Wednesday, April 25, 2012

BTDT, Got The FAHF-2 Food Allergy Clinical Trial T-Shirt!

Both...I think.
My son loves clever t-shirts. He got an opportunity to wear the one at left for a totally new outing this week: the FAHF-2 clinical trial.

As I mentioned in a post from last month, our family applied to the FAHF-2 clinical trial at Children's Memorial in Chicago. Getting in was actually a little iffy because my son's peanut numbers are so low. (Despite the low numbers, he had failed a peanut challenge last summer.) To participate, candidates had to be over the test threshold for SPT/RAST, have controlled asthma, be allergic to one of the allergens being studied (peanut, tree nuts, sesame, fish, or shellfish), be between the ages of 12 and 24 and not have a history of an allergy to corn or of a serious past reaction that required intubation or resuscitation.

Our initial visit included a thorough exam and consent paperwork for both me and him, since he's still underage. They took blood for a RAST (in our case, for both peanut and hazelnut to see which they preferred to challenge). They also did a skin prick test, a spirometric assessment of his lung function, an EKG, urinalysis and a general physical.

The next day, we got a call to say his peanut RAST was just over the 0.7ku/L cut-off. His SPT was also just over the line: 3.5mm, and it took until the very end of the time period to show up. Everyone shrugged and said perhaps we'd be celebrating him passing BOTH food challenges (the peanut and the placebo). The numbers were so low!

On the day of the food challenge, we got to the hospital at 8:30. He was allowed to eat up until 2 hours before the trial, as food in the stomach can help dampen reactions. However, he was not supposed to eat too close to the trial for the opposite reason - vomiting is common and they wanted food that was digested enough to not cause choking. Luckily, my teen-age wolf is able to eat anything at pretty much any time of day, so breakfast at 6:00 was no hardship.

The clinical research area is a very busy place! My son was only one of several test subjects there for the day. The area is divided into little clinical rooms that basically contain a treatment chair, some procedure carts and enough other chairs for the various people who come in and out. My son took the Chair of Honor and the nurses worked on getting an IV line in for him, a challenge given his strange veins. The doctor did another exam to make sure his health status had not changed from the initial exam, and asked him to blow into a peak flow meter several times so they could get his max. level. They took another set of blood from the IV line. Then we were ready to go.

The clinical trial manager brought into the room a big bin, filled with applesauce. There were two batches, labeled "A" and "B", divided into 9 doses. Should he finish them all, we were told, the total potential peanut dose was 2000mg, the equivalent of around 9 peanuts.

I did not get the dosing amounts during the trial, but they did tell us that the doses double and then double again, so this is about how many milligrams were probably in each dose*:

1
2
3
4
5
6
7
8
9
10
20
40 80
160
300
400
500
600
1 peanut = ~225-250mg

Because the trial was done "double blind", no one in the room knew which dose was going to contain peanut and which just applesauce. What we did know was that, if he did not react to the first batch, they would wait 2 hours to be sure and then go right into the second batch. No doubt every mother in the study whispered a prayer at the beginning of the day: "please let the first batch be placebo so this can all be over in one day!"

They started the dosing. Because of the delay in the reaction time on his SPT, the doses were spread out over a half hour, instead of the usual 10 minutes between. Around dose 4, my son started complaining of a tightening in his throat. Both the doctor and clinical trial nurse were with us and both asked for a number for the discomfort (2) and whether he wanted to continue. He did. We all really wanted to confirm that he was truly still allergic, given his numbers.

After dose 6, things started to get much worse. In the course of 20 minutes, his discomfort went from a 2 to a 7. The two clinicians looked uneasily at each other. They did a physical exam, listening for wheezing, and had my son blow again into the peak flow meter. His peak flow was down more than one hundred points. Additionally, I could see he was starting to panic.

"I'm calling it," said the doctor and the relief on the clinical study nurse's face was evident. They offered my son either liquid or IV push Benedryl (he took the liquid) and we all watched him like a hawk for the next half hour while it took effect. There were two other clinicians popping in at times now and asking how he was feeling. Finally, we all burst into laughter and the doctor said "we need to coordinate this better so we're not driving the poor guy crazy!" I laughed and said "hey, at least it's not just me bugging him for once!" The Benedryl kicked in quickly and everyone relaxed into the 4 hour observation period. They made sure we had our meds with us and sent us home around dinnertime. As fails go, it was as good as we could have hoped for.

The fail point? Just under 3 peanuts, according to the staff.

Monday, we girded our loins and drove back to the hospital for a repeat with Batch B. While we were all anticipating a fast, easy placebo day, there were no guarantees. Over the weekend, thoughts of psychosomatic reactions, sensitivity to something in the applesauce and EoE all went through my head. The good news is that it was indeed uneventful - he ate a bunch of applesauce, they waited two hours, and then they gave him his first dose of FAHF-2.

The pills are not small. They are a half-inch each in circumference, a little bigger than an M&M. Over the next six months, he will take THIRTY of them daily, 10 each with breakfast, lunch and dinner. Yesterday, I met with the school nurse to give her the permission slip, dosing schedule and medication. My son will need to stop by her office each day after lunch to take his mid-day dose. (For some strange reason, they object to teens popping 10 unlabeled pills at lunchtime in the cafeteria.)

From here on out, he will need to talk with the study coordinator once a week to report any issues. He will keep a journal to record medication dosage times and any illnesses or funny symptoms. Since these are natural substances that have a long track record in Eastern medicine, they do not expect side effects, but they are possible. We will return to the hospital for an exam and blood work every few months.

At the end, they will put him back through the two food challenges to see if anything has changed. If he is taking the placebo, they would expect to see a fail at about the same point as last time; if he's taking the real drug, we will have to see what happens. The ratio of real-to-placebo is 2:1, so we have good odds of getting the real drug.

I asked him after what the hardest part was and he replied, without hesitation, "discontinuing the antihistamine!" Apparently even the palms of his hands itched! However, that does put things in perspective. While he did not look forward to failing a food challenge, he's done it before. As fails go, this one was really very mild   no vomiting, no wheezing, moderate sense of doom, no major drop in blood pressure. We feel very lucky. However, it's also an important reminder: low numbers need to be tested once a history of allergy exists. It is very possible to be allergic with low numbers, just as it is possible to not have an allergy with high numbers.

The good news about this trial is that, if it works, it probably works for every allergen. As I mentioned, they did pull a RAST for hazelnut as well as peanut. Between January and this week, the number went from 3 to 12! My husband was very unhappy when he heard this. However, I reminded him that it's spring. It's possible that the spike in RAST is from a cross-reaction to birch pollen, not a real allergy to hazelnut. (My son has never reacted to hazelnut IRL.) The PPV for hazelnut is not well-determined, so it's hard to know if that 12 is important, but we will no doubt have to test this at some point down the road. (Hazelnut is a hassle because it's in so many coffees, so cross-contamination would be a serious issue.)

The expectation, as the trial continues, is that his RAST will go up....and then come down. No one knows why it works this way, but that seems to be the pattern, almost like the immune response has to be turned on before it can be tamped down.

If you are in the Midwest and interested in a trial, here's the link to the Children's Memorial research page. Our trial manager did mention that they are planning two more trials for 2012: one for the peanut patch used in Europe, and an oral tolerance study for wheat (not gluten intolerance/celiac, but true protein allergy).

*Based on the total of 2000mg and knowing he failed at Dose 6, which we were told was the equivalent of about 3 peanuts. 


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