Study: Bevacizumab Biosimilar Finds Acceptance in First-Line Treatment of mCRC

A retrospective, real-world study (N = 304) of the use of bevacizumab biosimilar (Mvasi, Amgen) in patients with metastatic colorectal cancer (mCRC) suggests physicians are comfortable prescribing the biosimilar in accord with historical use of the reference product (Avastin, Genentech), according to data presented at the ASCO Gastrointestinal Cancers Symposium 2021.

Investigators based that conclusion on evidence that patients who received bevacizumab biosimilar in the first line of treatment for mCRC had demographic and clinical characteristics similar to those for patients treated with the reference product.

In addition, they said, among patients who had prior treatment with bevacizumab reference product (n = 162), most received the biosimilar in the first line of treatment within 28 days, which indicated the switch to biosimilar treatment occurred within the same line of therapy.

Bevacizumab is administered intravenously and works by starving tumors of nourishment by counteracting a protein (vascular endothelial growth factor) that enables tumors to develop blood vessels. Avastin was approved by the FDA in 2006 and European Medicines Agency (EMA) in 2009. Mvasi launched in July 2019 in the United States and was the first biosimilar to Avastin to gain FDA approval.

The biosimilar’s approval was based on a comparative clinical study in non-squamous non–small cell lung cancer, the researchers examined real-world use of bevacizumab biosimilar in mCRC, an approved indication they said is “lacking clinical trial data.”

They identified 304 eligible patients using a database of US electronic medical records from ConcertAI. The patients were adults with a diagnosis of mCRC who had been treated with bevacizumab biosimilar the first year after the product launch.

The respective divide between patients treated at community cancer centers as opposed to academic institutions was 86% vs 14%, respectively. Investigators said 57% of patients treated at community centers had prior bevacizumab compared with 31% of patients at academic centers.

Just over half (53%) of the entire patient cohort had previously received treatment with the reference product. The majority of patients received tumor-marking genetic tests and 53% of tumors had KRAS mutations. The vast majority of tumors were negative for NRAS or BRAF mutations (92% and 86%, respectively). Microsatellite instability (MSI) and mismatch repair (MMR) testing indicated 93% of patients were MSI stable and 93% were MMR proficient.

Demographic characteristics and clinical characteristics, such as Eastern Cooperative Oncology Group performance status, tumor grade, comorbidities, and disease stage at diagnosis, were “comparable” between the 2 groups, according to the authors. Diabetes, chronic obstructive pulmonary disease, and renal disease were the most frequent comorbidities in both groups.

Investigators said 74% of patients who had prior bevacizumab treatment received bevacizumab biosimilar within 28 days of their last treatment with the reference product. Most (83%) experienced no disease progression between their last treatment with the reference product and starting treatment with bevacizumab biosimilar.

The study was conducted with Amgen funding.

Reference

DeClue RW, Rhodes W, Accortt NA, et al. Demographics and clinical characteristics of metastatic colorectal cancer patients treated with bevacizumab-awwb in real-world oncology clinics. Presented at: ASCO GI Cancers Symposium 2021; January 15-17, 2021. Accessed January 29, 2021. https://meetinglibrary.asco.org/record/194175/abstract