Molecular therapies and precision medicine for hepatocellular carcinoma

TLDR: Treatment advances have been made in the past few years, and further advancements are expected in the near future, including biomarker-driven treatments and immunotherapies, as discussed in this Review.

Abstract: The global burden of hepatocellular carcinoma (HCC) is increasing and might soon surpass an annual incidence of 1 million cases Genomic studies have established the landscape of molecular alterations in HCC; however, the most common mutations are not actionable, and only ~25% of tumours harbour potentially targetable drivers Despite the fact that surveillance programmes lead to early diagnosis in 40–50% of patients, at a point when potentially curative treatments are applicable, almost half of all patients with HCC ultimately receive systemic therapies Sorafenib was the first systemic therapy approved for patients with advanced-stage HCC, after a landmark study revealed an improvement in median overall survival from 8 to 11 months New drugs — lenvatinib in the frontline and regorafenib, cabozantinib, and ramucirumab in the second line — have also been demonstrated to improve clinical outcomes, although the median overall survival remains ~1 year; thus, therapeutic breakthroughs are still needed Immune-checkpoint inhibitors are now being incorporated into the HCC treatment armamentarium and combinations of molecularly targeted therapies with immunotherapies are emerging as tools to boost the immune response Research on biomarkers of a response or primary resistance to immunotherapies is also advancing Herein, we summarize the molecular targets and therapies for the management of HCC and discuss the advancements expected in the near future, including biomarker-driven treatments and immunotherapies

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Molecular therapies and precision medicine for hepatocellular carcinoma
1
Josep M. Llovet
1,2
, Robert Montal
2
, Daniela Sia
1
and Richard S. Finn
3
2
1)Mount Sinai Liver Cancer Program, Division of Liver Diseases, Tisch Cancer Institute,
3
Icahn School of Medicine at Mount Sinai, New York, NY, USA. 2)Liver Cancer Translational
4
Lab, Barcelona Clinic Liver Cancer (BCLC) Group, Liver Unit, Hospital Clinic Barcelona,
5
IDIBAPS, University of Barcelona, Barcelona, Spain. 3)Department of Medicine, Division of
6
Hematology/ Oncology, Geffen School of Medicine, University of California, Los Angeles
7
(UCLA), Los Angeles, CA, USA.
8
Abstract | The global burden of hepatocellular carcinoma (HCC) is increasing and might soon surpass an
9
annual incidence of 1 million cases. Genomic studies have established the landscape of molecular
10
alterations in HCC; however, the most common mutations are not actionable, and only ~25% of tumours
11
harbour potentially targetable drivers. Despite the fact that surveillance programmes lead to early
12
diagnosis in 40–50% of patients, at a point when potentially curative treatments are applicable, almost
13
half of all patients with HCC ultimately receive systemic therapies. Sorafenib was the first systemic
14
therapy approved for patients with advanced-stage HCC, after a landmark study revealed an
15
improvement in median overall survival from 8 to 11 months. New drugs — lenvatinib in the frontline
16
and regorafenib, cabozantinib, and ramucirumab in the second line — have also been demonstrated to
17
improve clinical outcomes, although the median overall survival remains ~1 year; thus, therapeutic
18
breakthroughs are still needed. Immune-checkpoint inhibitors are now being incorporated into the HCC
19
treatment armamentarium and combinations of molecularly targeted therapies with immunotherapies
20
are emerging as tools to boost the immune response. Research on biomarkers of a response or primary
21
resistance to immunotherapies is also advancing. Herein, we summarize the molecular targets and
22
therapies for the management of HCC and discuss the advancements expected in the near future,
23
including biomarker-driven treatments and immunotherapies.
24
Liver cancer is the second leading cause of cancerrelated death globally1 . Hepatocellular carcinoma
25
(HCC) accounts for 90% of primary liver cancers and can be caused by chronic infection with hepatitis B
26
virus (HBV) or hepatitis C virus (HCV), alcohol abuse, and metabolic syndrome related to diabetes and
27
obesity2,3 . In developed countries, surveillance programmes lead to early HCC diagnosis in 40–50% of
28
patients, at a stage amenable to potentially curative treatments2,4,5 . Patients with intermediate-stage
29
HCC are treated with locoregional therapies, whereas those with advancedstage disease can benefit
30
from systemic treatments2 . Overall, ~50% of patients receive systemic therapies at some point during
31
the disease course2,4,5 . In a breakthrough study6 , the multi-target tyrosine kinase inhibitor (TKI)
32
sorafenib, which has anti-angiogenic and anti-proliferative effects, extended the median overall survival
33
of patients with advanced-stage HCC from 8 to 11 months and had a manageable toxicity profile.
34
Sorafenib was the sole systemic therapy approved for the treatment of HCC between 2007 and 2016. In
35
the past year or so, however, improvements in patient outcomes have been demonstrated in
36
randomized phase III trials with lenvatinib7 in the frontline and regorafenib8 , cabozantinib9 , and
37
ramucirumab10 in the second line after disease progression on sorafenib; regorafenib is currently FDA
38
approved in the second-line setting. In addition, immunotherapy with nivolumab — a monoclonal
39
antibody targeting the inhibitory immunecheckpoint molecule programmed cell death protein 1 (PD-1)
40
— led to promising response rates and survival durations in a phase I–II study involving patients
41
previously treated with sorafenib11 and has been granted accelerated approval by the FDA. By contrast,
42
several kinase inhibitors (for example, sunitinib, brivanib, and erlotinib), doxorubicin, and
43
radioembolization with yttrium 90 (90Y) -microspheres failed to improve overall survival in patients with
44
unresectable HCC12.
45

