Thursday, January 21, 2010

Positive data presented at recent LC conference

At the recent AACR-IASLC Joint Conference on Molecular Origins of Lung Cancer in Coronado, CA, many positive advances were presented, including a new study, which suggested that retreating non-small cell lung cancer (NSCLC) patients with AstraZeneca's Iressa (gefitinib) could have a beneficial effect, Phase II study results of ASA404 (vadimezan) in patients with either squamous or non-squamous NSCLC and preclinical results showing that Synta Pharmaceuticals' STA-9090 is active against 100 per cent of all NSCLC cell lines tested.

With regard to the gefitinib study, researchers evaluated 15 patients who were retreated with the drug after more than one cycle of chemotherapy for advanced or metastatic NSCLC. Among the six patients who had showed partial response (PR) with initial gefitinib treatment, two patients showed an additional PR and three continued to show stable disease (SD). Among the nine patients who showed SD with the initial gefitinib treatment, two patients showed PR and three showed SD. The overall disease control rate was 66.7 per cent.

Separately, ASA404 showed promise in patients with either squamous or non-squamous NSCLC. These results support ongoing Phase III studies of the drug in NSCLC. Under development by Novartis, which licensed the drug from Antisoma, ASA404 has a unique mechanism of action against a tumour's blood supply. The product has been shown to cause selective disruption of the established tumour vasculature, inhibition of tumour blood flow and tumour necrosis. This unique mechanism of action could provide an option for patients with either squamous or non-squamous NSCLC. Treatment options for patients with advanced-stage NSCLC are limited, particularly for those with squamous histology where some treatments exhibit limited efficacy or serious side effects.

Further, preclinical results showed that STA-9090, a potent, synthetic inhibitor of heat shock protein 90, demonstrated potent activity against 100 per cent of all NSCLC cell lines tested, including those with EGFr, HER2 or KRAS mutations, including the EGFr T790 mutation that is present in approximately 50 per cent of cases of erlotinib or gefitinib resistance. Synta is currently enrolling patients in a single-arm, open-label, single-agent, Phase II study of STA-9090 in patients with Stage IIIb or IV NSCLC, with patient cohorts defined by the genetic profile of their tumours.

STA-9090 potently inhibited cell proliferation in 24 out of 24 human NSCLC lines tested, irrespective of EGFr, HER2 or KRAS mutational status. In vivo, STA-9090 stopped tumour growth in both erlotinib-sensitive and -resistant NSCLC xenograft models. In addition, in a HER2-positive adenosquamous LC study, three out of four animals treated with STA-9090 experienced partial responses, as measured by MRI. Dr Vojo Vukovic, Chief Medical Officer of Synta, stated: "taken together, the in vitro and in vivo results presented at this conference demonstrate the potency, broad activity and safety profile of STA-9090, both as a single agent and in combination with taxanes in NSCLC."

Alice Rossiter
Editor, Cancer Drug News

Wednesday, January 13, 2010

Advances in skin cancer R&D

The last week has seen notable advances in the field of skin cancer research and development, including the initiation of Plexxikon's pivotal Phase III trial of PLX4032 in patients with metastatic melanoma (MM), detailed results of Biofrontera's Phase III comparative study of BF-200 ALA for the treatment of actinic keratosis (AK) and a new study from Stanford University suggesting that an anti-inflammatory prescription drug can reduce the risk of a common skin cancer in humans.

Enrolment has been initiated and the first patient has been dosed in the pivotal Phase III trial of PLX4032, a novel, oral and highly-targeted drug that is designed to inhibit the BRAF cancer-causing mutation that occurs in approximately 50 per cent of melanomas. The randomised, controlled trial, called BRIM3 (BRAF Inhibitor in Melanoma), in previously-untreated patients is part of the planned registration programme for PLX4032. With some tumour shrinkage in nearly all mutation-positive melanoma patients, and 70 per cent of patients achieving at least 30 per cent tumour shrinkage in the company's most recent clinical study, PLX4032 has shown meaningful antitumour activity. BRIM3 is expected to enrol approximately 700 previously-untreated melanoma patients who will be randomised 1:1 with PLX4032 960mg twice daily or dacarbazine.

Separately, detailed results of Biofrontera's Phase III comparative study have confirmed the superiority of BF-200 ALA over Photocure's Metvix (methylaminolevulinate) for the treatment of AK. Patients were treated by photodynamic therapy, combining one of the test compounds or a placebo with a brief red light illumination. With different types of red light sources, BF-200 ALA on average erased all lesions in 78 per cent of the patients, whereas the registered comparator, methylaminolevulinate, only reached a complete healing rate of 64 per cent, and the placebo group of 17 per cent.

