There’s no pamphlet for this. No survivor forum thread. No “what to expect” blog post.
When I received TCR-T cell therapy at the National Institutes of Health, I was the first person in the world to receive this specific T-cell therapy — engineered to target the TP53 Y220C mutation — applied to a solid tumor. That means everything I’m about to tell you — the preparation, the brutality of IL-2, the month in a hospital bed, the results — didn’t exist as a patient resource before now.
This is that resource.
What Is TCR-T Therapy?
Let me break it down in plain language, because when I was researching this, most of what I found was written for scientists.
TCR-T stands for T-Cell Receptor engineered T-cell therapy. Here’s the basic idea: doctors take your blood, extract your T cells (immune cells that fight threats), and genetically engineer them in a lab to recognize a specific protein on your cancer cells. Then they grow billions of these engineered cells and infuse them back into your body.
Think of it like this: your immune system has soldiers, but they can’t see the enemy. TCR-T therapy gives those soldiers targeting goggles tuned to your exact tumor.
How it differs from other immunotherapies:
- Checkpoint inhibitors (like pembrolizumab) take the brakes off your existing immune system. They work well for some cancers but aren’t effective for most colorectal cancers unless you have specific mutations (MSI-H/dMMR).
- CAR-T therapy engineers T cells too, but targets surface proteins. It’s been revolutionary for blood cancers but has struggled with solid tumors.
- TCR-T therapy goes deeper — it targets proteins inside the cancer cell that get displayed on the surface. This opens up a much wider range of solid tumors, including colorectal cancer.
Most stage 4 CRC patients are told immunotherapy “doesn’t work for your type.” That’s true for checkpoint inhibitors if you’re microsatellite stable (MSS) — which is about 85% of CRC patients. But TCR-T is a completely different approach. It doesn’t rely on the same pathways.
How I Found This Trial
Three separate research teams — including my own oncologist’s — had searched for clinical trials on my behalf. None of them found this one.
I found it myself, late at night, digging through ClinicalTrials.gov with search terms I’d learned to refine over months of practice. The trial was at NIH, in Bethesda, Maryland. It was recruiting for patients with specific mutations, and I happened to match.
I almost didn’t apply. It sounded brutal — the listing described two rounds of immunodepleting chemotherapy, high-dose IL-2, and a minimum of three to four weeks as an inpatient. One line mentioned a one-in-ten chance of ending up in the ICU. But I kept coming back to one question the doctors at NIH later asked me directly: What do you have to lose?
My cancer had already responded to chemo. I was close to remission. But “close” isn’t cured. This trial could potentially push me the rest of the way. Worst case, I’d go back to the treatment that was already working. It wasn’t a reckless gamble — it was a door that could only add possibilities.
The Team at NIH
Walking into NIH feels different from any hospital I’d been in. There’s an energy — not softer, but more like a frontier outpost than a courtroom.
The fellow leading my recruitment knew every technical detail of the trial. I could ask her anything, no matter how deep into the weeds, and she’d answer with precision. She would sit with me for an hour if I needed — something my local oncologist could never do with twenty other patients waiting.
Then there was my primary trial doctor, who radiated a different kind of authority — wisdom, earned over decades. When my wife asked how TCR-T compared to a vaccine, he replied with calm certainty: “Oh, I’ve been working on those vaccines for two decades. We are the ones who invented them here. This TCR-T therapy is many times more potent than any vaccine.”
That single exchange shifted the knot in my stomach. What had been pure anxiety became something braided with excitement.
And hovering over all of it was the head of the department — a pioneer in immunotherapy with over fifty years in the field. He rarely spoke during rounds, just a grunt here or there, but his presence carried weight. Never did I imagine someone of that stature would be standing at my bedside while I looked like the worst version of myself.
The Preparation
Before you can receive TCR-T therapy, your existing immune system has to be destroyed. Completely. This is called lymphodepletion — two different chemotherapy agents designed to wipe your immune cells to near zero, making room for the engineered cells to take over.
They harvest your blood months in advance. Your T cells go to a lab where they’re genetically modified and then grown — billions of them. My cell production was delayed by two months due to staffing cuts at NIH. During that delay, I had to let my tumors grow back to measurable size just to qualify for the trial.
Let that sink in: I had to watch my cancer grow on purpose. It was the hardest thing I’d done since diagnosis.
The IL-2: Four Doses of Hell
I had read IL-2 “could” be harsh. That’s an understatement. I think they downplay it so you don’t psych yourself out.
The protocol called for up to five doses. They made clear most patients got one or two. Many who received a single dose ended up in the ICU.
I took four.
The first dose started with a faint shiver. Within seconds, it escalated into the most violent shaking of my life. My whole body convulsed, skin burning, clothes soaked with sweat. Minutes of uncontrollable shaking interrupted by bouts of full-body muscle lockup. I was fully conscious the entire time.
Normally they’d treat it with Demerol, but there was a nationwide shortage. The fallback was morphine — slower and far less effective. So I lay there for what felt like an hour, shaking and drenched, waiting for the morphine to kick in.
My wife held my hand while I curled into a fetal position. She held a steady, stone-cold calm. Her eyes started to water but the tears hadn’t fallen yet. I don’t know how she did it.
After every dose, I swore I wouldn’t do another. And then, eight hours later, I’d talk myself back into it. If this gives me even the slightest edge, why fight this hard only to shortchange myself at the last second?
