), which is suitable for routine clinical use. Briefly, an ethyl acetate extract of RBCs is evaporated and reconstituted in 0.1 M HCl. The methyl-TG is separated from other thiopurines by reversed-phase HPLC and quantitated using UV detection. For the measurement of methyl-TGNs the free base (methyl-TG) is obtained by acid hydrolysis of the nucleotide back to the parent thiopurine. The intra-assay C.V. over the concentration range of 0.055-1.10 nmol methyl-TG per 4x10(8) (100 microl) RBCs ranged from 2.8 to 8.5%, and the mean recovery of methyl-TG over the calibration range was 61.6% (coefficient of variation, C.V., 3.8%). The lower limit of reproducibility was 0.055 nmol extracted from 100 microl RBCs. Analysis of blood samples from children with leukaemia receiving 6TG chemotherapy, revealed RBC methyl-TGNs at concentrations ranging from 323 to 1365 pmol per 8x10(8) RBCs. No methyl-TG was detected in any of the patient samples.

Variable contribution of CYP2D6 to the N-dealkylation of S-(-)-propranolol by human liver microsomes

Recombinant cDNA expression systems for CYP2D6 have been shown to have significant catalytic activity with respect to the N-dealkylation of propranolol. However, the involvement of CYP2D6 in this reaction in human liver is inconclusive. We have re-evaluated the role of CYP2D6 in the dealkylation of S-(-)-propranolol using a bank of 10 human livers characterized for their specific CYP2D6 and CYP1A2 activities, the latter enzyme being known to be involved substantially in the formation of N-desisopropylpropranolol. Using quinidine (1 microM) or LKM-1 antibodies as selective inhibitors of CYP2D6, the contribution of this enzyme to net N-desisopropylation of S-(-)-propranolol (10 microM) by microsomes from the range of livers was found to vary from nil (poor metabolizer genotype) to 60%. N-desisopropylpropranolol formation inhibitable by quinidine was highly correlated with specific CYP2D6 activity, as measured by the alpha-hydroxylation of metoprolol (rs = 0.90; P < 0.001). The two livers with the highest proportion of CYP2D6-mediated N-dealkylation had relatively high ratios of specific CYP2D6 to CYP1A2 activity. These findings emphasize that data obtained using microsomes from single human livers or pooled microsomes from several livers may be misleading inasmuch as the relative contribution of different isoenzymes to the same metabolic reaction may show considerable between-subject variation.

Influence of amino acid residue 374 of cytochrome P-450 2D6 (CYP2D6) on the regio- and enantio-selective metabolism of metoprolol

Cytochrome P-450 2D6 (CYP2D6) is an important human drug-metabolizing enzyme responsible for the oxidation of more than 30 widely used therapeutic agents. The enzymes encoded by the published genomic [Kimura, Umeno, Skoda, Meyer and Gonzalez (1989) Am. J. Hum. Genet. 45, 889-904] and cDNA [Gonzalez, Skoda, Kimura, Umeno, Zanger, Nebert, Gelboin, Hardwick and Meyer (1988) Nature 331, 442-446] sequences of CYP2D6, and presumed to represent wild-type sequences, differ at residue 374 and encode valine (CYP2D6-Val) and methionine (CYP2D6-Met) respectively. The influence of this amino acid difference on cytochrome P-450 expression, ligand binding, catalysis and stereoselective oxidation of metoprolol was investigated by the heterologous expression of the corresponding cDNAs in the yeast Saccharomyces cerevisiae. The level of expression of apo- and holo-protein was similar with each form of CYP2D6 cDNA, and the binding affinities of a series of ligands to CYP2D6-Val and CYP2D6-Met were identical. The enantioselective O-demethylation and alpha-hydroxylation of metoprolol were also similar with each form of CYP2D6, O-demethylation being R-(+)- enantioselective (CYP2D6-Val: R/S, 1.6; CYP2D6-Met: R/S, 1.4), whereas alpha-hydroxylation showed a preference for S-(-)-metoprolol (CYP2D6-Val: R/S, 0.7; CYP2D6-Met: R/S, 0.8). However, although the favoured regiomer overall was O-demethylmetoprolol (ODM), the regioselectivity for O-demethylation of each metoprolol enantiomer was significantly greater for CYP2D6-Val [R-(+)-: ODM/alpha-hydroxymetoprolol (alpha OH), 5.9; S-(-)-: ODM/alpha OH, 2.5) than that observed for CYP2D6-Met [R-(+)-: ODM/alpha OH, 2.2; S-(-)-: ODM/alpha OH, 1.4]. The stereoselective properties of CYP2D6-Val were consistent with those observed for CYP2D6 in human liver microsomes. The difference in the stereoselective properties of CYP2D6-Val and CYP2D6-Met were rationalized with respect to a homology model of the active site of CYP2D6 based on an alignment with the crystal structure of the bacterial cytochrome P-450BM-3' CYP102.

