Biotech Strategy Blog

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

Posts tagged ‘Cancer Clinical Trial Design’

One of the most interesting sessions I attended at this year’s American Society of Clinical Oncology (ASCO) annual meeting in Chicago was the Clinical Science Symposium (CSS) on the next generation of EGFR inhibitors.

We’ve previously written on the blog about the data for AZD9291 and CO-1686 presented at ASCO, but the CSS also featured an informative discussion by Larry Schwartz, MD, Professor of Radiology at Columbia University Medical Center which raised questions about how we should evaluate new lung cancer drugs.

In a presentation entitled, “Getting the Right Drug to the Right Patient Faster,” Schwartz who is a diagnostic radiologist, discussed and critiqued abstract 8012 by Gideon Michael Blumenthal and colleagues at the U.S. Food and Drug Administration (FDA).

Larry Schwartz ASCO 2014

A meta-analysis of fifteen trials involving 12,534 patients (median N = 698) from nine experimental agents (tyrosine kinase inhibitor = 5, chemotherapy = 2, monoclonal antibody = 2) submitted to the FDA for treatment of metastatic non-small cell lung cancer (NSCLC) cancer in initial or supplemental New Drug or Biologics License Applications since 2003 was performed by Blumenthal and colleagues.

Their analysis showed a strong correlation (R² of 0.89) between overall response rate (ORR) and progression-free-survival (PFS) but only a weak or no correlation between ORR and overall survival (OS) (R² of 0.07) or between PFS and OS (R² of 0.09).

Dr Blumenthal noted in his conclusion that further work is ongoing to corroborate these findings given the lack of correlation between OS and ORR could have been due to high cross-over, under-power and long post-progression survival.

He went on to note that what the findings do show is that “a drug with a large effect on ORR is likely to have a large effect on PFS, conversely a drug with a small ORR may have a small effect on PFS.

The debate around objective response and outcomes is a very interesting one, as is the drive to find better biomarkers of response to improve chances of clinical trial success.

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A standing room only audience at the recent annual meeting of the American Association for Cancer Research (AACR) heard from several distinguished speakers on what the future of cancer drug therapy is likely to look like: combinations of novel cancer agents.

This AACR session was one of the highlights of the meeting and would have merited from being part of the plenary program.

Jeffrey Engelman from MGH persuasively presented on why we need combination therapies to overcome resistance. He noted that:

  • Most cancers are not sensitive to currently available single-agent therapies
  • Even when sensitive to single-agent therapies, cancers develop resistance, often necessitating combinations

One of the challenges of this approach will be “identifying effective combinations,” he said.

Roy Herbst from Yale, presented on some of the practical challenges involved with the early phase testing of two drugs, and challenged the audience with a critical question:

“Do we possess the necessary translational tools that will help us identify the right drug combinations, ratios and schedules with the right patient?”

Stuart Lutzker from Genentech described their experiences of clinical trials with rational drug combination of trastuzumab and pertuzumab for HER2+ breast cancer.  He concluded that:

“Rational drug combinations have begun to yield exciting Phase III results and should be preferred over empiric drug combinations.”

The Pharma Strategy Blog video interview with Gordon Mills from ECCO/ESMO 2011 in Stockholm offers some interesting insights into how MD Anderson are helping to facilitate academia-industry combination trials with novel compounds from different companies in order to achieve more rational drug design and improve outcomes for people with cancer.

If two or more novel cancer drugs are required to interrupt key pathways or to avoid adaptive resistance, what does this mean for the regulatory strategy?

Janet Woodcock addressed some of these challenges in her AACR presentation, and discussed how the:

“FDA would not want to approve a combination regimen with two new agents unless each contributed to the effect.”

Draft guidance on “Codevelopment of Two or More Unmarketed Investigational Drugs for Use in Combination” was published by the Agency in December 2010. Click here for a PDF copy.

The document gives examples of a number of different phase II trial designs that can be used to demonstrate the contribution each drug makes to the combination, and the additive effect seen.

As an example, if each drug in a combination has activity and can be administered individually then the guidance document suggests a multi-arm phase II trial may be needed that compares the impact of either drug alone versus the combination and standard of care.  An adaptive trial may also be used if appropriate.

Dr Woodcock noted that future cancer drug development is likely to include increasing use of combinations, adaptive trials to evaluate various drug and diagnostic combinations and increasing attention to the use of novel biomarkers.

The message I took home from the AACR annual meeting is that the future of cancer therapy is in combinations, and we can expect more clinical trials with two unapproved agents (novel-novel combinations) in the future.


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).

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