Tumor Mutational Burden a New Pan Cancer Marker for Immuno-Oncology?

By Anthony M Magliocco MD

A new molecular marker “Tumor Mutational Burden” is rapidly emerging in the immuno-oncology world. New trials are showing that TMB may be superior to PDL1 IHC analysis to determine a patients probability of responding to costly and potentially toxic immuno-therapy treatments such as immune checkpoint inhibitors.

Tumor Mutational Burden

The Cancer Genome Atlas (TCGA) has shown that cancers have significant variation in the burden of genomic mutations they carry.  Some tumors such as melanoma have extremely high burdens whereas others such as thyroid cancer have very low loads.

 

04_Frequency_Chart

FREQUENCY OF TMB ACROSS TUMOR HISTOLOGY TYPES

 

Some tumors have exceptionally high mutational loads which probably represents an underlying DNA repair deficiency such as POLE or MSI abnormalities. It may also reflect the mechanism of oncogenesis as UV induced tumors such as melanoma have very high burdens.

 

05_Pan-Cancer-Chart

THE NEOANTIGEN BURDEN IS DIRECTLY RELATED TO TMB

It is thought that TMB actually results in the development of neo-antigens, which are essentially immunogenic.  The probability of neo-antigens emerging is proportional to the total tumor mutational burden. However, this is still a probability measurement, its possible that tumors with even low mutational loads might still generate neo-antigens of interest to the immune system.

210-neoantigens-mobile

CANCER CELL WITH NEOANTIGENS STIMULATE IMMUNE CELLS

 

Recent Clinical Trials Point to TMB as an important pan-cancer marker

There have recently been three interesting trials in advanced lung cancer reported with a significant association between tumor mutational burden (TMB) and response to the PD-L1 inhibitor nivolumab (Opdivo).  CheckMate 012 trial, was a single-arm evaluation of the combination of the PD-1 inhibitor nivolumab (Opdivo) and the CTLA-4 inhibitor ipilimumab (Yervoy), reveled benefit in patients with high TMB independent of PDL-1 expression.

At AACR The CheckMate 568 trial,   used a TMB cutoff of ≥10 mutations per megabase of DNA (mut/Mb) as the definition of high TMB. Comparing TMB and response rate in 98 patients with untreated stage IV non-small cell lung cancer (NSCLC), investigators found a 44% response rate in association with TMB ≥10 mut/Mb and no further improvement in response with a higher TMB. The response rate fell dramatically with TMB <10 mut/Mb.  This finding is interesting as it may there is a “shelf” or a bimodal distribution of TMB

According to Dr Ramalingam  of Emory “PD-L1 and TMB identify distinct and independent populations of non-small cell lung cancer that independently are associated with enhanced objective response rate and progression-free survival.”

Investigators in the randomized CheckMate 227 trial prospectively applied the TMB cutoff of ≥10 mut/Mb.  There was aa threefold improvement in 12-month PFS (42.6% versus 13.2%) in the subgroup of patients with TMB ≥10 mut/Mb.

The PFS difference persisted across analyses of high and low PD-L1 expression and squamous versus nonsquamous histology.

“CheckMate 227 validates TMB as an important and independent biomarker to be routinely tested in treatment-naive, advanced non-small cell lung cancer,” said Matthew Hellmann, MD, of Memorial Sloan Kettering Cancer Center in New York City

“TMB should be a standard of care in the initial evaluation of the patient with non-small cell lung cancer,” said Naiyer Rizvi, MD, of Columbia University Medical Center in New York City. “PD-L1 as a biomarker remains as a standard of care in concert with TMB. a validated TMB platform needs to be used.”

Problems with TMB

TMB is definitely showing promise, but what are the drawbacks?

NGS is required

First, TMB calculations require that a significant portion of DNA be sequenced, to generate enough sequence information to determine the tumor mutational load. However, some recent studies suggest that even targeted sequencing panels may provide enough sequence information to determine if the load is high. Access to NGS sequencing remains a challenge. Due to low reimbursements and difficulty of implementing the technology many oncologists may have difficulty  accessing the technology

The calculation of TMB is currently non-standardized and non-trivial

Second, TMB calculation is not standardized. It is not a trivial bioinformatics process as the bioinformatifcs process needs to determine if a  DNA variation is “real” or an artifact of sequencing- this is non-trivial as filters need to be defined to define the criteria to make a “call” ie what the confidence of the read is, what the alleic fraction is and whether the mutation is somatic or germline. In addition it must be determined if the sequence affects the coding region of a gene.  Further complicating this is what the denominator might be in an assay- ie does the NGS sequence only coding regions or are there significant non-coding regions. If the non-coding regions are included in the calculation the number may be artifactually low.

