Determining If a Somatic Tumor Mutation Is Targetable and Options for Accessing Targeted Therapies

Dr. Nate Pennell discusses "How to Know if a Somatic Tumor Mutation is Targetable" with Suanna Bruinooge, the director of research, strategy, and operations at ASCO's Center for Research and Analytics, or CENTRA, and Dr. Richard Schilsky, senior vice president and chief medical officer at ASCO.

Read the related article "Determining If a Somatic Tumor Mutation Is Targetable and Options for Accessing Targeted Therapies."

 

[DR. NATHAN PENNELL]

Welcome to the latest Journal of Oncology Practice Podcast brought to you by the ASCO Podcast Network, a collection of nine programs covering a range of educational and scientific content and offering enriching insight into the world of cancer care. You can find all recordings, including this one, at podcast.asco.org.

My name is Dr. Nate Pennell, medical oncologist at the Cleveland Clinic and consultant editor for the JOP. Today, I want to talk to you about an increasingly common scenario encountered in clinical practice. Molecular testing for biomarkers to help guide treatment of patients has now become a standard part of treatment for many types of cancer. For example, HER2 testing and breast cancer or EGFR mutation testing in lung cancer.

But testing is also increasing in other cancer types often using broad, multiplex assays surveying hundreds of genes. Clinicians are being presented with a report that may seem dauntingly complex and hard to interpret. And even when you have a drug recommended, that may be off-label for its use or even experimental, leaving patients and clinicians perplexed as to how to access them.

With me today to discuss these issues are Suanna Bruinooge, the director of research, strategy, and operations at ASCO's Center for Research and Analytics, or CENTRA, and Dr. Richard Schilsky, senior vice president and chief medical officer at ASCO.

We'll be discussing their paper, "How to Know if a Somatic Tumor Mutation is Targetable-- Options for Accessing Targeted Therapies" published in the August 2019 JOP. Welcome Suanna and Rich, and thanks for joining me today.

[DR. RICHARD SCHILSKY]

Thanks for having us, Nate.

[SUANNA BRUINOOGE]

Thanks.

[DR. NATHAN PENNELL]

So Rich, give me a little background on the problem that you were hoping to address with this paper. Why did ASCO feel it was important to provide a guidance to oncologists about interpreting testing reports and accessing these drugs?

[DR. RICHARD SCHILSKY]

Well, I think you actually framed the problem very well in your introduction. Obviously there's a lot of tumor genomic profiling that's going on these days, oftentimes for very good reason to identify actionable alterations that are known targets of effective anti-cancer therapies.

And what we've been seeing, of course, in more recent years is the more widespread use of genomic profiling, oftentimes for people who have advanced cancer, who no longer have any standard treatment options available. And the physician is looking to see whether or not there's something that might be considered actionable in the tumor genome that could provide a therapy option that wasn't considered.

We're also seeing that the testing itself has become much more expansive. So instead of testing for a few genes, many tests are now testing for hundreds of genes. And, of course, they can be many different alterations that could occur within any given gene. So the amount of information that's being provided to oncologists in these test reports is enormous and very difficult to interpret.
The nomenclature is difficult to understand. The biological relevance of the alterations is difficult to understand. And whether or not they really lead to a potential course of therapy is oftentimes difficult to figure out, because a lot of what turns up in the reports is difficult to understand and difficult to interpret.

So one of our goals in putting this short paper together was to try to provide resources to oncologists to help them navigate these test reports to help them have resources available to, in essence, look up the abnormalities that are being detected and try to figure out whether or not that's something that might be targetable with a particular drug. And then, of course, secondarily as you pointed out, to help walk them through the various strategies they can use to actually obtain the drug that seems like it might be a good choice for their patient.

[DR. NATHAN PENNELL]

So if I'm looking at one of these reports now and seeing these alterations, how do I decide if that truly is actionable or not? And how do we decide what level of actionability, whether this is something that's really a standard of care now or something that's much more lower level of evidence?

