FDA Approval Summary: Durvalumab and Pembrolizumab, Immune Checkpoint inhibitors for the Treatment of Biliary Tract Cancer.

On September 2, 2022, the Food and Drug Administration (FDA) approved durvalumab in combination with cisplatin and gemcitabine, for the treatment of patients with unresectable or metastatic biliary tract cancers (BTC). On October 31, 2023, the FDA approved pembrolizumab in combination with cisplatin and gemcitabine for the same indication. Approvals were based on two randomized, multiregional, placebo-controlled trials, which randomly allocated patients to receive durvalumab (TOPAZ-1) or pembrolizumab (KEYNOTE-966) in combination with chemotherapy or placebo in combination with chemotherapy. Overall survival (OS) was the primary endpoint in both studies. In both studies, a statistically significant and clinically meaningful improvement in OS was demonstrated. In the TOPAZ-1 trial the median OS of patients receiving durvalumab was 12.8 months (95% confidence interval [CI] 11.1, 14.0) and 11.5 months (95% CI 10.1, 12.5) in patients receiving placebo (HR 0.80 [95% CI 0.66, 0.97]). In the KEYNOTE-966 trial, the median OS of patients receiving pembrolizumab was 12.7 months (95% CI 11.5, 13.6) and 10.9 months (95% CI 9.9, 11.6) in patients receiving placebo (HR 0.83 [95% CI 0.72, 0.95]). The addition of checkpoint inhibitors to standard of care chemotherapy for this indication did not reveal any new adverse event signals and the safety profile was generally consistent with the known clinical experience with durvalumab, pembrolizumab, and the backbone chemotherapy regimen. The approvals of durvalumab and pembrolizumab in combination with standard of care cisplatin and gemcitabine for the treatment of unresectable or metastatic BTC add two new therapeutic option for these patients.

FDA Approval Summary: Fruquintinib for the Treatment of Refractory Metastatic Colorectal Cancer.

On November 8, 2023, the FDA approved fruquintinib, an inhibitor of vascular endothelial growth factor receptors (VEGFR)-1, -2, and -3, for the treatment of patients with metastatic colorectal cancer (mCRC) who have been previously treated with fluoropyrimidine­, oxaliplatin­, and irinotecan­based chemotherapy, an anti­VEGF therapy, and, if RAS wild­type and medically appropriate, an anti EGFR therapy. Approval was based on Study FRESCO-2, a globally-conducted, double-blind, placebo-controlled randomized trial. The primary endpoint was overall survival (OS). The key secondary endpoint was progression-free survival (PFS). A total of 691 patients were randomized (461 and 230 into the fruquintinib and placebo arms, respectively). Fruquintinib provided a statistically significant improvement in OS with a hazard ratio (HR) of 0.66 (95% CI: 0.55, 0.80; p<0.001). The median OS was 7.4 months (95% CI: 6.7, 8.2) in the fruquintinib arm and 4.8 months (95% CI: 4.0, 5.8) for the placebo arm. Adverse events observed were generally consistent with the known safety profile associated with inhibition of the VEGFR. The results of FRESCO-2 were supported by the FRESCO study, a double-blind, single country, placebo-controlled, randomized trial in patients with refractory mCRC who have been previously treated with fluoropyrimidine­, oxaliplatin­, and irinotecan­based chemotherapy. In FRESCO, the OS HR was 0.65 (95% CI: 0.51, 0.83; p<0.001). FDA concluded that the totality of the evidence from FRESCO-2 and FRESCO supported an indication for patients with mCRC with prior treatment with fluoropyrimidine, oxaliplatin-, and irinotecan-based chemotherapy, an anti-VEGF biological therapy, and if RAS wild­type and medically appropriate, an anti-EGFR therapy.

FDA Approval Summary: Tremelimumab in Combination with Durvalumab for the Treatment of Patients with Unresectable Hepatocellular Carcinoma.

