OXGN seems to be preparing for a combination phase I/II trial with
ca4p in combination with A5B7. Here is why I think this is the case:

1. Graylab info:

"A trial of CA4-P combined with a radiolabelled antibody to an
antigen on colon cancer will also be starting in May 2003. Only
patients with certain types of cancer will be included in these
trials. "

http://www.graylab.ac.uk/lab/news/combretastatin.html

2. CRUK info:

"Planned early clinical trials
131I-A5B7 + Combretastatin A4 phosphate (CA4P)
Radioimmunotherapy uses an antibody to target radiation directly to
tumours to achieve selective therapy. A5B7 is an anti-CEA antibody
which targets colon tumours and when radiolabelled delivers
radiotherapy to the tumour rim. CA4P is an antivascular agent which
targets the hypoxic centre of the tumour causing extensive central
haemorrhagic necrosis. By combining these 2 agents the actions of
each should be enhanced in this Phase I trial in patients with
advanced colorectal carcinoma. CA4P for use in this study is being
supplied by Oxigene."

http://science.cancerresearchuk.org/fandm/drugdevelopment/curearlycts/
?version=1

This is the preclin results with the same combination:

http://cancerres.aacrjournals.org/cgi/content/full/61/12/4716

"In conclusion, CA4-P can significantly potentiate the antitumor
action of RIT and produce long-term cures. The current work has
established a factual basis to support our hypothesis that
antivascular and antibody-directed therapies are working, in a
synergistic and complementary manner, on different tumor regions.
There are three possible mechanisms: (a) a simple additive killing of
the more hypoxic tumor center by CA4-P and the radiosensitive rim by
RIT; (b) enhancement of the RIT effect by increased retention of
radioantibody after CA4-P-induced vessel collapse; or (c) a
combination of (a) and (b), with option (c) being the most probable.
This work demonstrates the need to consider cancer treatment in a
biologically heterogeneous setting. A greater understanding of the
effect of tumor biology on the outcome of different therapies will
allow us to translate our findings into optimized clinical trials."

Here is the article in BBC once again on these preclin results:

http://news.bbc.co.uk/1/hi/health/1390664.stm

"The combination therapy completely destroyed cancerous tumours in
85% of mice to whom it was administered. And more than nine months
after the treatment was stopped the animals were still clear of any
sign of cancer.

Dr Lesley Walker, the Cancer Research Campaign's Director of Cancer
Information, said: "This is the latest step in the very encouraging
development of this drug for treating cancer. "

I personally think OXGN is just waiting for approval from the FDA
before announcing this study. Would be really interesting to see this
combination in humans...