Thursday, October 3, 2024

Automatic Podcast with 2 Voices: FDA's PDL1 Ad-Comm Last Week

Header:  We copy a few major documents about the PDL1 workshop at FDA, and Google Notebook LM makes an AI podcast from it, with two voices.

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Last week, FDA held a much-discussed Ad Comm on what the future labeling shouold be for some major cancers regarding checkpoint inhibitor drugs in the presence of low or high PDL1 staining.

Two lead documents were circa 50 pages, one from FDA, one from BMS. 

I uploaded these two major documents plus a Genomeweb article plus a "Washington Analysis" article, and finally, a review published online at Friends of Cancer Resarch.  So here were five articls in one Google Notebook LM folder.

Google autogenerates four work products, three written ones and the fourth is an AI audio podcast.

1. A timeline of events (basck to 2021)

2. A "briefing guide" to all 5 documents.

3. A "study guide," largely in Q&A format.

4. A audio podcast with 2 AI voices in a "Dialog" over the material.

Find the TIMELINE, BRIEFING GUIDE, and STUDY GUIDE below in sequence.




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TIMELINE

Timeline of Main Events


This timeline focuses on the development and FDA review of PD-L1 inhibitors in combination with chemotherapy for the first-line treatment of advanced or metastatic HER2-negative gastroesophageal adenocarcinoma (GC/GEJC/EAC).


Unknown Date (Prior to 2020):

  • CHECKMATE-649 (CA209649) study begins. This international, multicenter, randomized, double-blind, placebo-controlled trial investigates nivolumab plus chemotherapy vs. chemotherapy alone in previously untreated patients with advanced or metastatic GC/GEJC/EAC.


May 27, 2020:

  • Primary analysis data cutoff for CHECKMATE-649.


Unknown Dates (Between 2020 and 2024):

  • FDA approves nivolumab plus chemotherapy for first-line GC/GEJC/EAC. The approval is not restricted by PD-L1 expression levels.
  • FDA approves pembrolizumab plus chemotherapy for first-line GC/GEJC/EAC. The approval is not restricted by PD-L1 expression levels.
  • BeiGene submits a Biologics License Application (BLA) for tislelizumab plus chemotherapy for the treatment of GC/GEJC/EAC.
  • FDA reviews data from CHECKMATE-649, KEYNOTE-859, and RATIONALE-305. Concerns arise regarding the benefit-risk profile of PD-L1 inhibitors in patients with low PD-L1 expression levels.


September 26, 2024:

  • FDA Oncologic Drugs Advisory Committee (ODAC) meeting convened. The meeting focuses on the emerging risk-benefit analysis of PD-L1 inhibitors as a class in GC/GEJC/EAC, particularly in patients with low PD-L1 expression.
  • Bristol-Myers Squibb (BMS) submits a supplemental BLA (sBLA) for nivolumab plus chemotherapy for first-line GC/GEJC/EAC. The sBLA includes data from longer-term follow-up of CHECKMATE-649.


September 27, 2024:

  • ODAC overwhelmingly recommends against the off-label use of PD-L1 inhibitors in combination with chemotherapy for patients with PD-L1 negative GC/GEJC/EAC.
  • Pharma sponsors agree to consider expanded access programs specifically for PD-L1 negative patients. This is in response to concerns raised by the FDA and patient advocacy groups about the potential for restricted access to these therapies if the indication is narrowed.


Cast of Characters


Richard Pazdur, MD: Director of the FDA's Oncology Center of Excellence (OCE). Dr. Pazdur led the ODAC meeting and expressed concerns about the use of PD-L1 inhibitors in patients with low PD-L1 expression.

Representatives from Bristol-Myers Squibb (BMS), Merck, and BeiGene: These companies presented data from their respective clinical trials and responded to questions from the ODAC members.

ODAC Members: A panel of experts in oncology, biostatistics, and other relevant fields. They reviewed the data presented by the FDA and pharmaceutical companies and voted on their recommendations.

Patient Advocates: Representatives from patient advocacy groups voiced concerns about the potential impact of restricting the indication for PD-L1 inhibitors on patient access.



BRIEFING GUIDE


FDA Panel Rejects PD-L1 Inhibitors for Low Expressors in Gastric Cancer


This briefing document reviews the FDA's Oncologic Drugs Advisory Committee (ODAC) meeting held on September 26, 2024, concerning the use of PD-L1 inhibitors in combination with chemotherapy for patients with gastroesophageal adenocarcinoma (GC/GEJC/EAC).