On October 21, 2022, the FDA approved tremelimumab (Imjudo) in combination with durvalumab for adult patients with unresectable hepatocellular carcinoma. The approval was based on the results from the HIMALAYA study, in which patients with unresectable hepatocellular carcinoma who were naïve to previous systemic treatment were randomly assigned to receive one of three study arms: tremelimumab in combination with durvalumab (n = 393), durvalumab (n = 389), or sorafenib (n = 389). The primary objective of improvement in overall survival (OS) for tremelimumab in combination with durvalumab compared with sorafenib met statistical significance with a stratified HR of 0.78 [95% confidence interval (CI), 0.66-0.92; P = 0.0035]. The median OS was 16.4 months (95% CI, 14.2-19.6) with tremelimumab in combination with durvalumab and 13.8 months (95% CI, 12.3-16.1) with sorafenib. Adverse reactions occurring in ≥20% of patients receiving tremelimumab in combination with durvalumab were rash, fatigue, diarrhea, pruritus, musculoskeletal pain, and abdominal pain. The recommended tremelimumab dose for patients weighing 30 kg or more is 300 mg, i.v., as a single dose in combination with durvalumab 1,500 mg at cycle 1/day 1, followed by durvalumab 1,500 mg, i.v., every 4 weeks. For those weighing less than 30 kg, the recommended tremelimumab dose is 4 mg/kg, i.v., as a single dose in combination with durvalumab 20 mg/kg, i.v., followed by durvalumab 20 mg/kg, i.v., every 4 weeks.

Highlights of FDA Oncology Approvals in 2023: Bispecific T-cell Engagers, Pediatric Indications, and Inclusive Drug Development.

SUMMARY: Cancer drug development remained robust in 2023. Highlights of U.S. drug approvals this year include new immunotherapies and targeted drug development in adult and pediatric patients as well as patients with rare diseases.

FDA Approval Summary: Selpercatinib for the Treatment of Advanced RET Fusion-Positive Solid Tumors.

On September 21, 2022, the FDA granted accelerated approval to selpercatinib (Retevmo, Eli Lilly and Company) for the treatment of adult patients with locally advanced or metastatic solid tumors with a rearranged during transfection (RET) gene fusion that have progressed on or following prior systemic treatment or who have no satisfactory alternative treatment options. The approval was based on data from Study LOXO-RET-17001 (LIBRETTO-001; NCT03157128), an international, non-randomized, multi-cohort clinical trial that included patients with advanced solid tumors harboring RET alterations. The overall response rate in 41 patients with locally advanced or metastatic RET fusion-positive solid tumors other than non-small cell lung cancer (NSCLC) or thyroid cancer was 44% [95% confidence interval (CI), 28%-60%], with median duration of response 24.5 months (95% CI, 9.2-not evaluable). Patients with 10 of 14 tumor types with a variety of fusion partners had objective responses, including patients with the following tumors: pancreatic adenocarcinoma, colorectal, salivary, unknown primary, breast, soft-tissue sarcoma, bronchial carcinoid, ovarian, small intestine, and cholangiocarcinoma. The recommendation for approval was supported by results from LIBRETTO-001 in patients with RET fusion-positive NSCLC and thyroid cancer, which formed the basis of prior approvals in these tumor types. The most common adverse reactions (>25%) were edema, diarrhea, fatigue, dry mouth, hypertension, abdominal pain, constipation, rash, nausea, and headache. This is the first tissue-agnostic approval of a RET-directed targeted therapy.

FDA Approval Summary: Tucatinib with Trastuzumab for Advanced Unresectable or Metastatic, Chemotherapy Refractory, HER2-Positive RAS Wild-Type Colorectal Cancer.

