GlaxoSmithKline expects to launch up to five major new medicines for oncology in next three years

London, UK GlaxoSmithKline plc (GSK) today presented an overview on its expanding and innovative oncology portfolio, with clinical updates on several important new medicines, to investors and analysts at a meeting in London.

Overview

· GSK expects to launch up to five major new compounds from 2007 — 2010 in cancer prevention, treatment and supportive care across a broad range of cancer types:

­ Cervarix, for prevention of cervical cancer

­ Pazopanib, for renal cell carcinoma

­ Promacta, for thrombocytopenia (initially ITP)

­ Rezonic, for emesis

­ Ofatumumab (HuMax-CD20®), for NHL/CLL.

· Tykerb, GSK’s new oral treatment for breast cancer, off to a strong start in USA with approximately 3,000 patients treated since launch in March.

· Together, these 6 significant opportunities will enter fast-growing, new markets:

­ Current oncology market valued at £20 billion and growing annually at 20%.

­ Pioneering products in cervical cancer and ITP meet significant unmet medical need.

Seminar highlights

· Latest phase II/III clinical data confirms innovative, competitive product profiles:

­ Tykerb: Significant efficacy seen in the treatment of HER2-positive breast cancer in relapsed and first-line metastatic settings. Large-scale clinical programme underway in the adjuvant setting with rapid enrolment in the landmark trial, TEACH. Promising activity also demonstrated in the treatment and prevention of breast cancer related brain metastases.

­ Pazopanib: Data demonstrate positive activity in renal cell carcinoma, soft tissue sarcoma and ovarian cancer; and suggest encouraging tolerability profile. Registration studies in renal cell carcinoma are now fully recruited and development programmes for combination therapy and monotherapy in 11 other cancer types are underway.

­ Promacta: Phase III data confirms increased platelet count and significantly lower incidence of bleeding in patients with ITP. Filing for use in treatment of short-term ITP expected by the end of 2007/early 2008.

­ Rezonic: New phase III data, presented for the first time today, demonstrate superiority of Rezonic in combination with Zofran, over Zofran alone. Planned filing for PONV & CINV in first half of 2008.

­ Ofatumumab: a fully human high-affinity antibody is in late-stage development for the treatment of follicular NHL and CLL.

­ MAGE-A3 ASCI: a novel vaccine to treat NSCLC is entering phase III in 2007. The phase III registration trial, involving over 2,200 patients, will be the largest clinical trial ever conducted for the treatment of lung cancer.


Commenting on the seminar today, Moncef Slaoui, Chairman of R&D, GSK said:

“Over the next three years, GSK will make a difference to millions of patients facing cancer, with up to five new products expected to be launched in this period. Today demonstrates the significant progress we have made to expand and develop our oncology portfolio. We are actively developing late-stage medicines in over twelve different cancer types, from pioneering treatments such as Tykerb to vaccines that can treat as well as prevent cancer. Moving deeper into the pipeline we believe that this productivity in oncology can be sustained as we have a significant number of promising new compounds in early-stage discovery. We expect our oncology pipeline to be a key area of success for GSK for many years to come.”

Additionally, Paolo Paoletti, SVP Oncology Medicine Development Centre, GSK commented:

“We will be launching an unprecedented number of products for use in treatment, prevention and supportive care of cancer patients. The promise of Tykerb is already being seen in the USA; and we believe the data presented today further support the innovative and competitive profiles of our oncology medicines currently in late-stage development. With over thirty new specialist oncologists recently recruited to work in this area, we will continue to invest in our oncology capability and vigorously pursue development of these new medicines for patients with cancer.”

TYKERB

Tykerb (lapatinib) — an oral, targeted, dual kinase inhibitor, therapy - is being developed for use in breast cancer and other tumour types across a range of clinical settings, including relapsed (patients who have received prior therapy and whose cancer has progressed), first-line (metastatic) and adjuvant (early breast cancer) use.

Tykerb approved by FDA in March, for use in advanced or metastatic breast cancer patients, who have received prior therapy:

Tykerbis approved for treatment in combination with capecitabine for patients with advanced or metastatic HER2-positive breast cancer and who have received prior therapy including an anthracycline, a taxane and trastuzumab. Approximately 3,000 patients have been treated since launch of the product in March. Tykerb has been filed for approval in Europe and International markets and GSK anticipates launching the product in Europe in the second half of 2007, where it will be known as Tyverb.