Third, thinking from a biological and mechanistic approach, it may matter whether the mutation actually produces a neo-antigen. Again this cannot be easily measured. It involves factors such as whehter the mutation is actually transcribed into protein, and whether the protein conformation is actually altered and neo-antigenic. Further issues include whether the sequence is secreted or made available when the cells degenerate.

TMB are not the only source of neo-antigens

DNA mutations may only account for some of the neo-antigens that a cancer can create. Other sources of neo-antigens in neoplasia include microbes (ie HPV virus in HPV driven cancers such as cervical or head and neck cancer. Other sources include post-translational modifications in cancer such as glycosolation events etc.

cgi-viruses

HPV VIRUSES ADD ANTIGENS TO TUMORS

 

Host Factors

Further complicating the impact of neo-antigens include the condition of the host immune system and its capacity to recognize and react to neo-antigens. For example in immune deficiency conditions, neo-antigens may be present but ignored by the immune systems. Or genetic variants in cellular receptors or MHC may affect how neo-antigens are presented to the immune system

patient-family

Neo-Antigens may be induced in tumors as a therapeutic strategy

Another interesting angle affecting therapy is the possibility that neo-antigens could be induced in a cancer to trigger immune response. This effect may be a side effect of some therapies such as temozolamide or radiation therapy.

Intraoperative-Radiation-Therapy-For-Breast-Cancer-1-550x330

RADIATION THERAPY MAY INDUCE NEO-ANTIGENS

 

Dr Magliocco is Chair of Pathology and director of the Morsani Molecular Laboratories at the Moffitt Cancer Center

 

 

 

BRCA Mutation Predicts Carboplatinum Response in Women with TNBC

Anthony M Magliocco MD

 

A recent study published in Nature Medicine reports that women with triple negative breast cancer with a BRCA mutation were much more likely to respond to treatment with carboplatin compared to treatment with docetaxel, which is the current treatment recommendation for these patients.

https://www.nature.com/articles/s41591-018-0009-7

Triple negative breast cancer remains a difficult disease to treat as standard anti-estrogen or anti-HER2 treatments are not considered.

In this study there were 376 women with advanced triple-negative breast cancer across the trial, regardless of BRCA gene status, the researchers found the 2 drugs worked similarly well. But among the 43 women in the study who also had BRCA gene mutations those who received carboplatin were twice as likely to respond to therapy as those given docetaxel.

The researchers have reported an observed resesponse of 68% of the patients treated with carboplatin, but only in 33% of the women on docetaxel.

 

 

 

Furthermore Carboplatin also appeared to cause fewer side effects along with prolonged tumor progression for longer in women with BRCA mutations—with a progression free survival of  7 months compared with 4 months for those treated with standard docetaxel.

The researchers believe carboplatin is more effective for this patient group because it works by damaging tumor DNA, and BRCA mutations impair the ability of cancer cells to repair the type of DNA damage created by this kind of platinum drug.

This study further highlights the need for availability of BRCA gene testing in women with breast cancer.

This study further highlights the need for NGS gene testing in women with breast cancer for the purpose of appropriate therapy selection

 

One curious feature of the study was women with BRCA1 gene methylation, low BRCA1 mRNA expression, or Myriad HRD analysis was not clearly associated with benefit of treatment with platinum based agents.

 

A study at the Moffitt Cancer Center recently showed many triple negative breast cancers may actually be misclassified due to errors in primary pathology biomarker analysis.