Further, according to researchers at Stanford University School of Medicine, a widely-available anti-inflammatory prescription drug can reduce the risk of a common skin cancer in humans. The scientists believe that although oral administration of celecoxib is associated with an increased risk of myocardial infarction and stroke in some people, it is possible that topical application could have a safer, protective effect for people prone to developing basal cell carcinomas (BCCs). The investigators dovetailed studies in mice with a randomised, double-blind, Phase II trial to reach their conclusions.

The researchers enrolled 60 people with a genetic predisposition to BCC in a three-year trial. Approximately half of the patients received celecoxib 200mg twice daily in a tablet format, while the others received a placebo. All patients were monitored at three-month intervals at one of four study sites for the development of new BCCs or the growth of previously-identified cancers. They found that, although both groups continued to develop new cancers during the study, oral celecoxib treatment decreased the growth of skin tumours by approximately 50 per cent, as compared to placebo, in participants who entered the trial with 15 or fewer BCCs. Celecoxib treatment also reduced the overall tumour burden in this group of patients.

Alice Rossiter
Editor, Cancer Drug News

Wednesday, December 2, 2009

Scientists battle cancer drug resistance

A main cause of failure in the treatment of cancer is the development of drug resistance by the cancer cells. Much research is already under way to investigate ways of reducing or preventing chemotherapy (CT) resistance. Now, scientists from Kingston University, London, the UK, have begun a three-year study to analyse why cancer patients become resistant to treatments designed to fight the disease. The team has been awarded £99,000 to investigate why some tumours are sensitive and respond to treatments, and why other tumours do not. The study, funded by cancer charity, BRIGHT (Better Research into Gastrointestinal Cancer Health and Treatment), will look at existing treatments for colorectal cancer (CRC).

Experts from Kingston's Faculty of Science will work with specialists at Royal Surrey County Hospital to examine tumour specimens from CRC patients. They aim to identify signs or markers that could indicate how patients respond to treatment with anticancer drugs. The scientists will also investigate whether cancer stem cells (SCs) play an important role in the progression of CRC, and could be responsible for the poor response or development of resistance to treatment with anticancer drugs.

The study could help local health authorities to target drugs more effectively and spare those who will receive no significant benefit from treatment with what are often expensive drugs. The researchers want to investigate why it is that after several cycles of CT, resistance to the CT agents occurs. Ultimately, the team hopes that the results of the investigation will improve survival among cancer patients. It should also help scientists to develop new drugs to target those patients who do not respond well to medication currently available.

Further research in the field of resistance to cancer therapy could come from a new exclusive licence between Clarient and Minerva Biotechnologies. Minerva has granted Clarient the exclusive right to develop and commercialise a test that identifies the MUC1* protein, a biomarker researchers believe may be implicated in the spread of many cancers, including breast cancer. Early research has demonstrated that MUC1* may play a role in developing resistance to cancer drugs, which means that if scientists can block MUC1*, patients may be able to overcome resistance to a drug and, once again, be offered that therapy.

The MUC1 story has garnered a great deal of attention recently with Minerva's discovery that MUC1 is in an altered form, called MUC1*, on embryonic SCs and cancer cells. This is the first direct evidence that cancer cells grow by hijacking a normal SC mechanism that usually exists in a dormant state on healthy adult cells. Minerva has compelling evidence that cancer cells that grow resistant to anticancer drugs do so by producing more MUC1*. A recent study by Minerva outlined how the blocking of MUC1* can reverse an acquired resistance to cancer drugs, increasing the therapeutic choices for certain solid tumours.

Alice Rossiter - Editor, Cancer Drug News

Wednesday, November 25, 2009

Various positive data disclosed at AACR-NCI-EORTC meeting

Scientists, pharmaceutical companies and industry experts from around the world recently gathered at the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics, held from 15th to 19th November, in Boston, MA, where much encouraging data were presented regarding a wide range of cancer indications. Of particular note, positive data were reported from studies in metastatic melanoma, lymphoma, and head and neck cancer.

Initial data from an ongoing Phase IIa study of Myriad Pharmaceuticals' Azixa (MPC-6827), a microtubule destabilising agent in Stage IV melanoma patients, demonstrated encouraging durations of response. The combination of Azixa at all concentrations with fixed-dose temozolomide, including the previously-determined single-agent maximum tolerated dose of Azixa, was safe and well tolerated. Ten patients achieved stable disease (SD) and two achieved confirmed partial responses (PRs). One patient had SD for four months before achieving a PR for an additional eight months. A second patient had SD for two months before achieving a PR for an additional four months.