A new analysis presented today from the pivotal registration study (EGF100151) assessing use of Tykerb + capecitabine (Xeloda®) for treatment of advanced or metastatic breast cancer demonstrated clinical benefit (complete response & partial response & stable disease at 6 months) in 29% of this very difficult to treat patient population.

Latest data show success as first-line treatment of metastatic breast cancer:

An analysis of 91 patients, who were identified as having HER2-positive breast cancer, in a trial assessing Tykerb plus paclitaxel (Taxol®) versus paclitaxel alone, showed that the combination increased time-to-progression in patients by 2.3 months versus paclitaxel alone (8.1 versus 5.8 months, p = 0.011):

· Median progression-free survival was 7.9 months versus 5.2 months (p = 0.007)

· Complete or partial response occurred in 60% of patients versus 36% (p = 0.027)

Large scale clinical development programme underway for use of Tykerb in adjuvant setting:

GSK has a comprehensive clinical trial programme of more than 60 studies, assessing Tykerb in other breast cancer settings, including the significant, large patient population using adjuvant therapy. Clinical trials assessing use of Tykerb in the adjuvant setting are now underway, with more than 1,200 patients already enrolled in the landmark phase III trial, TEACH (Tykerb Evaluation After CHemotherapy).

Latest Tykerb data show differentiation from current targeted breast cancer therapies — activity in treatment and possible prevention of brain metastases; and low cardiotoxicity:

Despite previous treatment with agents targeting HER2-positive breast cancer, one-third of women with HER2-positive metastatic breast cancer develop secondary brain metastases and once the disease advances to this stage, treatment options are severely limited and overall disease prognosis is poor.

Tykerb has shown preliminary activity for possible prevention of brain metastases. A retrospective analysis from a study (EGF100151) in patients whose tumours progressed on trastuzumab (Herceptin®), showed that fewer patients on Tykerb + capecitabine (Xeloda) had recurring brain metastases, than those treated with capecitabine alone (4 versus 13). These data suggest that the combination of Tykerb plus capecitabine may have a significant role to play in the prevention of brain metastases.

Furthermore, Tykerb has shown evidence of activity in the treatment of brain metastases. Results from an ongoing study (EGF105084), involving 241 heavily pre-treated patients, with progressive brain metastases suggest that Tykerb has clinical activity in the treatment of brain metastases in patients with HER2-positive breast cancer:

· 46 (19%) patients using Tykerb had a ≥ 20% volume reduction in brain metastases, of which 19 (8%) patients had a 50% volume reduction.

* In addition, 40 patients whose brain metastases progressed on Tykerb monotherapy then had capecitabine added to their Tykerb therapy; of these 16 (40%) patients showed a ≥20% reduction in the volume of these brain metastases, of which 8 (20%) patients had a 50% volume reduction,suggesting synergy between these agents.

· Interestingly, in this trial extension, a number of patients who benefited from the combination of Tykerb and capecitabine had tumours which had progressed whilst on prior treatment with capecitabine.

According to reported studies, cardiotoxicity has been associated with existing HER2-positive breast cancer treatment, therefore an assessment of this risk is important when evaluating new, Tykerb-based therapies. An analysis of data from over 3,000 patients treated with Tykerb has shown the incidence of cardiotoxicity (as measured by symptomatic decrease in Left Ventricular Ejection Fraction) was less than 0.5%. Other reported adverse events included diarrhoea, rash, nausea and fatigue, which were generally mild to moderate.

PAZOPANIB

Pazopanib - a potent, oral, once-daily multi-kinase inhibitor, targeting vascular endothelial growth factor (VEGF), platelet derived growth factor and c-kit receptors. Pazopanib inhibits angiogenesis, (the formation of new blood vessels) a process that plays a critical role in the growth and spread of many tumours.

Promising data seen in trials of pazopanib to treat three cancer types:

Pazopanib has shown high clinical response rates in advanced or metastatic renal cell carcinoma (RCC) and clear clinical activity in invasive soft tissue sarcoma (STS) and aggressive ovarian cancer.

