First Targeted Biological Therapy to Show Survival Benefit in Stomach Cancer

The European Commission has approved trastuzumab (herceptin, Roche Pharmaceuticals) in combination with chemotherapy for use in patients with HER2-positive metastatic stomach (gastric) cancer.

Trastuzumab is a humanized antibody, designed to target and block the function of HER2, a protein produced by a specific gene with cancer-causing potential. The mode of action of trastuzumab is unique in that it activates the body’s immune system and suppresses HER2 to target and destroy the tumor. trastuzumab has demonstrated unprecedented efficacy in treating both early and advanced (metastatic) HER2-positive breast cancer.

The approval of trastuzumab in combination with chemotherapy for the treatment of metastatic stomic cancer is based on the impressive results from the international ToGA trial, which showed that treatment with trastuzumab significantly prolongs the lives of patients with this aggressive cancer. Overall survival for patients with high levels of HER2 in the ToGA study was 16 months versus 11.8 months (on average) for patients receiving chemotherapy alone [1]

“Herceptin is the first targeted biological therapy to show a survival benefit in advanced stomach cancer and represents a significant advance in the treatment of this devastating disease”, said Pascal Soriot, Chief Operating Officer of, Roche’s Pharmaceutical Division. “We believe that Herceptin will help patients with HER2-positive stomach cancer, as much as it has helped so many women with HER2-positive breast cancer.”

Based on the strong results from the phase III ToGA study, the submission for the label extension was reviewed in an accelerated process by the European Health Authorities, allowing patients to benefit sooner from this life-extending treatment. This marketing authorization is valid with immediate effect in all European Union (EU) and EEA-EFTA states (Iceland, Liechtenstein and Norway). Following approval in the European Union, approvals for a label extension for trastuzumab in other regions of the world are expected to follow soon.

“I am delighted that today’s approval will make Herceptin available to patients with HER-2 positive metastatic stomach cancer across Europe,” said Professor Eric Van Cutsem, University Hospital Gasthuisberg, Leuven, Belgium, one of the lead investigators of the ToGA trial. “The approval of Herceptin for HER2-positive stomach cancer represents an important advance for the treatment of these patients. Clinicians will need to ensure that patients with metastatic stomach cancer are accurately tested for HER2 expression.”

Diagnosis and treatment
Stomach cancer is the second most common cause of cancer-related death in the world and is the fourth most commonly diagnosed cancer, with over 1,000,000 cases of stomach cancer diagnosed each year [2] Advanced stomach cancer is associated with a poor prognosis; the median survival time after diagnosis is approximately 10-11 months with currently available therapies. [3] Approximately 15 - 18% of stomach tumours show high levels of HER2 [4,5]. Early diagnosis of this disease is challenging because most patients do not show symptoms in the early stage.

ToGA is the first randomized Phase III trial investigating the use of trastuzumab in patients with inoperable locally advanced, recurrent and/or metastatic HER2-positive stomach cancer. Approximately 3,800 patients were tested for HER2-positive tumors and 594 patients with HER2-positive disease were enrolled into the study. The rationale for conducting this trial was based on the knowledge that the targeted therapy trastuzumab has demonstrated unprecedented efficacy in the treatment of HER2-positive breast cancer. In addition, the overexpression of HER2 was also observed in stomach cancer. Targeted cancer therapies are drugs or other substances that block the growth and spread of cancer by interfering with specific molecules involved in tumor growth and progression.

In the ToGA study, patients were randomized to receive one of the following regimens as their first line of treatment:

• A fluoropyrimidine (capecitabine (xeloda) or intravenous 5-FU (5-fluorouracil)) and cisplatin every 3 weeks for 6 cycles. Most patients were receiving capecitabine and cisplatin as chemotherapy
• Trastuzumab 6mg/kg every 3 weeks until progression in combination with a fluoropyrimidine and cisplatin for 6 cycles

Study results
The primary objective of the study was to demonstrate superiority in overall survival of the trastuzumab containing treatment arm compared to the chemotherapy alone arm. The pre-planned interim analysis was triggered by the occurrence of 347 events. Secondary endpoints for the study included progression-free survival, overall response rate, duration of response, safety and quality of life. In the ToGA study, no new or unexpected side effects were observed. For overall survival, the Hazard Ratio was 0.74 (CI 0.60, 0.91) with a highly significant p-value of p=0,0046.

