A phase 1 study of AS1409, a novel antibody-cytokine fusion protein, in patients with malignant melanoma or renal cell carcinoma

PURPOSE

AS1409 is a fusion protein comprising a humanized antibody BC1 linked to interleukin-12 (IL-12). It is designed to deliver IL-12 to tumor-associated vasculature using an antibody targeting the ED-B variant of fibronectin.

EXPERIMENTAL DESIGN

We conducted a phase 1 trial of weekly infusional AS1409 in renal carcinoma and malignant melanoma patients. Safety, efficacy, markers of IL-12-mediated immune response, and pharmacokinetics were evaluated.

RESULTS

A total of 11 melanoma and 2 renal cell carcinoma patients were treated. Doses of 15 and 25 μg/kg were studied. Most drug-related adverse events were grade 2 or less, and included pyrexia, fatigue, chills, headache, vomiting, and transient liver function abnormalities. Three dose limiting toxicities of grade 3 fatigue and transaminase elevation were seen at 25 μg/kg. IFN-γ and interferon-inducible protein-10 (IP-10) were elevated in all patients, indicating activation of cell-mediated immune response; this was attenuated at subsequent cycles. Antidrug antibody responses were seen in all patients, although bioassays indicate these do not neutralize AS1409 activity. Plasma half-life was 22 hours and not dose-dependent. Five patients received 6 cycles or more and a best response of at least stable disease was seen in 6 (46%) patients. Partial response was seen in a melanoma patient, and disease shrinkage associated with metabolic response was maintained beyond 12 months in another melanoma patient despite previous rapid progression.

CONCLUSIONS

The maximum tolerated dose was established at 15 μg/kg weekly. AS1409 is well tolerated at this dose. Evidence of efficacy assessed by RECIST, functional imaging, and biomarker response warrants the planned further investigation using this dose and schedule in malignant melanoma.

Characterisation of transient benign hCG elevations in women following chemotherapy for GTT

The occurrence of post-chemotherapy transient low level hCG elevations has been observed in a number of women treated for gestational trophoblastic tumours (GTT). The authors reviewed the records of patients treated at Charing Cross Hospital over the last 10 years and identified those with a benign rise in hCG. Stored serum samples were assayed for hCG, LH, FSH and oestradiol at varying points during patient management. The endocrine profile in patients experiencing benign hCG elevation is comparable with that seen in post-menopausal women, with low oestradiol, combined with greatly elevated LH and FSH levels. In contrast, women with genuine disease relapse as the cause of their post-chemotherapy hCG elevation had normal or only minor elevations of LH and FSH. These findings support the observation that a major rise in LH and FSH can be used as an indicator for benign pituitary hCG production in patients experiencing a low level rise in hCG levels following chemotherapy for GTT.

A phase I study of AS1409, a novel antibody-cytokine fusion protein, in patients with malignant melanoma (MM) or renal cell carcinoma (RCC)

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Background: AS1409 (huBC1-huIL-12) is a fusion protein combining a humanized antibody specific for the ED-B splice variant of fibronectin with human IL-12. ED-B-fibronectin is expressed in tumor vasculature. IL-12 stimulates T and NK cell activity. Responses to IL12 occur in MM and RCC, but with high systemic toxicity. AS1409 is designed to target IL-12 to tumor vasculature. Methods: Patients with MM or RCC were treated in a dose-escalating trial of weekly i.v. AS1409 for 6 weeks with a starting dose of 15mcg/kg. Patients without unacceptable toxicity or disease progression could continue therapy. IFN-gamma and IP-10 were measured as biomarkers of activation of cellular immunity. Results: 13 patients (9 males; median age 53 years; 11 MM, 2 RCC) were treated (7 at 15mcg/kg, 6 at 25mcg/kg). DLTs observed at 25 mcg/kg were transaminase elevation and fatigue. Other toxicities included flu-like syndrome, fever, myalgia, and mucositis. Three patients continued to receive AS1409 beyond 6 weeks and 1 patient remained on treatment beyond 30 weeks. All patients showed elevation of IFN-gamma and IP10 following the first dose, although subsequently attenuated; prominent anti-drug antibody (ADA) responses were seen. A partial response was seen in a patient with MM metastatic to lymph nodes treated at 15mcg/kg, and a best response of stable disease was seen in 4 patients. Mean AS1409 half-life was 19.3 ±5.3h, mean distribution volume was 0.25 ± 0.098L/kg and clearance was 9.8 ± 6.5mL/hr/kg. Conclusions: At 15mcg/kg AS1409 was well tolerated. Biomarker activation and objective radiological evidence of anticancer activity was observed at this dose. Further study of AS1409 is focussed on optimizing dosing and scheduling, characterizing the ADA response, and antibody biodistribution.

