Tuesday, March 15, 2022

Biosimilars for Follicular Lymphoma

The journal JAMA Oncology recently published a review of 31 biosimilars for different cancers, including Follicular Lymphoma. The results were very positive. It has some good implications for FL patients.

Some background first.

When a cancer treatment is developed, it usually takes years before it is available to all patients who could benefit from it. It goes from the laboratory, to being tested on cancer cells in test tubes, to being tried out on animal models (like mice), to then being tried on humans in a stage 1 clinical trial, and then if that goes well, in stage 2 and 3 trials. The maker of the treatment spends a lot of time and money developing and testing the treatment -- millions of dollars. When the treatment is finally available (and less than 10% of treatments will make it through a phase 3 trial), the maker is given a patent, where no one else is allowed to profit from that treatment. In the U.S. and Europe, the patent lasts 20 years. The idea is that the maker of the treatment is allowed all of that time to make back the money that they spend on developing the treatment.

After 20 years, the patent expires, and other companies are allowed to make their own versions of the treatment. If the treatment is made up of chemicals (something like a traditional chemotherapy), the new version is called a "generic." They are relatively easy to make -- it's a matter of figuring out the chemical formula and putting the right chemicals together. It's like following a recipe.

But if the treatment being copied was developed from something that was alive --something like Rituxan, that is developed from mouse cells -- it's a little more complicated. Living things tend to want to be different from other living things. It's why kids aren't exactly like their parents (which is probably good a lot of times, and not so good other times). I like to think of it this way. Creating a generic, where you're copying a chemical formula, is like following a recipe to bake a cake. But creating a biosimilar is like baking a cake, but first you have to grow the wheat and get chickens to lay the eggs, and hope that growing conditions on the farm are all OK and there isn't too much rain to affect the wheat and the chickens don't eat something weird that affects the taste of the eggs. And if everything works out, you can harvest the wheat and eggs and then make your cake. It's just more complicated -- there are more factors that have to be dealt with when the treatment is a biosimilar because it involves living things.

Because it's more difficult to develop a biosimilar -- to copy something that was alive once -- it's a big deal when one is developed and then tested and shown to be as effective and as safe as the original. 

The JAMA Oncology article, called "Characteristics of Clinical Trials Evaluating Biosimilars in the Treatment of Cancer: A Systematic Review and Meta-analysis," looks at 31 different clinical trials, involving 12,310 patients, that tested biosimilars for 3 different cancer treatments. One of them was Rituxan, and the trials tested biosimilars for patients with FL and other blood cancers. 

(Just to be clear -- this study didn't test biosimilars; it looked at studies that were already conducted.)

In reviewing all of these trials, the researchers found that the biosimilars were as effective and as safe as the treatments that they were copied from. That's not a surprise -- they wouldn't have been approved if they weren't. But what the study found was even more impressive. Basically, the clinical trials for the biosimilars were even better than the trials for the originals. They involved more patients, and the designed was better (more of them involved direct comparisons between Rituxan and the biosimilars). So basically, the developers of the biosimilars made sure that the trials were as rigorous as possible, so there were no questions about whether or not the treatments were really safe and effective.

So why does al of this matter? What's so great about biosimilars?

The big reason for using a biosimilar is that it is less expensive than the original. The original treatment was developed over years, and cost millions of dollars. The biosimilar's makers didn't need to spend all of that money. They can afford to sell it for less money.

And that's good for individual patients who have to pay for treatments on their own, as is the case for some patients in the U.S. But it's good for people in other countries as well. Lower medical costs are good for everyone.

In the U.S., the question is, will doctors prescribe biosimilars instead of the original? Will insurance companies insist on the biosimilars? 

Whatever the case, it's likely that more of us will see Rituxan biosimilars in the future. 

 

 


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