Nurse after nurse stopped by afterward, calling me “the four-dose guy.” One told me about a patient who made it to five doses — he became so delirious he held his wife and a nurse “captive” armed with nothing but a box of tissues. He still ended up in the ICU.
My doctors decided four was enough. They suspected fluid buildup in my lungs. They were probably right.
A Note on What They Tell You
I’m not telling you about the IL-2 to scare you. I went looking for this exact post before my infusion and it didn’t exist. I would rather have known.
The NIH team downplayed it — “just part of the process” — and honestly, maybe that was the right call. When my trial doctor walked into my room after the second dose and was surprised to find me sitting upright in a chair, let alone walking to Starbucks, I realized the gap between what they’d prepared me for and what I’d actually endured. Maybe he was protecting me. Maybe he didn’t want to plant a self-fulfilling prophecy. Maybe he didn’t want to scare me away from the trial. The reality is, nothing would have stopped me. I knew death was a plausible outcome. Once I make up my mind, it’s difficult to change it.
What bothered me — what still bothers me — wasn’t the downplaying of side effects. It was the certainty about my death. From the very first oncologist visit, it was: This will never go away. This can’t be cured. Once you’re stage 4, you will always be stage 4. You have maybe three years. If you’re lucky, five.
What does that do? Absolutely nothing but plant seeds of doubt. It helps no one, and it’s often inaccurate. They say it because they think they’re being helpful — direct and blunt so you’re not caught off guard three years in. But how many times has that prediction been wrong?
My wife’s uncle had metastasized lung cancer. They told him he had a treatable variant and could extend his life considerably. He watched his wife die while doing chemo. He decided he was going to let the cancer take its natural course. No chemo. No supplements. Nothing. He just lived his life and took pain meds when he needed them. Did he live six months? No. He lived five years.
That’s a single example, but it illustrates the point: their timelines are educated guesses applied to populations, not predictions written for you. The system’s biggest failure isn’t what happens in the treatment room. It’s the mindset they put you in before you even get there.
The Long Month
I spent over a month as an inpatient at NIH. The days dragged like the hands on the clock dragging through sand.
The fevers hit every night. They’d build from midday and climb to 101 or 102 by evening. That routine lasted almost three weeks. To cope, I created my own story: the fevers were proof the engineered T cells were doing their job — like how your immune system fights a flu, except this cancer was one hell of a flu.
One morning I decided to walk down to the hospital Starbucks to surprise my wife with coffee. I was the bubble boy — immune system wiped clean, hyper-aware of exposure. I got in line and immediately thought: What is wrong with me? I’m one floor away from my room and I feel like I’m going to pass out. My legs trembled from just standing.
When I made it back, she looked at me half laughing, half irritated. “Did you just walk down to Starbucks?” I nodded like a scolded kid. “You damn dummy. Thank you.”
One night burned into my memory forever. I was between sleep and waking — a fever dream with the room leaking into it. I felt paralyzed, trapped in a loop of pure terror, sensing threatening presences just out of focus. The same dark sequence over and over, what felt like a thousand times. At some point a terrible thought settled in: I’m in hell. This is my existence now.
I forced myself awake, drenched in sweat, and lay there the rest of the night too afraid to sleep. In those hours I replayed my entire life.
The Results
When the results came back, I felt something I hadn’t in two years: real, unshakable positivity.
First scan: 18% tumor shrinkage. CEA (tumor marker) dropped from 42 to 4.3. The imaging showed the T cells weren’t just pressing on the outside of the tumors — they were tearing them apart from the inside.
Six-week scan: CEA dropped to 1.4. Lung lesions resolved completely. Liver lesions became non-enhancing — meaning they were dying.
Three-month scan: Combined shrinkage of 41% by RECIST criteria. Officially declared a partial responder. The NIH team requested expanded blood samples.
I’m not sharing these numbers to brag. I’m sharing them because when I was lying in that hospital bed, shaking through my fourth dose of IL-2, I would have given anything to read that someone came out the other side with real, measurable progress.
What This Means for CRC Patients
Let me be honest about where things stand:
- TCR-T therapy is not available as a standard treatment for colorectal cancer. It’s in clinical trials only.
- You need specific mutations to qualify. Not everyone will match.
- The process is brutal. I’m not glossing over that.
- This was a proof of concept. The doctor told me it be prohibitively expensive to replicate outside a trial setting. It’s not going mainstream anytime soon in its current form.
But here’s what matters: it worked. In a cancer type where immunotherapy is routinely dismissed as ineffective, engineered T cells recognized and attacked my tumors. That’s not a minor finding — it’s a crack in the wall.
Versions of this approach are being refined right now. As the technology matures, costs will come down and eligibility will expand. The doctors at NIH believe this is a starting point, not an endpoint.
What I Want You to Take Away
If you’re a stage 4 CRC patient who’s been told immunotherapy doesn’t work for you — that statement is incomplete. Checkpoint inhibitors may not work for your specific subtype. But checkpoint inhibitors are not the only form of immunotherapy, and the field is moving fast.
Search ClinicalTrials.gov. Learn your mutations. Push your oncologist. And if three research teams can’t find a trial for you, search yourself.
I’m alive because I refused to accept that the options my doctors knew about were the only options that existed. The system wasn’t built to save everyone. But the doors are there if you’re willing to find them.
I’m Aaron — a stage 4 colorectal cancer survivor, the first patient to receive a TCR-T cell therapy targeting the TP53 Y220C mutation in a solid tumor, and the author of an upcoming book about surviving the system. If this post helped you, share it with someone who needs it.
Keep reading:
The CRC Roadmap 
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