Yesterday marked the beginning of cycle number six for my third-line chemotherapy treatment. In this regimen, one full cycle is comprised of four weeks. During week one, two different chemotherapeutics (carboplatin and paclitaxel) are given along with the requisite premedication (steroid, anti-nausea meds, and an antihistamine). During both the second and third weeks of a cycle, I receive only one chemotherapeutic (paclitaxel) and the same premeds. Week four is a holiday/break, with no scheduled treatment that helps provide recovery time for blood counts and other markers. Then the four-week cycle repeats.
Having received five cycles over the past five months, my blood counts are slower to recover – particularly my white blood cells. As a result, my medical oncologist (Dr. David Pfister at Memorial Sloan-Kettering Cancer Center (MSKCC)) modified the last treatment to forgo the third week of chemo since that is usually about the time that my white blood cells are on the low side. In other words, the most recent two cycles of treatment have been “two weeks on, two weeks off” meaning that I get two chemotherapeutics (carboplatin and paclitaxel) on week one, only paclitaxel on week two and then a two-week break during weeks three and four before starting the cycle over again.
Considering that the latest 2/5 cycles have been reduced in terms of the total amount of chemo I’m receiving, it is encouraging to see that each CT scan still shows decreases in the size of some tumors. For example, take the largest tumor (on my spleen) that originally measured 6.4 cm on its longest axis and 6.0 cm on its shortest axis back in early January 2017. Since starting third-line chemo over the summer, those dimensions have decreased on each subsequent CT scan: 5.4 x 4.8 cm, 3.2 x 2.6 cm and most recently 2.9 x 2.0 cm. Many other lymph nodes in my lungs and abdomen are also now 1 cm x 1 cm or smaller, which is typically the size of a “normal” lymph node—although PET imaging would help inform whether or not there is still disease activity.
But just exactly how unusual or encouraging is all of this? During the MSKCC appointment, I gathered that the general expectation would have been decreased disease from the first treatment cycle, perhaps stable disease on the second cycle and then possibly progressive disease on the third or later cycles. Bottom line: my cancer continued to decrease across all three recent scans, which is better than normally expected.
I’m happy about the results and extremely thankful that I received strong encouragement to give chemotherapy another chance. And it’s not just about tumors shrinking, there have also been meaningful improvements in my quality of life. For instance, at the start of chemotherapy I had not one but two chest tubes placed to help reduce fluid around my left lung. Both have since been removed, as the fluid buildup is gone. Associated side effects with the fluid, such as coughing and difficulty breathing have also disappeared. Oh, and it is a lot easier to shower without wrapping your chest and abdomen in plastic wrap each time to avoid water getting into the tubes!
I’m a curious person by nature and seeking potential answers as to “why” my disease is responding a bit better than expected to the current chemo regimen. As a long-time champion of immunotherapy, I can’t help but wonder about my prior second-line therapy with M7824, an experimental bispecific fully human antibody designed to simultaneously block two immuno-inhibitory pathways (both PD-L1 and TGF-β) that are commonly used by cancer cells to evade the immune system. The aim of this investigational drug is to control tumor growth by restoring and enhancing anti-tumor immune responses.
While receiving M7824 at the National Institutes of Health (NIH) as a participant in their Phase I trial, results from biopsies of both my tumor and pleural fluid provided evidence of immune system activation in the vicinity of the tumor, indicating that the experimental agent M7824 was performing as designed. In particular, the presence of tumor-reactive CD8-positive T-cells, which have emerged as the predominant effector in most cancer immunotherapy settings. In fact, one published study in 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 infiltrated.
It’s quite possible that based on the large tumor burden in my body, the immune system activation resulting from M7824 might not have been able to overpower the disease. However, with my tumor burden now having decreased substantially through subsequent chemotherapy, I can’t help but wonder if M7824 could be playing a role in my ongoing disease improvement.
While answering this question is purely academic, it could help inform the design of future combination studies with M7824 and chemotherapy. From a personal perspective, it would also validate that I made the right decision to jump into the M7824 trial after failing first-line therapy (chemoradiation).
As someone with no formal medical training, my initial thought was to have the largest, most accessible tumor biopsied to look for residual immune system activation. Unfortunately, the largest remaining tumor is on my spleen and my oncologist frowned on the prospects of poking needles around that area. A good to time to remind readers that while I have a fair amount of working knowledge in biotech, I always rely upon the wisdom and experience of the treating physician. They’ve gone to med school…I have not.
But I do feel it is very important, to the full extent possible and without substantial added risk to me, to find some signal—even if anecdotal—that M7824 did something good. For my friends in the medical community, please feel free to email me any ideas or thoughts!
 Targeting CD8+ T-cell tolerance for cancer immunotherapy. Stephanie R Jackson, Jinyun Yuan, and Ryan M Teague. Immunotherapy. 2014 Jul; 6(7): 833–852.
 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