[DR. RICHARD SCHILSKY]

Yeah, it's a great question. So, I mean, there are actually some conventions regarding the level of evidence to assign to genomic alteration to determine its actionability. And in fact, ASCO working together with the College of American Pathologists and the Association of Molecular Pathology published a paper a couple of years ago, now, sort of assigning levels of evidence.

But the convention goes something like this-- if the alteration is the target of an FDA-approved drug, then that's a high level of evidence that the alteration is of clinical importance. It may or may not be of the same level of importance in a histology that is outside of the FDA-approved indication for the drug.

Best known example that is often described as BRAF mutations in patients with colorectal cancer, which do not respond nearly as well to BRAF inhibitors, as the same mutations respond when they occur in patients with melanoma. But nevertheless, a BRAF mutation occurring outside of the melanoma indication has still might be considered to be sort of level two evidence of potential actionability.
Then as you get further and further away from FDA-approved therapies or FDA-approved indications, then you get into lower levels of evidence. So you have, as you mentioned earlier, variants of unknown significance. These generally are alterations that are detected in the genome that truly are of unknown significance.
They have not been well-characterized. It's not clear what their biological relevance is with respect to being related to tumor initiation or progression. It's not clear whether they represent markers of response or resistance to therapy. They're just alterations where really more research is necessary to determine their actionability.

Nevertheless, I can tell you that we often find that many physicians think that it might be worthwhile to target APUS sort of just to give something a try. Then at the lowest level of actionability are the germline alterations. Now, even there, it's complicated because, of course, there are some germline alterations that actually direct you to use an FDA-approved drug, like germline BRCA mutations used to direct therapy with PARP inhibitors.

But generally speaking, germline alterations or alterations that have been well characterized and known to be functionally benign, there, the evidence for actionability would be considered to be very low.

[DR. NATHAN PENNELL]

I've certainly seen people treated with targeted drugs for variants of unknown significance and, otherwise, actionable genes, such as EGFR mutations but well outside the tyrosine kinase domain. And it really depends a lot on how well it's presented in these reports as to how easy it is to figure out what's actionable and what's not.

[DR. RICHARD SCHILSKY]

Well, that's right. And one of the reasons we included in the paper that quite expansive table of knowledge bases that are available is to help oncologists help participants who have elected a tumor board determine where to go to look up an alteration that might actually give them useful information as to, has it ever been reported before in human cancer?

If so, is it an alteration that is likely to be biological significance based upon the nature of the alteration and where it's located in the DNA? How close it is to other known ontogenic alterations and so on. So hopefully, readers of the article will find one or more of those knowledge bases' valuable resources, particularly in the context of a molecular tumor board discussion.

[DR. NATHAN PENNELL]

Absolutely. This is a fantastic resource. And I've got a couple of these bookmarked on my own desktop so that I can look things up, such as mycancergenome.org, for example. So I think our readers hopefully will check into that. So now that we have identified an actionable alteration, and we have a recommendation for a particular drug, what are our options for going about accessing these drugs for our patients?

[SUANNA BRUINOOGE]

Thanks, Nathan. This is a really good question. And I think we created a figure in the manuscript to really help clinicians and patients walk through what the options are laid out in front of them. And as you can see from the figure, it really does depend on the initial question being, does the targeted drug have FDA approval?
And as Dr. Schilsky mentioned earlier, it may depend on whether the indications specifically include the cancer type or histology that your patient has. But let's just say, then that case, it would be considered an on-label indication, and largely be reimbursed by insurers.

But let's say, the indication-- the cancer type is not specifically mentioned in the label. In that case, it would be considered an off-label indication. And so in that situation, there is a chance that the company or other researchers are already looking at whether the drug works for that same alteration and other cancer type. In other words, research on off-label indication.

And in these situations, as trials have been completed and results are published, they might be noted in either clinical pathways or drug compendia. Or it might be published in scientific journals, like the Journal of Clinical Oncology and Journal of Oncology Practice.
So in those situations where there is published data, and that supports the use in a different cancer type, then, you might be in a situation where Medicare or private payers might provide coverage for that off-label use. So in those situations, contacting the insurance companies is what we reference in the article to obtain authorization to prescribe the medication and get coverage.