Second opinion analysis should be considered for women diagnosed with triple negative breast cancer as the original biomarker analysis may frequently be flawed and an actionable target such as estrogen receptor or HER2 is identified on reanalysis

 

TRIPLE NEGATIVE BREAST CANCER IS OVER DIAGNOSED

 

Morsani Molecular Lab at Moffitt Cancer Center is Central to its Personalized Oncology Mission

By Anthony M Magliocco MD

Moffitt Cancer Center, the largest and only NCI designated comprehensive cancer center in Florida and one of the largest in the country has been rapidly expanding its capabilities in molecular diagnostics with a clear focus on supporting its burgeoning personalized oncology programs which are led by internationally recognized expert Dr Howard McLeod.

It became clear several years ago that a huge revolution was coming in the area of personalized oncology and cancer treatments. That revolution is now here.

Explosive advances and numerous FDA approvals for new targeted therapies have emerged for treating and controlling once universal killers such as metastatic melanoma and advanced lung cancer.

These targeted therapy medicines, include vemurafenib targeting mutant BRAF, Erlotinib for EGFR mutant lung cancer, and crizontinib targeting ALK translocations. Further truly dramatic results have been seen with immunotherapy treatments such as the anti PDL-1 immune checkpoint inhibitor pembrolizumab for treatment of a variety of advanced cancers that over express the protein PDL-1 or carry MSI. More recently approvals of NTRK inibitors Larotrectinib and the PARP inhibitor Olaparib for BRCA mutant cancer have further increased demand for specialized testing as both of these treatments have companion diagnostic requirements

 

Immune cells (red and blue) surround a invasive cancer cells (green)

The approval of many new targeted treatments requiring companion biomarker evaluation is providing impetus to develop more advanced diagnostic technology including new cellular imaging methods

These rapid advances in treatment options hinge on the availability of routine, high quality, clinical grade, molecular analysis and diagnosis to properly identify patients who will be most likely to benefit from these costly and frequently toxic treatments.

The Morsani Molecular Laboratories were created to facilitate the rapid development and implementation of new molecular diagnostic assays into the routine CLIA laboratory at Moffitt

Moffitt leadership and its generous philanthropic doners and foundation laid the important cornerstone of the Moffitt Morsani Molecular Laboratories. Under the direction of Dr Magliocco, the laboratories had a singular mission to rapidly develop and deploy the advanced clinical grade diagnostic services necessary to support Moffitts rapidly maturing personalized medicine program.

The Laboratories were initially opened in 2012 and were first equipped with Mass array instruments and conventional Sanger sequencing, pyrosequencing and routine PCR ability. The decision was made to recruit PhD scientists who would help develop the new assays to a CLIA standard and then launch them into a “routine” production laboratory.

The demand from the Moffitt clincal services was high, especially from thoracic oncology, a ground breaking team offering a multitude of clinical trail options for Moffitt patients. This demand required that the assays be CLIA grade, complex and delivered in a rapid way.

This was very challenging. Launching a highly multiplex assay into a CLIA lab is not a trivial matter. The assay must be calibrated to show sensitivity, specificity, analytical performance, range, precision, accuracy and many other technical components. Further, any new assay must also be put through its paces to show its robustness and reproducibility when handled by different scientists and technologists.

Launching new assays into CLIA labs is not trivial and requires extensive expertise and investments

We initially chose to launch the LungCarta (TM) Mass Array Panel from Sequenom. This was very challenging to validate as it contained individual assays run in multiplex to assay over 213 distinct mutations. as these were separate mutations and assays, the decision was made to only validate the most clinically important ones, namely BRAF V600E, KRAS, EGFR, and PIK3CA. The next issue was obtaining appropriate clinical reference materials to validate these assays. Fortunately with Moffitt’s very high clinical volume, previous experience with single-plex testing, and availability of Total Cancer Care Protocol tumor bank which houses data and specimens from over 400,000 patients it was possible to obtain the necessary control and case materials to validate and launch the assays into clinical service.

The development of a CLIA assay requires access to appropriately characterized reference materials to enable clinical validation of the process and assay results.

Although the complete 213 mutation panel was run, only the CLIA validated assay results were reported to the treating physician. The remaining results were ported into Moffitt’s data warehouse for storage and use in properly approved research studies. Following the launch of the LungCarta assay, the Morsani Molecular laboratory also launched assays for melanoma, and a specially constructed Glioma panel assay.