Further, data from a Phase I study demonstrated that TopoTarget's belinostat (PXD101) in combination with Velcade (bortezomib) is well tolerated in patients with advanced solid tumours or lymphoma. A total of 22 were evaluable for toxicity and received a total of 58 treatment cycles. At the highest dose level, dose-limiting toxicity included Grade 4 thrombocytopenia and fatigue. Most adverse events (AEs) have been mild to moderate and four patients have maintained SD for four to six cycles of therapy.

Professor Peter Buhl Jensen, CEO of TopoTarget, commented: "we now know that full doses of belinostat can be given with full Velcade doses. This promising combination can now be tested in larger populations...belinostat may become an important treatment alone or may be part of an effective combination treatment as the safety profile of belinostat allows it to be combined in full dose with conventional and novel therapies like Velcade."

Separately, updated results from a Phase I/II trial (REO 011) of Oncolytics Biotech's Reolysin combined with carboplatin and paclitaxel (CP) for patients with advanced cancer, with a focus on H&N cancer, demonstrated that Reolysin was well tolerated when administered intravenously in combination with CP. Of 19 evaluable patients with H&N cancer, mostly squamous cell carcinoma of the H&N refractory to prior platinum-based chemotherapy for recurrent/metastatic disease, eight experienced PRs and six had SD. The total clinical benefit rate observed in H&N cancer patients in the trial was 74 per cent. Of four patients with malignant melanoma on the trial, one experienced a PR and one had SD.

Alice Rossiter - Cancer Drug News Editor

Wednesday, November 11, 2009

New direction needed for PC research

The current focus on individualised care in many different cancer indications has left pancreatic cancer (PC) behind. Patients diagnosed with this disease live no longer today than those diagnosed two decades ago, despite numerous amounts of clinical trials. Whilst there have been great advances in other cancers, with patients benefiting from targeted drugs such as Gleevec (imatinib) and Herceptin (trastuzumab), PC still remains aggressive as ever.

Published in the 26th October online edition of the Journal of Clinical Oncology (10.1200/JCO.2009.21.9022), an expert panel convened by the National Cancer Institute has issued a consensus report that discusses many aspects of developing and testing treatments in this disease, and charts a course for the next five years. The authors of the report have stressed that the recommendations be strongly considered in any clinical trial being planned for PC.

A recommendation is to design pilot studies that test potential treatments in smaller groups before proceeding to larger trials, which have previously yielded disappointing results. Decisions about which molecular targets and potential drugs to pursue will be made based on scientific evidence that will include preclinical and animal studies that better represent PC in humans.

As the report notes, a better understanding of the complex signalling pathways in pancreatic tumours and the role of the local tumour environment are needed. More sophisticated modelling systems and repositories of high-quality biological samples that can be shared among preclinical researchers are also essential. Published in the same issue the Journal of Clinical Oncology (10.1200/JCO.2009.24.2446), a study provides an example of the kinds of trials many in the field hope to avoid in the future. As has been the pattern for these studies, patients saw little or no benefit from the experimental treatment, in this case, a combination of gemcitabine and capecitabine, as compared with gemcitabine alone.

Scientists involved in clinical trials for PC are aware of the limited success, and have already begun to adopt new ideas about developing and testing treatments. Dr Philip A Philip, the report's senior author, commented: "we have to be more thoughtful and innovative in bringing forward new targeted therapies and treatment combinations." The hope is that the new strategy will ensure that resources and patient time are spent on the most promising treatments.

Separately, in findings that could help researchers focus their drug-development efforts, Massachusetts Institute of Technology cancer biologists have identified a subpopulation of cells that can give rise to PC. In mouse models, they also found that tumours can form in other, more mature pancreatic cell types, but only when they are injured or inflamed, suggesting that PC can arise from different types of cells depending on the circumstances. In future studies, the MIT researchers plan to use their mouse models to follow the molecular events that take place during PC development, and identify potential targets for drug treatments and protein markers for early diagnosis. These new mouse models could also help researchers test potential PC treatments.

Alice Rossiter - Cancer Drug News Editor

Wednesday, October 28, 2009

2,000 UK women denied BC treatment

Patients suffering from an aggressive form of breast cancer (BC) are being failed by the NHS and deprived of more treatment options as the National Institute for Health and Clinical Excellence (NICE) rejects GlaxoSmithKline's oral Tyverb (lapatinib) in combination with capecitabine for the treatment of ErbB2-positive BC.

