Xenova Group PLC
1 June 2000
Xenova Group plc: XR5000 Phase II Trial Data - Colorectal Study
Slough, UK, 1 June 2000 - Xenova Group plc (London Stock Exchange: XEN; Nasdaq
NM: XNVA) today announced trial data for a colorectal study which is one of
four open label Phase II efficacy studies currently being carried out in
conjunction with the European Organisation for the Research and Treatment of
Cancer (EORTC), on the topoisomerase I and II inhibitor, XR5000. The purpose
of these studies is to investigate the efficacy of XR5000 in a number of
different tumour types, in order to determine the best course of future
Patients received XR5000 at a dose of 3010 mg/m squared in a 120-hour
intravenous infusion every three weeks. Response was assessed following every
two courses of treatment according to WHO criteria. At this dose level, no
complete or partial responses to treatment have been observed. Two patients
have shown stable disease, and 13 patients have had disease progression.
XR5000 was shown to have a good safety profile. Results for patients in the
colorectal study have been reviewed by an independent panel. No further
recruitment is planned for this study.
A further three Phase II trials are currently in progress - for ovarian and
non-small cell lung cancers, and for glioblastoma. Recruitment is
substantially complete for two of these studies and it is anticipated that
final data from all three studies will be available during the course of this
calendar year. XR5000 is potentially the first in a new class of compounds
that exhibit a novel mechanism of action through inhibition of both
topoisomerases I and II.
Xenova also has two next generation topoisomerase I and II inhibitors in
preclinical development. XR11576 was adopted as a preclinical development
candidate in November 1999 and is from a different chemical class to XR5000.
XR11576 showed significantly increased potency preclinically when compared
with XR5000, and additionally has the potential for oral delivery. A second
novel inhibitor of topoisomerases I and II, XR5944, has shown high potency as
a cytotoxic agent in preclinical studies with several different human tumour
cell lines and is structurally distinct from both XR5000 and XR11576.
Xenova also has a series of Phase IIa trials nearing completion with its P-
glycoprotein pump (P-gp) inhibitor, XR9576. Positive interim PK data from the
XR9576/paclitaxel and XR9576/doxorubicin combination trials were announced in
March and May 2000 respectively. Early indications from the paclitaxel trial
have indicated a response rate to date greater than that which might have been
expected from patients administered paclitaxel alone. Data from several of
the patients enrolled in the third study (XR9576/vinorelbine) who have
received a medical imaging agent, sestamibi, with and without XR9576, have
shown that administration of a single iv infusion of XR9576 results in
inhibition of P-gp in the liver for periods of up to 48 hours. Inhibition of
P-gp with XR9576 is being developed with the objective of enhancing the
effectiveness of existing cytotoxics in patients with drug-resistant cancer.
As reported by the company in March 2000, it is expected that XR9576 will be
ready to enter pivotal Phase III trials before the end of this calendar year.
(See attached Notes to Editors)
Xenova Group plc Noonan/Russo Communications Inc
Tel: +44 (0)1753 706600 Tel: 001 212 696 4455
David A Oxlade, Chief Executive Officer Joy E Bessenger (Investors)
Daniel Abrams, Finance Director Tony Ho Loke (Media)
Hilary Reid Evans, Corporate Communications
Tel: +44 (0)207 831 3113
David Yates/Sarah Mehanna
Xenova Group plc is a London Stock Exchange techMARK listed company.
Notes to Editors
Xenova Group plc is an emerging bio-pharmaceutical company specializing in the
development of new small molecule drugs. The company's strategy is to develop
commercially attractive new drugs, primarily in the area of cancer
Xenova currently has two drug candidates, XR9576 and XR5000, undergoing Phase
II clinical trials, and a number of drug leads undergoing optimisation or
XR9576 is a P-glycoprotein pump (P-gp) inhibitor, which is being developed to
restore the sensitivity of multi-drug resistant cancer cells to specific
cytotoxic drugs. Phase I study results for the intravenous and oral
administration of XR9576 were presented at the May 1999 meeting of the
American Society of Clinical Oncologists. Preliminary Phase II pharmacokinetic
(PK) data, showing that XR9576 was well tolerated and without PK interaction,
was announced in November 1999. IND approval was also received in late
November 1999. Positive interim PK data from the XR9576 paclitaxel and
doxorubicin were announced in March and May 2000 respectively.
XR5000 acts as an inhibitor of both topoisomerases I and II, enzymes which are
critically involved in the replication of DNA during the process of cell
division and which therefore play a key role in the proliferation of cancer
cells. It has demonstrated significant activity in preclinical animal models
against several types of solid tumours, including multi-drug resistant
cancers. XR5000 completed Phase I studies in late 1998.
In addition to XR9576 and XR5000, Xenova is also currently undertaking cancer
research projects targeting MRP-related multi-drug resistance, next generation
topoisomerase inhibitors, telomerase (with Brunel University) and plasminogen
activator inhibitor-1 (PAI-1). Xenova has a drug development agreement with
Eli Lilly, based on small molecule inhibitors of PAI-1, to develop novel
antithrombotic drugs for chronic use.
Safe Harbor Statement under the US Private Securities Litigation Reform Act of
1995: Some or all of the statements in this document that relate to future
plans, expectations, events, performances and the like are forward-looking
statements, as defined in the US Private Securities Litigation Reform Act of
1995. Actual results of events could differ materially from those described
in the forward-looking statements due to a variety of factors, including those
set forth in the Company's filings with the US Securities and Exchange