Main Themes:

  • Limited Efficacy in PD-L1 Low Patients: The committee focused on the risk-benefit profile of PD-L1 inhibitors in patients with low PD-L1 expression. Analyses from three pivotal trials (CHECKMATE-649, KEYNOTE-859, and RATIONALE-305) and a pooled patient-level analysis revealed limited efficacy in patients with low PD-L1 expression (CPS <1 or TAP <1).
  • Potential for Harm: While combination therapies showed clear benefits for patients with higher PD-L1 expression, the panel expressed concern about the potential for harm in low expressors. These harms include serious immune-related adverse events, coupled with the significant impact of GC/GEJC/EAC on quality of life.
  • Harmonization of PD-L1 Testing: The use of different PD-L1 assays and cutoff points across trials raised concerns regarding consistent treatment algorithms and future drug development.

Important Ideas/Facts:

  • No benefit in Low Expressors: The FDA analysis concluded: "Addition of ICIs to standard of care chemotherapy for the treatment of patients with PD-L1 <1 does not appear to result in benefit."
  • Magnitude of benefit tied to PD-L1 levels: All three trials consistently showed greater benefit with increasing PD-L1 expression levels. As stated in the FDA analysis: "Benefit for patients with PD-L1 ≥10 have the greatest magnitude of benefit."
  • Testing inconsistencies: Different PD-L1 assays and cutoffs across trials complicate data interpretation and could lead to inconsistencies in treatment recommendations.
  • Impact on Future Research: Varying testing methodologies may hinder the design and interpretation of future clinical trials.
  • Patient Access: The FDA acknowledged concerns about restricting access to potentially beneficial therapies and requested pharmaceutical companies consider expanded access programs, particularly for PD-L1-negative patients.

Quotes:

  • FDA Briefing Document: "FDA believes a contemporary risk:benefit discussion evaluating the available data is required to further define the indication for these products for the treatment of gastric cancer to better match patients with a treatment that is likely to provide them benefit."
  • Washington Analysis: "FDA’s Oncologic Drugs Advisory Committee (ODAC) overwhelmingly supported FDA’s view that PD-L-1 inhibitors... should not be used in combination with standard chemotherapy in patients with PD-L-1 negative tumors."
  • Genomeweb: "Pazdur also sought commitment from pharma sponsors to establish expanded access... specifically for PD-L1 negative patients for these indications."

Conclusion:

The ODAC voted against recommending the use of PD-L1 inhibitors in combination with chemotherapy for patients with low PD-L1 expression in GC/GEJC/EAC. This decision reflects growing concern about the lack of demonstrated benefit and potential for harm in this specific patient population. The FDA highlighted the need for further research and emphasized the importance of harmonizing PD-L1 testing for future drug development and consistent treatment strategies. The agency also encouraged pharmaceutical companies to consider expanded access programs to ensure patient access to potentially beneficial therapies



A STUDY GUIDE (Q*&A)


Gastroesophageal Adenocarcinoma Treatment: Navigating PD-L1 Expression Levels in the Era of ICIs


Short-Answer Quiz


  1. What are the two main PD-L1 scoring methods discussed in the FDA briefing documents, and what are their key differences?
  2. Based on the FDA analysis of CHECKMATE-649, KEYNOTE-859, and RATIONALE-305, what overall trend emerges regarding the efficacy of ICI+chemo across different PD-L1 expression levels?
  3. What are two challenges in PD-L1 testing highlighted in the FDA documents?
  4. According to the FDA briefing document "2024 FDA 0926 PDL1 Low 41pp.pdf," what is the main reason for FDA's concern regarding off-label use of ICIs in PD-L1 low patients, despite the absence of PD-L1 restrictions on current approvals?
  5. Briefly describe the two potential labeling options for ICIs in first-line gastroesophageal adenocarcinoma that the sponsor presents in "2024 FDA 0926 BMS on PDL1 Low Issues 50p.pdf".
  6. What are the implications of having different PD-L1 cut-offs for different ICI drugs, as highlighted in the FDA document "2024 FDA 0926 PDL1 Low 41pp.pdf"?
  7. According to "2024 FDA 0926 PDL1 Low 41pp.pdf," what significant action did the FDA take in 2009 regarding EGFR inhibitors in colorectal cancer, and what is its relevance to the current discussion on PD-L1 in gastroesophageal adenocarcinoma?
  8. Based on the Washington Analysis report, what was the outcome of the FDA's ODAC meeting concerning the use of PD-L1 inhibitors in combination with chemotherapy?
  9. What commitment did Dr. Pazdur seek from pharmaceutical companies during the ODAC meeting, as reported in "2024 Genomeweb 0927 Kanci on PDLA debates at AD COMM.pdf"?
  10. Why is the inclusion/exclusion of esophageal adenocarcinoma (EAC) patients in clinical trials for gastric/GEJ adenocarcinoma a point of consideration, according to the FDA document "2024 FDA 0926 PDL1 Low 41pp.pdf"?

