Keeping the Faith with M7824

As evidenced by the extensive discussions following my biopsy from last Friday, a tumor is indeed a very complex structure. It comprises cancer cells and stromal cells, tumor infiltrating cells—both cells of the immune system and cells not by convention being of the immune system, as well as an extracellular matrix mainly of proteins and carbohydrates.

Following my recent CT scan, the hope from obtaining core biopsies from one of my lung nodules was to get a better sense of the cancer at a cellular level, which may help shed some light on whether or not treatment with M7824, a completely novel, first-in-class, bispecific fusion protein is working (see prior posts for more details).

In particular, the presence of immune system cells (T cells, or T lymphocytes) in tumor biopsies and their potential impact on prognosis have been studied for decades. T cells are a type of white blood cell that circulate around our bodies, scanning for cellular abnormalities and infections. Broadly speaking they can be divided into two different types, “killer” CD8-positive T-cells and “helper” CD4-positive T-cells. CD8-positive T cells are critical mediators of adaptive immunity. They include cytotoxic T cells, which are important for killing cancerous or virally infected cells, and CD8-positive suppressor T cells, which restrain certain types of immune response.

Despite contributions by other immune cell subsets, CD8-positive T cells have emerged as the predominant effector in most cancer immunotherapy settings¹. Accordingly, many immunotherapeutic strategies (including checkpoint inhibitors, such as anti-CTLA4, PD1, and PD-L1 antibodies) are dedicated to stimulating, enhancing and maintaining responses by tumor-reactive CD8-positive T-cells.

Favorable outcomes have been demonstrated in patients where high numbers of CD8-positive cells were found at the tumor site in patients with head and neck cancer, breast, colorectal cancer and also for others solid cancers. In one study, head and neck cancer patients whose tumors were densely infiltrated by CD3-positive and CD8-positive T cells had a significantly longer overall survival (OS) and progression-free survival (PFS) compared with patients whose tumors were poorly infiltrated².

While there seems to be a consensus that CD8 infiltration is a good prognostic marker in most malignancies analyzed, however, the impact of CD8-positive T cells on clinical outcome may differ and is difficult to quantify. Not only is the type of T cell important, but also its location, and moreover the specific phenotype and function of those cells in the particular environment.

Nonetheless, based on the preliminary results from my recent tumor biopsy and other factors, it appears that there is sufficient evidence of immune system activation in the vicinity of the tumor to indicate that the experimental agent M7824 may indeed be performing as we hoped. Accordingly, I am in 100% agreement with my doctor’s recommendation to continue on the therapy and will receive my next infusion this coming Tuesday at NIH. After a few more cycles of therapy, another CT scan will be taken in the future with the hope of demonstrating that the recent tumor growth was from treatment effect “pseudo-progression” rather than true disease progression, which has been previously described with immune checkpoint inhibitors like M7824.

References:

¹ Targeting CD8+ T-cell tolerance for cancer immunotherapy. Stephanie R Jackson, Jinyun Yuan, and Ryan M Teague. Immunotherapy. 2014 Jul; 6(7): 833–852.

² Tumour-infiltrating lymphocytes predict response to definitive chemoradiotherapy in head and neck cancer. P Balermpas, Y Michel, J Wagenblast, O Seitz, C Weiss, F Rödel, C Rödel and E Fokas. British Journal of Cancer (2014) 110, 501–509. doi:10.1038/bjc.2013.640

 

 

 

Not as We Had Hoped

The results of today’s CT imaging procedure were not as we had hoped. Ideally, the dozen or so tumors in my lungs would have shown signs of shrinkage – indicating that the investigational drug was having a positive effect on the cancer. Instead, several of the tumors actually increased in size and a new spot even appeared in my spleen.

One of the hallmarks of immunotherapy, such as the checkpoint inhibitors, is the potential for a “delayed” response, which is not routinely seen with chemotherapy or other cytotoxic agents. Another biologic phenomenon unique to immunotherapy is “pseudoprogression,” or the initial radiologic appearance of an increase in tumor burden subsequently followed by tumor regression¹.

The CT imaging study cannot distinguish between cancer progression or inflammation as the reason for the increase in tumor size, so there is a chance that it’s due to inflammation and subsequent imaging tests in a month could demonstrate a reversal. However, it is also possible that the cancer isn’t responding to the investigational treatment.

To get more details, I’m undergoing a biopsy this Friday so that one of the lung tumors can be sampled. The preliminary information from that biopsy, which should be available next week, will help guide between cancer progression and inflammation. Decisions regarding how to proceed will depend on that outcome.

