Virotherapy of ovarian cancer with polymer-cloaked adenovirus retargeted to the epidermal growth factor receptor.

Adenovirus gene therapy for intraperitoneal (IP) cancer is limited in clinical trials by inefficient tumor cell transduction and development of peritoneal adhesions. We have shown previously that normal virus tropism can be ablated by physically shielding the virus surface with reactive hydrophilic polymers and that linkage of novel ligands enables virus "retargeting" through chosen receptors. To achieve tumor-selective infection, polymer-coated virus was retargeted using murine epidermal growth factor (mEGF). The resulting mEGF-polymer coated adenovirus lost its normal broad tropism and transduced cells selectively via the EGF receptor (EGFR). We assessed whether this approach could be used to target lytic "virotherapy" using wild-type adenovirus (Ad5WT) in a peritoneal xenograft model of human ovarian cancer. Oncolytic activity of Ad5WT was retained following polymer coating and mEGF-retargeting. Importantly, adhesion formation was markedly decreased compared with the unmodified virus, and no dose-limiting toxicities were observed following treatment with mEGF-retargeted polymer-coated virus. Restricting virus tropism by physical coating, coupled with tumor-selective retargeting promises to combine good anticancer efficacy with acceptable toxicity, enabling application of elevated virus doses leading to an improved therapeutic outcome.

Cesarean section on demand.

The safety of cesarean section has improved dramatically over the past 50 years. During the past 20 years a greater awareness of and discussion about the symptomatic morbidity that can result for women following vaginal delivery has occurred and women's expectations for the outcome of pregnancy for them and their babies has increased. A culture of choice has been promoted in recent years, but contrary to the anticipated demand for less obstetric intervention by those promoting choice, there has been an increase in demand for delivery by cesarean section rather than the reverse. With the balance in favor of benefit for the baby from delivery by cesarean section, it is now difficult to sustain the argument favoring vaginal delivery rather than planned cesarean section, using maternal morbidity and mortality statistics. A critical evaluation of the costs indicates that there are probably few grounds for denying women their request for cesarean section for economic reasons. It seems likely, therefore, that in the near future those advising women on the options for delivery will need to ensure that the risks of vaginal delivery are explained as well as those for planned cesarean section.

'Two week wait' standards for suspected gynaecological malignancy. On target, but missing the point?

OBJECTIVE: To assess the two-week rapid access referral system for UK general practitioners introduced in April 2000 for women suspected of having a gynaecological cancer. STUDY DESIGN: An audit of details of women referred between 1st April 2000 and 31st March 2003 via the two-week rapid access system to one gynaecological consultant who performs gynaecological oncology surgery at the John Radcliffe Hospital, Oxford. MAIN OUTCOME MEASURES: Information on waiting times, clinical indication (postmenopausal bleeding, suspicious pelvic mass, vulval lesions, or "other" symptoms including postcoital vaginal bleeding, suspicious lesions of the cervix or vagina), and subsequent diagnosis were recorded. Data on all other women in whom a diagnosis of a gynaecological malignancy was made during the same period following referral to the same consultant's routine gynaecological outpatient clinic were also collected. RESULTS: The target time of two weeks to see a consultant was met for 94% of women referred via the rapid access system. The response time declined slightly with increasing numbers of referrals. However, the majority of women with a gynaecological malignancy were not referred via the rapid access system. CONCLUSIONS: To accommodate the two-week rapid access referrals and achieve UK government targets, there was a reduction in appointments for routine outpatient referrals. However, as the majority of women with gynaecological malignancy presented via traditional referral routes, there is a danger that their diagnoses are being delayed.

Adenovirus serotype 11 causes less long-term intraperitoneal inflammation than serotype 5: implications for ovarian cancer therapy.

In a phase II/III clinical trial intraperitoneal (i.p.) administration of a group C adenovirus vector (Ad5) caused bowel adhesion formation, perforation and obstruction. However, we had found that i.p. group B, in contrast to group C adenoviruses, did not cause adhesions in nude BALB/c ovarian cancer models, prompting further investigation. Ex vivo, group B Ad11 caused lower inflammatory responses than Ad5 on BALB/c peritoneal macrophages. In vivo, i.p. Ad11 triggered short-term cytokine and cellular responses equal to Ad5 in both human CD46-positive and -negative mice. In contrast, in a long-term study of repeated i.p. administration, Ad11 caused no/mild, whereas Ad5 induced moderate/severe adhesions and substantial liver toxicity accompanied by elevated levels of IFNγ and VEGF and loss of i.p. macrophages, regardless of CD46 expression. It appears that, although i.p. Ad11 evokes immediate inflammation similar to Ad5, repeated administration of Ad11 is better tolerated and long-term fibrotic tissue remodelling is reduced.