Answer Key

  1. TPS (Tumor Proportion Score): Evaluates the percentage of viable tumor cells showing membrane staining at any intensity (0-100% scale). CPS (Combined Positive Score): Considers the number of PD-L1 positive tumor cells and immune cells in relation to the total number of viable tumor cells, providing a score (e.g., 1, 5, 10).
  2. The FDA analysis consistently reveals that the efficacy of ICI+chemo generally increases with higher PD-L1 expression levels. Patients with higher PD-L1 scores consistently demonstrate greater benefit compared to those with lower scores, suggesting a predictive role of PD-L1 expression.
  3. Tumor heterogeneity: PD-L1 expression can vary within a tumor, potentially leading to inaccurate scoring from a single biopsy. Interobserver variability: Pathologists might interpret PD-L1 staining differently, leading to discrepancies in scoring.
  4. The FDA is concerned that off-label use in PD-L1 low patients might expose them to potential harms associated with ICI therapy, such as serious immune-related adverse events, without clear evidence of clinical benefit. This is particularly concerning as data suggests these patients may not benefit from this treatment.
  5. Option 1: Indication based on individual trial results. This option would consider each trial's specific PD-L1 testing methodology and statistical analysis plan, potentially leading to different PD-L1 cut-offs for different ICIs. Option 2: Indication based on totality of data. This option would analyze data across trials to determine a single PD-L1 cut-off for all ICIs, acknowledging potential differences in PD-L1 tests used.
  6. Different cut-offs could create inconsistencies in patient treatment, potentially leading to confusion among healthcare providers and impacting insurance coverage for specific tests. It could also complicate the design of future clinical trials aiming to improve patient outcomes.
  7. In 2009, the FDA restricted the use of EGFR inhibitors (cetuximab and panitumumab) in metastatic colorectal cancer to patients with KRAS wild-type tumors, based on the analysis of multiple clinical trials. This decision underscores the FDA's willingness to refine indications based on accumulating data to ensure that treatments are directed towards patients most likely to benefit.
  8. The ODAC overwhelmingly supported the FDA's view that the use of PD-L1 inhibitors should not be expanded off-label for patients with low PD-L1 expression in combination with chemotherapy.
  9. Dr. Pazdur urged pharmaceutical companies to consider establishing expanded access programs specifically for patients with PD-L1 negative tumors, recognizing potential access challenges if labeling were to be restricted based on PD-L1 status.
  10. While there are anatomical differences between EAC and gastric/GEJ adenocarcinomas, they share histological similarities. This raises questions about the appropriateness of combining or separating these patient populations in clinical trials, as it may impact the generalizability of findings and subsequent treatment recommendations.

Essay Questions

  • Critically analyze the ethical implications of restricting ICI treatment based on PD-L1 expression levels, considering potential benefits and harms to patients, as well as implications for healthcare resource allocation.
  • Considering the FDA's concerns about potential harms in the PD-L1 low population, propose a research agenda to better understand the risk-benefit profile of ICI+chemo in this patient group, outlining specific research questions, study designs, and ethical considerations.
  • Compare and contrast the two potential labeling options for ICIs in first-line gastroesophageal adenocarcinoma presented in the sponsor briefing document, discussing the advantages and disadvantages of each approach in terms of scientific rigor, clinical practicality, and patient access.
  • Given the challenges and variability inherent in PD-L1 testing, discuss strategies to improve standardization and accuracy in PD-L1 assessment for gastroesophageal adenocarcinoma.
  • Drawing parallels with the FDA's past decisions on biomarker-driven therapies (e.g., EGFR inhibitors in colorectal cancer), analyze the potential future implications of the ODAC's recommendations regarding PD-L1 and ICIs in gastroesophageal adenocarcinoma.

Glossary of Key Terms

  • ICI (Immune Checkpoint Inhibitor): A type of drug that blocks proteins called immune checkpoints, which normally help prevent the immune system from attacking healthy cells. By blocking these checkpoints, ICIs allow the immune system to recognize and attack cancer cells more effectively.
  • PD-1 (Programmed Death Protein 1): A protein found on the surface of T cells (a type of immune cell) that helps regulate immune responses. Cancer cells can exploit PD-1 to evade immune detection.
  • PD-L1 (Programmed Death Ligand 1): A protein often found on the surface of cancer cells that binds to PD-1 on T cells, inhibiting the immune response and allowing cancer cells to escape destruction.
  • CPS (Combined Positive Score): A method used to quantify PD-L1 expression on tumor cells and immune cells within a tumor sample, providing a score that can guide treatment decisions.
  • TPS (Tumor Proportion Score): A method that measures the percentage of tumor cells in a sample that express PD-L1, regardless of the staining intensity.
  • Gastroesophageal Adenocarcinoma: A type of cancer that occurs in the esophagus, the tube that connects the mouth to the stomach, or in the gastroesophageal junction, the area where the esophagus meets the stomach.
  • ODAC (Oncologic Drugs Advisory Committee): A panel of independent experts who provide recommendations to the FDA on the approval of cancer drugs.
  • Expanded Access Program: A pathway for patients with serious or life-threatening conditions who cannot participate in clinical trials to access investigational drugs not yet approved by the FDA.
  • Biomarker: A measurable characteristic (e.g., a protein) that can be used to indicate the presence of a disease, predict the likelihood of treatment response, or assess disease progression.
  • Off-label Use: The use of a drug for a medical condition or in a dosage or manner not specifically approved by the FDA.
  • Risk-Benefit Profile: An assessment of the potential benefits and harms associated with a particular medical intervention or treatment.
  • Tumor Heterogeneity: The presence of genetic and phenotypic differences between cancer cells within a tumor, which can influence treatment response and disease progression.
  • Interobserver Variability: The extent to which different observers, such as pathologists interpreting biopsy results, may arrive at different conclusions or assessments.