Indeed, HCC is a highly therapy resistant and thus difficult to treat cancer; although systemic therapies
46
have clinical benefits, the improvements in patient outcomes have been modest and incremental. Thus,
47
novel therapies for HCC remain an unmet medical need. In this regard, important insights into the
48
biology of the disease have been obtained through genomic, transcriptomic, and epigenomic studies2,3
49
. In this Review, we analyse the molecular targets and therapies for the management of HCC and
50
highlight the advancements in biomarker-driven treatments and immunotherapies that are expected in
51
the near future.
52
The molecular landscape of HCC
53
Molecular drivers
54
HCC development is a complex multistep process, with 70–80% of cases occurring in the context of
55
established liver cirrhosis2,3 . The natural history of HCC in patients with cirrhosis progresses through a
56
sequence of clinicopathological events starting with the appearance of pre-cancerous cirrhotic nodules
57
(so-called dysplastic nodules), which can ultimately transform into HCC3 . Overall, one-third of patients
58
with cirrhosis will develop HCC during their lifetime, with different rates per year observed according to
59
aetiology2 . The median time between development of cirrhosis and the development of HCC is ~10
60
years13. In the non-cirrhotic liver, HCC can arise principally on a background of HBV infection or
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nonalcoholic steatohepatitis and more rarely through the malignant transformation of hepatocellular
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adenoma, a monoclonal and typically benign lesion14. Malignant transformation from adenomas occurs
63
in <10% of cases and has been associated with TERT and CTNNB1 mutations14. Mature hepatocytes
64
have been identified as the cell of origin for most HCCs; however, a subset of ~20% of HCCs with
65
progenitor cell markers, such as epithelial cell adhesion molecule (EPCAM) and cytokeratin 19 (CK19),
66
can arise from either progenitor cells or dedifferentiated mature hepatocytes15.
67
HCC results from the accumulation of somatic genomic and epigenomic alterations in the tissue of origin
68
over time. In HCCs, an average of 40–60 somatic alterations are detected in protein-coding regions of
69
the genome2,16. Most of these alterations occur in ‘passenger’ genes that are not directly implicated in
70
neoplasia, but a few genomic alterations are considered to be ‘drivers’ involved in activating key
71
signalling pathways for hepatocarcinogenesis. The identification of recurrently mutated genes and copy
72
number alterations through integration of data from whole-exome sequencing (WES) studies and single-
73
nucleotide polymorphism (SNP) array analyses has enabled deciphering of these pivotal pathways,
74
which include telomere maintenance, cell cycle control, WNT–β-catenin signalling, chromatin
75
modification, receptor tyrosine kinase (RTK)–RAS–PI3K cascades, and oxidative stress16–21 (Table 1).
76
Unfortunately, most of the clonal, ‘trunk’ mutations and prevalent drivers (TERT, CTNNB1, TP53, AXIN1,
77
ARID1A, and ARID1B) detected in HCCs are not clinically actionable16 — at least at present. Indeed,
78
reports of WES studies indicate that only ~25% of HCCs harbour alterations that are potentially
79
targetable with existing drugs16. DNA methylation profiling also enabled the discovery of IGF2
80
overexpression and CDKN2A silencing as epigenetic mechanisms of HCC tumorigenesis22.
81
Molecular classifications
82
Integrative molecular analyses involving genomic, transcriptomic, and/or epigenomic profiling of
83
thousands of surgically resected tumours have provided the basis for the molecular classification of HCC
84
subtypes21,23–26. These distinct molecular classes reflect different biological backgrounds with
85
potential implications in patient prognostication and selection for therapies. Specifically, two major
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molecular subtypes of HCC, each encompassing ~50% of patients with this disease, have been proposed:
87
a proliferation class and non-proliferation class3,27,28 (Fig. 1).
88
As their designation suggests, HCCs of the proliferation class are characterized by activation of signalling
89
pathways involved in cell proliferation and survival, such as the PI3K–AKT–mTOR, RAS–MAPK, and MET
90

