Press releases 10 /11 /2009 Antisoma AGM update and Interim Management Statement London, UK, and Cambridge, MA: 10 November 2009 – Antisoma plc (LSE: ASM; USOTC: ATSMY) holds its AGM today and provides an update, which also serves as the Company's Interim Management Statement for the period from 1 July 2009 to 9 November 2009. Antisoma's CEO Glyn Edwards, said: "We are finishing 2009 in a strong position, with two drugs well into pivotal phase III trials and significant cash resources. We are focused on completing key studies of our late-stage drugs and preparing for their commercialisation, while also continuing to explore opportunities to add new assets to our business." ASA404 – a potential blockbuster ASA404 , our Tumour-Vascular Disrupting Agent, continues to make good progress in the capable hands of our partner, Novartis. In September, we announced that the ATTRACT-1 phase III trial had completed patient enrolment. This 1200- patient study is evaluating ASA404 in combination with standard chemotherapy as a first-line treatment for non-small cell lung cancer. We expect data from the trial in late 2010 or early 2011 , with applications for marketing to follow during 2011 if the data are positive. Novartis is also conducting ATTRACT-2 , a 900- patient phase III trial testing ASA404 as a second-line treatment for non-small cell lung cancer. Testing the drug in both the first- and second-line settings will ensure that a broad spectrum of lung cancer patients could be eligible for treatment with the drug. Novartis also intends to develop ASA404 in another major indication, HER2- negative metastatic breast cancer. More details of the plans for this indication will be available in the near future. Antisoma has the option to co-commercialise ASA404 with Novartis in the US, which fits with Antisoma's plans to become directly involved in the commercialisation of its products. The deal with Novartis could yield substantial milestone payments based on the progress of ASA404 as well as royalties on all sales of the drug worldwide. AS1413 – second key phase III product AS1413 is a novel chemotherapy drug with promising potential as a treatment for blood cancers. A key property of AS1413 is its ability to evade a variety of multi-drug resistance mechanisms, such as Pgp, MRP-1 and BCRP. These are molecular pumps used by cancer cells to expel drugs, including some of the major chemotherapies in use today. By evading these mechanisms, AS1413 has the potential to work in settings where other treatments provide limited benefit. We are developing AS1413 initially as a treatment for secondary acute myeloid leukaemia (secondary AML), a form of AML that evolves from prior bone marrow disease or develops following radiotherapy or chemotherapy for other cancers. Patients with secondary AML often have multi-drug resistant disease and there are no drugs approved specifically for this condition. We are enrolling patients into a pivotal, randomised phase III trial of AS1413 in secondary AML. This trial, called ACCEDE, compares AS1413 plus cytarabine with daunorubicin plus cytarabine, the most common initial treatment for AML. The ACCEDE study builds on positive data from previous studies: from a phase I trial, just published in Leukemia Research , which highlighted the drug's potential in this setting, and from a phase II trial that evaluated the drug in 88 patients with secondary AML. Final follow-up data from the phase II trial will be presented at this year's ASH meeting in December. Results from the ACCEDE trial are expected to be available in late 2010 or early 2011. Should these be positive, we plan to market the drug ourselves in the US while seeking partners for marketing in other territories. We believe that AS1413 could achieve worldwide sales running into hundreds of millions of dollars as a treatment for secondary AML, and that there is also a wider opportunity for the drug in other blood cancer settings. AS1411 – significant developments ahead Earlier this year we presented positive data from a phase II trial of our aptamer drug, AS1411 , in AML. The addition of 10 or 40 mg/kg/day AS1411 to cytarabine chemotherapy increased the response rate without significantly increasing side-effects. We now plan to build on these findings by conducting a phase IIb trial, which is expected to begin early next year. The new trial will include around 90 patients in three treatment groups: a control group will get chemotherapy alone while two combination groups receive AS1411 together with chemotherapy. AS1411 will be given at 40 or 80 mg/kg/day, so the highest dose tested will be twice that used in the previous trial. The dose of cytarabine chemotherapy will also be slightly higher than that used previously. In addition, the patient population will be refined: the prior trial included patients who had proved unresponsive (refractory) to previous therapy or who had suffered up to three relapses, whereas the new trial will only include patients in first relapse or refractory to one previous treatment. The phase IIb trial will capture the initial response to treatment, how long patients remain disease-free and how long they survive following treatment. The goal is to provide a data-set that allows us to make optimal plans for a registration study. In parallel with the programme in AML, we have been running a single-arm phase II trial in renal cancer. This completed patient enrolment in May, and is expected to report initial data before the end of 2009. As with AS1413 , Antisoma currently retains all marketing and commercialisation rights to AS1411. We plan to continue development through late-stage trials and to commercialise the product ourselves in the US while seeking partners for other territories. Strong financial position We reported in our year-end financial results that we had GBP 67.0 million at the end of June 2009 , and indicated that these funds were sufficient to support all our priority programmes until mid-2011 , beyond the time when data are expected from the key phase III studies of ASA404 and AS1413. Outlook Before the end of this year, we expect the first data from our phase II trial of AS1411 in renal cancer and additional details of Novartis' plans for developing ASA404 in breast cancer. We are moving forward with our plans to transition from a company focused on developing cancer drugs into one that can also successfully commercialise them. While our principal focus is the completion of phase III trials on ASA404 and AS1413 , we also continue to advance the earlier stage products in our portfolio and to explore opportunities to add new drugs to the pipeline. Enquiries : Antisoma plc + 44 (0)203 249 2100 / + 44 (0) 7909 915068 Glyn Edwards, Chief Executive Officer Daniel Elger, VP, Marketing & Communications Alison Saville, Senior Marketing & Communications Executive |