 

In 2014, clinical demands for even more complex sequencing arose for proper management of Myelodysplastic Syndrome (MDS) mounted. The hematology team needed access to over 30 genes and potentially thousands of mutations. It was time for the big guns, time for next generation sequencing. At the same time Moffitt molecular pathologists also saw increasing needs for more complex sequencing for solid tumors as well. After careful discussions and further evaluations it was decided to begin next generation sequencing. Following some debate, the consensus was to start with Illumina, given their long history in next gen sequencing and also the experience with the technology in Moffitt’s core genetic research laboratory. It was decided to develop an off the shelf 26 gene panel TST26 that covered most of the key mutations in lung cancer and in melanoma. In addition Moffitt CLIA scientists, molecular pathologists, and clinicians worked with Illumina to design a 32 gene myeloid NGS panel.

Bringing on NGS brought new challenges of a complex wet lab and also a very complex bioinformatics dry lab. At Moffitt we worked with PierianDx who helped design bioinformatics pipelines and an efficient validation program for both the wet and dry lab as well as an information system – a genome workbench- which allows molecular pathologists to rapidly review cases and access a knowledge database to enable rapid sign out. We also required access to numerous control samples to validate the assays. Again these came from Moffitts vast biospecimen resources and also Horizon Discovery, a company specializing the the provision of reference materials for clinical validations. To date Moffitt has run over 10,000 NGS assays.

By 2017, clinical demands continued to mount for even more complex testing. There were new drugs approved that needed to evaluate fusions, “exon skipping” mutations, and even MSI and tumor mutational burden. With these demands, we turned to illuminas TST170 assay, a new type of sequencing assay that had both DNA and RNA. In addition the assay was designed with “actionable targets” in mind. Meaning, that targeted agents in clinical trials were scrutinized to determine the collection of genes and mutations that would likely be most informative for treatment selection in solid tumor oncology. This approach makes the assay very useful and practical for deployment in a busy cancer center where multiple trials are underway and complex patients with unusual cancers are presenting. Moffitts Morsani molecular team worked hard and spent several months validating the assay to bring it to acceptable CLIA standard finally launching it as “Moffitt STAR” an assay to screen for actionable mutations.

Since its launch, demand has been exceptionally high with hundreds of physician orders in the first week alone.

 

Moffitt laboratories continue to work closely with the worlds leading oncologists and pharma and technology companies to ensure that Moffitt Patients always have access to the latest diagnostic tools to enable them access to the most current treatment options.

That is what makes Moffitt an exceptional hospital for cancer patients seeking innovative treatments and explains why Moffitt has some of the best cancer outcome response rates in the country.

 

A Tale of 2 Biomarkers: CTCs and cfDNA are Key to Managing the Plethora of New Trial Options

By Anthony M Magliocco MD

 

We are currently living in revolutionary times when it comes to cancer therapy and treatment options. There are literally hundreds of clinical trials under way evaluating dozens of new therapeutic compounds and combinations of therapy. In fact there are so many trials that its difficult to always find enough patients for them and also to design them to produce the level of evidence expected in traditional multi-armed phase III trials.

There are hundreds of open clinical trials testing dozens of compounds and combinations of therapy

 

Indeed, we seem to be arriving at the point where cancer therapy really is being tailored and delivered to the individual. This shift from evidence based conventional cancer therapy clinical trials, to newer, matched and “N of One” trials creates new challenges for the oncologist and diagnostic laboratory industry.

In a traditional trial, selection and enrollment would depend on results of a key biomarker such as HER2 overexpression for Trastuzumab therapy

Traditionally a biomarker would be required to select a patient for a specific therapy. For example, in breast cancer, presence of HER2 over expression or amplification was a marker to help select patients for enrollment in a trial. Because the frequency of the biomarker was relatively common in a common disease, it was possible to build a well powered phase III trial to collect convincing evidence that on a population based setting that this was an effective strategy. This led to FDA approval and the development of companion diagnostics such as the Herceptin Test.

Fast forward twenty years or so. Now we have so called “basket trials” where cancers can be tested with complex genomic tests that will evaluate hundreds of genes, for example the Moffitt STAR assay that covers 170 actionable mutations and alterations resulting in detection of relatively rare, but still actionable mutations in many tumors. However the mutations are variable and the choices for treatment complex meaning that more than one combination of therapy could be considered. Whats an oncologist to do?