cascades21,23,24. Chromosomal instability seems to be a driving force in these tumours, with a
91
particular enrichment of TP53 inactivation and FGF19 and/or CCND1 amplifications29. Our group and
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others3,27,28 have proposed that two subclasses exist within the proliferative class: a WNT–TGFβ group
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(also known as S1 tumours) characterized by non-canonical activation of WNT; and a progenitor cell
94
group (also known as S2 tumours) characterized by overexpression of EPCAM, AFP, and IGF2, and a
95
unique DNA hypermethylation signature30 (Fig. 1a). Overall, the proliferation class of HCC is associated
96
with HBV-related aetiology and poor clinical outcomes.
97
The non-proliferation class is more heterogeneous than the proliferative class and might consist of at
98
least three HCC subclasses3,21 (Fig. 1). One clear subclass has been delineated and is characterized by
99
activation of the canonical WNT signalling pathway, often owing to mutation of CTNNB1 (encoding β-
100
catenin)31, and is also associated with higher rates of TERT promoter mutations. From the clinical
101
standpoint, non-proliferation class tumours are associated with alcohol-related and HCV-related
102
aetiologies and better outcomes. These proposed molecular classes have been confirmed and further
103
characterized in the comprehensive molecular analysis of 363 patients with HCC — the largest cohort
104
published to date — reported by The Cancer Genome Atlas (TCGA) Research Network18. The integration
105
of up to 5 other platforms — DNA copy number, DNA methylation, mRNA expression, microRNA
106
(miRNA) expression, and reverse phase protein array (RPPA) assays — for 196 tumours yielded 3
107
subtypes, including a poor prognosis iClust1 subtype with a gene expression profile that closely
108
resembles that of the progenitor cell subclass tumours and a lower-grade iClust2 subtype that shares
109
molecular and pathological characteristics (for example, CTNNB1 mutations and less frequent
110
microvascular invasion) with the non-proliferation class. The third TCGA cluster, iClust3, generated a
111
TP53 signature associated with chromosomal instability and poor prognosis. Beyond tumour cell-
112
intrinsic molecular aberrations, an altered tumour microenvironment (TME) is now recognized as a key
113
enabling factor in the development of HCC32,33. In fact, HCC is a prototypical inflammationassociated
114
cancer attributable to viral hepatitis or steatohepatitis (alcoholic or nonalcoholic). Multiple cell types
115
interact with hepatocytes in the chronically inflamed liver, including lymphocytes, macrophages, stellate
116
cells, and endothelial cells. In this regard, a novel molecular classification of HCC based upon immune
117
status has been proposed34 (Fig. 1b). Through analyses of inflammatory gene-expression profiles,
118
infiltrates, and regulatory molecules, 30% of HCCs could be classified into an ‘immune class’, with high
119
levels of immune cell infiltration, expression of PD-1 and/or programmed cell death 1 ligand 1 (PD-L1),
120
activation of IFNγ signalling, markers of cytolytic activity (such as granzyme B and perforin 1), and an
121
absence of CTNNB1 mutations34. Within this class, two distinct ‘active immune’ and ‘exhausted
122
immune’ subclasses, characterized by markers of an adaptive T cell response or exhausted immune
123
response, respectively, have been identified34. The exhausted immune tumours express many genes
124
regulated by TGFβ, which mediate immunosuppression and T cell exhaustion. An ‘immune excluded
125
class’ accounting for ~25% of HCCs was characterized by T cell exclusion from the TME and CTNNB1
126
mutations34. The immune exhausted class mostly overlaps with the proliferative WNT–TGFβ subclass,
127
whereas the immune excluded class overlaps with the CTNNB1 mutated non-proliferative class. Our
128
group is currently exploring whether the immune active class is associated with responsiveness to
129
immune-checkpoint inhibitors and whether, conversely, the immune exhausted and/ or the immune
130
excluded classes are associated with primary resistance to these agents.
131
Clearly, further research is needed to translate the current knowledge of HCC biology into prognostic
132
and predictive biomarkers in order to guide clinical decisionmaking and, ultimately, improve patient
133
outcomes. In this regard, analysing the molecular landscape of tumour tissues obtained from patients
134
with advancedstage HCC, predominantly through tumour-tissue and liquid biopsy procedures, is of
135
crucial relevance because these are the patients who are actually treated with systemic therapies in
136
clinical trials. Notably, the fact that systemic drugs with demonstrated survival benefits in patients with
137
HCC (sorafenib, regorafenib, lenvatinib, cabozantinib, and ramucirumab) share an — at least partially —
138