Trastuzumab increased the median overall survival time by 2.7 months to 13.8 months (intent to treat patient group, defined as IHC3+ or FISH-positive, represented 22% of patients tested for HER2 in the ToGA study). The response rate was increased with trastuzumab from 34.5 % to 47.3%. Patients with tumors exhibiting high levels of HER2 (IHC3+ or IHC2+/FISH-positive, 16% of patients tested for HER2 in the ToGA study) experienced even greater benefit from the addition of trastuzumab. For these patients, overall survival in the study was 16 months on average versus 11.8 months for patients receiving chemotherapy alone. The EU label recommends trastuzumab for patients expressing high levels of HER2.

Personalized Healthcare: Fitting treatments to patients
Different people respond differently to medicines. The aim of aim of a personalized approach to healthcare is to target treatments to the patients most likely to benefit. This means tailoring treatments to specific patient sub-groups who share similar characteristics in their genetic makeup or in the molecular nature of their disease. This approach has enormous potential to make healthcare better, safer and more effective, with benefits for patients, physicians, payers, and society at large.

Trastuzumab treatment in breast cancer is a case in point: Measuring the levels of the protein HER2 in breast cancer cells with specific tests reliably identifies patients who are likely to respond to trastuzumab. The same approach can also be applied in the diagnosis and the treatment of HER2-positive metastatic gastric cancer with trastuzumab.

References
[1]Van Cutsem et al. Abstract #7BA ECCO/ESMO 2009
[2]American Cancer Society. Global Cancer Facts & Figures 2007
[3] Ohtsu A. J Gastroenterol 2008;43:256-264
[4] Hofmann M, Stoss O, Shi D, Buttner R, van d, V, Kim W et al. Assessment of a HER2 scoring system for gastric cancer: results from a validation study. Histopathology 2008; 52(7):797-805.
[5] Park DI, Yun JW, Park JH, Oh SJ, Kim HJ, Cho YK et al. HER-2/neu amplification is an independent prognostic factor in gastric cancer. Dig Dis Sci 2006; 51(8):1371-1379.

Also:

• Onco’Zine – The International Cancer Network

Researchers find Drug that Reverses Resistance to Chemotherapy in Pancreatic Cancer

Pancreatic adenocarcinoma is a common malignancy that remains refractory to many available therapies. For many years, 5-fluorouracil (5-FU) in combination with radiation therapy has been the only available treatment for patients with a resectable tumor. For patients whom the tumor had not metastasized but could not be surgically removed either, the combination of 5-FU and radiation therapy appeared to retard tumor growth and prolong survival.

Today, gemcitabine (Gemzar®, Eli Lilly and Company, USA) is the standard, first-line agent in advanced disease. The epidermal growth factor receptor (EGFR) is a commonly expressed target in pancreatic cancer that is involved in tumor proliferation, metastasis, and induction of angiogenesis. The addition of the EGFR inhibitor erlotinib to gemcitabine has recently been demonstrated to provide a small, yet statistically significant, survival benefit in advanced disease. Ongoing studies are comparing gemcitabine as a single therapy and in combination with of 5-FU. Researchers are also exploring the benefit of gemcitabine in combination with other chemotherapeutic agents such as cisplatin, docetaxol (Taxotere®, Sanofi-Aventis, France), or irinotecan (Camptosar®, Pfizer, USA).

Now, for the first time researchers have shown that by inhibiting the action of an enzyme called TAK-1, it is possible to make pancreatic cancer cells sensitive to chemotherapy, opening the way for the development of a new drug to treat the disease.

Dr Davide Melisi told Europe’s largest cancer congress, ECCO 15 – ESMO 34, the combined the 15th congress of the European CanCer Organisation and the 34th congress of the European Society for Medical Oncology, in Berlin, Germany, that resistance to chemotherapy was the greatest challenge to treating pancreatic cancer.