The incidence of RCC is rising throughout the world with 208,000 new cases diagnosed annually. New data from an ongoing phase II study evaluating 225 patients with recurrent or metastatic RCC demonstrated a 12 week clinical benefit (partial response and stable disease) in 73% of patients.

STS is a disease in which malignant cancer cells begin growing in soft tissues, such as muscles, tendons, nerves and tissues around joints. Pazopanib is being evaluated in an ongoing phase II study in patients with STS who have failed prior therapy for advanced disease. Currently there is no standard treatment for such patients. Four types of STS were included in the study. In an interim analysis, pazopanib demonstrated activity in three of these (leiomyosarcoma, synovial sarcoma and other soft tissue sarcomas) with progression-free survival rates of between 34% and 44% at 12 weeks.

The majority of patients with ovarian cancer have advanced disease at the time of initial diagnosis. Although the majority of patients respond initially to first-line therapy, recurrent disease remains a significant burden. Promising data from an ongoing phase II study has shown activity with pazopanib, in 9 (41%) of 22 evaluable patients with relapsed disease.

Pazopanib tolerability profile also expected to be an important area of differentiation:

A favourable tolerability profile will potentially enable patients to remain on therapy for longer, help differentiate pazopanib from other treatments and enable use of pazopanib in combination with other therapies.

Clinical data from the phase II study in RCC supports pazopanib’s promising tolerability profile. The most commonly reported adverse events were diarrhoea, hypertension and nausea. The most common laboratory abnormality was elevation in liver transaminases which were asymptomatic and reversible.

PROMACTA

Promacta (eltombopag) - is the first oral novel compound for thrombocytopenic (decreased platelet count) patients who are at significant risk of uncontrolled bleeding. GSK is currently investigating Promacta for the treatment of idiopathic thrombocytopenic purpura (ITP), Hepatitis C-associated thrombocytopenia and chemotherapy-induced thrombocytopenia (CIT).

Phase III data demonstrate significant efficacy for Promacta:

New clinical data from a phase III trial in 114 adults with chronic ITP, and platelet counts of less than 30,000/µL who had failed or stopped responding within three months of receiving one or more ITP therapies, have demonstrated significant efficacy with Promacta.

* In the largest ever controlled study in ITP, 59% of patients treated with Promacta and 16% of patients given placebo achieved a platelet count of more than 50,000/µL.
* Importantly, there was a significantly lower incidence of bleeding events during treatment with Promacta compared to placebo (p0.05), with clinically significant bleeding observed in fewer Promacta patients (16%) than placebo patients (36%). Promacta is the first agent to demonstrate an improvement in bleeding in a randomised study in ITP patients.

The most common adverse events observed in the phase III ITP study were headache, nausea, nasopharyngitis, diarrhoea and vomiting. No safety concerns were identified.

The company plans to file Promacta for short-term use in ITP by the end of 2007/early 2008 and studies assessing use in long-term treatment of chronic ITP continue. Following positive phase II results in patients suffering from thrombocytopenia associated with hepatitis C, phase III studies are commencing later this year. The phase II programme for use of Promacta in treating thrombocytopenia in cancer patients treated with chemotherapy is ongoing.

REZONIC

Rezonic (casopitant) - is an anti-emetic medicine currently being developed by GSK to prevent both post-operative nausea and vomiting (PONV) and chemotherapy-induced nausea and vomiting (CINV).

New phase III data presented today:

40% to 50% of surgical patients still experience nausea and vomiting despite the availability of current anti-emetic medicines. New phase III data presented for the first time today, demonstrates Rezonic when used in combination with Zofran (ondansetron), for treatment of PONV, delivers enhanced benefit over ondansetron alone. Importantly, these data were seen in both intravenous (IV) and oral formulations of Rezonic, supporting use of the product in both the hospital and outpatient setting.

· Rezonicplus ondansetron demonstrated a complete response rate at 24 hours of 69% in patients dosed with oral Rezonic, compared to 59% in patients dosed with ondansetron;

· Rezonicplus ondansetron demonstrated a complete response rate at 24 hours of 69% in patients dosed with IV Rezonic, compared to 53% in patients dosed with IV ondansetron.

