Biotech Strategy Blog

Commentary on Science, Innovation & New Products with a focus on Oncology, Hematology & Cancer Immunotherapy

Posts tagged ‘Cancer Targeted Therapies’

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).

Academic institutions are now bringing pharma/biotech companies together and facilitating rational combination trials that make solid scientific sense.

Combining at least two targeted drugs looks to be increasingly necessary in order to develop innovative new cancer treatments, where turning off one target may stimulate another, thus both need to be targeted for there to be an overall effect.

However, one company may not have all the pathways and drug targets covered by their portfolio.  The result is that companies may have to work together in combination trials with each providing one drug from their portfolio.

That was one of the key messages I took from Gordan Mills (UT MD Anderson Cancer Center) in his recent video interview with Sally Church from Pharma Strategy Blog:

Sally Church’s video interview with Professor Mills is well worth watching if you have not already done so.

Not only are universities and research institutions well placed to judge the scientific merits, but as Mills points out they can facilitate things as an independent third party and actively help bring partnerships together.  Given that combination therapies may be needed in order to turn off different parts of signaling pathways and cross-talk, I think we are likely to see more of this approach.

It’s going to be new territory for many companies – how to enter into a potential joint venture or alliance? However, if it results in a therapy that works, it is going to be win-win for all parties. It may also improve efficiency in drug development and lead to better use of patients in early stage development.

Some examples of where this is happening already in oncology include AstraZeneca and Merck with their MEK-AKT approach and GSK (MEK) with Novartis (PI3K), to name a couple.  This is a new trend we are likely to see more of in the future.

I can see universities hiring alliance managers who have industry experience to ensure these collaborations run smoothly.

The topic of the industry/academia interface in rational cancer drug development will also be discussed in a plenary session at the forthcoming American Association for Cancer Research (AACR) meeting on Molecular Targets and Cancer Therapeutics (November 12-16, 2011) in San Francisco.

How academia can better help the pharma/biotech industry bring innovative, rational drug combinations to market is a topic that I think we will be reading more about in coming months.

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