Friday, November 16, 2012

My Clinical Trial has Ended

In late June, at a routine endocrinology appointment, I was asked if I was interested in participating in a clinical trial for the Minimed Veo Pump and the Enlite Sensor. I was told that after this study, which would include over 250 participants across the country, the data would be presented to the FDA to gain approval for sale in the United States. I jumped at the chance to be involved in the latest technology to help people have an easier, better and more informed approach to managing diabetes.

I had seen information on these products, which are currently available for sale in Europe, on the internet. The Enlite sensor was smaller than the current sensors on the market in the US. They are inserted into subcutaneous fat tissue at a 90-degree angle, rather than the 45-degree angle that the current sensors need to be inserted, which meant there was a new insertion device. And there was also a new taping system that was supposed to eliminate the need to use over-tape on the sensor and transmitter. Even with these advertised improvements, it was the Veo that I was most excited about. The Veo has a new feature called Low Glucose Suspend (LGS). If the sensor reads that your glucose is below a particular number (one that you can set) it will alarm. If you, the human, do not respond to the alarm it will automatically suspend all basal insulin for 2 hours. In the short-term, this sounded great for those overnight lows that often go untreated because I don't hear the alarms. In the long-term, though, this is a huge technological step as research moves towards a closed-loop system, or artificial pancreas.

In mid-July, per study protocol, I went to my initial screening visit. At the visit I needed to answer all sorts of questions to make sure there was nothing that excluded me from being in the study. I also needed to prove that I was Type 1 Diabetic by drinking a particular amount of Boost without delivering an insulin bolus, have c-peptide labs drawn, wait two hours, then have more c-peptide labs drawn. Let me just say that by the time I was able to test my sugar and take a bolus I was well over 300mg/dl and felt nauseous. I don't understand why the study protocol was written this way, but it was a sacrifice I was willing to make to be a part of the study. A few days later the tests confirmed that my original diagnosis in 1982 was correct, and I did have Type 1 diabetes. My appointment for visit #2 was set up for late July.

At visit #2 I said good-bye to my pump (Minimed Revel), infusion sets (Sof-sets), sensors and blood glucose meter (OneTouch UltraLink). In their places I was put on a Revel 2, Quick-set infusion sets, Enlite sensors and the Bayer Contour Next Link meter. For the next few weeks I was to use and wear this new equipment to see if my blood sugars resulted in a specific glucose pattern, which would allow me to continue on in the study. What the study coordinators were not allowed to tell me, but I already knew, was that I needed to have episodes of hypoglycemia between the hours of 10pm and 8am.

At visit #3, in mid-August, I was officially told that I did have qualify based on the number of overnight lows needed to advance in the study. It was then that I found out that I had been randomized to the Veo. Some study participants, if they continued on in the study, would remain on the Revel 2. Others, like me, were randomized to the Veo with the LGS feature. I transitioned pumps again and was off with my experimental equipment for the next three months.

Just this past Tuesday, was visit #4, the final visit for the trial. At this visit I needed to return all of the equipment given to me at the beginning of the study and I went back to my own pump, my own infusion sets, my own meter and my own sensors. While I am so grateful that I was able to participate in this clinical trial, I am glad that it is over. Having to check and log urine ketones, low glucose symptoms, exercise and illness daily becomes quite cumbersome when it was added on top of everything that I do to manage my diabetes. Below I've listed the pros and cons with the Veo and Enlite sensors that I experienced over the course of the study


  • How the new sensors are inserted. During the course of the study I didn't bleed one single time when a sensor was inserted. 
  • The small size of the meter.
  • That advances are being made towards a closed loop system.

  • The series of 4 alarms that occur whenever the LGS turns on.
  • The Quick-set infusion sets. Since 1998, using Sof-sets, I NEVER received a no delivery alarm. During the study I received at least 5 no delivery alarms.
  • The new meter takes longer to transmit the blood sugar reading to the pump.
  • The Veo did not have the 8-hour calibration reminder.
  • The Enlite sensors did not seem to be any more accurate than the sensors currently on the market, so LGS would turn on when I wasn't low, which sometimes resulted in very high blood sugars and ketones in the morning.
  • The new taping system for the sensors did not work for me. I found myself several times needing to use over-tape because the transmitter would get caught on my clothes and start to pull away from my skin.
  • I could not set the amount of time that basals were suspended when LGS was turned on; my only option was 2 hours.

Overall: I have no doubt that this system will gain FDA approval and will be sold in the US. I, however, will not rush out to buy a VEO. Until the accuracy of the sensor greatly improves the LGS feature is not something I would use. I distinctly remember one night being awakened by the alarms. My sensor reading indicated that I was in the 50's, but when I tested my blood sugar I was in the 200's. If I would not have awakened, my basal would have stopped for 2 hours and who knows what level of ketones I would have had in the morning. The sensors on the other soon as those are on the market I want them. The accuracy is not better, but it is not worse, and I much prefer the insertion of the Enlite sensor.

Disclaimer: I did receive $300 for my participation in the study. I am in no way connected with Minimed, Bayer, OneTouch or any other company involved in this trial, other than being a user of their products. The views expressed above completely my own opinion.

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