In situations where there isn't published data, there might be clinical trials that are under way. And in those situations, obviously, the clinical trial-- you'd have to look at the eligibility criteria for the clinical trial. Is it something that's available at your clinic? If it's not available at your clinic, is it something that the patient could travel to obtain enrollment in the clinical trial?

So that's really on all along that left side of the figure related to whether the cancer type is mentioned on the drug label, whether there's published data. And the payer might cover it off-label, or if the patient would qualify for a clinical trial. If none of those are a possibility, then there still might be an occasion in which the patient would still be interested in accessing the therapy. And then you might want to look into financial assistance options for the patient. And in the manuscript, we talk about, there's recently been a compilation of patient assistance programs. And we include the website in our manuscript. And that does allow a clinician and a patient to look across multiple pharmaceutical companies to see if there might be patient assistance options available if it's already an FDA-approved approved drug.

[DR. NATHAN PENNELL]

Oh, that's great. So what about for patients who want to access drugs, but for whatever reason, don't have either an approval for off-label use, or there's no trial available? How would patients access drugs in that setting?

[SUANNA BRUINOOGE]

In that setting, you're probably thinking about a drug that's an investigational use if it does not have an FDA approval. And in this situation, there certainly may be circumstances in which a clinical trial isn't available. Or maybe your patient is not available at your site. Or maybe your patient doesn't qualify and meet the eligibility criteria or isn't able to travel for the clinical trial.

And in those situations, there may be options that you and your patient could explore through something called expanded access program. And there's really three options that are sort of broadly described as expanded access program. A company might offer a large or mid-sized expanded access program.

It's essentially like a clinical trial, although it may be collecting less data in the course of the clinical trial. It might be for a broader patient population who might not otherwise qualify for the clinical trial. And typically the company might conduct this as a broader access for patients who don't qualify for a clinical trial.

Or perhaps in the interim period between which a company submits its application to the FDA, and they're waiting to hear about the FDA review of the drugs. So these are often sort of in that interim time period before a drug might be approved.

The third type of expanded access program is an individual patient use. And this is something that is there's actually new resources that are available on a couple of different locations. There's an organization called the Reagan Udall Foundation. So that's Reagan as in the former president. And Udall-- U-D-A-L-L.

This is a foundation that supports the work of the FDA in a broad sense. And they have something that's called the Expanded Access Navigator Program that's available on their website. You are a patient Google Expanded Access Navigator. The Reagan Udall website will certainly become available in the listing.

And what this does is list all the companies that provide expanded access program. So this is a good starting point to see if a company might be offering either a large or midsize expanded access programs and also list the company context at the company so you can also figure out how to contact the company to find out if your patient qualifies.

If there isn't a program. Then fortunately, in oncology, we also have another option that clinicians can explore. The FDA Oncology Center of Excellence recently launched a program that's called Project Facilitate. And this provides both web-based resources, as well as a phone line that is available during business hours which are largely East Coast business hours.

And it's a resource for clinicians to contact related to individual patient access requests. And the FDA has staff who are very knowledgeable about the individual patient access pathway. They can help with contacting companies and sort of serve as an intermediary to help navigate those situations.

And the FDA role is actually in any of these three expanded access programs. The FDA plays a very important role in reviewing requests from clinicians. And they provide sort of a third-party review of the circumstances. And they're very quick to respond to inquiries in this regard and really do approve virtually all of the requests for access that they receive.

And so long as the company provides access to the drug, ultimately, the decision about whether to provide access to the drug is up to the company.

There is another avenue, which is described in our manuscript as well. Some states have also passed right-to-try laws. In these circumstances, these laws are at the state level. So not all states have passed them. But they provide a pathway that bypasses FDA review and assessment. They do not require that a company provide the investigational drug. So that circumstance is really still up to the individual company, whether they want to make the drug available outside of clinical trials.