Direct link to FOCR Essay


https://friendsofcancerresearch.org/blog/stakeholder-connect-insights-from-the-september-26-2024-meeting-of-the-oncology-drugs-advisory-committee/



OTTER.ai Summary of Auto Transcript of PODCAST


This is a Google link to the podcast audio file; you may need to be signed into a google account to play it. Earlier in this essay I also provided the audio podcast as a YouTube link.


https://notebooklm.google.com/notebook/0f6f27ad-9002-42cb-96e8-a45988986f52/audio

Google Notes "PODCAST" PLD1 REVIEW

The discussion delves into the complexities of PDL1 testing for gastric and esophageal cancers, focusing on the immunotherapy drug OPDIVO. The FDA's briefing document highlights the critical need for accurate PDL1 testing, as its inconsistency across labs and pathologists can lead to life-or-death decisions. Despite OPDIVO showing overall survival benefits, its efficacy is strongly linked to PDL1 levels, raising questions about its use in patients with low PDL1. The conversation also touches on the broader implications for personalized medicine, emphasizing the importance of informed consent, second opinions, and patient advocacy.

Transcript

https://otter.ai/u/6TD_3GzDaOXLmQpTG6h_qAUJdXU?view=transcript

Action Items

  • [ ] Advocate for the right PD-L1 test to be used and ensure it is interpreted correctly.
  • [ ] Discuss the risks and potential benefits of immunotherapy treatment based on individual PD-L1 levels.
  • [ ] Consider other biomarkers, such as MSI and TMB, in the treatment decision-making process.
  • [ ] Obtain a second opinion, especially for complex cancer treatments.

Issues & Risks

  • Inconsistency in PDL1 testing results between different labs and pathologists.
  • Potential overtreatment of patients with low PDL1 expression.
  • Lack of PDL1 testing for about 40% of patients.
  • Concerns about the smaller survival benefit for low PDL1 patients versus the risks of immunotherapy.
  • Ethical concerns about limiting access to treatment based on an inconsistent test.

Next steps

  • More research needed on PDL1 testing and immunotherapy efficacy.
  • Development of more consistent testing methods.
  • Creation of clearer guidelines for doctors.

Questions discussed

  • What is PDL1 and how does it relate to immunotherapy?
  • How reliable is PDL1 testing?
  • What should patients ask their doctors about PDL1 testing and immunotherapy?
  • Should drug approval be based on overall benefit to a larger group or push for truly personalized medicine?

Outline

FDA Briefing on OPDIVO and PDL1 Testing

  • Speaker 1 introduces the topic of cancer treatment, focusing on gastric and esophageal cancers, and mentions PDL1 testing.
  • Speaker 2 emphasizes the importance of PDL1 testing for real patients and life-or-death decisions.
  • Speaker 1 and Speaker 2 discuss the FDA briefing document on OPDIVO, a key drug, and the implications of PDL1 testing.
  • The document paints a grim picture for gastric and esophageal cancers, highlighting the critical nature of first-line treatment.

Understanding PDL1 and Immunotherapy

  • Speaker 1 and Speaker 2 explain that PDL1 is a signal on cancer cells that attracts the immune system, making it a target for immunotherapy.
  • Speaker 2 describes how different tests and labs measure PDL1 levels, leading to inconsistent results.
  • Speaker 1 and Speaker 2 discuss the potential life-or-death consequences of these inconsistencies in PDL1 testing.
  • The conversation shifts to the real-world impact of PDL1 testing on patients, emphasizing the need for accurate and consistent results.

FDA Meeting and Expert Panel Discussion

  • Speaker 2 mentions the FDA meeting coverage by Geno Webb, which raised serious doubts about OPDIVO's effectiveness.
  • The expert panel noted that OPDIVO showed a stronger survival benefit in patients with higher PDL1 levels.
  • Speaker 1 and Speaker 2 discuss the debate over whether a smaller benefit for low PDL1 patients justifies the risks of immunotherapy.
  • The conversation highlights the importance of informed consent and the challenges of making life-or-death decisions based on unreliable testing.

