Trio of biosimilars have good showing

Funding Mylan sponsored the HERITAGE trial. Disclosures Dr Rugo disclosed that she receives travel, accommodations, and/or expenses from Mylan. Source Manikhas A et al. Biosimilar trastuzumab-dkst monotherapy versus trastuzumab monotherapy after combination therapy: Toxicity, efficacy, and immunogenicity from the phase 3 Heritage trial. ASCO 2018, Abstract 110. https://meetinglibrary.asco.org/record/161572/abstract. Clinical trial registry number NCT02472964 https://clinicaltrials.gov/ct2/show/NCT02472964
 

Filgrastim biosimilar

Investigators led by Nadia Harbeck, MD, PhD, head of the Breast Center and chair for Conservative Oncology in the department of OB&GYN at the University of Munich (Germany), compared efficacy of filgrastim-sndz (Zarxio), a biosimilar of filgrastim (recombinant granulocyte colony-stimulating factor, or G-CSF), in a trial population with that of a real-world population of women receiving chemotherapy for breast cancer.

Data for the former came from PIONEER, a phase 3, randomized, controlled trial among patients with nonmetastatic breast cancer undergoing docetaxel, doxorubicin, and cyclophosphamide (TAC) chemotherapy in the neoadjuvant or adjuvant setting (Ann Oncol. 2015;26[9]:1948-53). Data for the latter came from MONITOR-GCSF, a postmarketing, open-label, observational cohort study among patients from 12 European countries receiving chemotherapy for various solid and hematologic malignancies (Support Care Cancer. 2016;24[2]:911-25).

Dr Harbeck and her colleagues compared 217 women who had nonmetastatic breast cancer from the trial with 466 women who had any-stage breast cancer (42% metastatic) from the real-world cohort.

Results showed that the 6.2% rate of chemotherapy-induced febrile neutropenia in any cycle seen in the real-world population was much the same as the 5.1% rate seen previously in the trial/biosimilar population. Findings were similar for temperature exceeding 38.5°C in any cycle: 3.4% and 5.6%, respectively. The real-world population had a lower rate of severe neutropenia than did the trial population (19.5% and 74.3%) and higher rates of infection (15.5% and 7.9%) and hospitalization caused by febrile neutropenia (3.9% and 1.8%). Findings were essentially the same in cycle-level analyses.

The real-world cohort had many fewer any-severity safety events of special interest than did the trial cohort, such as musculoskeletal/connective tissue disorders (20 and 261 events, respectively) and skin/subcutaneous tissue disorders (5 and 258 events). “Seeing these data, you have to keep in mind that the patients received totally different chemotherapy. TAC chemotherapy has a lot of chemotherapy-associated side effects,” Dr Harbeck noted. “The other thing is that MONITOR was a real-world database, and one could assume that there is some underreporting of events that are not directly correlated to the events that are of particular interest.”

Additional results available only from the trial showed that no patients developed binding or neutralizing antibodies against G-CSF.

“From a clinician’s point of view, it is very reassuring that we did not see any other safety signals in the real-world data than we saw in the randomized controlled trial and the efficacy was very, very similar,” Dr Harbeck commented. “Having seen the discrepancies in the data, I think it’s important to have randomized controlled trials to assess and monitor AEs for registration purposes and real-world evidence to reflect the daily clinical routine,” she concluded.
 

Funding Sandoz sponsored the PIONEER and MONITOR-GCSF trials. Disclosures Dr Harbeck disclosed that she has a consulting or advisory role with Sandoz. Source Harbeck N et al. Comparison of efficacy and safety of biosimilar filgrastim in a RCT (PIONEER) and real-world practice (MONITOR-GCSF). ASCO 2018, Abstract 111. https://meetinglibrary.asco.org/record/161688/abstract. Clinical trial registry number NCT01519700 https://clinicaltrials.gov/ct2/show/NCT01519700