A diagnosis of stage IV pancreatic cancer is pretty much a death sentence. People are often diagnosed in the advanced
San Francisco – the AACR-NCI-EORTC international conference on Molecular Targets and Cancer Therapeutics kicked off last Saturday with two educational sessions, including one that I attended on “Clinical Trial Paradigms in the Era of Novel Therapies.”
The session had an impressive line-up of speakers:
- New paradigms for early-phase trials (James Doroshaw)
- Phasing out phase III trials: How much evidence do we need if the target is clearly hit? (Jaap Verweij)
- Development of clinical trials incorporating genomic signatures: Lessons learned? (Lisa McShane)
- Clinical trial designs for targeted therapies (John Crowley)
James H. Doroshow, deputy director for clinical and translational research at the National Cancer Institute, started his presentation by reviewing the causes of phase II trial failure:
- 19% Safety
- 51% Efficacy
- 29% Strategic
He stated that the overall success rate of recent phase II trials was 18%.
As the debate continues about whether more cancer clinical trials should be done in Phase 2, the key issue according to Doroshow remains lack of a demonstrable proof of mechanism (POM) in many drug trials. That goes hand-in-hand with a lack of molecular markers which can be used to select trial subjects.
“Lack of molecular markers with proven clinical utility follows lack of clinically-demonstrable proof of mechanism”
He provocatively asked:
Should we perform early phase trials without generating evidence supporting POM patient by patient?
His view was that to obtain POM, you need to demonstrate drug action on intended tumor target early in development, prior to expectation of efficacy.
Jaap Verweij in his presentation used the examples of crizotinib, vismodegib, vemurafenib and imatinib in GIST as examples of drugs that had:
- functionality for a target
- aimed at a specific population
- availability of a selection marker.
They are the poster children of targeted therapy, and he convincingly showed that the phase 1 trials of those compounds were largely predictive of the phase 3 results.
His conclusion was that phase I trial can be considered predictive of a phase III study so long as there is a large enough sample size.
“We may need to look for bigger increments which should allow us to perform smaller trials,” he said. This would allow trials that are quicker and cheaper. However, he acknowledged that it was not likely we can completely eliminate phase 3 trials particularly for combination therapies or chemotherapies.
John Crowley reviewed the different phase III trial designs, including my least favorite, the “all comer” design. The ridaforolimus sarcoma phase 3 trial presented at ASCO this year is a good example of how an “all comer” design yielded less than stellar results, and failed to identify the subset of sarcoma patients that optimally respond. This is the type of phase 3 trial that runs the risk of failure if there are too many non-responders in the heterogeneous patient population. This problem can often be avoided by more rigour in phase 2 trials to identify the optimal treatment period, relevant biomarkers and subsets of patients most likely to respond.
There is a lot of interest in how to design cancer clinical trials better, bring drugs to market more quickly and more efficiently. While I enjoyed the content of this session, I did wonder whether it would have been better presented as a roundtable with more audience interaction and engagement rather than the perspective of a few.
A webcast of this session will be available on December 8 from the American Association for Cancer Research (AACR).
I will be flying to Stockholm next week for the European Multidisciplinary Cancer Congress (twitter #EMCC2011), more commonly known as ECCO or ESMO 2011.
What are the sessions that look interesting at the meeting? I previously wrote about the phase III ALSYMPCA trial data for Alpharadin that will be presented as a late breaking abstract.
In addition, the best abstract at ECCO 2011 is on vismodegib in basal cell carcinoma. Sally Church on Pharma Strategy Blog has written extensively about the hedgehog pathway and role of smoothend inhibition in the treatment of cancer.
What else has attracted my attention at ECCO 2011 in Stockholm? In looking at the preliminary program I was struck by the large number of scientific symposia throughout the meeting. However, many occur at the same time! On Saturday 24th two in particular caught my attention:
Molecular Imaging of Hypoxia
Nanotechnologies for Targeted Drug Delivery
Later in the conference, there is another block of scientific symposia on Monday 26th, again all at the same time! Several that look particularly interesting include:
- How to understand and to Reverse Drug Resistance in Metastatic Breast Cancer
- From New Targets to New Drugs in Prostate Cancer
- Tailoring Personalized Medicine for the Future
- The Role of IGFs/IGF-1R Pathway in Paediatric Malignancies
And in case one still hasn’t had enough science, there’s another group of scientific symposia on the final day of the conference on Tuesday, 27 September including:
- Unravelling Ras PI3 Kinases Targets
- PARP inhibiting strategies: from Molecular Mechanisms to Rational Clinical Applications
I expect Stockholm to be expensive, they jokingly say you can buy a brewery in America for the price of a beer in the city, but it looks like there’ll be some interesting news and scientific data from the meeting. Hopefully I’ll have a few hours sometime to see something of what looks like a stunningly beautiful city.
If you plan to be in Stockholm do let me know. I can be reached via twitter (@3NT).