On January 19, 2023, the FDA granted accelerated approval to tucatinib in combination with trastuzumab for the treatment of patients with unresectable or metastatic RAS wild-type, HER2-positive colorectal cancer who have received prior treatment with fluoropyrimidine, oxaliplatin, and irinotecan. Approval was based on the pooled analysis of patients receiving tucatinib in combination with trastuzumab in MOUNTAINEER (NCT03043313), an open-label, multicenter trial. The primary endpoint was overall response rate (ORR) by RECIST 1.1 as per blinded central review committee (BIRC) assessment. The main secondary endpoint was duration of response (DOR) per BIRC assessment. Eighty-four eligible patients received the combination tucatinib and trastuzumab. With a median follow-up of 16 months, the ORR was 38% [95% confidence interval (CI): 28-49] and median DOR was 12.4 months (95% CI: 8.5-20.5); 81% of responders had a response lasting more than 6 months. The most common adverse reactions observed in at least 20% of patients receiving tucatinib in combination with trastuzumab were diarrhea, fatigue, rash, nausea, abdominal pain, infusion-related reactions, and fever. FDA concluded that the magnitude of ORR and durable responses observed in patients treated with tucatinib in combination with trastuzumab in the MOUNTAINEER trial are clinically meaningful, particularly in the context of a disease with estimated survival of 6-7 months with available therapy. This is the first approval for the subset of patients with HER2-positive colorectal cancer. This article summarizes the FDA's thought process and review of the data supporting this accelerated approval.

FDA Approval Summary: Futibatinib for Unresectable Advanced or Metastatic, Chemotherapy Refractory Intrahepatic Cholangiocarcinoma with FGFR2 Fusions or Other Rearrangements.

On September 30, 2022, the FDA granted accelerated approval to futibatinib for the treatment of adult patients with previously treated, unresectable, locally advanced or metastatic intrahepatic cholangiocarcinoma (iCCA) with FGFR2 fusions or other rearrangements. Approval was based on Study TAS-120-101, a multicenter open-label, single-arm trial. Patients received futibatinib 20-mg orally once daily. The major efficacy outcome measures were overall response rate (ORR) and duration of response (DoR) as determined by an independent review committee (IRC) according to RECIST v1.1. ORR was 42% (95% confidence interval, 32%-52%). Median DoR was 9.7 months. Adverse reactions occurring in ≥30% patients were nail toxicity, musculoskeletal pain, constipation, diarrhea, fatigue, dry mouth, alopecia, stomatitis, and abdominal pain. The most common laboratory abnormalities (≥50%) were increased phosphate, increased creatinine, decreased hemoglobin, and increased glucose. Ocular toxicity (including dry eye, keratitis, and retinal epithelial detachment) and hyperphosphatemia are important risks of futibatinib, which are listed under Warnings and Precautions. This article summarizes the FDA's thought process and data supporting the approval of futibatinib.

FDA Approval Summary: Ripretinib for Advanced Gastrointestinal Stromal Tumor.

On May 15, 2020, the FDA approved ripretinib for adult patients with advanced gastrointestinal stromal tumor who have received prior treatment with three or more kinase inhibitors, including imatinib. The approval was based on results from INVICTUS (NCT03353753), an international, multi-center, double-blind, placebo-controlled trial. Patients were randomly allocated (2:1) to receive either ripretinib 150 mg once daily (n = 85) or matching placebo (n = 44). The trial demonstrated a statistically significant improvement in progression-free survival (PFS) as assessed by modified RECIST v1.1 by blinded independent central review for patients randomized to ripretinib, with a median PFS of 6.3 months [95% confidence interval (CI): 4.6-6.9] compared with 1.0 month (95% CI: 0.9-1.7) for placebo [HR: 0.15 (95% CI: 0.09-0.25); P < 0.0001, stratified log-rank test]. There was no statistically significant difference in objective response rate in the ripretinib arm, 9% (95% CI: 4.2-18) compared with placebo 0% [(95% CI: 0-8); P = 0.0504, Fisher exact test]. The median overall survival (OS) in the ripretinib arm was 15.1 months (95% CI: 12.3-15.1) compared with 6.6 months (95% CI: 4.1-11.6) in the placebo arm. A formal statistical comparison of OS was not made due to the prespecified hierarchical analysis plan. The most common (≥20%) adverse events with ripretinib, in order of decreasing frequency, were alopecia, fatigue, nausea, abdominal pain, constipation, myalgia, diarrhea, decreased appetite, palmar-plantar erythrodysesthesia, and vomiting. Other important risks of ripretinib include new primary cutaneous malignancies, hypertension, and cardiac dysfunction.

