(HCC), according to findings from an open-label phase 2 clinical trial published in The Lancet Gastroenterology and Hepatolgy.
The study compared the anti-PD1 antibody nivolumab (Opdivo, Bristol Myers Squibb) alone and nivolumab plus the anti-CTLA-4 antibody ipilimumab (Yervoy, Bristol Myers Squibb) among patients with resectable disease at a single center in Sweden. The treatments were found to be “safe and feasible in patients with resectable hepatocellular carcinoma,” wrote researchers who were led by Ahmed O. Kaseb, MD, a medical oncologist with MD Anderson Cancer Center, Houston.
The rate of 5-year tumor recurrence following HCC resection can be as high as 70%, and there are no approved neoadjuvant or adjuvant therapies.
Immune checkpoint therapy has not been well studied in early-stage HCC, but it is used in advanced HCC.
The combination of PDL1 blockade with atezolizumab and VEGF blockade with bevacizumab, is currently a first-line treatment for advanced HCC. “Checkpoint inhibitors targeting PD1 and PDL1 and CTLA4 are active, tolerable, and clinically beneficial against advanced HCC,” according to researchers writing in a Nature Reviews article published in April 2021.
There are other promising immunotherapies under study for HCC, such as additional checkpoint inhibitors, adoptive cell transfer, vaccination, and virotherapy.
Small study of 27 patients
The Lancet study included 27 patients (64 years mean age, 19 patients were male). Twenty-three percent of patients on nivolumab alone had a partial pathological response at week 6, while none in the combination group had a response. Among 20 patients who underwent surgery, 3 of 9 (33%) and 3 of 11 (27%) in the combination group experienced a major pathological response. Two patients in the nivolumab and three patients in the combination group achieved a complete pathological response.
Disease progression occurred in 7 of 12 patients who were evaluated in the nivolumab group, and 4 of 13 patients in the combination group. Estimated median time to disease progression in the nivolumab group was 9.4 months (95% confidence interval, 1.47 to not estimable) and 19.53 months (95% CI, 2.33 to not estimable) in the combination group. Two-year progression-free survival was estimated to be 42% (95% CI, 21%-81%) in the nivolumab group and 26% (95% CI, 8%-78%, no significant difference) in the combination group.
Among 20 patients who underwent surgery, 6 patients had experienced a major pathological response. None of the 6 patients had a recurrence after a median follow-up of 26.8 months, versus 7 recurrences among 14 patients without a pathological response (log-rank P = .049).
Seventy-seven percent of patients in the nivolumab group experienced at least one adverse event (23% grade 3-4), as did 86% in the combination group (43% grade 3-4, difference nonsignificant). No patients delayed or canceled surgery because of adverse events.
Patients who had a major pathological response on the combination treatment had higher levels of immune infiltration versus baseline values. Those who had complete pathological responses in the nivolumab group had high infiltration at baseline. Those results imply some optimism for further study. “These data suggest that, with the immune-priming ability of anti–CTLA-4 treatment, nivolumab plus ipilimumab was able to generate a major pathological response even in tumours that had low immune infiltration at baseline,” the authors wrote.
The study was limited by its open-label nature and small sample size, and it was conducted at a single center.
The study was funded by Bristol Myers Squibb and the National Institutes of Health. Dr. Kaseb reports consulting, advisory roles or stock ownership, or both with Bristol-Myers Squibb.