Needless to say, everyone’s hope was to have seen some sign of cancer regression on today’s CT scan and many teardrops were shed. The chances for a favorable outcome have diminished and must be acknowledged, but for now I’m persevering and will evaluate next steps following the biopsy results.

Sincere thanks to everyone who has offered their positive thoughts, prayers, and support. It is difficult to respond to each and every communication, but please know that I read “everything” and your time and effort is greatly appreciated. Special thanks to everyone at NIH for being so wonderful — even when faced with delivering bad news.

Now, more than ever, please keep all those positive vibes coming my way.

References:
¹ Amidst the excitement: A cautionary tale of immunotherapy, pseudoprogression and head and neck squamous cell carcinoma. Baxi SS, Dunn LA, Burtness BA.
Oral Oncol. 2016 Nov;62:147-148. doi: 10.1016/j.oraloncology.2016.10.007. Epub 2016 Oct 21.

Feelin’ Alright

Standing on the train platform this morning on my way to NYC, the late British rocker Joe Cocker’s version of Feelin’ Alright was playing over the sound system. Not only a good song to start the daily commute, it seemed an appropriate theme for this blog post.

It was exactly one week ago today that I received my first infusion of an experimental cancer immunotherapy agent, called M7824, as part of a Phase 1 clinical trial at the National Institutes of Health (NIH). Recall from my prior post that M7824 is a completely novel, first-in-class, bispecific fusion protein of an avelumab-like antibody linked to two molecules of TGF-beta trap. While very early in the process, I’m happy to report that so far I’m feelin’ alright.

As someone who has received three cycles of chemotherapy and a total radiation dose of 70 Gray over seven weeks, I can say with conviction that, so far, being treated with an immunotherapy agent has been a proverbial walk in the park. In fact, if it weren’t for the fact that this clinical study is not placebo controlled, I would seriously question whether or not I was in the active arm of the study.

For example, in contrast to chemotherapy and radiation, I haven’t experienced any of the hallmarks of traditional cancer therapy, such as nausea or fatigue, with the experimental immunotherapy agent. Important to note, however, every drug has side effects and checkpoint inhibitors like M7824 are associated with their own unique spectrum of immune-related adverse events. These include dermatologic, gastrointestinal, hepatic, endocrine, and other less common inflammatory events. In some cases, these side effects can be managed with corticosteroids or diphenhydramine. Less frequently, clearly defined autoimmune systemic diseases, such as lupus, have been reported.

In fact, approximately 30-40% of patients treated with approved PD-1/PD-L1 checkpoint inhibitors (nivolumab/pembrolizumab) will have dermatologic complications. For most patients, dermatologic toxicity is the earliest immune-related adverse event experienced, with onset an average of 3.6 weeks after treatment initiation¹. Accordingly, it may be too early for me to be experiencing any such side effects.

Of course, having a “safe” drug is important – but for me, the real hope is that M7824 is effective in treating my recurrent disease. In this regard, in an interview with EP Vantage earlier this month, Luciano Rossetti, Merck KGaA’s head of R&D, told EP Vantage that M7824 is “the most exciting clinical asset in our pipeline right now” adding that it has yielded “spectacular” early data. You can read the full interview by clicking here.

I remain hopeful and strongly believe that my generation could be among the last to experience toxic upfront treatments like chemotherapy and radiation thanks to the many advances being made with immunotherapy.

References:

¹ Source: http://www.uptodate.com/contents/toxicities-associated-with-checkpoint-inhibitor-immunotherapy

Starting Treatment – Again

First, my apologies for the length of time from my last clinical update. I’m not generally a superstitious person, but I wanted to wait for a few formalities to be addressed before posting.

Previously, I referenced that my next therapy would likely be at Memorial Sloan-Kettering Cancer Center (MSKCC) and include Opdivo® (nivolumab), a form of immunotherapy called a “checkpoint inhibitor.” What is that, you ask? Human cells carry certain proteins on their surface that enable them to escape attack from the body’s immune system. Some cancer cells wear one of those same proteins, called programmed death ligand 1 (PD-L1), which renders the cancer cells invisible to the body’s immune system. Blocking either PD-L1 or its receptor, programmed death 1 (PD-1), appear to be Achilles’ heels for multiple tumor types. Coincidentally, I covered the exciting early developments in the checkpoint inhibitor field in July 2013, which you can read by clicking here.