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Understanding extraction and beam transport in the ISIS H(-) Penning surface plasma ion source

The ISIS H(-) Penning surface plasma source has been developed to produce beam currents up to 70 mA and pulse lengths up to 1.5 ms at 50 Hz. This paper details the investigation into beam extraction and beam transport in an attempt to understand the beam emittance and to try to improve the emittance. A scintillator profile measurement technique has been developed to assess the performance of different plasma electrode apertures, extraction electrode geometries, and postextraction acceleration configurations. This work shows that the present extraction, beam transport, and postacceleration system are suboptimal and further work is required to improve it.

Placental site trophoblastic tumor with an ovarian metastasis

Placental site trophoblastic tumors (PSTT) are the rarest form of gestational trophoblastic disease (GTD). The clinical management of PSTT differs from the other forms of GTD as surgery plays a more important role. The most common metastatic sites are the lung, liver, and vagina while spread to the adnexa is relatively unusual. We describe a case of a 35-year-old woman presenting with PSTT and ovarian metastasis who was successfully treated with radical hysterectomy, bilateral oophorectomy, pelvic lymph node dissection, and postoperative chemotherapy. The case highlights the possibility of ovarian metastases despite normal preoperative imaging and confirms the value of multidisciplinary management of this rare illness.

Perifosine (P) as an active agent in the treatment of patients with advanced sarcoma

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Background: Clinical benefit rate (CBR), defined as complete or partial responses (RECIST) or stable disease > 4 months, has been taken as evidence for the activity of mTOR inhibitors in sarcomas, (Chawla ASCO 2006). P is a novel oral alkylphosphocholine that targets the PI3K pathway upstream from mTOR by inhibiting the phosphorylation of Akt. (Kondapaka, Mol Cancer Ther 2003). P's activity against sarcomas has now been evaluated in 121 patients enrolled in one of 3 phase (ph) I trials or 4 ph II studies. Five of these studies have been published. All of the data are in the Keryx database from which this analysis was performed. Methods: Dose-schedules in the ph I trials were weekly (wkly) 100–800 mg; loading dose (LD) 300 - 1,800 following by daily (d) 50 - 21 every 21 days; LD 400 - 900 & d 50 - 100 continuously. In the ph II trials doses were LD 900 & d 150 every 21 days, LD 900 and d 100 continuously, d 50 mg continuously; wkly 900, wkly1200 & wkly 1,500. Regimens that included a wkly or LD of 1,200 mg or more or a d dose of ≥ 150 mg were more toxic and are defined as “higher dose” for this analysis. Results: 121 pts with sarcoma were entered on studies prior to 9/1/2006 and could be assessed for CBR. CBR is shown in the table below. Toxicities were mainly gastrointestinal and/or fatigue. The percentage of pts with grade 0 nausea (N), vomiting (V), diarrhea (D) and fatigue (F) for lower dose P was 40, 60, 45 and 57% respectively compared to 29, 38, 24 and 66% for higher dose P. The proportion of patients with grade 2+ N, V, D and F was 19, 15, 17 and 21% for lower dose P and 46, 31, 40 and 21% for higher dose P. Conclusions: In the ph I/II studies of P the CBR was 50%. This compares favorably with the activity of the mTOR inhibitors. There was no suggestion of greater activity in those given higher doses of P, but there was substantially more toxicity and greater earlier withdrawal from therapy with the higher doses.

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No significant financial relationships to disclose.

Shortened duration of human chorionic gonadotrophin surveillance following complete or partial hydatidiform mole: evidence for revised protocol of a UK regional trophoblastic disease unit

Following hydatidiform mole, women are at increased risk of persistent gestational trophoblastic neoplasia (pGTN) and are therefore monitored using serum human chorionic gonadotrophin (hCG) concentration measurements. We retrospectively evaluated the policy of extended (2 year) follow up for women with hCG concentrations returning to normal >56 days after evacuation. Of 6701 women registered for hCG follow up, 422 (6%) developed pGTN, 412 (98%) of these women presented within 6 months after evacuation. Three developed pGTN at 402, 677 and 1267 days after evacuation following spontaneous normalisation of hCG levels. Only one woman was detected by routine extended follow up. Prolonged surveillance after molar pregnancy causes significant anxiety and is not cost-effective. Therefore, the current revised protocol comprises hCG follow up for 6 months after spontaneous return of hCG levels to normal for all women.