anti-angiogenic mechanism of action highlights the importance of this hallmark of cancer, which is
139
mainly promoted by endothelial cells35. Indeed, angiogenic signalling is prominent in all subclasses of
140
HCC36,37 . Understanding how the distinct angiogenic signalling pathways interact with the immune
141
component of HCCs and how mechanisms of resistance to antiangiogenic agents arise could potentially
142
reveal novel therapeutic strategies.
143
Clinical management of HCC
144
Several HCC staging systems have been proposed during the past four decades38–41; however, the
145
Barcelona Clinic Liver Cancer (BCLC) staging classification is the most widely recognized clinical algorithm
146
used for patient stratification and treatment allocation4,5,42. As mentioned previously, in developed
147
countries, 40–50% of patients with HCC are diagnosed at early stages (BCLC stage 0–A), when potentially
148
curative treatments (resection, liver transplantation, or local ablation) are possible4 . These treatments
149
can result in median overall survival durations >60 months4 . Nevertheless, up to 70% of patients
150
undergoing HCC resection or ablation present with disease recurrence within 5 years2 , and no adjuvant
151
therapies tested to date are able to prevent this complication43. Patients with intermediate-stage
152
disease (BCLC stage B) with preserved liver function (Child–Pugh class A without any ascites) can benefit
153
from transarterial chemoembolization (TACE), as reported in two randomized studies comparing this
154
approach with best supportive care44,45 and one meta-analysis46, with estimated median overall
155
survival durations of 25–30 months. No combination of kinase inhibitors (such as sorafenib or
156
brivanib)47–49 with TACE has been shown to provide additive improvements in patient outcomes.
157
Nevertheless, most patients with HCC (>50%) will eventually receive systemic treatments: patients with
158
disease progression after TACE or those who are diagnosed with advanced-stage HCC (BCLC stage C) can
159
benefit from sorafenib6 . More recently, first-line lenvatinib7 and second-line regorafenib8 ,
160
cabozantinib9 , and ramucirumab10 have also been demonstrated to provide survival benefits for
161
patients with advancedstage disease. In clinical trials, the median overall survival durations achieved
162
with these therapies are around 1 year. Nivolumab is another new option in the secondline setting on
163
the basis of the promising response rates and durations observed in the phase I–II trial of this agent11.
164
Patients with end-stage disease (BCLC stage D) should be considered for nutritional and psychological
165
support and appropriate management of pain. In 2018, international guidelines4 have been revised to
166
provide updated recommendations on the treatment of HCC based on levels of evidence, encompassing
167
all major treatments tested in this cancer (Fig. 2).
168
Molecular targeted therapies
169
First-line treatments
170
Most patients with HCC are diagnosed at advanceddisease stages, at which the natural history of the
171
disease carries a dismal prognosis. In this setting, conventional systemic chemotherapy lacks survival
172
benefits. Phase III trials of doxorubicin alone, the PIAF regimen (cisplatin, IFNα2b, doxorubicin, and
173
fluorouracil), and the FOLFOX4 regimen (fluorouracil, leucovorin (folinic acid), and oxaliplatin) all had
174
negative results, in some instances with substantial toxicity50–52. Randomized studies also failed to
175
prove any clinical effects of anti-oestrogen therapies or vitamin D derivatives53,54.
176
Sorafenib. In 2007, results of the phase III SHARP trial6 demonstrated survival benefits with sorafenib
177
versus placebo (median overall survival 10.7 months versus 7.9 months; HR 0.69, 95% CI 0.55–0.87; P <
178
0.001), thus representing a breakthrough in the management of advanced-stage HCC. A similar
179
magnitude of benefit was observed in another phase III study of sorafenib conducted in parallel in Asian
180
patients, mostly with HBV-related HCC55. In these trials, treatment was generally associated with
181
manageable adverse events (AEs), such as diarrhoea (grade 3 in 8–9%), hand–foot skin reactions (grade
182
3 in 8–16%), fatigue (grade 3 in 3%), and hypertension (grade 3 in 2%). Intolerance to sorafenib
183