FDA Approval Summary: Pemigatinib for Previously Treated, Unresectable Locally Advanced or Metastatic Cholangiocarcinoma with FGFR2 Fusion or Other Rearrangement.

On April 17, 2020, the FDA granted accelerated approval to pemigatinib (PEMAZYRE, Incyte Corporation) for the treatment of adults with previously treated, unresectable locally advanced or metastatic cholangiocarcinoma with an FGFR2 fusion or other rearrangement as detected by an FDA-approved test. Approval was based on FIGHT-202 (NCT02924376), a multicenter open-label single-arm trial. Efficacy was based on 107 patients with locally advanced unresectable or metastatic cholangiocarcinoma whose disease had progressed on or after at least one prior therapy and had an FGFR2 gene fusion or rearrangement. Patients received pemigatinib, 13.5 mg orally, once daily for 14 consecutive days, followed by 7 days off therapy. Safety was based on a total of 466 patients, 146 of whom had cholangiocarcinoma and received the recommended dose. Efficacy endpoints were overall response rate (ORR) and duration of response (DOR) determined by an independent review committee using RECIST 1.1. ORR was 36% (95% confidence interval: 27-45). Median DOR was 9.1 months. The most common adverse reactions were hyperphosphatemia, alopecia, diarrhea, nail toxicity, fatigue, dysgeusia, nausea, constipation, stomatitis, dry eye, dry mouth, decreased appetite, vomiting, arthralgia, abdominal pain, hypophosphatemia, back pain, and dry skin. Ocular toxicity and hyperphosphatemia are important risks of pemigatinib. The recommended dosage is 13.5 mg orally once daily for 14 consecutive days followed by 7 days off therapy in 21-day cycles. FDA also approved the FoundationOne CDX (Foundation Medicine, Inc.) as a companion diagnostic for patient selection.

FDA Approval Summary: Nivolumab for the Adjuvant Treatment of Adults with Completely Resected Esophageal/Gastroesophageal Junction Cancer and Residual Pathologic Disease.

The FDA approved nivolumab on May 20, 2021, for the adjuvant treatment of completely resected (negative margins) esophageal or gastroesophageal junction cancer (EC/GEJC) in patients who had residual pathologic disease following chemoradiotherapy. The approval was based on data from the double-blind CheckMate 577 trial, which randomly allocated patients to receive nivolumab or placebo. Disease-free survival (DFS) was the primary endpoint. At the time of the final DFS analysis and the prespecified interim overall survival (OS) analysis, the estimated median DFS was 22.4 months [95% confidence interval (CI), 16.6-34.0] in the nivolumab arm versus 11.0 months (95% CI, 8.3-14.3) in the placebo arm, with an HR of 0.69 (95% CI, 0.56-0.85; two-sided P value = 0.0003). An unblinded review of OS did not indicate a detrimental effect on survival. Adverse reactions occurring in ≥20% of patients receiving nivolumab were fatigue/asthenia, diarrhea, nausea, rash, musculoskeletal pain, and cough. Approval of nivolumab is likely to change the treatment paradigm for the adjuvant treatment of patients with completely resected (negative margins) EC/GEJC who have residual pathologic disease following chemoradiotherapy based on the study results and favorable risk:benefit of nivolumab administration.

FDA Approval Summary: Ivosidenib for the Treatment of Patients with Advanced Unresectable or Metastatic, Chemotherapy Refractory Cholangiocarcinoma with an IDH1 Mutation.