Uterine arteriovenous malformation: fertility-sparing surgery using unilateral ligation of uterine artery and ovarian ligament

Arteriovenous malformations (AVM) are rarely found in the uterus and are usually acquired. The method of treatment is determined by symptoms, desire for future fertility, extent, and location of the malformation. Selective ligation of the vessels supplying the malformation is an effective treatment option when conservative methods have failed and uterine preservation is of primary concern. Measurement of uterine O(2) saturation and perfusion index has been shown to be effective in the intraoperative assessment of uterine viability, pre- and postligation of pelvic vasculature. We present the case of a 32-year-old woman with a postmolar uterine AVM treated surgically with unilateral uterine artery and ovarian ligament ligation.

The outcome of patients with relapsed gestational trophoblastic neoplasm (GTN) after the completion of chemotherapy

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Background: Women requiring chemotherapy for GTN are stratified into low risk and high risk disease and treated accordingly. The vast majority of patients are cured with chemotherapy. Despite this a small number relapse after completing treatment. The prognostic factors predictive of outcome for these relapsed patients are unclear and are investigated here. Methods: Clinical data at presentation and at the time relapse on patients with relapsed GTN was collected from a prospective data base at the Charing Cross Hospital. This included stage of disease, time to relapse, treatment details and rate of HCG rise. Statistical analysis was performed using the Kaplan Meier method. Univariant and multivariant analysis was performed on the data. Results: Between 1980 and 2004 1708 patients were treated with chemotherapy for GTN. Sixty of these patents have relapsed. The median age of these 60 patients was 29 years (range 30–51) and the median follow up was 10 years. The overall 5 year survival for patients with relapsed GTN was 91% (84–99%). All deaths were tumour related. Patients who initially presented with low risk disease (n = 27) had an overall survival of 100% while those who presented with high risk disease had an overall survival of 91% (66–96%) (p < 0.05). Five patients progressed during treatment for relapsed disease, all of these patients died. Ten patients relapsed for a second time. All of these patients are currently alive and disease free with a median of 11 years of follow up. Significant prognostic factors included stage of disease at presentation, the presence of metastatic disease at relapse and the rate of rise of HCG at relapse. Conclusions: The outcome for patients with relapsed GTN is good especially those who relapse after initially having low risk disease. Failure to obtain a complete remission on 2nd line chemotherapy is a poor prognostic indicator.

No significant financial relationships to disclose.

The place of VEGF inhibition in the current management of renal cell carcinoma

Vascular endothelial growth factor (VEGF) is overexpressed in around 80% of patients with clear cell carcinoma of the kidney owing to the inactivation of von Hippel Lindau gene activity. VEGF stimulates angiogenesis and acts as an autocrine growth factor. A number of different agents are now available which target VEGF and its signalling pathways. A significant body of evidence has accumulated demonstrating that antagonism of VEGF and its downstream pathways is clinically useful in a significant proportion of patients with metastatic clear cell carcinoma of the kidney. Enough data is now available to recommend that patients with metastatic clear cell carcinoma of the kidney should at some point during the course of their disease be offered entry into a clinical trial enabling exposure to a targeted inhibitor of VEGF or its signalling pathways. Assuming early clinical trial data is substantiated by ongoing registration studies, efforts should be made to minimise the time taken between licensing and general availability of these active agents.

Redirection of CMV-specific CTL towards B-CLL via CD20-targeted HLA/CMV complexes

B-cell chronic lymphocytic leukaemia (B-CLL) is a slowly progressing malignancy of CD5(+) B cells, for which at present no curative treatment is available. In our current study, we apply a novel bridging reagent to redirect cytomegalovirus (CMV)-specific cytotoxic T lymphocytes (CTL) to target B-CLL. A streptavidin-fused anti-CD20 single-chain variable fragment (scFv) is used in combination with biotinylated MHC class I molecules containing CMV pp65 peptide (HLA/CMV). We demonstrate that B-CLL cells coated with this CD20-HLA/CMV complex can be lysed by autologous CMV-specific CTL with similar efficiency as B-CLL cells directly loaded with CMV peptide. Killing is HLA restricted and occurs at scFv CD20 concentrations of >/=100 ng ml(-1) and HLA/CMV concentrations of >/=20 ng ml(-1). Furthermore, complex-coated B-CLL cells induce both proliferation and cytokine production (interferon gamma, tumour necrosis factor alpha and macrophage inflammatory protein-1 beta) in CMV-specific CD8(+) T cells. Hereby, a necessary step towards possible application of CD20-HLA/CMV complexes for immunotherapy of B-cell malignancies is constituted.

Residual lung lesions after completion of chemotherapy for gestational trophoblastic neoplasia: should we operate?