Going forward, it appears that if patients cannot be managed or enrolled in large trials, there will need to be an approach to effectively manage the so called “N of One” patient. In fact, it could be considered that almost every patient is a now unique in some way and could be classified as a rare disease

With a movement away from classical evidence based clinical trials toward n of one trials, off label therapy, and basket trials new approaches to companion diagnostics are urgently needed

In this situation, it appears that physicians will need to act on “best available evidence” or actual bioinformatics or other predictive models of possible response based on understanding the underlying molecular circuitry in the cancer in question. In this situation a “best guess” is made for assignment of therapy (either in a basket trial or in an off-label situation).

This approach can be problematic and has numerous complications such as the possibility of providing futile or toxic treatment. Fortunately, there are plenty of new advances in technology that might address this problem. The most help may come from the so-called “liquid biopsy”. Which is essentially usually a simple blood test evaluated with a exotic new technology.

Liquid Biopsy

The main components of a liquid Biopsy include circulating normal cells (WBC, Platelets, RBCs) possibly circulating living cancer cells (CTCs) and bits of dying cancer cells (cell free DNA, miRNA etc).

A Story of Two Biomarkers CTCs and cfDNA

CTCs Circulating Tumor Cells

The CTCs are very fragile, rare and hard to detect but give a window into the living cancer in the patient as treatment progresses. These cells can be further evaluated to determine if they are proliferating or if certain signalling pathways are active. In fact they can also be harvested, sequenced, and in some cases grown and expanded in culture.

Cell Free DNA cfDNA

Cell Free DNA or cfDNA gives a more stable read out of the tumor load, and mutation composition of the DNA, or at least the DNA leaking into the blood. It might be expected that when a new treatment begins, cancer cells in the host may undergo death and leak DNA into the blood. Consequently there could be an initial “Spike” in the amount of circulating DNA – this could be a positve signal. In other instances, cfDNA might indicate if there is residual cancer left in a patient after a surgery was completed that was initially intended to remove all disease giving a type of molecular staging. If a therapy is working well we would expect that CTCs and cfDNA would decrease and perhaps become immeasurable. On development of resistance there would be detection of new clones and expansion of the concentration of CTCs and cfDNA fragments.

Liquid biopsy provides a means to monitor tumor response to therapy in a dynamic and real time manner giving unprecedented opportunities to modulate treatment and truly personalize therapy for cancer patients

I expect that the twin technologies of CTC and cfDNA analysis will become more valued by oncologists, patients and payers as these tools will provide a way to dynamically monitor tumor response to treatment and provide immediate evidence of efficacy of a therapy or also of impending relapse potentially allowing a window of opportunity to adjust treatment.

 

FDA approves osimertinib for first line use in lung cancer with EGFR mutation

By Anthony Magliocco MD

TAGRISSO delivered unprecedented median progression-free survival of 18.9 months versus 10.2 months for EGFR-TKIs (erlotinib or gefitinib) in 1st-line EGFRm NSCLC

 

the US Food and Drug Administration (FDA) has approved TAGRISSO® (osimertinib) for the 1st-line treatment of patients with metastatic non-small cell lung cancer (NSCLC) whose tumors have epidermal growth factor receptor (EGFR) mutations (exon 19 deletions or exon 21 L858R mutations), as detected by an FDA-approved test. The approval is based on results from the Phase III FLAURA trial, which were presented at the European Society of Medical Oncology 2017 Congress and published in the New England Journal of Medicine.

 

The results of the phase III FLAURA trial were impressive with dramatic improvements to progression free survival.

The FLAURA trial compared TAGRISSO to current 1st-line EGFR tyrosine kinase inhibitors (TKIs), erlotinib or gefitinib, in previously untreated patients with locally advanced or metastatic EGFR-mutated (EGFRm) NSCLC. TAGRISSO met the primary endpoint of progression-free survival. PFS results with TAGRISSO were consistent across all pre-specified patient subgroups, including in patients with or without central nervous system (CNS) metastases. Overall survival data were not mature at the time of the final PFS analysis.

 

Osimertinib was previously approved for use as second line therapy in patients who had progressed on a TKI treatment or for those whose tumors developed a T790M mutation confering resistance to the first generation TKI therapies.