BC is now the most common cancer in the UK. In 2006, >45,500 women were diagnosed with the disease; that is approximately 125 women a day, and in the last ten years, incidence rates in the UK have increased by 6 per cent. As an oral treatment, lapatinib gives patients suffering from ErbB2-positive BC the freedom to spend precious additional months with friends and family without the restrictive ties of regular hospital visits.

The decision to deny NHS patients access to treatment with lapatinib follows the request in July by NICE's Appeal Panel that the Appraisal Committee should reconsider lapatinib under the Institute's end of life (EOL) supplementary guidance. The EOL guidance was specifically developed to help small numbers of patients who have only a few months to live, gain access to important new medicines. GSK submitted additional data demonstrating that lapatinib met all three of the EOL criteria.

NICE recognised that lapatinib met the EOL criteria, acknowledging that additional data submitted by GSK demonstrated that the drug could offer a significant extension to life, but it felt lapatinib was still not a cost-effective use of NHS resources. This decision has been made despite GSK offering the Tyverb patient access programme, which allows NHS patients in the UK free access to lapatinib for the first three months of treatment.

GSK proposed the patient access programme in the UK when NICE indicated early on in its review that it did not consider lapatinib to be cost effective in treating this patient population. The company will continue to honour the access programme for NHS trusts in the UK. A total of 26 trusts have already enrolled in this programme, reflecting the clinical demand for lapatinib and recognising the potential cost effectiveness for the NHS. Simon Jose, General Manager of GSK UK commented: "it is disappointing that, despite acknowledging Tyverb meets these criteria and GSK offering to bear the cost of lapatinib for up to 12 weeks, NICE is still proposing to reject lapatinib. We will continue to offer our patient access programme to individual NHS Trusts to ensure patients have access to Tyverb."

This decision will result in 2,000 UK women a year being denied access to lapatinib on the NHS. These are women for whom there are very few other treatment options available to them at this stage of their disease. By comparison, lapatinib is funded in 18 other European countries for the treatment of women whose advanced BC has returned despite treatment with standard chemotherapy regimes, including intravenous Herceptin (trastuzumab).

Alice Rossiter - Cancer Drug News Editor

Thursday, October 22, 2009

Cancer proven to pass from mother to baby

A rare case of a mother and her infant developing the exact same cancer has allowed an international team of researchers from the Institute of Cancer Research (ICR), to solve a puzzle that has perplexed scientists and clinicians for a century. The scientists, with funding from Leukaemia Research, investigated a situation in which leukaemic cells appeared to have defied accepted theories of biology and spread through the womb from a Japanese woman to her daughter.

Approximately 30 previously-known cases of a mother and infant appearing to share the same cancer had already raised suspicions that such spread was possible. However, there was no genetic evidence to support this theory, and investigators did not know how it could occur as the baby's immune system should have recognised and destroyed any invasive cancer cells that were of maternal, and therefore foreign, origin. In a study, published in the 12th October online edition of PNAS (10.1073/pnas.0904658106), the scientists used advanced genetic fingerprinting to prove for the first time that the infant's leukaemic cells were unquestionably of maternal origin.

The researchers found that both patients' leukaemic cells carried the identical mutated cancer gene, Bcr-Abl1, but the infant had not inherited this gene. This meant that the child could not have developed this type of leukaemia in isolation. To investigate how the cells could have crossed the placental barrier and survived in the offspring, the scientists looked for evidence of some form of immunological acceptance or tolerance of the foreign cells by the foetus. They examined the genes of the cancer cells in the infant and found some DNA missing in the region that controls expression of the major histocompatibility locus. This was significant because HLA molecules primarily distinguish one individual, and his or her cells, from another, so the absence of these molecules on the cancer cells meant that the infant's immune system would not have recognised that they were foreign.

It appears that in this and, the scientists presume, other cases, the maternal cancer cells did cross the placenta into the developing foetus and succeeded in implanting because they were invisible to the immune system. Dr David Grant, Scientific Director at Leukaemia Research, commented: "the important message from this fascinating piece of research is that leukaemia cells can be destroyed by the immune system. Harnessing the power of the immune system to first cure and then protect patients from leukaemia is one of our priority areas of research."

According to Professor Peter Johnson, Cancer Research UK's Chief Clinician, this finding provides further evidence that cancers are generated more often than first thought. A large part of cancer research is on cancer immunity; scientists have known for quite some time that people with deficient immune systems, perhaps because of HIV or immunosuppression after organ transplants, are much more prone to certain types of cancer. The real challenge for researchers now is to work out how to invigorate the immune system so it recognises cancer cells.

Alice Rossiter
Cancer Drug News Editor