How biosimilars expand treatment options for patients with retinal disease

"[Biosimilars are] in the interest of the community, the whole community of patients, and in the interest of the health care system,” Dr Lanzetta said. Image credit: ©jittawit.21 – stock.adobe.com

Over the last 15 years, biosimilars have become a major feature of the health care landscape. Physicians in many disciplines, particularly oncology and immunology, have embraced biosimilars. However, access to educational resources on these powerful biologics can be inconsistent, and in turn, some ophthalmologists who could benefit from the adoption of biosimilars are left in the dark.

The real-world application of biosimilars was the focus of discussion for Martin Zinkernagel, MD, PhD, chair of the Department of Ophthalmology at the University Hospital of Bern, Switzerland, and Paolo Lanzetta, MD, professor of ophthalmology and chairman of the Department of Medicine-Ophthalmology at the University of Udine in Italy. In their discussion, the experts addressed several common questions, framed around the phase 3 clinical trial for biosimilar SB11 (BYOOVIZ) from Biogen. SB11 is approved in Europe and the United Kingdom. Like the reference product ranibizumab (Lucentis), SB11 is approved for the treatment of retinal disease including neovascular age-related macular degeneration (nAMD).

Why biologics and biosimilars stand out

Addressing physicians’ levels of familiarity with biosimilars, Dr Lanzetta attributed much of the variation to regulatory discrepancies. “The uptake of biosimilars varies throughout Europe by country and by product,” he said. “Obviously, variation in the uptake of biosimilars [is] influenced by government involvement, reimbursement issues and tender procurement policies.” Recent survey data have revealed gaps in awareness across Europe and in the United States on the efficacy and safety of biosimilars for retinal diseases, Dr Lanzetta said, especially in terms of “real-world data.”

In a clinical application, Dr Lanzetta said, biosimilars may exhibit minor differences from the reference products, but they aren’t considered to have significant impact on the efficacy or safety profile. Typically, the biosimilar and reference medicine must have the same posology and route of administration, with few exceptions, he added.

Dr Lanzetta also said that in the last 10 years, the European Medicines Agency (EMA) has approved the highest number of biosimilars worldwide.¹ “And this means, to us physicians, having both the possibility to have experience on their use in terms of safety and evaluating the efficacy after that,” he explained.

One common misconception about biosimilars is that these therapeutics are interchangeable with the idea of generic medicines. But there is a key indicator that biosimilars are unique: the cost. “While generic medicines are marketed at a significantly lower price than name brand ones, why do we not see the same level of cost savings with biosimilars?” Dr Zinkernagel asked.

Dr Lanzetta explained that biosimilars are developed via a rigorous, complex and highly regulated manufacturing process. “Generics are simple chemical medicines or agents, which is not the case for biosimilars and biologics,” he said. “Unlike generics, biologics, and therefore biosimilars as well, are very complex; they’re very difficult to copy. And the development processes are patented and proprietary to the originators.” The proprietary nature of biologic development, he added, is why biosimilars may have differences from their originators.

Case study: sb11 trial

Prof Zinkernagel and Dr Lanzetta used data from the SB11 phase 3 trial to expand upon the capabilities of biosimilars. Prof Zinkernagel detailed the study: over 700 patients were included in the randomised, double-masked, parallel-group multicentre trial. Over 52 weeks, investigators evaluated the efficacy and the safety profile of this biosimilar SB11 in comparison with monthly ranibizumab for the treatment of nAMD.

“Patients with neovascular AMD were included, [with a] visual acuity range between 20/40 and 20/200,” Prof Zinkernagel said. “[Patients] were randomised in a 1:1 ratio to either have the originator or the biosimilar every 4 weeks from baseline up to week 48.”

Primary end-points were change from baseline in best corrected visual acuity at week 8 and change from baseline in central subfield thickness at week 4. The pre-specified secondary efficacy end-points included longer-term assessments of change from baseline in visual acuity, and the proportion of participants who lost fewer than 15 letters or who gained 15 or more letters in visual acuity from baseline at weeks 24 and 52.

“Other secondary end-points included, of course, change from baseline in central subfield thickness and central retinal lesion thickness at week 24, as well as change from baseline in choroidal neovascularisation [CNV] size and proportion of participants with active CNV leakage seen via OCT [optical coherence tomography] at week 24,” Prof Zinkernagel continued. Describing the results, he said, “When you look at the visual acuity improvements, it’s really equivalent. You have equivalence between the originator and the biosimilar, and the same holds true for a decrease in central retinal thickness. So the curves are basically the same, and also the secondary end-points.”

Prof Zinkernagel also spoke about the immunogenicity outcomes of the SB11 trial, as immunogenicity reactions have been a common problem in past assessments of anti–vascular endothelial growth factor (VEGF) agents. Along with detrimental effects to visual acuity, immunogenicity reactions can also lead to vasculitis and vitritis.

“Now, in this trial, the overall cumulative incidence of anti-drug antibodies, antibodies reacting against this specific drug up to week 52, was very low,” Prof Zinkernagel said. “For the SB11 biosimilar, it was 4.2%, and for the originator it was 5.5%. So very, very similar.”

He also noted that most antibodies were non-neutralising, which generally indicates a weak antibody response. “Furthermore, no statistical or clinically relevant differences in the incidence of anti-drug antibodies and neutralising antibodies were observed between treatment groups at any of the time points,” Prof Zinkernagel explained.

Who benefits from biosimilars?

Dr Lanzetta highlighted the unique potentialities for anti-VEGF therapies as an area where physicians can consider treating patients with a biosimilar. “You can either switch a patient from the originator, obviously, or you can also consider treating with a biosimilar treatment-naive patients who may benefit…from being treated with that reference agent or originator agent,” he said. When to deploy a biosimilar will depend on many factors, including the locality where a patient is being treated. “Europe has different countries, different health care systems,” Dr Lanzetta said. “You may consider treating with the biosimilar patients who may not be strictly adherent to the cost of therapy and the frequency of treatment because of some cost issues.”

Just as education on biosimilars is vital to practitioners, awareness and education resources for patients are vital, too. “We spend a lot of time with our patients in letting them know that biologics did undergo a very rigorous approval process through studies, efficacy and safety studies,” Dr Lanzetta emphasised. This education is vital to getting patients on board with biosimilars, and it sparks enthusiasm about the potential benefits. “Once they do understand that, I think they will be very prone to receive a biosimilar; [it’s] in their interest and in the interest of the community, the whole community of patients, and in the interest of the health care system,” Dr Lanzetta said.

Reference

1. Biosimilars in the EU: information guide for healthcare professionals. European Medicines Agency. Updated December 2, 2019. Accessed October 3, 2023. https://www.ema.europa.eu/en/documents/leaflet/biosimilars-eu-information-guide-healthcare-professionals_en.pdf

Editor’s note: A prior version of this article contained a misspelling of the product name BYOOVIZ. It has been corrected. We regret the error.