On August 25, 2021, the FDA approved ivosidenib for the treatment of adult patients with unresectable locally advanced or metastatic hepatocellular isocitrate dehydrogenase 1 (IDH1) mutated cholangiocarcinoma (CCA) as detected by an FDA-approved test with disease progression after 1 to 2 prior lines of systemic therapy for advanced disease. The approval was based on data from Study AG120-C-005 (ClarIDHy), a double-blind placebo-controlled trial that randomly allocated (2:1) patients to receive either ivosidenib or placebo. Independently assessed progression-free survival (PFS) was the primary endpoint. With a median follow-up of 6.9 months, the HR for PFS was 0.37 [95% confidence interval (CI), 0.25-0.54; P < 0.0001). Overall survival (OS) was the key secondary endpoint. At the final analysis of OS, with 70.5% of patients in the placebo arm receiving ivosidenib post disease progression, a non-statistically significant improvement in the ivosidenib arm with an HR = 0.79 (95% CI, 0.56-1.12) and median OS of 10.3 months (95% CI, 7.8-12.4) and 7.5 months (95% CI, 4.8-11.1) in the ivosidenib and placebo arms, respectively, were reported. Adverse reactions occurring in >20% of patients receiving ivosidenib were fatigue/asthenia, nausea, diarrhea, abdominal pain, ascites, vomiting, cough, and decreased appetite. Adverse reactions occurring in >20% of patients receiving placebo were fatigue/asthenia, nausea, abdominal pain, and vomiting. This is the first approval for the subset of patients with CCA harboring an IDH1 mutation.

Tissue-Agnostic Drug Development: A New Path to Drug Approval.

In recent years, there has been remarkable progress in our understanding of cancer biology, host responses, and the concept of precision oncology. These advances have focused attention on biomarker-driven, tissue-agnostic drug development strategies. The recent approvals by the FDA of pembrolizumab for the treatment of unresectable or metastatic, microsatellite instability-high or deficient mismatch repair solid tumors, and more recently for the treatment of tumor mutational burden-high tumors; and of larotrectinib and entrectinib for the treatment of neurotrophic tyrosine kinase (NTRK) fusion-positive solid tumors, have further heightened interest in target-driven as opposed to histology-driven drug development. Herein, we focus on tissue-agnostic clinical drug development with an understanding of target modulation in the context of histology. The use of molecular genetics and biomarker-driven strategies rather than traditional histology based on organ of origin has reinforced the concept of tissue-agnostic drug development. Recent approvals in the United States, Europe, Japan, Australia, and other regions have further heightened interest in target-driven as opposed to histology-driven drug development.

FDA Approval Summary: Pembrolizumab for the Treatment of Tumor Mutational Burden-High Solid Tumors.

The FDA approved pembrolizumab on June 16, 2020, for the treatment of adult and pediatric patients with unresectable or metastatic tumor mutational burden-high [TMB-H; ≥10 mutations/megabase (mut/Mb)] solid tumors, as determined by an FDA-approved test, that have progressed following prior treatment and who have no satisfactory alternative treatment options. FDA granted the approval based on a clinically important overall response rate (29%; 95% confidence interval, 21-39) and duration of response (57% of responses lasting ≥ 12 months) in the subset of patients with TMB-H solid tumors (n = 102) spanning nine different tumor types enrolled in a multicenter single-arm trial (KEYNOTE-158). The efficacy of pembrolizumab was supported by the results of whole-exome sequencing (WES) analyses of TMB in additional patients enrolled across multiple pembrolizumab clinical trials, and a scientific understanding of the effects of PD-1 inhibition. Overall, the adverse event profile of pembrolizumab was similar to the adverse event profile observed in prior trials that supported the approval of pembrolizumab in other indications. This approval of pembrolizumab is the first time that the FDA has approved a cancer treatment for an indication based on TMB, and the fourth based on the presence of a biomarker rather than the primary site of origin.

Subgroup Analyses in Oncology Trials: Regulatory Considerations and Case Examples.

Subgroup analyses are assessments of treatment effects based on certain patient characteristics out of the total study population and are important for interpretation of pivotal oncology trials. However, appropriate use of subgroup analyses results for regulatory decision-making and product labeling is challenging. Typically, drugs approved by the FDA are indicated for use in the total patient population studied; however, there are examples of restriction to a subgroup of patients despite positive study results in the entire study population and also extension of an indication to the entire study population despite positive results appearing primarily in one or more subgroups. In this article, we summarize key issues related to subgroup analyses in the benefit-risk assessment of cancer drugs and provide case examples to illustrate approaches that the FDA Oncology Center of Excellence has taken when considering the appropriate patient population for cancer drug approval. In general, if a subgroup is of interest, the subgroup analysis should be hypothesis-driven and have adequate sample size to demonstrate evidence of a treatment effect. In addition to statistical efficacy considerations, the decision on what subgroups to include in labeling relies on the pathophysiology of the disease, mechanistic justification, safety data, and external information available. The oncology drug review takes the totality of the data into consideration during the decision-making process to ensure the indication granted and product labeling appropriately reflect the scientific evidence to support patient population for whom the drug is safe and effective.