“Pancreatic cancer is an incurable malignancy, resistant to every anti-cancer treatment. Targeting TAK-1 could be a strategy to revert this resistance, increasing the efficacy of chemotherapy,” Melisi said, who until the start of September was a Fellow at the M.D. Anderson Center in Houston (Texas, USA); he has now moved to a staff position at the National Cancer Institute in Naples (Italy). “During the past few years we have been studying the role played by a cytokine or regulatory protein called Transforming Growth Factor beta (TGFbeta) in the development of pancreatic cancer. Recently we focused our attention on a unique enzyme activated by TGFbeta, TAK-1, as a mediator for this extreme drug resistance.”

Melisi and his colleagues investigated the expression of TAK-1 (TGFbeta-Activated Kinase-1) in pancreatic cell lines and developed a drug that was capable of inhibiting TAK-1. They tested the activity of the TAK-1 inhibitor on its own and in combination with the anti-cancer drugs gemcitabine, oxaliplatin and SN-38 (a metabolite of the anti-cancer drug irinotecan) in cell lines, and the activity of the TAK-1 inhibitor combined with gemcitabine against pancreatic cancer in mice.

“The use of this TAK-1 inhibitor increased the sensitivity of pancreatic cells to all three chemotherapeutic drugs. By combining it with classic anti-cancer drugs, we were able to use doses of drugs up to 70 times lower in comparison with the control to kill the same number of cancer cells. In mice, we were able to reduce significantly the tumour volume, to prolong the mice survival, and to reduce the toxicity by combining the TAK-1 inhibitor with very low doses of a classic chemotherapeutic drug, gemcitabine, that would have been ineffective otherwise,” noted Melisi.

The use of gemcitabine on its own against the cancer in mice was ineffective because of the drug resistant nature of the disease. However, once it was combined with the TAK-1 inhibitor, Dr Melisi and his colleagues saw a 78% reduction in tumour volumes. “The median average survival for the control, TAK-1 inhibitor, gemcitabine on its own, or TAK-1 inhibitor combined with gemcitabine was 68, 87, 82 and 122 days respectively,” he explained.

“This is the first time that TAK-1 has been indicated as a relevant target for the treatment of a solid tumor and that it is a valid approach to reverting the intrinsic drug resistance of pancreatic cancer. The TAK-1 inhibitor used in this study is an exciting drug that warrants further development for the treatment of pancreatic cancer. In the near future, we will study whether it is also able to make other chemotherapeutic agents, such as oxaliplatin, 5-FU or irinotecan, work against pancreatic cancer in mice."

“Our main goal is to translate this combination approach from the bench to the bedside, conducting a clinical trial that could demonstrate the safety of this TAK-1 inhibitor in combination with gemcitabine, and its efficacy, in pancreatic cancer patients,” Melisi told his audience.

For more information:

• Abstract no: 1002, Basic science/translational research session, Thursday 09.00 hrs CEST (Hall 14.2)

Also read these PubMed Abstracts:

• Ge C, Luo X, Chen X, Guo K. Enucleation of Pancreatic Cystadenomas. J Gastrointest Surg. 2009 Sep 25. [Epub ahead of print]
• Melisi D, Niu J, Chang Z, Xia Q, Peng B, et al. Secreted interleukin-1alpha induces a metastatic phenotype in pancreatic cancer by sustaining a constitutive activation of nuclear factor-kappaB. Mol Cancer Res. 2009 May;7(5):624-33. Epub 2009 May 12.
• Cotton RT, Li D, Scherer SE, Muzny DM, Hodges SE, et al. Single nucleotide polymorphism in RECQL and survival in resectable pancreatic adenocarcinoma. HPB (Oxford). 2009;11(5):435-44.
• Faller BA, Burtness B. Treatment of pancreatic cancer with epidermal growth factor receptor-targeted therapy. Biologics. 2009;3:419-28. Epub 2009 Sep 15.