Osimerinibs mechanism of action is thought to be irreversible binding to the EGFR receptor.  Perhaps this explains the improvement in PFS compared to other TKIs. These findings are potentially practice changing.

Despite these impressive improvements in PFS almost all patients eventually fail targeted therapies with TKI agents. Consequently more work is needed to understand the biological mechanisms of resistance and progression in lung cancer patients to enable more effective therapies to be developed.

https://www.onclive.com/web-exclusives/fda-approves-frontline-osimertinib-for-nsclc

Loxo Oncology work with Illumina to develop Cdx NGS assay for Larotrectinib (NTRK) and LOXO-292 (RET)

Anthony Magliocco MD

In an important announcement Industry sequencing leader Illumina and LOXO Oncology, released that they are working on developing a companion diagnostic for larotrectinib, a NTRK inhibitor and LOXO-292 which targets ret.

 

It appears that they intend to use the TST170 as a basis and perhaps a DX version of the Nexseq 500

This is an important development for 2 reasons. The first is the molecular alterations in question are relatively rare, but they can occur in any tumor type regardless of the tissue of origin. The second is the identification of a standard instrument platform and multi-gene assay panel that is already in clinical use (Moffitt has recently deployed a version of TST170 for patient care as Moffitt STAR) will undoubtedly expedite the capability to scale this test for widespread deployment accross laboratories

The fact that TST170 is so comprehensive potentially offers the opportunity for other oncology drug developers to consider using this versatile assay as a companion diagnostic as well.

https://ir.loxooncology.com/press-releases/loxo-oncology-and-illumina-to-partner-on-developing-next-generation-sequencing-based-pan-cancer-companion-diagnostics

STAMFORD, Conn. and SAN DIEGO, April 10, 2018 (GLOBE NEWSWIRE) —  Loxo Oncology (Nasdaq:LOXO) and Illumina, Inc. (Nasdaq:ILMN) today announced a global strategic partnership to develop and commercialize a multi-gene panel for broad tumor profiling, resulting in a distributable, next-generation sequencing (NGS) based companion diagnostic (CDx) with a pan-cancer indication. The co-development partnership will seek approval for a version of the Illumina TruSight Tumor 170 as a companion diagnostic (CDx) for Loxo Oncology’s larotrectinib, which targets NTRK gene fusions, and LOXO-292, which targets RET gene alterations, across tumor types.

TruSight Tumor 170 is a comprehensive, state-of-the-art, next-generation sequencing test that interrogates point mutations, fusions, amplifications and splice variants in 170 genes associated with common solid tumors. The CDx version of TruSight Tumor 170 will allow local laboratories to provide referring physicians with comprehensive genomic information, so that patients can be matched to the most appropriate therapeutic options. This version of TruSight Tumor 170 will run on the NextSeq 550Dx platform.

“We are leveraging our leadership in next-generation sequencing to deliver in-vitro diagnostic solutions to improve the management of cancer patients in the clinic,” said Garret Hampton, Ph.D., executive vice president of clinical genomics at Illumina. “To this end, we are partnering with leading biotechnology companies, such as Loxo Oncology, to develop companion diagnostics for best-in-class therapeutics. Distributable diagnostic solutions, such as a CDx version of TruSight Tumor 170, in combination with the NextSeq 550Dx platform, will enable labs to perform precision medicine testing in-house.”

Under the partnership, the companies will collaborate to validate a CDx version of TruSight Tumor 170 for NTRK fusions and RET fusions/mutations as a Class III FDA-approved diagnostic in conjunction with larotrectinib and LOXO-292, respectively. The companies are also planning to broaden the clinical utility of the full panel by obtaining regulatory approval for the other assay content, to be marketed as a tumor profiling test. Illumina will lead regulatory activities related to the Class III plans for NTRK and RET, the Class II plans for the tumor profiling content, and CE marking.

“We are very excited to announce this collaboration with Illumina, the world’s leader in NGS technology,” said Jacob Van Naarden, chief business officer of Loxo Oncology. “We have piloted numerous NGS assays, and the Illumina TruSight Tumor 170 assay has consistently demonstrated robust performance with its assessment of both DNA and RNA, including highly sensitive gene fusion detection. The broad 170-gene assay content has the potential to deliver meaningful insights from a single tumor specimen, identifying patients with NTRK fusions, RET fusions, RET mutations, and many other actionable tumor alterations. Furthermore, we believe that this collaboration will improve patient access to high-quality NGS testing because pathologists will be able to run TruSight Tumor 170 locally and receive reimbursement.”