Challenges in PDL1 Testing and Patient Advocacy

  • Speaker 1 and Speaker 2 discuss the Flatiron data showing that 40% of patients are not tested for PDL1, leading to decisions without crucial information.
  • The conversation emphasizes the need for patients to be informed about their PDL1 levels and the potential risks and benefits of treatment.
  • Speaker 1 and Speaker 2 stress the importance of open communication with doctors and advocating for oneself.
  • The discussion includes the need for consistent testing and clear guidelines for doctors to ensure accurate and reliable results.

Broader Implications and Personalized Medicine

  • Speaker 1 and Speaker 2 discuss the broader implications of PDL1 testing and the need for personalized medicine.
  • The conversation touches on the importance of considering other biomarkers like MSI and TMB in treatment decisions.
  • Speaker 1 and Speaker 2 emphasize the need for second opinions and the importance of feeling confident in one's treatment plan.
  • The discussion highlights the complexities of cancer treatment and the need for ongoing research and better testing methods.

FDA's Consideration of Immunotherapy Drugs

  • Speaker 2 mentions that the FDA meeting also considered three HP immunotherapy drugs: OPDIVO, Keytruda, and Tevimbra.
  • The expert panel voted on whether the data supported using these drugs in patients with low or no PDL1 expression.
  • For all three drugs, the majority of experts voted no, raising concerns about the smaller survival benefit in low PDL1 patients.
  • Speaker 1 and Speaker 2 discuss the potential narrowing of immunotherapy access based on PDL1 testing and the ethical and medical complexities involved.

Patient Advocacy and Personalized Medicine

  • Speaker 1 and Speaker 2 emphasize the importance of patients advocating for themselves and asking tough questions.
  • The conversation highlights the need for clear and consistent guidelines for doctors to ensure accurate and reliable testing.
  • Speaker 1 and Speaker 2 discuss the broader implications of PDL1 testing and the need for personalized medicine.
  • The discussion underscores the importance of being informed and confident in one's treatment plan, emphasizing the need for ongoing research and better testing methods.

Final Thoughts and Next Steps

  • Speaker 1 and Speaker 2 summarize the key points of the discussion, emphasizing the importance of knowledge and advocacy.
  • The conversation highlights the need for ongoing research and better testing methods to ensure accurate and reliable results.
  • Speaker 1 and Speaker 2 encourage listeners to keep asking questions and advocating for themselves.
  • The discussion concludes with a reminder of the importance of being informed and confident in one's treatment plan.

FINALLY, Transcript of PODCAST

Speaker 1  0:00  
All right, buckle up listeners, because today's deep dive is taking us straight into the world of cancer treatment,

Speaker 2  0:06  
straight into you said it no sugarcoating here,

Speaker 1  0:09  
absolutely not. We're going deep specifically for gastric and esophageal cancers. And we're talking PDL one testing, which, let me tell you, it's a mouthful. It is a mouthful, but it's way more interesting, and honestly, way more important than it might sound at first. You're

Speaker 2  0:24  
not kidding. This isn't just some technical jargon. We're talking about real people here.

Unknown Speaker  0:28  
Real people, real decisions, exactly

Speaker 2  0:30  
whether a patient gets the right treatment, the wrong treatment, or maybe even no treatment at all.

Speaker 1  0:36  
And those are life and death decisions. No two ways about it. So where are we jumping in from? We've got excerpts from an FDA briefing document on a drug called OPDIVO key drug, yep. Plus, we've got some coverage of the actual FDA meeting from Geno Webb. Now I know this is your bread and butter, day in day out, but even for me, just skimming these documents, I felt like

Unknown Speaker  0:57  
a detective, ha,

Speaker 1  0:58  
ha, yeah, like we're on the trail of some big medical mystery. Well,

Speaker 2  1:02  
you're not wrong. The FDA is trying to figure out this whole thing with PDL one, and who should be eligible for these immunotherapies. And

Unknown Speaker  1:09  
what are the implications there?

Speaker 2  1:11  
The implications huge, both for patients and the whole field. It's really something.

Speaker 1  1:16  
Okay, so let's set the scene the document. It doesn't really sugarcoat things, does? It paints a pretty snark picture for gastric and esophageal cancers. It's

Speaker 2  1:26  
a tough landscape treatment options, especially later on, very limited. We're

Speaker 1  1:30  
talking what? Fifth deadliest globally. That's right. Fifth deadliest globally.

Speaker 2  1:34  
So that first line treatment, critical, absolutely critical. The

Speaker 1  1:37  
FDA isn't messing around, and neither are we. Which brings us to immunotherapy, immunotherapy. Now I'm hearing immunotherapy more and more these days. It's like this big. It's huge. It feels almost like a medical revolution, right? Yeah, using your own wn body to fight cancer. It's a game changer, for sure. Optivo That falls under this umbrella, right?