Highlights of Prescribing Information:

• Gemcitabine (Gemzar®) hydrochloride for injection
• Docetaxel (Taxotere®) Injection Concentrate
• Irinotecan hydrochloride injection (Camptosar®)

For your patients:

• Onco'Zine - The International Cancer Network
• The national Pancreas Foundation: Frequently Asked Questions
• American Cancer Society: What is Pancreatic Cancer (Detailed guide)

Images courtesy American Society of Clinical oncology (ASCO).

Standard of Care for Anal Cancer Should Not Be Changed

Findings from the largest trial ever conducted for anal cancer have shown that the current standard of care, using a novel, continuous radiation therapy delivery program combined with 5-fluorouracil (5-FU) , (a drug commonly used to treat many types of cancer including, breast, head and neck, anal, stomach, colon and some skin cancers), and mitomycin-C (a chemotherapy drug mainly used to treat bladder and rectal cancers, but also sometimes pancreatic, lung and breast cancers), results in the best outcomes so far reported for patients with anal cancer, and that cisplatin chemotherapy (a drug approved to be used together with other drugs to treat many different cancers), is not superior to mitomycin-C.

The study, presented on Saturday, May 30, 2009 by Roger James, MD, Maidstone Hospital, Kent, UK, during the 45th Annual Meeting of the American Society of Clinical Oncology (ASCO) being held from May 27 – June 2, 2009 in Orlando, Florida, also showed no evidence of a benefit of adding maintenance chemotherapy to the standard of care.

Anal cancer is rare, with about 5,000 patients diagnosed in the United States each year. In the United Kingdom about 850 people are diagnosed with this disease each year. It is slightly more common in women than men, with rates increasing in women over the past 10 years.

Unlike colorectal cancer, the majority of patients with anal cancer do not need surgery, largely because the tumors are the squamous cell type, which are very responsive to chemotherapy and radiation. Cisplatin is commonly used for other squamous cell cancers, but it is less convenient to deliver and is known to have different toxicities from mitomycin-C, such as neurological and renal side effects and hearing loss.

The current study, called ACT II, conducted by the National Cancer Research Institute in the United Kingdom, and funded by Cancer Research UK, randomized 940 patients to receive radiation therapy given at the same time as 5-FU with either mitomycin-C or cisplatin. Patients were also randomized to receive follow-up maintenance therapy with cisplatin and 5-FU after chemoradiation or no maintenance therapy.

After a median follow-up of three years, the investigators found no significant difference in outcome in the two randomized comparisons:

• The complete response rate at 6 months (the number of patients who had all signs of their cancer disappear) was 94 percent in the mitomycin-C group compared with 95 percent in the cisplatin group.
• Recurrence-free survival at 3 years (the number of patients whose tumors did not return) was 75 percent both in patients who got maintenance therapy and in those who did not.
• Overall survival at 3 years was 85 percent in patients who received maintenance therapy and 84 percent in those who did not.

“These findings are good news in spite of the lack of evidence for an improvement in giving either cisplatin or maintenance therapy, since the standard chemoradiation schedule given in this trial was highly effective,” said Roger James, MD, FRCP, FRCR, a radiation oncologist from Maidstone Hospital, Kent, United Kingdom, and the study’s lead author. “Although this trial did not show an improvement from adding maintenance therapy, some form of additional treatment will be the subject of future studies, to determine whether some subset of patients might benefit from it.”

For more information:

• The National Cancer Research Institute (NCRI)
• Cancer Research UK
• Anal Cancer trials (UK)
• Glynne-Jones R, Mawdsley S, Anal Cancer: The End of the Road for Neoadjuvant Chemoradiotherapy? Journal of Clinical Oncology (JCO), Vol 26, No 22 (August 1), 2008: pp. 3669-3671

2009 ASCO Annual Meeting Abstracts:

• James R, Wan S, Glynne-Jones R, Sebag-Montefiore D, Kadalayil L, Northover J, Cunningham D, Meadows M, Ledermann J, National Cancer Research Institute (NCRI) ACT II Trial Management Group. A randomised trial of chemoradiation using mitomycin or cisplatin, with or without maintenance cisplatin/5FU in squamous cell carcinoma of the anus (ACT II) LBA4009

Illustration courtesy of the American Society of Clinical Oncology.