Michael D. Becker being infused with M7824 for the first time

Michael D. Becker being infused with M7824 for the first time on 1/25/17 at NIH

My concern is that across clinical studies in numerous cancer types, only about 20% of patients receiving checkpoint inhibitors have a durable response. For these patients, the benefits tend to last for years – perhaps even indefinitely. Exciting, yes. But for the other 80% of patients, the results are less dramatic. For example, in the recurrent head and neck cancer study for Opdivo, the median overall survival was 7.5 months for patients that received Opdivo versus 5.1 months for patients that received standard therapy options (cetuximab, methotrexate, or docetaxel). Clearly, Opdivo was superior to standard therapies and definitely worth considering. But the median overall survival is the time period lying at the midpoint of a frequency distribution of observed values, such that there is an equal probability of falling above or below it. The prospect of being in the 80% group with less than a year to live forced me to consider alternatives.

Fortunately, I became aware of a clinical trial for an investigational agent called M7824, a bifunctional fusion protein targeting PD-L1 and TGF-β, that was developed by EMD Serono, the biopharmaceutical division of Merck KGaA, Darmstadt, Germany. M7824 is currently being studied in a Phase 1 trial for patients with advanced solid tumors (ClinicalTrials.gov Identifier: NCT02517398). The principal investigator for the study is James L. Gulley, M.D., Ph.D., F.A.C.P. of the National Institutes of Health, Center for Cancer Research. In addition to his role as Chief of the Genitourinary Malignancies Branch, Dr. Gulley is also Director of the Medical Oncology Service, Office of the Clinical Director. He is an internationally recognized expert in cancer immunotherapy and I’ve had the honor of knowing him professionally for more than a decade – starting back when I was at Cytogen Corp (just an amazing individual and I cannot say enough good things about him!). Other key members of my fabulous team so far include Dr. Julius Strauss, Lead Associate Investigator for the study and Fellow Physician in Oncology at the National Institutes of Health, Andrea D. Burmeister, Physician Assistant, and Elizabeth Lamping RN, BSN, Research Nurse Specialist.

M7824 consists of a fully human monoclonal antibody against PD-L1 plus a transforming growth factor beta (TGF-β)-neutralizing trap component. This means that M7824 should confer all of the benefits of a checkpoint inhibitor against PD-L1, but with the added punch of neutralizing TGF-β. Dual targeting of the PD-L1 and TGF-β pathways makes sense because both are key immune evasion pathways with independent yet complementary functions.

The TGF-β signaling pathway is complex – resulting in either tumor suppressor or tumor-promoting activity depending on the cellular context in which the pathway is active. In advanced disease, the tumor suppressor arm of TGF-β signaling is lost and, instead, tumor cells proliferate. Further, TGF-β overexpression in advanced disease enhances tumor growth, suppresses the immune system, and exacerbates invasive and metastatic tumor cell behavior.

The more I researched TGF-β, the more encouraged I became about enrolling in the M7824 clinical trial – especially given the specific profile of my disease. Recall that I was diagnosed with human papillomavirus “HPV” positive, squamous cell carcinoma (SCC), which is cancer that begins from squamous cells, a type of skin cell. In addition to being one of the main types of skin cancer, cancers that involve the anus, cervix, head and neck, and vagina are also most often SCC.

Only a minority of people exposed to human papillomavirus develop HPV-related cancer, such as oropharyngeal cancer (lucky me!) or cervical cancer. In a paper published December 2014 in Cancer Research, Levovitz et al. demonstrated that genetic variation in immune-related genes is a determinant of susceptibility to oropharyngeal cancer and other HPV-associated cancers, particularly those related to TGF-β signaling. In other words, it is possible that people carrying genotypes with such variants are more likely to have an HPV-positive tumor compared to patients with the wild-type genotype. The likely functional significance of altered TGF-β signaling in HPV-related cancers is further supported by the finding by Levovitz et al. that TGF-β receptor type 1 is significantly overexpressed in both oropharyngeal cancer and cervical cancer.

In a paper published in February 2015 in Cell, Oshimori et al. establish a surprising non-genetic paradigm for TGF-β signaling in fueling heterogeneity in squamous cell carcinoma (SCC) stem cells, tumor characteristics, and drug resistance. Armed with this insight as well as the relevance for HPV-positive cancers, I decided to enroll in the study and passed the screening process.

In December 2016, Dr. Gulley presented preliminary data from the ongoing Phase 1 study of M7824 at the 28th symposium on Molecular Targets and Cancer Therapeutics, also known as the ENA symposium. Early results were encouraging, with M7824 associated with complete (CR) and partial responses (PR) in patients with advanced refractory cancer.

Today is my first one-hour infusion of M7824 and I look forward to reporting on my experience with immunotherapy in subsequent posts. With just a few minutes remaining for the infusion – so far, so good!