Inhibition of CYP2D6 activity by treatment with propranolol and the role of 4-hydroxy propranolol

1. The 4-hydroxylation of propranolol by rat and human liver microsomes is associated with formation of a chemically reactive species which binds irreversibly to cytochrome P4502D6 (CYP2D6) destroying its catalytic function. Therefore, the effect of propranolol treatment (80 mg twice daily) on debrisoquine phenotype was examined, to see if it resulted in phenocopying in vivo. The role of 4-hydroxypropranolol (4OHP) in the inhibition of CYP2D6 activity was also studied using microsomes from yeast expressing CYP2D6 and from human livers; metoprolol was used as the CYP2D6 substrate. 2. Although a significant effect on apparent oxidation phenotype was demonstrated, the absolute change in the urinary debrisoquine/4-hydroxydebrisoquine ratio (D/4HD) was small, such that no extensive metaboliser who received propranolol treatment was reclassified as a poor metaboliser. The in vitro studies indicated that 4OHP is a potent inhibitor of metoprolol metabolism (Ki approximately 1 microM). This inhibitory effect was enhanced when 4OHP was pre-incubated in the presence of a NADPH generating system and human liver microsomes. The effect was decreased significantly when reduced glutathione was added to the pre-incubation mixture. Metabolism of 4OHP occurred when incubated with human liver microsomes in the presence of a NADPH generating system and irrespective of CYP2D6 phenotype; yeast expressing CYP2D6 did not metabolise 4OHP. 3. We conclude that, although treatment with propranolol 80 mg twice daily significantly decreases the catalytic function of CYP2D6, the inhibition is insufficient to result in phenocopying. The reactive intermediate produced by further metabolism of 4OHP is probably scavenged effectively in vivo by glutathione and other nucleophiles.

Pre-treatment prognostic factors in stage III non-small cell lung cancer patients receiving combined modality treatment

Approximately one-third of non-small cell lung cancer (NSCLC) patients present with locally advanced disease. Increasing numbers of clinical trials are being conducted in this group of patients and recently a new international staging system has been introduced, resulting in the sub-division of Stage III into IIIa (potentially operable disease) and IIIb (inoperable disease). Kaplan-Meier survival analyses and Cox regression analyses were used to analyze data from 129 Stage III NSCLC patients who had been treated on two consecutive Phase II trials testing combined modality treatment. The pretreatment characteristics of these patients were: median age--59 years, males/females--87/42, caucasian/non-caucasian--111/18, squamous cell or adenocarcinoma/large cell carcinoma--57/72, previous weight loss less than or equal to 5%/greater than 5%-76/46, previous history of cardiorespiratory disease--no/yes--91/36, performance status (PS) 0-1/2-3--102/27, Stage III, 2 groups--IIIa/IIIb--83/46, Stage III, 3 groups--IIIa T3 N0/IIIa N2/IIIb--41/41/47, surgical eligibility--eligible/ineligible--83/46. Kaplan-Meier statistics revealed significantly longer survival for PS 0-1 versus 2-3 (p = .001), for eligible versus ineligible for surgery (p = .003), for Stage-IIIa versus IIIb (p = .004), and for Stage-IIIa T3N0 versus IIIa N2 versus IIIb (p = .004). The best model developed from Cox regression analyses included stage (IIIa T3 N0 vs IIIa N2 vs IIIb), PS, and sex. These observations appear to have implications for clinical research in Stage III NSCLC.

