A REFLECT study, a phase 3 open-label, multicenter noninferiority trial, showed the efficacy of a multi-kinase inhibitor, Lenvatinib, which was published in the Lancet journal (
11). Patients treated with Lenvatinib, which met the study's primary criteria of non-inferiority, had longer median OS (13.6 months) than sorafenib (12.3 months). In August 2018, it was approved by the FDA as a first-line treatment drug for patients with unresectable advanced HCC. More importantly, the REFLECT trial excludes patients with bile duct invasion, main PVTT, or more than 50 % intrahepatic lesions.
Checkmate 040 is a multi‐center, open‐label, phase I/II study in which Nivolumab, as a complete human immunoglobulin G4 immune checkpoint inhibitor antibody in several cancers, was used for advanced HCC for both sorafenib‐naïve and ‐experienced patients. And the results showed only 29% (sorafenib‐naïve) and 18% (sorafenib‐experienced) patients demonstrated grade 3 - 4 AEs after Nivolumab treatment, indicating it was a safe and well-tolerated drug. In addition, as a second-line treatment for advanced HCC, Nivolumab was granted by the FDA but not EMA or several other global agencies (
7). Similarly, an open-label and phase III clinical trial CheckMate 459 is also used to evaluate the efficacy of head-to-head Nivolumab versus sorafenib for advanced HCC patients as the first-line treatment. However, this study did not reach the intended primary endpoint; that is, Nivolumab did not exhibit an improvement in OS when compared to sorafenib (
12).
Basic studies have shown that vascular endothelial growth factors can inhibit the immune function of the tumor, and anti-angiogenic drugs might locally improve the immune microenvironment inhibition of the tumors, suggesting a synergistic effect of anti-angiogenic drugs and immune checkpoint inhibitors (
13). IMbrave150 is an open-label, phase 3 clinical trial for unresectable HCC patients to evaluate the efficacy of atezolizumab + bevacizumab versus sorafenib, which revealed decreased hazard ratio of death treated with atezolizumab-bevacizumab (OS rate at 12 months: 67.2%, median PFS: 6.8 months) when compared with sorafenib (OS rate at 12 months: 54.6%, median PFS: 4.3 months) (
14). Our results showed that the OS rate at 12 months was 42.8%, the median OS of 8.7 (3.7 - 36) months, and the median PFS of 5.7 (2.1 - 36) months. A phase Ib study KEYNOTE 524 expanding the sample size was reported at ASCO Congress in 2020, which evaluated the use of Lenvatinib in combination with pembrolizumab for unresectable HCC, and the resulted showed that ORR, DCR, and mPFS were 46%, 88%, and 9.3 months, respectively (
15). There were only a few HCC cases that underwent treatment with Nivolumab plus Lenvatinib (
16). One ongoing open-label phase Ib study, Study117, was the only study that used Nivolumab combined with Lenvatinib in the treatment of unresectable HCC. Preliminary results of the American Society of Clinical Oncology Gastrointestinal Cancers Symposium 2020 ASCO (GI) included 30 patients, wherein 17 cases were of BCLC-B, and 13 cases were of BCLC-C. According to the study on salvage treatment for recurrent HCC, Kim et al. confirmed that 66 patients (93%) achieved CR after proton beam therapy (
17). Lou et al. found that after hypofractionated radiotherapy (HFRT), 22.7% of patients achieved CR, 73.3% achieved PR, 4.0% had SD, and there were no cases of PD (
18). In our research, the results showed that there were 3 (10%) patients who achieved CR, 20 (66.7%) patients had a PR, ORR was found in 76.7% of patients, and the DCR was 96.7%.
At present, second-line treatments for advanced HCC mainly include regorafenib, cabozantinib, and ramucirumab. The emergence of these drugs has improved the dilemma of first-line resistance, but the ORR remains unsatisfactory. The phase III clinical data of second-line treatments for advanced liver cancer with Nivolumab and pembrolizumab showed no survival benefit. In Western countries, the third-line treatment of liver cancer is considered the best supportive therapy. In fact, due to the advent of immune drugs and targeted drugs, the survival time of HCC patients has increased. For patients with good liver function and physical fitness scores, targeted drugs combined with immunotherapy can be used.