Clinical development of Rezonic continues with over 4,000 patients studied to date, including the completed enrollment of phase III studies in both highly and moderately emetogenic chemotherapy. The most frequently reported adverse events were constipation, fatigue, asthenia, headache and dizziness. GSK plans to file Rezonic for approval to treat both PONV and CINV in the first half of 2008.

OFATUMUMAB

GSK continues to pursue new opportunities to treat and prevent cancer through biological clinical development and expansion of the company’s biopharmaceutical pipeline.

At the seminar GSK also presented data for ofatumumab (HuMax-CD20) - a fully human high-affinity antibody which is currently in late stage development for the treatment of follicular non-Hodgkin’s lymphoma (FL) and chronic lymphocytic leukaemia (CLL), the most common form of adult leukaemia.

· Data from a phase I/II study in relapsed/refractory follicular NHL showed objective response rates up to 63% including responses in 9 of 14 evaluable patients who had received prior rituximab therapy.

· Data from a Phase I/II study in relapsed/refractory CLL showed a 50% objective response rate supporting the activity of ofatumumab in this difficult to treat, low CD20 receptor expressing, B cell malignancy.

Furthermore, new, positive primary efficacy data (evaluated at 24 weeks) were recently reported from a phase II study of ofatumumab in patients with rheumatoid arthritis (RA). GSK plans to initiate phase III trials in RA by the end of 2007.

· In the intention-to-treat study population, comprising 224 patients who had failed at least one prior DMARD including anti-TNF therapy, an ACR20 response was obtained by 41% (p = 0.002), 49% (p0.001) and 46% (p0.001) of patients receiving 300mg, 700mg and 1000mg of ofatumumab compared to 15% on placebo.

In studies (CLL, FL & RA) of ofatumumab it has been shown to be generally well tolerated. The most frequently reported adverse events in FL were rigours, fatigue, headache and rash. In the CLL phase I/II most frequent adverse events were rash, urticaria, rigours, pyrexia, fatigue, dizziness, hypertension and backpain. In the Phase II RA study no increased frequency of serious infections compared to placebo was observed. The most frequently reported adverse events in ofatumumab patients were mild or moderate infusion-related events and included throat irritation, dyspnoea and rash.

MAGE-A3 ASCI

GSK has an active, unique, immunotherapeutic clinical development programme for cancer — known as the Antigen-Specific Cancer Immunotherapeutic (ASCI) programme, which benefits from GSK’s own proprietary adjuvant systems specifically designed to enhance ASCI’s anti-tumour activity.

This includes an ASCI targeting MAGE-A3— being developed for use in treatment of MAGE-A3 positive patients with Non-Small Cell Lung Cancer (NSCLC). MAGE—A3 is a tumour-specific antigen which is present in approximately 35% to 50% of early NSCLC. Final results of a phase II proof-of-concept clinical trial in MAGE-A3 positive patients with stage IB or II NSCLC showed a 27% reduction in the relative risk of cancer recurrence following surgery in patients treated with the MAGE-A3 ASCI, compared to placebo. Following these positive results, MAGE-A3 ASCI is entering a phase III registration trial in 2007 — involving over 2,200 patients. This will be the largest clinical trial ever conducted in lung cancer treatment.

The most commonly reported adverse events with MAGE-A3 ASCI were mild, local (pain, redness, swelling) or systemic (fever, fatigue, muscle pain) reactions observed within the 24 hours of injection.

Notes to editors:

List of abbreviations

ASCI - antigen-specific cancer immunotherapeutic

CINV - chemotherapy-induced nausea and vomiting

CIT - chemotherapy-induced thrombocytopenia

CLL - chronic lymphocytic leukaemia

CNS - central nervous system

DMARD - disease modifying anti-rheumatic drugs

FL — follicular non-Hodgkin’s lymphoma

ITP - idiopathic thrombocytopenic purpura

IV - intravenous

NHL - non-Hodgkin’s lymphoma

NSCLC - non-small cell lung cancer

PDGF - platelet derived growth factor

PONV - post-operative nausea and vomiting

RA - rheumatoid arthritis

RCC - renal cell carcinoma

STS - soft tissue sarcoma

TEACH - Tykerb Evaluation After Chemotherapy study

TNF - tumour necrosis factor

VEGF - vascular endothelial growth factor