Understanding and using biosimilars

Dr. KircikOne of the only things the dermatology community knows about biosimilar use is that there are many unknowns. Still, biosimilars are on dermatologists’ radars as having the potential to lower the high costs of biologic treatments for chronic skin diseases, including psoriasis.

There also are misperceptions-even among dermatologists-about what biosimilars are and if these drugs can be used to treat patients, according to Leon H. Kircik, M.D., clinical associate professor of dermatology at Indiana University School of Medicine, Indianapolis; clinical associate professor of dermatology at Mount Sinai Medical Center, New York City; and medical director of Physicians Skin Care in Louisville, Ky. who presented “Biosimilars: What You Need to Know” at the Orlando Derm Aesthetic and Clinical conference in Miami, Fla., in January 2017.

Misperception number one

The first misperception is that biosimilars are generic biologics. They’re not, he says.

“You cannot have a generic of a biologic because every biologic is made differently. So, it is important for everybody to understand that biosimilars are not generics,” says Dr. Kircik,

As a result, the approval process for biosimilars is different for that of generics. Biosimilars came about because of the Biologics Price Competition and Innovation Act of 2009, which passed in Congress as a provision of the Affordable Care Act. Biosimilars have an abbreviated licensure pathway, but it’s a different pathway compared to a generic.

“Biopharmaceuticals are biopolymers of organic molecules that are manufactured in living systems. Function is based not only on the amino acid number and sequence but also on posttranslational modification (e.g. glycosylation) that are added by virtue of manufacture in living systems.”

Complexities and blurred lines

The FDA’s definition of a biosimilar, according to Dr. Kircik is, “A biological product that is highly similar to the reference product, notwithstanding minor differences in clinically inactive components. There are no clinically meaningful differences from the reference product in terms of the safety, purity, and potency”

“Those are very vague terms,” Dr. Kircik says.

The first biosimilar (not for use in dermatology), Zarxio [Sandoz], was FDA approved in March 2015. Zarxio is biosimilar to Neupogen (Amgen, filgrastim)¹

More than a year later, the first biosimilar to have dermatologic indications received FDA approval-a biosimilar of infliximab, by the name of Inflectra (Celltrion). Interestingly, Inflectra, a biosimilar to Janssen Biotech’s Remicade, has an indication for psoriasis but no data on dermatologic disease, including psoriasis, Dr. Kircik says.

“They did all the studies in rheumatoid arthritis and ankylosing spondylitis. So, there are no studies on psoriasis or psoriatic arthritis. But the government says that’s ok,” Dr. Kircik says.

The second approval was for a biosimilar for adalimumab, Amjevita (Amgen). The corresponding biologic drug is Humira (Abbvie). Amjevita was studied in psoriasis patients, he says. Still another is etanercept biosimilar, Erelzi (Sandoz). It’s the biosimilar for Enbrel (Amgen). Erelzi also has psoriasis patient data, according to Dr. Kircik, who says he has been involved in studies for several biosimilars.

For the biosimilars that have psoriasis data, the results tend to be similar to their corresponding biologics. That was the case in a study for the adalimumab biosimilar, Amjevita, in which the psoriasis area and severity index (PASI) 75 at week 16 for the biosimilar was 74 percent and, for Humira, was 82 percent. PASI 90 for the biosimilar was 47 percent; for Humira, it was 47 percent, Dr. Kircik says.

Next: Does A equal B?

Does A equal B?

Among the questions that dermatologists will ask regarding biosimilar use is, can they switch patients from a biologic to a corresponding biosimilar?

“Let’s say someone is originally on Humira, can you switch them to adalimumab?” Dr. Kircik says. “It depends on the approval process. Right now, the adalimumab and etanercept biosimilars are not approved as interchangeable drugs. That means that if you have somebody on the original Humira, you are not supposed to switch them to the biosimilar.”

However, you can start as a new patient on the biosimilar.

Another question: Let’s say you have biosimilar B, similar to biologic A, and biosimilar C is similar to biologic A. Can you switch back and forth between biosimilar B and biosimilar C, since they are both similars to biologic A?

“That’s called transitivity. Nobody knows the answer for that,” Dr. Kircik says.

What to do in practice

There are no clear-cut rules and regulations yet when it comes to biosimilars in dermatology, Dr. Kircik says.

When they happen, they’ll happen at the state level, he says.

“For example, in my state of Kentucky, the legislation says that the pharmacist can switch the patient to a biosimilar without telling me and let me know within five business days. In some states, that rule is 72 hours, in some states there’s no rule. In some states, it’s 24 hours. Most states don’t even have the rules yet,” Dr. Kircik says.

The caveat to all this is patents. Even though biosimilars are approved, none of them are going to be able to come to market anytime soon because of the patent wars, according to Dr. Kircik.

Etanercept, the Enbrel biosimilar, is approved by the FDA but the company cannot bring it to market yet because Enbrel is patented for several years.

“Therefore, you can rest assured that for the next couple of years nothing is going to happen. But eventually, it will,” Dr. Kircik says.

If the Affordable Care Act, which includes the biosimilar approval process, goes away, things could still change. But Dr. Kircik says he doubts that will happen because biosimilars are meant to reduce drug costs, he says.

Disclosure: Dr. Kircik has been a speaker, consultant, and investigator or advisory board member for most companies involved in manufacturing biologics or biosimilar products.

References:

¹ FDA approves first biosimilar product Zarxio. http://bit.ly/FDAApproveZarxio