Combined modality therapy for locally advanced non-small cell lung carcinoma

Multi-modality treatment consisting of cisplatin, VP-16, and 5-fluorouracil chemotherapy given concomitantly with external beam radiation was used to treat 64 patients with locally advanced Stage III non-small cell lung carcinoma. This regimen was used in a preoperative fashion for four cycles in patients considered surgically resectable and with curative intent for six cycles in the remainder of patients. The clinical response rate for the entire group was 84% and the overall local control rate was 74%. The median survival was 13 months with a median follow-up for live patients of 19 months. The actuarial 3-year survival and disease-free survival rates were 30% and 23%, respectively. Histologic complete response was 39% and appeared to predict for survival. The 3-year actuarial survival and disease-free survival rates for 23 resected patients were 69% and 45%, respectively, with the complete histologic responders having a disease-free survival of 78%. The pattern of first recurrence did not appear to differ by histology or presence of lymph nodes in this subset of patients. The actuarial 3-year survival and disease-free survival rates for inoperable patients receiving six cycles of treatment were 18% and 23%, respectively. The local control was 67% with the majority of these patients having Stage IIIB disease. The Mountain International staging system appeared to predict for operability, local recurrence, and survival. This concomitant treatment regimen is feasible, with the major toxicities being leukopenia, nausea, and vomiting.

The discharge of elderly patients from an accident and emergency department: functional changes and risk of readmission

Four hundred and fifty patients aged 75 years or older were followed up after discharge from an accident and emergency department. Forty-three per cent of all patients experienced some loss of functional independence. A small number, 5.6%, were readmitted to hospital within 14 days. This group were significantly less able to perform certain activities of daily living than those not readmitted. Attention to functional assessment by casualty staff may help to prevent readmission to hospital of this frail elderly group of patients.

A comparative study of the injury profile of the elderly patients in an accident and emergency department

Four hundred and fifteen patients aged over 75 were compared with a comparable group of 351 below 75 adult attenders. The over 75s were referred by 999 call and general practitioners more frequently. They also suffered more fractures and multiple injuries. The implications of these different injury patterns for the accident service are discussed.

Evaluation of homoharringtonine efficacy in the treatment of squamous cell carcinoma of the head and neck: a phase II Illinois Cancer Council Study

Eighteen patients entered this study of the efficacy of homoharringtonine (HHT) treatment in advanced squamous cell carcinoma of the head and neck (SCCHN). Seventeen eligible patients received at least one day of the first 5-day cycle of HHT (4.0 mg/m2/day) by continuous IV infusion. Cycles were scheduled to repeat every 28 days. The major severe toxicities encountered were hypotension and myelosuppression. There was one drug-related death. Fourteen patients were evaluable for response, and no patient exhibited an objective response to treatment with HHT.

Preoperative combined modality therapy for stage III M0 non-small cell lung carcinoma

More than 1/3 of all non-small cell lung carcinoma (NSCLC) patients present with locally advanced non-metastatic disease. Despite radiation therapy and surgery the survival of these patients remains poor. In an effort to improve upon these results 33 clinical Stage III M0 patients from April 1985 through September 1986 were entered into a Phase II study at Rush-Presbyterian-St. Luke's Medical Center. Treatment included 5-FU by continuous infusion, VP-16, cisplatin and concurrent split course radiation therapy followed by surgical resection when possible. The overall clinical response rate is 74%. Fifty-seven percent of the preoperative group of patients went to surgery with a 100% resectability rate. These patients had a 50% pathologic complete response with no tumor found in the resected specimen. All surgical margins were free of disease and there were no operative deaths. This concurrent combined modality therapy is feasible with the major toxicities being leukopenia, nausea, and vomiting. With an overall median follow-up of 15 months, 36% of the patients remain alive. Overall local control is 71%. Actuarial observed 2 yr. survival is 33% and the median survival is 15 months. Histologic complete response appears to be an early indicator of the efficacy of this treatment regime. With 83% of the resected pathologic complete responders alive without evidence of disease, this preoperative combined modality therapy offers an appealing approach.