[DR. NATHAN PENNELL]

I think a couple incredibly important things that I want to make sure everybody got out of this. One is that all of this relies on the pharmaceutical company actually being willing to provide these drugs. So even the right-to-try laws on the state and federal level don't require that the companies give access to the drugs to the patient. So both of those are necessary.

And second of all, that the FDA is incredibly helpful in providing access to these drugs. I've personally gone several times through compassionate use single patient's drug access through the FDA. And they've been tremendously helpful and never were in any way a barrier to getting access to the drug. They're fast and responsive.

And so I actually haven't personally heard much in terms of the use of the right-to-try laws to access drugs. I don't know if that's something that there was a lot of attention, of course, when the federal government passed the law. But I haven't heard much about it since then.

[DR. RICHARD SCHILSKY]

Nor have we. I don't think we're aware of any circumstances in oncology where patients have access to investigational drugs through the right-to-try pathway. That may be because the companies are reluctant to make drugs available. Or it may be because appropriate drugs just haven't been on the radar screen.
I think all of us, though, would agree that a much better way of providing access to drugs would be to do it in a way where you're actually collecting the information on the efficacy of the drugs and the toxicity of the drugs where you can learn about that process and help lead to an eventual approval. So what is ASCO doing that can help provide access to promising drugs, perhaps, an off-label setting for patients?

Many people know the TAPUR is an acronym that stands for Targeted Agents and Profiling Utilization Registry. So it's a quite a mouthful. And so we like to call it TAPUR. So TAPUR is a prospective multi-arm phase II basket trial, which is matching commercially available targeted drugs used to off-label against a genomic alteration in a patient's tumor.

So, in essence, we set up TAPUR to be able to learn from the off-label prescribing of targeted drugs to patients who have advanced cancers. And the study has been ongoing now since March of 2016. There are about 1,600 patients who have been enrolled at about 120 sites around the country.

We've started to report out both negative and positive results. And we think that negative and positive results are equally important in this setting, because, for example, if a doctor could prescribe a drug off-label, but there's no evidence that the drug actually is beneficial, then those patients are better served by being directed to other clinical trials.

So for example, last year, we reported that palbociclib is not effective in either pancreatic or biliary tract cancers that have a CDKN2A alteration. So the implication being, of course, that the next time a doctor sees that alteration showing up on a tumor genomic test report for a patient with one of those cancers, they probably should look for something other than palbociclib.

Now, alternatively, we've also begun to identify signals of activity that either have been already reported in more formal clinical trials. And we're just able to affirm that the therapy works in a more real world population or in some cases haven't really yet been identified.
So, for example, at this year's ASCO annual meeting, the 2019 meeting, we reported that pembrolizumab has activity in patients with breast cancer that have a high tumor mutational burden. And we think that's an exciting observation. Some of those patients actually had quite prolonged disease control and that the abstract has been presented.

The poster is available on the TAPUR website, tapur.org, for anyone who wants to look at the details. And there are some manuscripts of preparation. So TAPUR we hope over time we'll continue to report out both positive and negative results. They can't really help to guide the use of these well-sampled therapies. And, of course, it's also a mechanism, whereby the drugs can be provided to patients at no cost to them, because all the drugs in the study are being provided by the participating pharmaceutical companies.

[DR. NATHAN PENNELL]

Yeah, it really is a win-win situation. The patients get access to the drugs without having to worry about whether their insurance will cover the off-label use. And the companies learn whether their drugs may have expanded indications outside of where they're currently used.

Well, Suanna and Rich, thanks so much for joining me on the podcast today.

[DR. SCHILSKY AND MS. BRUINOOGE]

Thank you.

[DR. NATHAN PENNELL]

And until next time, thank you for listening to this Journal of Oncology Practice Podcast. I hope you enjoyed what you heard today. And if you did, don't forget to give us a rating or review on Apple podcasts or wherever you listen. While you're there, be sure to subscribe so you never miss an episode.

JOP's podcasts are just one of ASCO's many podcast programs. You can find all recordings at podcast.asco.org. The full text of the paper will be online at ascopubs.org/journal/jop in August 2019. This is Dr. Nate Pennell for the Journal of Oncology Practice signing off.