Francisco J. Esteva, MD, PhD
After years of discussion and debate, the oncology drug development pipeline is pulsing with biosimilar candidates for at least four of the most widely used monoclonal antibodies in cancer treatment, raising the possibility of price competition at a time of increased anxiety about rising costs.
The 2016 ASCO Annual Meeting featured phase III clinical trial results demonstrating that MYL- 1401O, a biosimilar version of trastuzumab (Herceptin), is equivalent in efficacy and safety to the branded product among patients with HER2-positive metastatic breast cancer (Rugo et al. Abstract LBA503). The Heritage study evaluating MYL- 1401O represents one of the first trials in which an oncology biosimilar has shown similar efficacy, safety, and immunogenicity against the reference product, researchers said.
The findings will help support biosimilar applications for MYL-1401O in the United States and Europe that are expected to be filed within the next several months, according to Mylan NV, a generic and specialty pharmaceutical company developing the drug along with Biocon Ltd.
If approved, MYL-1401O would be the first oncology therapeutic biosimilar available in the United States but industry activity suggests a wave of new agents will be coming to the market in the next several years (Table)
Table. Therapeutic Oncology Biosimilars in Development, Selected Studiesa
aMost trials listed on www.ClinicalTrials.gov.
bListed on Amgen website at http://goo.gl/g1NgCb. CRC indicates colorectal cancer; DLBCL, diffuse large B-cell lymphoma; NHL, non-Hodgkin lymphoma; NSCLC, non–small cell lung cancer; ORR, objective or overall response rate; pCR, pathological complete response.
There are multiple companies working on biosimilar versions of the monoclonal antibodies trastuzumab, rituximab (Rituxan), bevacizumab (Avastin), and cetuximab (Erbitux). The field has attracted large pharmaceutical companies that develop innovative drug portfolios, such as Amgen and Pfizer, along with generic drug makers. Many of the clinical trials are being conducted outside of the United States.
Despite the intensifying activity, however, pharmaceutical industry analysts expect the market for biosimilars to unfold in the United States at a slower pace than the number of projects underway suggests. The price discount for new biosimilars will not be as deep as a comparable new generic would be—and probably not as dramatic as initial projections— and there are important clinical and regulatory issues that remain unresolved, experts say.
Additionally, US oncology specialists and their patients may be reluctant to embrace the new drugs. “We will need a lot of education both for the patients and the physicians to make sure they’re comfortable with this approach and that we communicate this effectively to both patients and physicians,” said Francisco J. Esteva, MD, PhD, director of Breast Medical Oncology at the Perlmutter Cancer Center at NYU Langone Medical Center, during an education session presentation at ASCO.
Notably, ASCO is using its clout with oncology specialists to promote acceptance of biosimilars on a conceptual level. In February, ASCO Connection featured an article exploring what it called misconceptions about biosimilars within the oncology community including concerns about whether the reduced cost would imply a compromise on safety and whether adverse events experienced by patients would be adequately tracked (https://goo.gl/J2sMIP
). “Perhaps the largest hurdle to the integration of biosimilars will be acceptance of these agents by physicians and patient consumers,” wrote Robert M. Rifkin MD, of Rocky Mountain Cancer Centers.
“Toward this end, careful regulatory review during the approval process and rigorous postapproval monitoring of safety and efficacy will be essential in building confidence in the use of these agents.”
Current Biosimilar Landscape
The move to developed biosimilars in oncology therapeutics is part of a broader push across the healthcare spectrum.