The significance of residual lung metastasis from malignant gestational trophoblastic neoplasm (GTN) after the completion of chemotherapy is unknown. We currently do not advocate resection of these masses. Here, we investigate the outcome of these patients. Patients with residual lung abnormalities after the completion of treatment for GTN were compared to those who had a complete radiological resolution of the disease. None of the residual masses post-treatment were surgically removed. In all, 76 patients were identified. Overall 53 (70%) patients had no radiological abnormality on CXR or CT after completion of treatment. Eight (11%) patients had residual disease on CXR alone 15 patients had residual disease on CT (19%). During follow-up, two patients (2.6%) relapsed. One of these had had a complete radiological response post-treatment whereas the other had residual disease on CT. Patients with residual lung lesions after completing treatment for GTN do not appear to have an increased chance of relapse compared to those with no residual abnormality. We continue to recommend that these patients do not require pulmonary surgery for these lesions.

Overdiagnosis of Complete and Partial Hydatidiform Mole in Tubal Ectopic Pregnancies

Partial or complete hydatidiform mole (HM) affects approximately 1 in 500 to 1,000 pregnancies. Previous small series suggest that histopathologic diagnosis of HM may be difficult in tubal ectopic pregnancies. The histopathology database of a regional Trophoblastic Disease Unit was searched to identify cases with a referral diagnosis of tubal HM, and the histopathologic findings were reviewed. During the study period (1986-2004 inclusive), there were 132 cases. After central review by specialist histopathologists, the final diagnosis was ectopic partial mole in two, ectopic complete mole in five, and ectopic hydatidiform mole (not otherwise specified) in one. The final diagnosis of definite hydatidiform mole was made in eight (6%) cases, significantly less than in referred uterine curettage specimens, in which approximately 90% have a confirmatory diagnosis of HM (Z = 12.9; p < 0.0001). No cases in this series developed persistent gestational trophoblastic disease, the human chorionic gonadotropin concentration spontaneously returning to normal. Ectopic pregnancies, where managed surgically, should be submitted for histopathologic examination; however, the pathologist should be aware that the degree of extravillus trophoblastic proliferation may appear more florid compared with evacuated uterine products of conception. Molar pregnancy should only be diagnosed when strict criteria regarding morphologic abnormalities previously described in uterine evacuation material are applied.

Patient and operator dose during fluoroscopic examination of swallow mechanism

Dose-area product (DAP) measurements were made for 21 patients undergoing a modified barium swallow. The procedures were performed by a radiologist and speech and language therapist, to characterize swallowing disorders in patients with head or spinal injury, stroke, other neurological conditions or simple globus symptoms, in order to inform feeding strategies. The DAP values were used to estimate effective dose to the patient, in order to provide a measure of the radiation risk associated with the procedure. Whole body doses to operators, together with equivalent doses to extremities and eyes were also measured to inform the employer's risk assessment. Median DAP for the series was 3.5 (3.1-5.2) Gycm(2) with a corresponding effective dose to the patient of 0.85 (0.76-1.3) mSv, and a low associated risk, mainly of cancer induction, of about 1 in 16 000. The organ receiving the greatest dose was the thyroid, with a calculated median equivalent dose of 13.9 (12.3-20.7) mSv. Median screening time was 3.7 (2.5-4.3) min. Mean operator doses were 0.5 mSv equivalent dose (eyes), 0.9 mSv (extremities), and less than 0.3 mSv whole body dose. Extrapolating for an annual workload of 50 patients per year, this work will lead to annual operator doses of less than 0.6 mSv whole body dose, and approximately 1 mSv equivalent dose (eyes) and 1.8 mSv (extremities), against corresponding legal dose limits of 20 mSv, 150 mSv and 500 mSv, respectively.

Managing errors in radiology: a working model

AIM

To develop a practical mechanism for reviewing reporting discrepancies as addressed in the Royal College of Radiologists publication "To err is human. The case for review of reporting discrepancies".

MATERIALS AND METHODS

A regular meeting was developed, and has evolved, within the department to review discrepancies. Standard forms were devised for submission of cases as well as recording and classification of discrepancies. This has resulted in availability of figures that can be audited annually.

RESULTS

Eighty-one cases involving error were reviewed over a 12-month period. Seven further cases flagged as discrepancies were not identified on peer review. Twenty-four reports were amended subsequent to the meeting. Nineteen additional cases were brought to the meeting as illustrative of teaching points or for discussion.

CONCLUSION

We have evolved a successful process of reviewing reporting errors, which enjoys the confidence and support of all clinical radiologists, and is perceived as a method of improving patient care through an increasing awareness of lapses in performance.

