As Reassuring Data on Anticancer Biosimilars Grow, ESMO Ups Its Biosimilar Education

The European Society for Medical Oncology (ESMO) 2018 Congress, held October 19-23, 2018, in Munich, Germany, featured multiple presentations on biosimilars in oncology, all of which are contributing to the body of evidence that points to the safety and efficacy of these products.

Specifically, one study¹ closely investigated the efficacy of the trastuzumab biosimilar SB3, approved in the European Union and sold as Ontruzant, with the reference product in patients with early breast cancer (EBC).

The study enrolled 800 total patients, with 402 given the biosimilar and 398 given the reference trastuzumab. Patients were treated for 8 cycles concurrently with chemotherapy. Patients underwent surgery, and then 10 more cycles of SB3 or the reference.

The primary endpoint was breast pathologic complete response (bpCR) rates, which were measured at 51.7% for SB3, and at 42.0% for the reference with an adjusted difference of 10.7% (95% CI, 4.13-17.26).

Overall, the researchers found that the analysis results of bpCR, total pathologic response rate, and overall response rate leaned toward greater efficacy in patients treated with SB3 compared with the reference product.

In another study,² researchers conducted a systematic review to examine whether demonstrating bioequivalence in terms of efficacy is different in EBC versus metastatic breast cancer (MBC) when patients are treated with a biosimilar trastuzumab versus the reference product.

In total, researchers identified 8 phase 3 clinical trials for 6 proposed biosimilars. Of these, 4 were conducted in EBC, and 4 were in MBC. In all trials, the proposed biosimilars were found to be equivalent to the reference in terms of efficacy. Two biosimilars showed equivalent efficacy in both the EBC and MBC settings.

Regardless of clinical setting, all biosimilars analyzed demonstrated equivalent efficacy to reference trastuzumab.

Despite such reassuring data for biosimilars, however, many stakeholders have noted that lack of provider education on biosimilars is holding back progress with uptake of these products.

Concurrently with the meeting, ESMO published a new paper³ on the integration of biosimilars into routine oncology practice. The paper reports that, when questioned about their knowledge of and comfort with biosimilars, many oncologists exhibited only “moderate confidence” in their understanding of key concepts related to biosimilar drug development and use. Nearly 87% of respondents said that they need more educational activities on the subject.

The paper also found that extrapolating the use of a biosimilar to all indications approved for the reference product seemed to be the most common misunderstanding among physicians, nurses, and patients alike.

“It is a very difficult concept to explain outside of the regulatory setting,” said Elena Wolff-Holz, MD, of the European Medicines Agency. “This is what we educational activities should focus on—not just for oncologists, but for all healthcare professionals and for patients,” said Josep Tabernero, MD, PhD, MSc, president of ESMO.

Among ESMO’s attempts to provide such education are its position paper on using biosimilars and its multistakeholder discussion forums held both at this year’s congress and the 2017 meeting.

References

1. Castan J, et al. Subgroup analyses of efficacy from a phase 3 study comparing SB3 (trastuzumab biosimilar) with reference trastuzumab in early breast cancer patients. Presented at the European Society for Medical Oncology (ESMO) 2018 Congress, October 19-23, 2018; Munich, Germany. Abstract 217P. https://cslide.ctimeetingtech.com/esmo2018/attendee/confcal/session/calendar?q=217P&c=abs.

2. Rugo H, et al. Settings-based efficacy comparison of trastuzumab biosimilars in breast cancer: a systematic literature review. Presented at the European Society for Medical Oncology (ESMO) 2018 Congress, October 19-23, 2018; Munich, Germany. Abstract 324P. https://cslide.ctimeetingtech.com/esmo2018/attendee/confcal/session/calendar?q=217P&c=abs.

3. E Wolff-Holz, J Garcia Burgos, R Giuliani, et al. Preparing for the incoming wave of biosimilars in oncology. ESMO Open. 2018;3:e000420. doi: 10.1136/esmoopen-2018-000420.