Optivo's clinical results for Koreans with gastric cancer

'Improved overall survival"

Subgroup analysis involving 291 Korea patients…lowered the disease progression risk by 47%↓

The first immunotherapy to receive reimbursement to treat HER2-negative gastric cancer

Product photo of the immunotherapy Optivo.

 

Optivo, an immunotherapy used to treat certain types of cancer, showed a positive result in gastric cancer clinical trials that involved Koreans.

 

The study demonstrated a 47% reduction in the disease progression and death risk compared to conventional therapies.

 

According to industry sources on November 6th, Bristol Myers Squibb (BMS) and Ono Pharmaceutical have recently presented the subgroup analysis results from Phase 3 'ATTRACTION-4,' evaluating Optivo as a treatment for East Asian patients.

 

The clinical trial involved 724 patients with HER2-negative gastric cancer, including 291 Korean patients.

 

The study evaluated Optivo in combination with platinum-based chemotherapy as a first-line treatment for patients compared to a combination therapy of placebo plus platinum-based chemotherapy.

 

Based on the clinical result, Optivo combination therapy's benefit of improving progression-free survival (PFS) was prominent in the Korean patient group compared to those from other countries.

 

In detail, the Korean subgroup's median PFS was 14.8 months for Optivo combination therapy and 8.3 months for placebo, showing 47% lower disease progression and death risk with Optivo combination therapy.

 

The objective response rate (ORR) was 54.7% for the Optivo combination therapy group, which was higher than the placebo group's.

 

The median duration of response (DOR) was 16.0 months for the Optivo combination therapy group, which was longer than the 9.9 months for the placebo group.

 

In the total patient group, about 80% of the patients who showed complete response (CR) in the Optivo combination therapy group survived over three years.

 

New safety-related adverse reactions associated with Optivo combination therapy had not been reported.

 

In a retrospective clinical analysis conducted in Asan Medical Center involving patients with advanced gastric cancer who also have advanced deficient mismatch repair (dMMR), patients treated with Optivo combination therapy had a 12-month PFS of 69.4%, which was longer than 20.6% for the placebo group.

 

"The subgroup analysis from the ATTRACTION-4 study, which enrolled many Koreans, showed that Optivo combination therapy yielded positive data during about three years of follow-up.

 

This study results support the treatment effects of Optivo combination therapy, currently listed as a reimbursable first-line treatment for HER2-negative advanced or metastatic gastric cancer," Hyung-Don Kim, a Professor of the Department of Oncology at Asan Medical Center in Seoul, said.

 

Optivo is the only reimbursable drug among immunotherapies…has been established as a standard therapy In South Korea, Optivo was approved in June 2021 as a first-line treatment in combination with fluoropyrimidine- and platinum-containing chemotherapy for patients with advanced or metastatic gastric adenocarcinoma, gastroesophageal junction (GEJ) adenocarcinoma, or esophageal adenocarcinoma.

 

It was listed for reimbursement last year.

 

The average OS was below 1 year for HER2-negative patients, about 80% of advanced·metastatic cancer, who received conventional chemotherapy as a first-line treatment.

 

Compared to immunotherapy for cancer, several targeted therapies used in clinical trials as a first-line treatment had not shown significant clinical benefits.

 

The treatment practices for HER2-negative advanced gastric cancer started to change following the introduction of a treatment strategy of using an immunotherapy agent in combination with conventional chemotherapy.

 

Optivo is now established as a standard therapy after becoming the first immunotherapy to win approval for the indication to treat advanced·metastatic gastric cancer as a first-line treatment in combination with chemotherapy.

 

The basis for Optivo combination therapy used as a first-line treatment of advanced gastric cancer was the Phase 3 CheckMate-649 study, which showed relatively high ORR and longer DRR compared to single chemotherapy in all patient groups, including patients with below PD-L1 CPS 5.

 

Such treatment benefits were repeated in the fourth-year follow-up results presented at the ASCO Gastrointestinal (GI) Cancers Symposium (ASCO GI), held in January.

 

The clinical results showed that the Optivo combination therapy group's below CPS 5 patient group had an ORR of 55%.

 

Optivo combination therapy provided an OS benefit for the patient group accompanying microsatellite instability-high (MSI-H) regardless of the PD-L1 expression rate.

 

"Gastric cancer is a type of cancer with the highest prevalence in South Korea, but Korean patients faced difficulties because of limited treatment option availability," Professor Kim said.

 

"As Optivo combination therapy has demonstrated OS extension in HER2-negative gastric cancer as the first first-line combination therapy, it is meaningful because it provides a treatment option with long-term survival goal." "With reimbursement listing, many patients could benefit from Optivo combination therapy over a year.

 

It might have brought positive changes to the survival rate of advanced or metastatic gastric cancer," Professor Kim added.