Challenges in Incorporating Integral NGS into Early Clinical

Trials

Dr Shivaani KummarHead, Early Clinical Trials Development

Office of the Director Division of Cancer Treatment and Diagnosis

National Cancer Institute

May 3, 2012

Clinical Applications of Cancer Genomics

Prevention: prediction of disease risk based on inherited or early somatic changes before neoplastic transformation

Diagnostic: early disease diagnosis

Therapeutic: identify cancer subtypes likely to respond; treatment selection-sensitivity or resistance to an agent

Prognostic: Identify subsets with good or poor prognosis

Molecular Profiling to Assign “Treatments”

Growing interest in early drug development

Hypothesis: Assigning treatment based on current MP technologies would provide superior clinical benefit to this patient population as opposed to treatment based on an experienced clinician’s best judgment

Evaluate this approach in patients with refractory tumors, essentially a population eligible for phase 1 studies

Personalized medicine in a phase I clinical trials Program: M. D. Anderson Cancer Center Initiative

Tumor molecular analysis for samples from 852 (89%) of 955 consecutive patients with advanced cancer.

354 (41.5%) had ≥ 1 aberration: 10% of patients had a PIK3CA mutation; 19% KRAS; 8% NRAS; 19% BRAF; 3% EGFR; and 2% had a CKIT mutation; 21% had PTEN loss.

Median time to treatment failure (TTF) in 161 pts with 1 aberration treated with matched targeted therapy was 5.3 months (95%CI: 4.1, 6.6) vs 3.2 months (95%CI: 2.9 - 4.0) for prior systemic therapy

No significant difference in TTF or CR+PR in patients with 2 or 3 aberrations between matched targeted therapy vs without matching.

Tsimberidou AM, et al. J Clin Oncol 29: 2011 (suppl; abstr CRA2500)

Molecular Profiling for Potential Targets and Treatment Selection

Nine centers across US, obtained fresh biopsies, IHC/FISH and oligonucleotide microarray

Compared PFS for regimen chosen based on MP results versus PFS for most recent prior regimen ( ‘patients as their own controls’)

PFS on MP-selected therapy/PFS on prior therapy of ≥ 1.3 was considered positive

Molecular target detected in 84 of 86 pts(98%)

Commercially available agents used for treatment

18 of 66 (27%) had PFS ratio ≥ 1.3

Von Hoff DD, et al. J Clin Oncol 2010; 28(33): 4877; Doroshow JH. J Clin Oncol 2010; 28(33): 4869

What have we learnt from our experience so far?

It is feasible to obtain fresh tissue, perform MP

Turn around time 3-4 weeks (clinically relevant time frame)

To assign therapy need validated assays (CLIA)

Targeted sequencing for actionable mutations versus whole genome sequencing

A subset of patients with refractory tumors may benefit from treatment assignment using MP

Treatment not pre-defined, ad hoc assignment Assignment bias- availability of appropriate agent, which

pts get assigned, other factors

What have we learnt from our experience so far?

TTP on prior systemic therapy pre-study TTP not well defined using uniform imaging

techniques and intervals; participation in prior trial or design trials with specific TTP

lead in period; randomized design

Includes commercially available and investigational agents (NCI data on phase 1 trials reported a 17% RR)

May include agents such as vemurafenib, doesn’t truly test the hypothesis for assigning therapy with inhibitors of pathways

Importance of target may be disease context dependent (vemurafenib in melanoma vs colorectal cancer)

Sosman JA, et al. N Engl J Med 2012; 366(8):707; Prahallad A, et al Nature 2012; 483(7387):100

Practical Application of Molecular Profiling in Early Phase Trials

Turn around time of 3-4 weeks

Interpretation of the data-how do you assign clinical significance?

Finding a target in a patient’s tumor and having access to an agent that inhibits the given target does not imply clinical benefit

Report needs to be in a format to make it easy to interpret with guidance on which class of agents to administer

Multidisciplinary molecular tumor board

Molecular Tumor Board

Multidisciplinary- expertise in clinical oncology (early drug development, disease specific), genomics, signal transduction pathways, genetic counseling, bioethics, pathology Ad hoc or regularly scheduled meetings/committees

Tumor heterogeneity, biopsy techniques, low tumor purity (microdissection, cell based enrichment, ploidy based sorting)

Which aberrations are clinically significant? What percent of cells demonstrating mutation are

significant?

Molecular Tumor Board

Need to address: Driver versus passenger mutations (single tumor

carries an average of 80 somatic mutations that change the amino acid sequences of proteins)

If more than one aberration is present, which one to target first, which sequence?

How to we “validate” the performance of the tumor board? 

Will decisions be made the same way on different days?

Informed Consent

Biopsy associated risks

How much information to share? incidental findings?

Genetic Counseling, absence of outcome data to guide counseling

Patient should decide whether to find out about incidental findings

Involve Bioethicists

Verbalize understanding of the consent

Confidentiality issues

M-PACT: Molecular Profiling based Assignment of Cancer Therapeutics

Pilot Trial to Assess the Utility of Genetic Sequencing to Determine

Therapy and Improve Patient Outcome in Early Phase Trials

NCI-Sponsored Clinical Trial

Objective

Assess whether the response rate (CR+PR) and/or 4-month PFS is improved following treatment with agents chosen based on the presence of specific mutations/amplifications in patient tumors. Only patients with pre-defined mutations/amplifications of interest

will be eligible

Cohort A: Receive treatment based on an agent prospectively identified to work on that mutation/pathway

Cohort B: Receive treatment with one of the targeted agents in the complementary set (identified to not work on one of the detected mutations/pathways)

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Statistical Design

Patients will be randomized 2:1 in Cohort A vs Cohort B

Within cohort A, up to 30 patients will be treated within each of the treatment strata; discriminate between tumor response rates of 25% vs. 5% and 2-month PFS rates of 80% vs. 50% (corresponding to median PFS of 4.8 vs. 2 months).

The two arms will be compared with respect to both objective response rate and PFS

Within each stratum of Cohort A, objective response rate and PFS will be assessed against the historical standards of 5% response rate and 50% 2-month PFS

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Acknowledgements

National Cancer Institute Developmental Therapeutics Team

All the patients who participate in early-phase clinical trials