Biosimilars as Effective as Reference Biologics for Cancer Treatment

Image of vials.
Image of vials.
The biosimilars proved as effective as the original biologics in all cancers studied.

Biosimilars have comparable efficacy to reference biologics for the treatment of several cancer types, according to a meta-analysis published in JAMA Oncology.1

For this study, researchers identified 31 trials published through April 2021 that compared the efficacy of a cancer biologic with that of a biosimilar.

The trials encompassed 3 biologics—bevacizumab, trastuzumab, and rituximab—and 28 unique biosimilars, 10 of which have been approved by the US Food and Drug Administration (FDA).

The biosimilars proved as effective as the original biologics in all cancers studied.

“At least for these 3 drugs, all the available evidence suggests that the biosimilars work just as well as the original biologic products, which should hopefully help if there is remaining skepticism on that question from physicians and patients based on concerns about safety or effectiveness,” said study author Aaron Kesselheim, MD, of Brigham and Women’s Hospital in Boston. 

Dr Kesselheim and colleagues noted that the biosimilar comparison trials were well designed and larger than the 6 trials that supported the FDA approvals of the reference biologics. The comparison trials included a mean 397 patients, compared with a mean 302 patients in the reference trials.

Additionally, the comparison trials all had a randomized design, and most were double blind. Only half of the reference studies were randomized clinical trials, and most were open label. 

Among the comparison trials, 11 compared a biosimilar with bevacizumab, 6 of them for patients with non-small cell lung cancer and 5 for patients with metastatic colorectal cancer.

There were 9 comparison trials for trastuzumab involving patients with either metastatic (4 trials) or early (5 trials) ERBB2-positive breast cancer.

Of the 11 comparison trials for rituximab, 7 enrolled patients with follicular lymphoma, 3 diffuse large B-cell lymphoma, and 1 chronic lymphocytic leukemia.

Although the researchers did not analyze the safety data from the comparison trials, Dr Kesselheim expects that safety outcomes would not differ between the biologics and biosimilars.

An earlier meta-analysis of trials published through 2018 that compared bevacizumab, trastuzumab, and rituximab with biosimilars reported comparable efficacy and safety outcomes.2

“It’s important to continue to ensure that we follow these drugs in their routine clinical use and make sure that the expectations are met” in terms of both safety profiles and survival outcomes associated with biosimilars, Dr Kesselheim noted.

“The [new] study is an additional reassurance that some people may need,” said Katherine H.R. Tkaczuk, MD, of the University of Maryland School of Medicine in Baltimore, who was not involved in the study.

Dr Tkaczuk noted that she routinely uses biosimilars in her practice and has become confident in their efficacy and safety. However, she added that “I still hear from patients that they don’t want a ‘generic’ (as biosimilars are still sometimes called), but that is extremely rare.”

Disclosures: Dr Kesselheim and Dr Tkaczuk reported having no relevant conflicts of interest.


  1. Bloomfield D, D’Andrea E, Nagar S, Kesselheim A. Characteristics of clinical trials evaluating biosimilars in the treatment of cancer: A systematic review and meta-analysis. JAMA Oncol. 2022;e217230. doi:10.1001/jamaoncol.2021.7230
  2. Yang J, Yu S, Yang Z, et al. Efficacy and safety of anti‐cancer biosimilars compared to reference biologics in oncology: A systematic review and meta‐analysis of randomized controlled trials. BioDrugs. 2019;33(4):357-371. doi:10.1007/s40259-019-00358-1

This article originally appeared on Cancer Therapy Advisor