A phase Ib/II study has shown that Celltrion’s trastuzumab biosimilar, sold as Herzuma, is effective in patients with human epidermal growth factor receptor 2 positive (HER2+) gastric cancer when used in combination with the antibody treatment pembrolizumab (Keytruda) and chemotherapy.

Herzuma is a monoclonal antibody produced by the South Korean biotechnology company Celltrion and has been sold internationally. It was launched in Canada in September 2019 [1] for example, and in the US in March 2020 [2] under an exclusive partnership between Celltrion Healthcare and Teva Pharmaceutical in October 2016 to commercialize Herzuma in the US and Canada.

The PANTHERA trial was designed to evaluate the efficacy of biosimilar trastuzumab plus chemotherapy and first-line immunotherapy in gastric cancer, based on evidence that the immune system contributes to the therapeutic effects of monoclonal antibodies in treating tumours.

The trial was carried out in Seoul, South Korea and included 43 patients who were treated with pembrolizumab (200 mg IV, day 1), biosimilar trastuzumab (6 mg/kg, day 1), capecitabine (100 mg/m² bid, day 1 to day 14) and cisplatin (80 mg/m², day 1 every 3 weeks). 

The results were presented at the virtual American Society of Clinical Oncology (ASCO) Annual Meeting in May 2020 and showed a significant reduction in tumour size in over 95% of patients. The overall response rate (ORR) of patients was 76.7% and no new adverse effects were noted.

Dr Sun Young Rha, Chief of Medical Oncology at Yonsei University College of medicine in Seoul, commented:

‘Enabling access to first immunotherapy plus chemotherapy combination with biosimilar trastuzumab in the first-line setting will make a real difference to patients. With the costs of oncology treatments being so burdensome, the availability of biosimilar trastuzumab could reduce the overall cost by combination treatment with innovative new drugs and chemotherapy’.

Additional data presented at the Virtual Edition of the 25th European Hematology Association (EHA) Annual Congress suggests that Celltrion’s rituximab biosimilar, sold as Truxima, may be effective in B-cell lymphoma.

Rituximab is a chimeric monoclonal antibody against the protein CD20, which is primarily found on the surface of immune system B cells. Rituximab destroys B cells and is therefore used to treat diseases that are characterized by excessive number of B cells, overactive B cells or dysfunctional B cells. This includes many lymphomas, leukaemias, transplant rejection and autoimmune disorders.

Celltrion’s biosimilar version was the first rituximab biosimilar to be approved in the US [3] and has more recently been approved in Brazil [4].

The data relate to a phase II clinical trial conducted in South Korea between July 2019 and February 2020. The trial tested the efficacy of a regimen of Truxima and two anticancer small molecule drugs, lenalidomide and acalabrutinib – known as the R2A regimen – in relapsed/refractory aggressive B-cell lymphoma.

In the trial, 22 patients were treated with a median follow up of 3.2 months. Patients were treated with rituximab 375 mg/m² (Day 1 IV injection), lenalidomide (20 mg Day 1 to Day 21, once daily), and acalabrutinib (100 mg Day 1 to Day 28, twice daily). Each cycle of treatment was delivered over 4 weeks and each patient received 6 cycles in total. Acalabrutinib maintenance therapy was administered to responders for up to one year.

Thirteen patients underwent disease assessment following treatment, of which 31% experienced complete remission. The ORR was 69%. The six-month progression-free survival rate was 83% and only one patient experienced disease progression after the initial objective response. 

Dose reduction was performed in some cases due to haematologic side effects, but overall the data suggest the regimen is well tolerated in relapse/refractory B-cell lymphoma patients. On the basis of these promising results, it is hoped that adding biosimilar rituximab to the R2A regimen could significantly reduce the costs of treatment.

Mr Hyoung-Ki Kim, Vice Chairman at Celltrion Healthcare said: ‘There is a rising interest towards lenalidomide and acalabrutinib in the haematology community and Celltrion Healthcare is committed to continuing its innovative research into new regimens such as R2A combination therapy to support patient care’.

Related articles
Teva launches rituximab biosimilar Truxima in US

Celltrion to build facility in China and increase new drug output

Celltrion and Juno make biosimilars deal in Australia and Herzuma launches in Iraq

References
1. GaBI Online - Generics and Biosimilars Initiative. Trastuzumab biosimilar Herzuma approved in Canada [www.gabionline.net]. Mol, Belgium: Pro Pharma Communications International; [cited 2020 Sep 11]. Available from: www.gabionline.net/Biosimilars/News/Trastuzumab-biosimilar-Herzuma-approved-in-Canada
2. GaBI Online - Generics and Biosimilars Initiative. Celltrion/Teva launch trastuzumab biosimilar Herzuma in US [www.gabionline.net]. Mol, Belgium: Pro Pharma Communications International; [cited 2020 Sep 11]. Available from: www.gabionline.net/Biosimilars/News/Celltrion-Teva-launch-trastuzumab-biosimilar-Herzuma-in-US
3. GaBI Online - Generics and Biosimilars Initiative. FDA approves first rituximab biosimilar Truxima [www.gabionline.net]. Mol, Belgium: Pro Pharma Communications International; [cited 2020 Sep 11]. Available from: www.gabionline.net/Biosimilars/News/FDA-approves-first-rituximab-biosimilar-Truxima
4. GaBI Online - Generics and Biosimilars Initiative. Celltrion launches Truxima in Brazil [www.gabionline.net]. Mol, Belgium: Pro Pharma Communications International; [cited 2020 Sep 11]. Available from: www.gabionline.net/Biosimilars/News/Celltrion-launches-Truxima-in-Brazil 

Permission granted to reproduce for personal and non-commercial use only. All other reproduction, copy or reprinting of all or part of any ‘Content’ found on this website is strictly prohibited without the prior consent of the publisher. Contact the publisher to obtain permission before redistributing.

Copyright – Unless otherwise stated all contents of this website are © 2020 Pro Pharma Communications International. All Rights Reserved