(treatment discontinuation owing to AEs) typically occurs in 10–15% of patients6,55. The severity of
184
toxicities — particularly hand–foot syndrome — has been associated with better survival outcomes in
185
cohort studies56. A meta-analysis of the two phase III trials testing sorafenib revealed a consistent
186
survival benefit across all clinical subgroups57. The greatest magnitude of the benefit was observed in
187
patients with tumour confined to the liver, those who were HCV-positive, or those with a low
188
neutrophil-to-lymphocyte ratio57. Sorafenib is indicated for patients with well-preserved liver function
189
(Child–Pugh class A) and BCLC stage C disease or BCLC stage B disease that has progressed after
190
locoregional therapy. Of note, the median overall survival of patients with BCLC stage B HCC treated
191
with sorafenib is 15–20 months according to the findings of post-marketing studies58,59. Similarly,
192
surveys conducted in >3,000 patients to evaluate the safety and tolerability of sorafenib in clinical
193
practice reported median overall survival durations of 13.6 months for the Child–Pugh class A group and
194
5.2 months for a Child–Pugh class B group60,61. From the mechanistic standpoint, the efficacy of
195
sorafenib probably results from a balance between targeting cancer cells and cells of the TME: this
196
agent can inhibit up to 40 kinases, including mainly angiogenic RTKs (including VEGF receptors (VEGFRs)
197
and PDGF receptor-β (PDGFRβ)) and drivers of cell proliferation (such as RAF1, BRAF, and KIT)62.
198
Unfortunately, at least partially owing to this pharmacological complexity, no predictive biomarkers of a
199
response to sorafenib have been identified; however, the companion biomarker study conducted within
200
the SHARP trial showed a nonsignificant trend towards a greater survival benefit of sorafenib in patients
201
with tumours harbouring high levels of KIT and low plasma HGF concentrations63. The efficacy of
202
sorafenib in the advanced-stage setting has led to testing of this drug at earlier clinical stages. In the
203
phase II SPACE and phase III TACE 2 placebo-controlled trials involving patients with intermediate-stage
204
HCC47,48, sorafenib plus TACE was safe, but the combination did not improve time to progression (TTP)
205
in a clinically meaningful manner. Similarly, in the adjuvant setting after surgical resection or local
206
ablation (phase III STORM trial)43, sorafenib did not improve recurrence-free survival (RFS) compared
207
with that observed with placebo. A thorough molecular analysis of resected tumours from this trial
208
enabled the design of a multi-gene signature that could be used to identify patients who benefited from
209
adjuvant sorafenib treatment64; however, this biomarker test requires prospective validation. The
210
successful SHARP trial6 provided a framework for trial design that has been implemented in subsequent
211
phase III studies65. The main traits of this design are the selection of an adequate target population:
212
patients with well-preserved liver function (Child–Pugh class A), to minimize the risk of liver failure and
213
death as a result of cirrhosis, and patients with either advanced-stage (BCLC stage C) or intermediate-
214
stage (BCLC stage B) disease that has progressed following TACE, to provide clear results for this clinical
215
stage. Moreover, overall survival was established as the most robust end point to assess efficacy in this
216
population. Surrogate end points, such as TTP, have been associated with inconsistent results and are
217
currently being revisited12. In this regard, use of the modified Response Evaluation Criteria in Solid
218
Tumors (mRECIST), which are based on the concept of viable tumour, generally provides greater
219
sensitivity in the assessment of response than the standard RECIST guidelines66; in phase III trials of
220
sorafenib, objective response rates (ORRs) were 10–15% by mRECIST versus 2–6% by RECIST67. Several
221
phase III trials have failed to demonstrate the superiority of a number of agents over sorafenib in the
222
frontline setting (Fig. 3a). These therapies include brivanib (a selective VEGFR and FGF receptor (FGFR)
223
TKI)68, sunitinib (a multi-target TKI with activity against VEGFRs, PDGFRs, and KIT)69, linifanib (a VEGFR
224
and PDGFR TKI)70, and erlotinib (an EGFR inhibitor)71. The reasons for the disappointing phase III trial
225
results include overinterpretation of marginal antitumour efficacy in small phase II studies, considerable
226
liver toxicity, flaws in trial design, and the lack of biomarker-based enrichment12. Moreover, the results
227
of the phase III SARAH72 and SIRveNIB73 superiority trials of internal radiation with 90Y resin
228
microspheres versus sorafenib in patients with advanced-stage HCC (including >30% with main portal
229
vein thrombosis) did not fulfil the primary overall survival end points. In these studies72,73, median
230
overall survival was 8.0–8.8 months in the 90Y-microsphere arms compared with 9.9–10.0 months in the
231
sorafenib arms, resulting in nonsignificant detriments in survival with radioembolization (HR 1.12–1.15)
232
(Fig. 3a). Per-protocol subgroup analyses did not reveal any survival advantages72,73. The authors of
233

Frequently asked questions

Q1. What are the contributions in this paper?