Speaker 2  1:57  
Got it? Optivo? It's an immunotherapy drug, specifically what we call an immune checkpoint inhibitor. Okay, so

Unknown Speaker  2:03  
there's a butt coming. I

Speaker 2  2:04  
can feel it. Well, there's always a but in medicine, isn't there? It's given alongside chemo, which, as you know, chemo not exactly a walk in the park Exactly. And right now, OPDIVO is approved regardless of your PDL one level. But like you said, the FDA, they're taking a second look, and this, this is where things get really interesting, because

Speaker 1  2:23  
it all hinges on this, this Pdl, one thing. So what is PDL one? I got to be honest, the document all the acronyms, CPS, TPS, different cutoff points a lot, right? It was like I needed a decoder ring just to understand what I was reading. I

Speaker 2  2:37  
hear you think of it this way. Imagine PDL one is like a signal on these cancer cells,

Unknown Speaker  2:42  
a signal like a warning sign, not

Speaker 2  2:45  
quite more like a like a come get me. Flag waving to

Speaker 1  2:49  
the immune system. I see so the immune system is like, send a security guard patrolling around, and the flags are saying, hey, problem over here? Exactly, more flags,

Speaker 2  2:57  
stronger signal, and potentially a better response to these immunotherapy drugs. Okay,

Speaker 1  3:02  
that makes sense. So, CPS, TPS, these are just different ways of different ways

Speaker 2  3:06  
of measuring those flags. But, and this is a big but, oh boy, there we go, measuring those flags. It's not an exact science. We're talking different tests, different labs. I've even seen cases, and this is wild, where two pathologists, two

Unknown Speaker  3:21  
pathologists. So the people who actually analyze the samples the very same.

Speaker 2  3:24  
They can look at the same sample and come to different conclusions about the PDL. One,

Speaker 1  3:29  
Wait, seriously. So it's not like sending a blood test to two labs and they might be off by a point of two. Sometimes it's more than that. This is like, positive versus negative kind of different.

Speaker 2  3:39  
It could be that different? Yes, and that's why this whole thing is such a big deal. We're not talking about a subtle difference in measurement. Here.

Speaker 1  3:46  
We're talking about life or death decisions. Exactly, life

Speaker 2  3:50  
or death decisions based on what, at least right now seems like a shaky foundation. You're

Speaker 1  3:55  
not mincing words, and I appreciate that this isn't just some scientific headache. This

Speaker 2  4:00  
is real world stuff. This is impacting real

Speaker 1  4:03  
patients right now, I think it's time we dive into those real world consequences. What do you say?

Unknown Speaker  4:09  
Let's do it. This is where it gets really eye opening. It's

Unknown Speaker  4:12  
like we're talking about two different universes here.

Speaker 2  4:14  
It's true. You've got this FDA briefing document painting this really optimistic picture of OPDIVO, even for patients with low Pdl, one

Speaker 1  4:23  
which, and maybe I'm jumping the gun here, but that doesn't exactly scream reliable testing. To me, you're

Speaker 2  4:29  
not wrong to be thinking that I've got inconsistent testing, different labs, different results, and then you've got the Gina web coverage of the FDA meeting itself, a whole other story. Okay,

Speaker 1  4:37  
hold on so the FDA meeting, they weren't exactly sold on optivo for everyone.

Speaker 2  4:42  
Let's just say the expert panel, they brought up some serious doubts, doubts

Unknown Speaker  4:46  
like, what? Give me the rundown. So

Speaker 2  4:47  
optivo, it did show a survival benefit overall, but, and this is a big but, that benefit was much stronger in the patients with higher PDL one the

Speaker 1  4:57  
come get me. Flags are waving loud and clear. In this case. This Exactly. So

Speaker 2  5:00  
now the question becomes, is a smaller benefit for the low Pdl, one patients, is it worth the extra risks that come with immunotherapy? That's the debate. Man,

Speaker 1  5:11  
that is a tough one. If it's your life on the line, you want every fighting chance, right? But not if the treatment might do more harm than good, then that's the tightrope they're walking, and it's not even like everyone at is getting this. PDL one, testing didn't we see something about that in the data? Oh,

Speaker 2  5:25  
yeah, you're remembering correctly. The flatiron data, it showed something like 40% of patients didn't even get tested for Pdl, one, 40% we're

Speaker 1  5:33  
talking almost half the patients. So they're making these huge decisions, life or death decisions, without even having this one piece of information,

Speaker 2  5:42  
it's happening. And it's not just about getting the treatment or not. It's also about being informed about understanding the potential risks and benefits based on your individual situation. Imagine

Speaker 1  5:53  
being that patient, you have cancer, there's this treatment, but this one test, this Pdl, one thing, it's like a gatekeeper.

