The US Is Entering Round 2 of Biosimilar Activity, Says Cardinal Health’s Oskouei

One of the key promises of biosimilars is to reduce costs, and right now the drugs that either have biosimilars approved or in the pipeline are some of the most expensive on the market, said Sonia Oskouei, PharmD, vice president, biosimilars, Cardinal Health, during a session at Asembia’s Specialty Pharmacy Summit, held May 2-5 in Las Vegas, Nevada.

At the beginning of her presentation, Oskouei showed a slide with the top 20 drugs by overall expenditure in 2021. At the top was Humira, which faces competition from at least 7 adalimumab biosimilars in 2023. Also in the top 10 were Lantus (insulin glargine), which already has 2 approved biosimilars, and Enbrel (etanercept), which also has 2 approved biosimilars, although they won’t come to market until 2029.

Other drugs in the top 10 that don’t have approved biosimilars yet, but that have products in the pipeline are Stelara (ustekinumab) and Keytruda (pembrolizumab).

The latest estimates for how much biosimilars could save show that aggregate savings for biosimilars could exceed $133 billion by 2025, she said. In 2020, biosimilars drove $8 billion in savings.

The oncology space has been hugely successful for biosimilars. Not only do a majority of FDA-approved biosimilars have oncology indications (17 of 35), but adoption has been strongest among the oncology biosimilars. Filgrastim biosimilars have reached 92% market share, bevacizumab biosimilars have 77% market share, rituximab biosimilars have 72% market share, and trastuzumab biosimilars have 61% market share.

“Although there's been successes in certain areas, there are still barriers to adoption, broadly speaking,” Oskouei said.

Infliximab biosimilars have only reached 37% market share despite the first infliximab biosimilar launching in 2016, and the sole epoetin alfa biosimilar has only reached 55% despite launching in 2018.

Cardinal Health surveys have gauged provider perceptions and experience with biosimilars and found oncologists were the most comfortable. Two-thirds of oncologists said they both feel comfortable starting new patients on biosimilars and switching existing patients from the originator product to a biosimilar.

In comparison, only 11% of rheumatologists said they were comfortable switching existing patients and 42% were comfortable starting new patients on biosimilars instead of the originator. In addition, 25% of ophthalmology prescribers said they are not likely to prescribe a biosimilar for any patient.

“So, you can see in these new therapeutic areas, there's greater hesitation with even utilizing these biosimilars at all,” Oskouei said.

The future pipeline for biosimilars includes agents for new therapeutic areas. Some examples include:

• Eylea, which treats age-related macular degeneration, macular edema, and diabetic retinopathy, could see 7 aflibercept biosimilars in 2023 and 2024
• Stelara, which can treat plaque psoriasis and psoriatic arthritis, could have 5 ustekinumab biosimilars in 2023 and 2024
• Simponi, which treats rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, and ulcerative colitis, could have a golimumab biosimilar in 2024
• Prolia, which can treat osteoporosis, hypercalcemia, and bone problems in patients with cancer, may have 5 denosumab biosimilars in 2024 and 2025

Overall, the number of biologics facing biosimilar competition will more than double by 2026 based on what is in the pipeline.

“It's like we've had round 1 of biosimilar activity in the United States and now we're about to enter round 2, which is this whole expansion of therapeutic area of product types,” Oskouei said.

Part of round 2 is when the adalimumab biosimilars come market to in 2023. She called it a “monumental year” because Humira is the top selling drug in the world. Amgen’s product, Amjevita, will launch first in January 2023 and have a 6-month lead on the rest of the approved biosimilars. And there are more adalimumab biosimilars seeking approval.

Cyltezo is the only adalimumab biosimilar that was granted interchangeability status by the FDA, but others are seeking the designation.

Humira has a unique situation among the products with biosimilars. When it originally launched, it was a low-concentration version, but AbbVie submitted a supplemental biologics license application for a high-concentration, citrate-free version. The approved biosimilars are all for the low-concentration version, but several manufacturers are seeking to develop high-concentration versions.

There is a debate about the interchangeability for adalimumab biosimilars, Oskouei said. If an interchangeable adalimumab biosimilar is based on the low-concentration version, is it also interchangeable with the high-concentration version?

In addition to the 7 adalimumab biosimilars that have been approved but kept off the market so far because of patent challenges and litigation, 2 etanercept biosimilars have been approved but are unable to launch in the United States. Although biologics exclusivity is only supposed to last 12 years, Humira and Enbrel have both been able to extend this exclusivity. By the time the adalimumab biosimilars come to market in 2023, Humira will have had exclusivity for more than 20 years. If the etanercept biosimilars stay delayed until a 2029 launch, then Enbrel will have had exclusivity for more than 30 years, Oskouei noted.

“And so, the patent process and these exclusivity periods really can have a significant role on when these products come to market,” she said. “In fact, this is what's driving quite a bit of policy discussions, economists’ discussions on how can we bring lower-cost, high-quality alternatives to market quicker and make sure that any exclusivity period granted to an innovator product is on the basis of true innovation vs seeking to delay competition.”