Sorafenib was the first systemic 14 therapy approved for patients with advanced-stage HCC, after a landmark study revealed an 15 improvement in median overall survival from 8 to 11 months. Herein, the authors summarize the molecular targets and 22 therapies for the management of HCC and discuss the advancements expected in the near future, 23 including biomarker-driven treatments and immunotherapies. In a breakthrough study6, the multi-target tyrosine kinase inhibitor ( TKI ) 32 sorafenib, which has anti-angiogenic and anti-proliferative effects, extended the median overall survival 33 of patients with advanced-stage HCC from 8 to 11 months and had a manageable toxicity profile. In addition, immunotherapy with nivolumab — a monoclonal 39 antibody targeting the inhibitory immunecheckpoint molecule programmed cell death protein 1 ( PD-1 ) 40 — led to promising response rates and survival durations in a phase I–II study involving patients 41 previously treated with sorafenib11 and has been granted accelerated approval by the FDA. In this Review, the authors analyse the molecular targets and therapies for the management of HCC and 50 highlight the advancements in biomarker-driven treatments and immunotherapies that are expected in 51 the near future. These proposed molecular classes have been confirmed and further 103 characterized in the comprehensive molecular analysis of 363 patients with HCC — the largest cohort 104 published to date — reported by The Cancer Genome Atlas ( TCGA ) Research Network18. A similar 179 magnitude of benefit was observed in another phase III study of sorafenib conducted in parallel in Asian 180 patients, mostly with HBV-related HCC55. Similarly, 192 surveys conducted in > 3,000 patients to evaluate the safety and tolerability of sorafenib in clinical 193 practice reported median overall survival durations of 13. 198 Unfortunately, at least partially owing to this pharmacological complexity, no predictive biomarkers of a 199 response to sorafenib have been identified ; however, the companion biomarker study conducted within 200 the SHARP trial showed a nonsignificant trend towards a greater survival benefit of sorafenib in patients 201 with tumours harbouring high levels of KIT and low plasma HGF concentrations63. The 210 successful SHARP trial6 provided a framework for trial design that has been implemented in subsequent 211 phase III studies65. The main traits of this design are the selection of an adequate target population: 212 patients with well-preserved liver function ( Child–Pugh class A ), to minimize the risk of liver failure and 213 death as a result of cirrhosis, and patients with either advanced-stage ( BCLC stage C ) or intermediate214 stage ( BCLC stage B ) disease that has progressed following TACE, to provide clear results for this clinical 215 stage. In this regard, use of the modified Response Evaluation Criteria in Solid 218 Tumors ( mRECIST ), which are based on the concept of viable tumour, generally provides greater 219 sensitivity in the assessment of response than the standard RECIST guidelines66 ; in phase III trials of 220 sorafenib, objective response rates ( ORRs ) were 10–15 % by mRECIST versus 2–6 % by RECIST67. The authors of 233 both trials highlighted the better response rates and quality of life ( QOL ) outcomes with 234 radioembolization, thus suggesting this treatment as an alternative to sorafenib for selected patients. Of note, patients with ≥50 % liver occupation, 249 obvious invasion of the bile duct, and/or invasion at the main portal vein were excluded from this 250 study7. On the basis of these results, lenvatinib can be considered as an alternative first-line treatment option 260 to sorafenib for patients with advanced-stage HCC ( except those with main portal vein thrombosis or 261 > 50 % liver involvement ) or intermediate-stage disease after progression following TACE ; FDA and 262 European Medicines Agency ( EMA ) approvals are pending. Since 276 2017, however, the authors have witnessed the reporting of positive results from three phase III trials in patients 277 who had disease progression on, or were intolerant of, sorafenib8–10, as well as promising data from 278 two phase II studies of different anti-PD-1 antibodies11,81. A small, single-arm phase II 289 study of regorafenib provided some evidence of antitumour activity in the second-line setting83 ; 290 however, the efficacy signals were not dissimilar from those obtained with other agents studied in this 291 space. A subsequent evaluation of overall 301 survival from the start of sorafenib treatment to death on study demonstrated a median duration of 26 302 months for regorafenib-treated patients versus 19 months for those in the placebo arm84. Cabozantinib was initially 313 evaluated in both patients with untreated HCC