FDA Approval Summary: Pembrolizumab for the First-line Treatment of Patients with MSI-H/dMMR Advanced Unresectable or Metastatic Colorectal Carcinoma.

The FDA approved pembrolizumab on June 29, 2020, for the treatment of patients with unresectable or metastatic microsatellite instability-high (MSI-H) colorectal cancer with no prior systemic treatment for advanced disease. The approval was based on data from Study Keynote-177, which randomly allocated patients to receive either pembrolizumab or standard of care (SOC) with chemotherapy. Overall survival (OS) and independently assessed progression-free survival (PFS) were the primary endpoints. At the time of the final PFS analysis and second prespecified interim OS analysis, the estimated median PFS was 16.5 months (95% CI: 5.4-32.4) versus 8.2 months (95% CI: 6.1-10.2) in the pembrolizumab and SOC arms, respectively [HR: 0.60 (95% CI: 0.45-0.80); two-sided P = 0.0004]. FDA assessed unblinded OS data during the review of the application and identified no safety concerns that would preclude approval of this supplement. Adverse reactions occurring in >30% of patients receiving pembrolizumab were diarrhea, fatigue/asthenia, and nausea. Adverse reactions occurring in >30% of patients receiving SOC were diarrhea, nausea, fatigue/asthenia, neutropenia, decreased appetite, peripheral neuropathy (high-level term), vomiting, abdominal pain, constipation, and stomatitis. Duration of treatment in the pembrolizumab arm was almost double (median 11.1 months, range 0-30.6 months) than the duration of treatment in patients receiving SOC (median, 5.7 months). Approval of pembrolizumab is likely to change the treatment paradigm for first-line treatment with MSI-H advanced colorectal cancer given the study results and different safety profile.

The FDA Oncology Center of Excellence Scientific Collaborative: Charting a Course for Applied Regulatory Science Research in Oncology.

The FDA Oncology Center of Excellence (OCE) is a leader within the agency in scientific outreach activities and regulatory science research. On the basis of analysis of scientific workshops, internal meetings, and publications, the OCE identified nine scientific priority areas and one cross-cutting area of high interest for collaboration with external researchers. This article describes the process for identifying these scientific interest areas and highlights funded and unfunded opportunities for external researchers to work with FDA staff on critical regulatory science challenges.

Neoadjuvant Therapy for Melanoma: A U.S. Food and Drug Administration-Melanoma Research Alliance Public Workshop.

Tremendous progress has been made in treating patients with metastatic melanoma over the past decade. In that timeframe, the FDA has approved 12 novel treatments for patients with advanced unresectable melanoma, comprising both kinase-targeted therapies and immune checkpoint inhibitors (ICI), and five treatments for adjuvant (postoperative) use in patients with high-risk resectable stage III melanoma. It is not known whether outcomes can be further improved by administering kinase inhibitors or ICI in the neoadjuvant (presurgical) setting in patients with high-risk resectable melanomas. Noting research community interest in exploring the neoadjuvant approach for treating melanoma and recognizing that early harmonization of methodologies may expedite the development of therapeutics in this space, the FDA and Melanoma Research Alliance convened a public workshop on November 6, 2019, in National Harbor, Maryland, to discuss key issues. The workshop consisted of 23 faculty and included more than 250 live participants. Topics discussed included opportunities for advancing novel endpoints for regulatory purposes as well as translational research, clinical trial design considerations, and strategies for optimizing patient selection while mitigating risk.

FDA Approval Summary: Atezolizumab Plus Bevacizumab for the Treatment of Patients with Advanced Unresectable or Metastatic Hepatocellular Carcinoma.