FDA Approved PARP Inhibitor Rucaparib For Maintainance Treatment for Recurrent Ovarian Cancer Boosting Need for Clinical NGS Testing

By Anthony M Magliocco MD

On April 6, 2018, the Food and Drug Administration approved rucaparib (Rubraca®, Clovis Oncology Inc.), a poly ADP-ribose polymerase (PARP) inhibitor, for the maintenance treatment of recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer who are in a complete or partial response to platinum-based chemotherapy.      

Approval was based on ARIEL3 (NCT01968213), a randomized, double-blind, placebo-controlled trial in 561 patients with recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer who had been treated with at least two prior treatments of platinum-based chemotherapy and were in complete or partial response to the most recent platinum-based chemotherapy. Patients were randomized (2:1) to rucaparib 600 mg orally twice daily (n=372) or placebo (n=189) and were treated until disease progression or unacceptable toxicity. 

Tumor tissue samples were examined with a next-generation sequencing assay to determine whether DNA contained a deleterious somatic or germline BRCA mutation (tBRCA). This test was also used to determine the percentage of genomic loss of heterozygosity (LOH). Positive homologous recombination deficiency (HRD) status was defined as tBRCA-positive and/or LOH high. Three patient outcomes analyses were performed on the following groups: all patients, HRD subgroup, and tBRCA subgroup.

NGS ASSAY WAS REQUIRED TO IDENTIFY BRCA MUTATIONS

 

ARIEL3 demonstrated a statistically significant improvement in estimated median progression-free survival (PFS) assessed by investigator for patients randomized to rucaparib compared with placebo in all patients (median PFS 10.8 vs. 5.4 months, HR 0.36; 95% CI:0.30, 0.45; p<0.0001), in the HRD subgroup (median PFS 13.6 vs. 5.4 months, HR 0.32; 95% CI: 0.24, 0.42; p<0.0001), and in the tBRCA subgroup (median PFS 16.6 vs. 5.4 months, HR 0.23; 95% CI: 0.16, 0.34; p <0.0001).

 

The FDA also concurrently approved the complementary diagnostic test, FoundationFocusTM CDx BRCA LOH, for tumor samples to determine HRD status. 

In ARIEL3, the most common adverse reactions in at least 20% of patients treated with rucaparib included nausea, fatigue (including asthenia), abdominal pain/distension, rash, dysgeusia, anemia, ALT/AST elevation, constipation, vomiting, diarrhea, thrombocytopenia, nasopharyngitis/URI, stomatitis, decreased appetite, and neutropenia. Myelodysplastic syndrome and/or acute myeloid leukemia occurred in 7 of 372 (1.9%) patients treated with rucaparib and in 1 of 189 (0.5%) patients assigned to placebo. Discontinuation due to adverse reactions occurred in 15% of patients receiving rucaparib and 2% of those assigned to placebo. 

The recommended rucaparib dose is 600 mg (two 300 mg tablets) taken orally twice daily with or without food.

FDA granted this application priority review. A description of FDA expedited programs is in the Guidance for Industry: Expedited Programs for Serious Conditions-Drugs and Biologics, available at:

 

This approval is another example of the exploding need to broad access to next generation sequencing in routine clinical care of cancer patients forming the foundational basis of personalized oncology

” This most recent approval of yet another therapeutic advance that is reliant on NGS for patient selection further increases the urgency for access to routine NGS for all cancer patients”  – Anthony M Magliocco MD

The Moffitt Morsani Laboratories have developed and launched a new NGS assay ‘Moffitt STAR(TM)” that covers the key actionable target genes including BRCA1 and BRCA2

Moffitt STAR NGS panel covers the key mutations

PierianDx Customer, Moffitt Cancer Center, Launches Clinical NGS Assay, STAR

VISIT MOFFITT CANCER CENTER WEBSITE

http://www.moffitt.org

 

MOFFITT NGS STAR* Enters Clinical Service

Moffitt’s latest NGS sequencing assay the Moffitt STAR (Solid Tumor Actionable Result) panel was validated by the Moffitt Morsani Molecular Laboratory and launched into service this month at the busy Florida Comprehensive Cancer Center in Tampa.