Cetuximab retargeting of adenovirus via the epidermal growth factor receptor for treatment of intraperitoneal ovarian cancer.

Gene and virotherapy of ovarian cancer, using type 5 adenovirus (Ad5), has demonstrated good activity in preclinical animal studies, particularly after intraperitoneal administration of virus; however, success in clinical trials has been limited by poor infectivity of ovarian cancer cells and inflammatory responses to Ad5. We previously demonstrated that covalent modification of Ad5 with reactive copolymers on the basis of poly(hydroxypropylmethacrylamide) can shield the virus, offering protection from neutralizing antibodies and enabling retargeting to cancer-upregulated receptors with peptide ligands (basic fibroblast growth factor [bFGF] and murine epidermal growth factor [EGF]). These ligands may be less than ideal for clinical use, however, because they are potential mitogens. Accordingly, in this study we investigated the use of an anti-EGF receptor (EGFR) antibody, cetuximab, to retarget adenoviral transduction of EGFR-positives in vitro and in vivo. Cetuximab retargeting altered the physicochemical characteristics of Ad5, although it did not cause particle aggregation. Although cetuximab stimulated internalization of EGFR, similarly to EGF, it inhibited EGFR phosphorylation. Adenoviral transduction was inhibited after polymer coating, but was rescued in EGFR-positive cells (and not in EGFR-negative cells) by cetuximab retargeting. Cetuximab retargeting of wild-type adenovirus serotype 5 (Ad5WT) prolonged survival in an animal model of human ovarian cancer, similar to unmodified Ad5WT, but polymer coating ameliorated stimulation of adhesion formation. We conclude that polymer coating and covalent attachment of cetuximab successfully retargeted adenovirus to EGFR-positive cells, retained in vivo efficacy of an oncolytic adenovirus, and ameliorated side effects caused by unmodified adenovirus.

Retargeting polymer-coated adenovirus to the FGF receptor allows productive infection and mediates efficacy in a peritoneal model of human ovarian cancer.

BACKGROUND: Transductional targeting of adenovirus following systemic or regional delivery remains one of the most difficult challenges for cancer gene medicine. The numerical excess and anatomical advantage of normal (non-cancer) cells in vivo demand far greater detargeting than is necessary for studies using single cell populations in vitro, and this must be coupled with efficient retargeting to cancer cells. METHODS: Adenovirus (Ad5) particles were coated with reactive poly[N-(2-hydroxypropyl)methacrylamide] copolymers, to achieve detargeting, and retargeting ligands were attached to the coating. Receptor-mediated infection was characterised in vitro and anticancer efficacy was studied in vivo. RESULTS: Polymer coating prevented the virus binding any cellular receptors and mediated complete detargeting in vitro and in vivo. These fully detargeted vectors were efficiently retargeted with the model ligand FGF2 to infect FGFR-positive cells. Specific transduction activity was the same as parental virus, and intracellular routing appeared unaffected. Levels of transduction were up to 100-fold greater than parental virus on CAR negative cells. This level of specificity permitted good efficacy in intraperitoneal cancer virotherapy, simultaneously decreasing peritoneal adhesions seen with parental virus. Following intravenous delivery FGF2 mediated unexpected binding to erythrocytes, improving circulation kinetics, but preventing the targeted virus from leaving the blood stream. CONCLUSIONS: Polymer cloaking enables complete adenovirus detargeting, providing a versatile platform for receptor-specific retargeting. This approach can efficiently retarget cancer virotherapy in vivo. Ligands should be selected carefully, as non-specific interactions with non-target cells (e.g. blood cells) can deplete the pool of therapeutic virus available for targeting disseminated disease.

Audit of the care of women requesting induced abortion.

This paper describes a prospective audit of all induced abortions performed between May and July 2000, in a Buckinghamshire district general hospital, to evaluate practice compared to the Royal College of Obstetricians and Gynaecologists Guidelines (RCOG Evidence-Based Guideline No. 7, 2000). Areas for improvement were identified and department guidelines were produced to address these. This audit highlights how change can be implemented when local practice is audited against national guidelines.