Xenova Demonstrates Clear Clinical Responses in a 'Prime-Boost' Phase IIa Clinical Trial Targeting HPV Associated AGIN
SLOUGH, England, April 14 /PRNewswire-FirstCall/ -- Xenova Group plc (Nasdaq: XNVA - News; London Stock Exchange: XEN - News) today announced the results of an open label, physician-sponsored Phase II 'prime-boost' study, targeting the treatment of human papillomavirus (HPV) associated ano-genital intraepithelial neoplasia (AGIN). The announcement, made at the British Society for Colposcopy & Cervical Pathology (BSCCP) meeting in Manchester on Saturday 12th April, relates to a study carried out on 29 patients at three centres in the UK. Early results indicate that a prime boost strategy, using a combination of Xenova's TA-CIN and TA-HPV candidate therapeutic vaccines, is both safe and well tolerated and has demonstrated clear clinical responses, even in women with long-standing disease.
Human papillomavirus (HPV) is a large family of small DNA viruses associated with a number of conditions ranging from skin warts and genital warts to cervical cancer. Infection with high risk types of HPV (such as HPV16 and HPV18) is strongly associated with ano-genital cancer and its precursor AGIN. These diseases are difficult to treat and have a high recurrence rate.
TA-HPV is an immunotherapeutic vaccine which is being developed for use alongside surgery in the treatment of cervical cancer and for the treatment of high-grade AGIN. TA-CIN is a recombinant fusion protein, designed as a treatment for women with cervical dysplasia. Preclinical studies, conducted by Xenova in conjunction with scientists at Leiden University Medical Centre, The Netherlands, demonstrated that use of TA-CIN together with TA-HPV, resulted in an immune response that was significantly greater than that observed with either product alone. The present trials were designed to evaluate results in women using TA-CIN and TA-HPV in a "prime-boost" combination.
In the reported study, 29 women with stable, non-cervical disease were recruited in three centres: St Mary's Hospital, Manchester; Llandough Hospital, Cardiff; and Addenbrooke's Hospital, Cambridge. Three doses of TA-CIN were given intramuscularly, at four-weekly intervals, followed four weeks later by a single dose of TA-HPV by dermal scarification. Women have been followed up for 12 weeks following completion of the vaccination schedule. Safety, clinical and immunological responses, and viral status were assessed.
Both the individual vaccines (TA-CIN and TA-HPV) and the combination regime, were shown to be safe and well tolerated. Of the 26 patients meeting the entry requirements of the study; 15 (60%) showed evidence of symptomatic improvement. Five (19%) showed a partial response (defined as a lesion area reduction of 50% or greater). One patient had a complete response, confirmed by histological examination and viral clearance and 5 (20%) were HPV16 negative at the end of the study. Two women in the study with vaginal intra-epithelial neoplasia both showed a partial response.
Assessment of clinical and immunological response is on-going and additional follow up visits are planned to see whether patients with a partial response go on to a complete response. The responses seen during the initial stages of the immunisation regimen were particularly encouraging, and indicated that further development is warranted. |