and those with progression on, or intolerance of, 314 sorafenib in a randomized phase II discontinuation study, resulting in an overall median PFS of 5. This trial was 319 stopped after a second interim analysis of data from the entire study population revealed a median 320 overall survival of 10. On the basis of encouraging activity observed in a pilot study88, 330 ramucirumab was compared with placebo in the phase III REACH trial involving patients with advanced331 stage HCC and prior sorafenib treatment78. The study was negative for its primary end point of overall 332 survival in the intentionto-treat population, although a subgroup of patients with a baseline serum AFP 333 levels ≥400ng/ml had a significant improvement in median overall survival from 4. 2 months with 334 placebo to 7. 8 months with ramucirumab ( HR 0. 67, 95 % CI 0. 51–0. 90 ; P=0. 006 ). Results of this trial were reported in abstract form at the 2018 ASCO Annual Meeting10 and 338 indicate a superior median overall survival duration of 8. A detailed description of the 350 therapeutic mechanisms is beyond the scope of this Review, but in general, they involve blockade of 351 negative feedback pathways of the immune system that mediate immunosuppression in the setting of 352 malignancies91,92. Given the unmet 375 needs in the second-line setting, the FDA granted accelerated approval to nivolumab for patients with 376 advanced-stage HCC previously treated with sorafenib on the basis of the efficacy and safety data 377 reported for a subpopulation comprising 154 sorafenib-treated patients included in CheckMate 040. In 378 this subgroup, the ORR confirmed through blinded independent central review was 14. In KEYNOTE-224 ( ref. 100 ), a single-arm study 390 of pembrolizumab for second-line treatment after frontline sorafenib, the ORR in 104 patients was 391 16. Longerterm follow-up data from this study are awaited, as are the results of 394 KEYNOTE-240, a randomized, placebo-controlled phase III trial of pembrolizumab101. In this study102, durvalumab had an acceptable safety profile and 397 demonstrated antitumour activity ( ORR 10 % ). The trial is based on a phase I–II study evaluating the durvalumab– 413 tremelimumab combination109, which resulted in a confirmed ORR of 15 % among 40 evaluable patients 414 included in the phase I component. In a study involving patients with non-HCC malignancies, those with RCC had an ORR to 421 the lenvatinib and pembrolizumab combination of 63 % ; the median PFS and overall survival durations 422 had not been reached at the time of presentation110. Indeed, the combination of bevacizumab and 430 atezolizumab is now being compared with sorafenib in a phase III study in the frontline setting 431 ( NCT03434379 ) and the FDA has granted this combination breakthrough designation on the basis of an 432 ORR of 65 % in 23 patients111. Subgroup analyses of a phase II study testing the 445 small-molecule MET inhibitor tivantinib in 107 patients previously treated with sorafenib revealed a 446 correlation of high MET expression by IHC ( ≥2+ in ≥50 % of tumour cells ) with an unfavourable prognosis 447 but improved survival with tivantinib versus placebo113. This concept was then tested in a prospective, 448 randomized, phase III study in the second-line setting in patients with MET-high HCC. This study did not 449 meet its primary end point of an improvement in overall survival with tivantinib versus placebo80 450 ( Fig. 3b ). This survival duration is the longest ever reported for patients with advanced-stage HCC in 452 the context of a second-line phase III trial, raising the question of whether or not a high level of MET 453 expression is a negative prognostic marker in this setting. Everolimus, an allosteric inhibitor of mTOR complex 1 484 ( mTORC1 ), has been evaluated in a phase III study as a second-line treatment of HCC77 but yielded 485 negative results in an unselected patient population. In a 490 retrospective analysis of a single-arm phase II study evaluating refametinib plus sorafenib in patients 491 with advanced-stage HCC, the best clinical responses were seen in patients with RAS mutations130. This clear 521 strategy is based upon the following concepts of precision medicine. Conversely, if the study fails to hit the primary end point, a clear understanding of the 561 biomarkers for predicting a response or primary resistance to these agents will be essential for future 562 efforts to establish immunotherapy as a treatment strategy for patients with HCC. In developed countries, surveillance programmes lead to early HCC diagnosis in 40–50 % of 28 patients, at a stage amenable to potentially curative treatments2,4,5. Indeed, 78 reports of WES studies indicate that only ~25 % of HCCs harbour alterations that are potentially 79 targetable with existing drugs16. These distinct molecular classes reflect different biological backgrounds with 85 potential implications in patient prognostication and selection for therapies. 