The assay is based on Illumina’s TruSight Tumor 170 assay which is a next-generation sequencing assay designed to cover 170 genes that are commonly designated as drivers in solid tumors. The assay evaluates both DNA and RNA and focuses on detecting actionable mutations which include SNV, dels, insertions, amplifications, and translocations. Such alterations are the target for many new targetable therapies including anti-EGFR agents, anti BRAF therapies and treatments targeting the Tropomyosin Receptor Kinase fusions (TRK) such as Larotrectinib.

Many key actionable mutations only occur rarely, making detection by single marker tests problematic and wasteful. However, the Moffitt STAR assay now allows the Moffitt molecular laboratory to screen patient tumors for multiple targetable mutations efficiently in a single test using a relatively small amount of nucleic acid extracted from routine formalin fixed, paraffin embedded tissues (FFPE). This important advance enables the Moffitt molecular diagnostic laboratory to effectively evaluate a patient for eligibility to receive treatment with a FDA approved targeted therapy, or be considered for clinical trial enrollment. Moffitt STAR is essentially an “All in one” test that can provide multiple functions.

Moffitt NGS STAR* is an exciting new “all in one” technology advance for Moffitt Cancer Center patients enabling rapid assessment of their tumors for presence of key mutations directing selection of effective approved targeted therapies or for qualification to enroll in the latest generation of clinical trials

Evidence is also emerging the assay, despite its mid size, Moffitt STAR could also reliably measure tumor mutational load and microsatellite instability. These molecular features are often associated with potential response to the latest immune check point inhibitors such as Pembrolizumab which has recently received FDA approval for use in tumors with high microsatellite instability.

Moffitt NGS STAR also provides information on tumor mutational burden and microsatellite instability- key features which may drive patient response to the latest immuno-oncology check point inhibitor therapies

Moffitt NGS STAR can also detect mutations in BRCA genes, a molecular feature that may predict response to parp inhibitors such as olaparib.

Moffitt NGS STAR can be performed on as little as 40ng of input nucleic acid.

Development and launch of Moffitt NGS STAR was made possible through collaboration with industry partners PierianDx and Illumina Inc.

The Moffitt Cancer center is one of the largest in the United States, is consistently ranked in the top cancer centers by U.S. News & World Report. Moffitt Cancer Center has a mission to “contribute to the prevention and cure of cancer” and the vision ” to transform cancer care through service, science, and partnership”

For further details contact anthony.magliocco@moffitt.org

TRIPLE NEGATIVE BREAST CANCER IS OVER DIAGNOSED

By Dr. Anthony Magliocco

Getting a second opinion for a cancer diagnosis is highly recommended, but even more so if you face triple negative breast cancer, which can be aggressive and difficult to treat.

A new study led by Moffitt Cancer Center pathologist Dr. Marilin Rosa shows that triple negative breast cancer may be frequently overdiagnosed and reclassified after expert review and biomarker retesting. Moffitt investigators presented the data at the 2018 United States & Canadian Academy of Pathology Annual Meeting in Vancouver.

Researchers reviewed over 560 cases of breast cancer referred to Moffitt and found that 113 were initially classified as triple negative by external evaluation. After biomarker retesting, about 28 percent of the triple negative cases were reclassified as hormone receptor positive.

Moffitt’s study demonstrates the value of biomarker retesting for triple negative breast cancers before selecting an appropriate treatment plan. A second opinion that changes your diagnosis can have a huge impact on survival.

In triple negative breast cancer, the three most common types of receptors known to fuel most breast cancer growth — estrogen, progesterone and the HER-2 gene — are not present. This makes common treatments such as hormone therapy and drugs that target the three missing receptors ineffective.

Up to 20 percent of breast cancer diagnoses are triple negative and are more likely to affect younger patients, blacks, Hispanics and those with a BRCA1 gene mutation. This disease is also more likely to spread and recur.

The takeaway: Having an accurate cancer diagnosis is critical to planning appropriate treatment. If you are diagnosed with triple negative breast cancer, consider getting a second opinion before starting a treatment plan.