IBI301 (Biosimilar of Rituxan) Meets Primary Endpoints in 2 Clinical Trials in China for B-cell Lymphomas

IBI301, a biosimilar of Rituxan (rituximab), behaves similarly in the body and has a similar efficacy as the original product in patients with B-cell cancers, according to results from two clinical trials in China, IBI301’s co-developers, Innovent Biologics and Eli Lilly, has announced.

“The results of clinical studies of IBI301, a potential biosimilar of rituximab, are encouraging. We hope that the launch of IBI301 in the China market will improve its affordability, so more patients with lymphoma can benefit from the drug,” Michael Yu, founder, CEO, and chairman of Innovent said in a press release.

A biosimilar is a biological medical product that is nearly identical to its original product, but manufactured by a different company after the original product’s patent expires. Biosimilars are usually sold at significantly lower prices.

“Malignant lymphoma is one of the top 10 malignancies in China and incidences thereof are still rising and pose a heavy economic burden for the vast majority of patients. Anti-CD20 monoclonal antibodies are effective treatments for lymphoma. However, currently there is only one approved biosimilar in China,” Yu added.

Innovent Biologics and Eli Lilly‘s IBI301, like Rituxan, is an antibody that targets the CD20 molecule found in healthy B-cells and lymphoma cells. By inhibiting the excessive growth and spread of B-cells, the treatment can alleviate lymphoma symptoms.

However, unlike chemical compounds (which are made through chemical reactions), biological medicines are grown in cells and may show some differences from similarly designed products.

As a result, regulatory agencies require extensive data showing that a biosimilar has equivalent safety and effectiveness, and behaves similarly in the body — in its absorption, distribution, metabolism, and excretion — as the original medicine.

To address that, researchers conducted two separate studies in China comparing IBI301 to Rituxan, in B-cell lymphoma patients. Both studies have met their primary goals.

“We are extremely happy that through the efforts of all investigators, the two key studies have both met the primary endpoints. This has laid a solid foundation for the next steps in the new drug application (NDA) of the biosimilar candidate,” added professor Zhu Jun, Beijing Cancer Hospital.

The CIBI301A201 Phase 1 trial (NCT02945215) was designed to compare the behaviour of the two medicines once inside the body, namely how they were absorbed, distributed, metabolized, and excreted. It included 181 patients with CD20-positive B-cell lymphomas. Secondary measures included safety, tolerability, and immunogenicity (i.e., whether the immune system reacts against the compound).

The CIBI301A301 Phase 3 trial (NCT02867566), on the other hand, aimed to determine if IBI301 had a similar safety and efficacy profile as Rituxan in newly diagnosed diffuse large B-cell lymphomas (DLBCL). It enrolled 420 patients, randomly assigned IBI301 or Rituxan, plus standard CHOP chemotherapy — a combination of cyclophosphamide, doxorubicin, vincristine, and prednisone — as a first-line treatment. Its primary goal is objective response rate, or the proportion of patients with a predefined reduction in tumor size.

While full data has not been disclosed, the companies announced that both trials met their primary objectives, meaning that IBI301 behaves similarly in the body as Rituxan, and leads to a similar proportion of patients responding to treatment. Additional results are expected to be announced in future conferences and publications in scientific journals.

“DLBCL is the most common type of lymphoma in China and rituximab is the standard treatment for DLBCL patients. The launch of a high quality rituximab biosimilar will improve drug accessibility and benefit more patients,” said professor Lugui Qiu from the Blood Diseases Hospital, Chinese Academy of Medical Sciences.

Added Wang Li, senior vice-president of Lilly China and head of Lilly China Drug Development and Medical Affairs: “The results of these studies have significant clinical value and show the outstanding research and development capabilities of Innovent. We hope that IBI301 can be approved soon in order to offer an affordable treatment option for lymphoma patients in China.”