88 As their designation suggests, HCCs of the proliferation class are characterized by activation of signalling 89 pathways involved in cell proliferation and survival, such as the PI3K–AKT–mTOR, RAS–MAPK, and MET 90 cascades21,23,24. 131 Clearly, further research is needed to translate the current knowledge of HCC biology into prognostic 132 and predictive biomarkers in order to guide clinical decisionmaking and, ultimately, improve patient 133 outcomes. Understanding how the distinct angiogenic signalling pathways interact with the immune 141 component of HCCs and how mechanisms of resistance to antiangiogenic agents arise could potentially 142 reveal novel therapeutic strategies. As mentioned previously, in developed 147 countries, 40–50 % of patients with HCC are diagnosed at early stages ( BCLC stage 0–A ), when potentially 148 curative treatments ( resection, liver transplantation, or local ablation ) are possible4. Nivolumab is another new option in the secondline setting on 163 the basis of the promising response rates and durations observed in the phase I–II trial of this agent11. Data from QOL studies suggest a similar 263 overall profile for both drugs7. Furthermore, in the pivotal phase III SHARP trial of sorafenib6, 271 patients were allowed to remain on treatment beyond radiological progression, ultimately adding 272 additional layers of complexity. HCC develops in 361 an inflammatory milieu, and various studies have revealed a role for immune tolerance in the 362 development of this cancer96, hinting at the potential of immune-checkpoint inhibition as an effective 363 treatment strategy. These studies are building on the fact that these drugs have single-agent activity in 426 patients with advanced-stage HCC, and as multi-target TKIs of VEGFRs and other kinases, lenvatinib and 427 regorafenib have potential effects on the TME that might promote a response to immunotherapy36,37. As the above sections highlight, promising and robust clinical trial results have been presented in the 436 past 2 years that are changing the treatment options for patients with advanced-stage HCC. While FGFR2 463 alterations are being pursued as therapeutic targets in several cancers116,117, in HCC, FGFR4 — the 464 predominant FGFR expressed in the liver118 — has been identified as a potentially important target. FGF19 amplification 466 occurs in ~5–10 % of HCC and has been shown to be an oncogenic driver implicated in sorafenib 467 resistance120 and a potential predictive marker of response to FGFR kinase inhibitors121–123. Mature data are awaited while this drug class moves through 478 development as single agents and potentially in combination with other agents, particularly immune479 checkpoint inhibitors ( as in NCT02325739 ). In HCC, the landscape of mutations and targetable drivers has been defined, and ~25 % of 533 them are considered potentially actionable16. In a 546 small proportion of patients, immunotherapy can cause severe and potentially permanent autoimmune 547 AEs140 ; therefore, the identification of candidate biomarkers to target patients who are most likely to 548 benefit is becoming crucial. These data are 553 consistent with findings in melanoma showing that activation of the β-catenin ( CTNNB1 ) pathway is 554 associated with T cell exclusion and resistance to immunotherapy144, suggesting that the immune 555 exclusion class of HCC encompasses patients with ineffective or suboptimal responses to 556 immunotherapies. 

Q2. what is the fda’s breakthrough therapy designation for tecentriq?

FDA grants breakthrough therapy designation for Genentech’s TECENTRIQ in combination with avastin as first-line treatment for advanced or metastatic hepatocellular carcinoma (HCC). 

Q3. What are the main funding sources for J.M.L.?

The work of J.M.L. is supported by grants from the European Commission Horizon 2020 programme (HEPCAR, proposal number 667273–2), the US Department of Defense (CA150272P3), the US National Cancer Institute (P30 CA196521), the Samuel Waxman Cancer Research Foundation, the Spanish National Health Institute (SAF 2016–76390), Asociación Española Contra el Cáncer (AECC), and the Generalitat de Catalunya (AGAUR, SGR-1162 and SGR-1358). 

Q4. what is the EVOLVE-1 randomized clinical trial?

Effect of everolimus on survival in advanced hepatocellular carcinoma after failure of sorafenib: the EVOLVE-1 randomized clinical trial. 

Q5. what is the phenotype of hepatocellular carcinoma?

A randomized phase III study of doxorubicin versus cisplatin/interferon α2b/doxorubicin/ fluorouracil (PIAF) combination chemotherapy for unresectable hepatocellular carcinoma.