Speaker 2  6:00  
It's a gatekeeper to a potentially life saving treatment. That's exactly right, and it might not even be about your cancer itself, but about all this messiness around the test. I feel

Speaker 1  6:07  
like we've stumbled onto something really important here. This isn't just about optivo or even just these types of cancer. This is bigger. Oh,

Speaker 2  6:14  
absolutely. This is about the reliability of testing. It's about informed consent. It's about patients being able to advocate for their own health.

Speaker 1  6:21  
And speaking of advocating, put yourself in that patient's shoes for a second. What would you want to know? What would you ask your doctor?

Unknown Speaker  6:30  
Okay, deep breath. Put myself in those shoes. It'd be terrifying. But like you said, knowledge is power. So first off, if they're recommending op, devo or something like it, another

Unknown Speaker  6:41  
immunotherapy in this class. Yeah,

Speaker 1  6:42  
I'd want to know, have I been tested with the right PDL one test? What's the point of a test? If it's not even the right one for the job, you're hitting on

Speaker 2  6:51  
something crucial there. There are so many variations on this test. It's wild, and they're not all created equal, that's for

Speaker 1  6:56  
sure. Okay, so right test, check. What else is on this hypothetical checklist for our listeners. Next

Speaker 2  7:02  
up, risk versus benefit? This is a big one. You'd want to have a real conversation with your doctor about your own personal risk tolerance,

Speaker 1  7:10  
especially given my PDL one level, right? Because if it's low, those potential benefits, they might be smaller too.

Speaker 2  7:16  
And are you willing to take on more risk from the immunotherapy if the potential upside might be smaller,

Speaker 1  7:22  
so much to weigh, and this is all assuming you even get the test in the first place, and that's the right one.

Speaker 2  7:28  
It really highlights the importance of that open communication with your doctor. Don't be afraid to ask those tough questions, voice your concerns, make sure you really understand what those risks and potential benefits look like for you specifically,

Speaker 1  7:42  
two big things. Then write test and write for Emmy based on risks and all that is there a third thing our listener should keep in mind, don't leave us hanging, right? So

Speaker 2  7:51  
we've talked about Pdl, one, but remember those other biomarkers, MSI, TMB, all those. They can be part of the conversation too.

Speaker 1  7:57  
So it's not just about one piece of the puzzle. It's about how it all fits together,

Speaker 2  8:02  
exactly and honestly. Don't ever hesitate to get a second opinion, especially with something as complex as cancer, a second opinion can be invaluable, like

Speaker 1  8:11  
getting a second mechanic's opinion before a major car repair, right? Better safe than sorry. 100%

Speaker 2  8:17  
it's your health, your life. You deserve to feel totally confident in your treatment plan, whatever that

Speaker 1  8:23  
looks like. Zooming back out a bit, it seems like this FDA meeting, it was grappling with something even bigger than just OPDIVO, wasn't it?

Speaker 2  8:29  
Oh, for sure, we've been talking about optivo, but they were actually looking at three HP immunotherapy drugs, optivo, Keytruda and tevimbra, all being used with chemo for these advanced gastric and esophageal cancers. Wow. Okay,

Speaker 1  8:43  
so triple the impact then and this whole PDL one debate, this testing dilemma, it's swirling around all of them. All of

Speaker 2  8:49  
them. They asked the expert panel to vote on whether the data supported using these drugs in patients with low or even no PDL one expression.

Speaker 1  8:58  
So those patients where the flags are either super faint or non existent. That's right.

Speaker 2  9:03  
And for all three drugs, the majority of experts actually voted no. Wow.

Speaker 1  9:08  
Okay, so it sounds like the FDA might actually be moving towards narrowing who gets these immunotherapies, at least for these types of cancer, it's definitely

Speaker 2  9:15  
on the table. They voiced real concerns about that smaller survival benefit in the low PDL one group, they felt the risks might outweigh the benefits in those cases. You

Speaker 1  9:25  
know, logically, I get it. But then there's this other layer, this whole testing issue. It almost feels like a catch 22 right? It's

Speaker 2  9:31  
incredibly complex. You've got a test with no limitations, inconsistencies, and they're considering limiting access based on that test. It's a tough call, ethically, medically, all of it, and

Speaker 1  9:41  
even if you do get the test, there's no guarantee it'll be the right one, or that it'll even be interpreted the same way by different doctors. It

Speaker 2  9:49  
just shows how much we still don't know and how much work still needs to be done, more research, more consistent testing, clearer guidelines for doctors. But. Whole Nine Yards.

Speaker 1  10:01  
In the meantime, it's the patients who are stuck in this incredibly difficult position. You're facing a serious illness. There's this potentially life saving treatment, and then this test which

Unknown Speaker  10:10  
which might not be the magic bullet we

Speaker 1  10:12  
wish it was exactly. It really underscores how important it is to be your own advocate. Ask the tough questions. Don't be afraid to get a second opinion. Push for clarity and information. It's your health on the line. Couldn't set it better myself. You know, what's really got me thinking is this goes way beyond just this one test or these particular drugs. This brings up a much bigger question. What's that? Should drug approval be based solely on the overall benefit to a larger group, or should we be pushing for truly personalized medicine, even if it's Messier, more complex? That's

Unknown Speaker  10:45  
the million dollar question, isn't it?