For recurrent HCC, there is no research report on the combination of immune checkpoint inhibitors and targeted drugs used in second or third-line therapy. The literature on the combination therapy of Nivolumab and Lenvatinib to treat HCC is sparse, let alone after first-line or even multi-line treatment failure. The researchers in our center enrolled 6 patients with recurrent HCC from China, and all had a history of hepatitis B cirrhosis, Child-Pugh stadium A, and BCLC stage C. After first-line treatment or even multi-line treatment failure, all the patients received treatment with Nivolumab plus Lenvatinib. Patient NO.1 received sorafenib, apatinib, and axitinib successively, and patient NO.5 received sorafenib and Apatinib before the combination therapy of Nivolumab and Lenvatinib. HCC patients with PVTT are prone to liver metastasis and portal hypertension, and PVTT is one of the factors for the poor prognosis of HCC. Therefore, patients with PVTT are excluded from clinical studies such as REFLECT. In our cohort, all patients had PVTT, and the combination of Nivolumab and Lenvatinib achieved satisfactory curative effects (3 cases showed complete remission, and 20 cases were stable) in the absence of serious drug side effects. Several risk factors in all 28 patients were analyzed, and according to their experience in radiotherapy for PVTT, they had a longer survival rate. Patient No. 5, who was evaluated to have progressive disease, did not receive PVTT external irradiation. Patient NO.2, who was assessed to achieve complete remission, received PVTT external irradiation before the combination therapy of Nivolumab and Lenvatinib. The rest of the patients with stable disease received PVTT external irradiation during the combination therapy. Studies have proved that the complications caused by PVTT are considered a common cause of death in HCC patients. Therefore, radiotherapy with PVTT can prolong the survival rate and improve liver blood perfusion and liver function, thus providing a basis for systemic treatment (
19). Whether early PVTT external irradiation intervention is more conducive to survival needs to be further explored.
The side effects of immunotherapy and targeted drugs are different from those of chemotherapy. HCC treatment with immune checkpoint inhibitors demonstrated a substantial increase in AST/ALT levels when compared with other solid tumors (
20). Other common side effects included rash, lipase increase, and amylase increase (
21). The side effects associated with Lenvatinib treatment mainly include hyperbilirubinemia, hypertension, and diarrhea, and the occurrence probability of grade 1 - 2 hyperbilirubinemia is 60%, and that of grade 3 - 4 hyperbilirubinemia is 20% among these patients. Furthermore, the rate of hyperbilirubinemia of the CP-B group was higher than that of the CP-A group (
22).
The side effects associated with Nivolumab and Lenvatinib include liver function lesions; however, the effects of combination therapy on bilirubin are unknown. Among the 28 patients in our study, 18 patients developed grade 1 hyperbilirubinemia, 13 patients returned to normal after terminating the medication and nursing support, and 5 patients failed to continue the treatment due to a continuous increase in bilirubin because of liver tumor progression. In our study, 9 patients developed hypertension, which is considered a common side effect of Lenvatinib, and was cured by an anti-hypertensive drug. Both checkpoint inhibitors and Lenvatinib were associated with the side effects of diarrhea, which was reported in 5 patients in this study and treated with glucocorticoid therapy. In general, the side effects associated with combination therapy of Nivolumab and Lenvatinib on patients in the treatment of HCC were controllable, and no grade 3 - 4 side effects were observed.
However, there are still several limitations demonstrated as follows: Firstly, this is a retrospective study, and bias in patient selection could exist. Secondly, a larger sample size was needed for further investigation.
As a salvage treatment of patients with advanced HCC, the practical experience of Nivolumab and Lenvatinib combination after first-line or even multi-line treatment was proved to be efficacious and safe.