On May 29, 2020, the FDA approved atezolizumab for use in combination with bevacizumab, for the treatment of adult patients with unresectable locally advanced or metastatic hepatocellular carcinoma (HCC) with no prior systemic treatment. The approval was based on data from Study IMbrave150, which randomly allocated (2:1) patients to receive either atezolizumab plus bevacizumab (atezolizumab-bevacizumab) or sorafenib. Overall survival (OS) and independently assessed progression-free survival (PFS) in the intent-to-treat population were the primary endpoints. At the time of the primary analysis, the estimated median OS could not be estimated in the atezolizumab-bevacizumab arm and was 13.2 months in the sorafenib arm [HR, 0.58; 95% confidence interval (CI), 0.42-0.79]. The estimated median PFS was 6.8 months (95% CI, 5.8-8.3) and 4.3 months (95% CI, 4.0-5.6) in the atezolizumab-bevacizumab and sorafenib arms, respectively. Adverse reactions occurring in >20% of patients receiving atezolizumab-bevacizumab were hypertension, fatigue/asthenia, and proteinuria. Adverse reactions occurring in >20% of patients receiving sorafenib were palmar-plantar erythrodysesthesia, diarrhea, hypertension, and decreased appetite. Hemorrhage was reported more frequently in patients receiving atezolizumab-bevacizumab (25%) than in patients receiving sorafenib (17%). An evaluation for the presence of varices is recommended within 6 months of initiation of atezolizumab-bevacizumab in patients with HCC. Approval of atezolizumab-bevacizumab is likely to change the treatment paradigm for HCC, given that treatment with atezolizumab-bevacizumab resulted in improved OS and PFS compared with sorafenib, an accepted standard of care for first-line treatment of patients with unresectable HCC.See related commentary by Castet et al., p. 1827.

Immune Response Evaluation and Treatment with Immune Checkpoint Inhibitors Beyond Clinical Progression: Response Assessments for Cancer Immunotherapy.

PURPOSE OF REVIEW: This review provides a comprehensive assessment of recent literature reports describing atypical response patterns observed with immune checkpoint inhibitors (ICIs), modifications to response evaluation criteria for ICIs, and treatment beyond progression in clinical trials. RECENT FINDINGS: Certain response patterns such as durable response, pseudoprogression, hyperprogression, and dissociated responses can be seen with ICI treatment. These patterns carry differing prognoses and are associated with varied factors. There are multiple modifications of standard Response Evaluation Criteria in Solid Tumors (RECIST) that have been proposed to better characterize immunotherapy response; however, standard RECIST1.1 remains most commonly used in clinical trials. Treatment beyond progression varies in frequency and benefit depending on assessment criteria and cancer type. Future research incorporating modified imaging criteria and biomarker assessments may serve to clarify who will benefit most from treatment beyond progression.

FDA Approval Summary: Pembrolizumab for the Treatment of Microsatellite Instability-High Solid Tumors.

The FDA approved pembrolizumab on May 23, 2017, for the treatment of adult and pediatric patients with unresectable or metastatic, microsatellite instability-high (MSI-H), or mismatch repair deficient (dMMR) solid tumors that have progressed following prior treatment and who have no satisfactory alternative treatment options and for the treatment of unresectable or metastatic MSI-H or dMMR colorectal cancer that has progressed following treatment with a fluoropyrimidine, oxaliplatin, and irinotecan. The FDA granted the approval based on an understanding of the biology of MSI-H/dMMR across different tumors along with the clinically important effects on overall response rate (ORR) observed in patients who were enrolled in 1 of 5 single-arm clinical trials. The ORR was 39.6% among 149 patients with 15 different tumor types (95% confidence interval, 31.7-47.9), with a 7% complete response rate. The duration of response ranged from 1.6+ months to 22.7+ months, with 78% of responses lasting ≥6 months. Overall, the adverse event profile of pembrolizumab was similar to the adverse event profile observed across prior trials that supported the approval of pembrolizumab in other indications. This approval of pembrolizumab is the first time that the FDA has approved a cancer treatment for an indication based on a common biomarker rather than the primary site of origin.