Transmission of donor melanoma to multiple organ transplant recipients

Malignant melanoma represents the most common tumour responsible for donor-derived post transplantation malignancies. We report the varied presentation and outcome of three graft recipients (two kidney and hepatic) who developed metastatic melanoma following cadaveric organ transplantation from a single multiorgan donor. Two of the recipients presented with symptomatic metastatic lesions and the third patient, despite being carefully monitored, developed evidence of metastatic cutaneous melanoma. Two of the patients died as a direct result of their melanomas. The recipients of corneal and cardiac grafts remain disease-free. We conclude that despite careful screening, donor-derived tumours remain a not uncommon clinical entity. The identification of a lesion in one recipient should prompt immediate examination and investigation of the remaining recipients of multiorgan donations.

Coronary Stent Strut Size Dependent Stress–Strain Response Investigated Using Micromechanical Finite Element Models

Cardiovascular stents are metal scaffolds that are used in the treatment of atherosclerosis. These devices are typically composed of very thin struts (< or = 100 microm thickness, for coronary applications). At this size-scale the question arises as to the suitability of using bulk material properties in stent design. This paper investigates the use of finite element analysis to predict the mechanical failure of stent struts, typical of the strut size used in coronary stents. 316 L stainless steel in uniaxial loading was considered. To accurately represent the constitutive behavior of the material at this size-scale, a computational micromechanics approach was taken involving an explicit representation of the grain structure in the steel struts, and the use of crystal plasticity theory to represent the constitutive behavior of the individual grains. The development of the finite element models is discussed and results are presented for the predictions of tensile mechanical behavior as a function of strut thickness. The results showed that using this modelling approach, a size effect, already seen experimentally, is produced. This has significant implications for stent design, especially in the context of the desire to produce smaller stents for small bore neurovascular and peripheral artery applications.

An investigation of fetal, postnatal and childhood growth with insulin-like growth factor I and binding protein 3 in adulthood

OBJECTIVE

Weight at birth and adult height are positively associated with cancer risk. These patterns may be mediated by the insulin-like growth factor (IGF) axis. We have examined whether pre- and postnatal growth patterns have a long-term influence on adult IGF-I and IGFBP-3 levels.

DESIGN

A follow-up study of a randomized controlled trial of milk supplementation in pregnancy and childhood.

SUBJECTS

A total of 951 individuals took part in a study of diet and growth in South Wales between 1972 and 1974 followed up from birth until their mid-20s.

MEASUREMENTS

Anthopometric measures at birth, postnatally up to 5 years of age and in adulthood, and serum measures of IGF-I and IGF-I to IGFBP-3 ratio at mean age of 25 years.

RESULTS

A total of 63 subjects (70%) provided blood for analysis. We found no association between birth dimensions and adult IGF-I. Subjects who exhibited 'catch-down growth' had lower IGF-I levels (P-value for trend 0.02). Adult height was positively related to IGF-I, for every one standard deviation increase in adult height, IGF-I increased by 3.75 ng/dl (95% CI 0.46-7.08, P = 0.03). Adiposity was inversely associated with the IGF-I and IGF-I to IGFBP-3 ratio and positively associated with IGFBP-3. The strength of the associations increased with age. Downward centile crossing at any time in childhood was associated with lower IGF-I whilst the highest levels were observed in subjects who were tall throughout their early life course. Adult height remained a significant predictor of IGF-I even after adjustment for earlier growth.

CONCLUSIONS

Our results indicate that IGF-I levels in early adulthood are associated with patterns of childhood growth as well as adult stature and adiposity. These associations suggest the IGFs may contribute to anthropometric associations with cancer risk.

The stress-strain behavior of coronary stent struts is size dependent

Coronary stents are used to re-establish the vascular lumen and flow conditions within the coronary arteries; the typical thickness of a stent strut is 100 microm, and average grain sizes of approximately 25 microm exist in stainless steel stents. The purpose of this study is to investigate the effect of strut size on the stress strain behavior of 316 L stainless steel. Other materials have shown a size dependence at the micron size scale; however, at present there are no studies that show a material property size dependence in coronary stents. Electropolished stainless steel stent struts within the size range of 60-500 microm were tensile tested. The results showed that within the size range of coronary stent struts a size dependent stress-strain relationship is required to describe the material. Finite element models of the final phase of fracture, i.e., void growth models, explained partially the reason for this size effect. This study demonstrated that a size based stress-strain relationship must be used to describe the tensile behavior material of 316 L stainless steel at the size scale of coronary stent struts.