Speaker 1  10:47  
No easy answers there, not at all, but definitely a conversation worth having. Well, this

Speaker 2  10:51  
has been one heck of a deep dive. We've covered a lot of ground. We went from dense FDA documents to questioning the very foundation of how we made treatment decisions. Hopefully our listeners still with us, and

Speaker 1  11:03  
hopefully we feel a little more equipped to navigate this whole complex landscape. Knowledge is power. Never forget that couldn't agree more. Big. Thanks to you, as always, for breaking it all down and to our listener, keep asking those questions, keep advocating for yourself, and we'll catch you on the next deep dive. So we've talked about PDL one, but remember those other biomarkers we touched on earlier? MSI, TMB, all those, they can be part of the conversation too. Absolutely,

Unknown Speaker  11:27  
it's not just about PDO one and isolation.

Speaker 1  11:30  
So it's not just about one piece of the puzzle. It's about how it all fits together exactly

Speaker 2  11:34  
and honestly, don't ever hesitate to get a second opinion, especially with something as complex as cancer, a second opinion can be invaluable, like getting

Speaker 1  11:44  
a second mechanic's opinion before a major car repair. Better safe than sorry. 100%

Speaker 2  11:49  
it's your health, your life. You deserve to feel totally confident in your treatment plan, whatever that

Speaker 1  11:54  
looks like. Zooming back out a bit, it seems like this FDA meeting, it was grappling with something even bigger than just OPDIVO, wasn't it? Oh, for sure,

Speaker 2  12:02  
we've been talking about OPDIVO, but they were actually looking at three each immunotherapy drugs, OPDIVO, Keytruda and tevimbra, all being used with chemo for these advanced gastric and esophageal cancers. Wow. Okay,

Speaker 1  12:14  
so triple the impact then, and this whole PDO one debate, this testing dilemma, it's swirling around all of

Speaker 2  12:21  
them. All of them. They asked the expert panel to vote on whether the data supported using these drugs in patients with low or even no Pdl, one expression,

Speaker 1  12:29  
so those patients where the flags are either super faint or non existent, that's

Speaker 2  12:33  
right. And for all three drugs, the majority of experts actually voted no. Wow. Okay,

Speaker 1  12:38  
so it sounds like the FDA might actually be moving towards narrowing who gets these immunotherapies, at least for these types of cancer, it's

Speaker 2  12:44  
definitely on the table. They voiced real concerns about that smaller survival benefit in the low PDL one group. They felt the risks might outweigh the benefits in those cases,

Speaker 1  12:54  
which logically, I get it. But then there's this other layer, this whole testing issue, it almost feels like a catch 22 right? It's

Speaker 2  13:00  
incredibly complex. You got a test with known limitations, inconsistencies, and they're considering limiting access based on that test. That's a tough call, ethically, medically, all of it.

Speaker 1  13:11  
And even if you do get the test, there's no guarantee it'll be the right one, or that it'll even be interpreted the same way by different doctors. It

Speaker 2  13:18  
just shows how much we still don't know and how much work still needs to be done, more research, more consistent testing, clearer guidelines for doctors the whole nine yards.

Speaker 1  13:27  
In the meantime, it's the patients who are stuck in this incredibly difficult position. You're facing a serious illness. There's this potentially life saving treatment, and then this test, which

Unknown Speaker  13:38  
might not be the magic bullet, we wish it was exactly

Speaker 1  13:41  
it really underscores how important it is to be your own advocate. Ask the tough questions. Don't be afraid to get a second opinion. Push for clarity and information. It's your health on the line.

Unknown Speaker  13:52  
Couldn't have said it better myself. You know? What's

Speaker 1  13:54  
really got me thinking is this goes way beyond just this one test or these particular drugs. This brings up a much bigger question, what's that? Should drug approval be based solely on the overall benefit to a larger group, or should we be pushing for truly personalized medicine, even if it's Messier, more complex? That's

Speaker 2  14:13  
the million dollar question, isn't it? No easy answers there. Not at all,

Speaker 1  14:17  
but definitely a conversation worth having. While, this has been one heck of a deep dive, we've covered a lot of ground. We went from dense FDA documents to questioning the very foundation of how we make treatment decisions. Hopefully our listeners still with us, and hopefully

Speaker 2  14:32  
they feel a little more equipped to navigate this whole complex landscape. Knowledge is power. Never forget that couldn't

Speaker 1  14:39  
agree more big. Thanks to you as always for breaking it all down and to our listener, keep asking those questions, keep advocating for yourself, and we'll catch you on the next deep dive. You.

Transcribed by https://otter.ai