Survival outcomes in older men with non-metastatic castration-resistant prostate cancer treated with androgen receptor inhibitors: a US Food and Drug Administration pooled analysis of patient-level data from three randomised trials.

BACKGROUND: Little is known about the benefit-risk profile of second-generation androgen receptor inhibitors in older men with non-metastatic castration-resistant prostate cancer. We aimed to examine the efficacy and safety of second-generation androgen receptor inhibitors in men aged 80 years or older with non-metastatic castration-resistant prostate cancer. METHODS: We searched for all randomised controlled clinical trials evaluating second-generation androgen receptor inhibitors in patients with non-metastatic castration-resistant prostate cancer submitted to the US Food and Drug Administration before Aug 15, 2020, and pooled data from three trials that met the selection criteria. All three trials enrolled patients who were aged 18 years or older with an Eastern Cooperative Oncology Group performance status of 0-1, castration-resistant prostate cancer, prostate-specific antigen (PSA) 2·0 µg/L or greater, PSA doubling time of 10 months or less, and no evidence of distant metastatic disease on conventional imaging per the investigator's assessment at the time of screening. All patients had histologically or cytologically confirmed adenocarcinoma of the prostate without neuroendocrine differentiation or small-cell features. All patients who were randomly assigned to androgen receptor inhibitor or placebo groups in these trials were considered assessable and were included in this pooled analysis. We evaluated the effect of age on metastasis-free survival and overall survival across age groups (<80 years vs ≥80 years) in the intention-to-treat population. Safety analyses were done in patients who received at least one dose of study treatment. FINDINGS: Between Oct 14, 2013, and March 9, 2018, 4117 patients were assigned to androgen receptor inhibitor (apalutamide, enzalutamide, or daralutamide; n=2694) or placebo (n=1423) across three randomised trials. The median follow-up duration for metastasis-free survival was 18 months (IQR 11-26) and for overall survival was 44 months (32-55). In patients aged 80 years or older (n=1023), the estimated median metastasis-free survival was 40 months (95% CI 36-41) in the androgen receptor inhibitor groups and 22 months (18-29) in the placebo groups (adjusted hazard ratio [HR] 0·37 [95% CI 0·28-0·47]), and the median overall survival was 54 months (50-61) versus 49 months (43-58), respectively (adjusted HR 0·79 [0·64-0·98]). In patients younger than 80 years of age (n=3094), the estimated median metastasis-free survival was 41 months (95% CI 36-not estimable [NE]) in the androgen receptor inhibitor groups and 16 months (15-18) in the placebo groups (adjusted HR 0·31 [95% CI 0·27-0·35]), and the median overall survival was 74 months (74-NE) versus 61 months (56-NE), respectively (adjusted HR 0·69 [0·60-0·80]). In patients aged 80 years or older, grade 3 or worse adverse events were reported in 371 (55%) of 672 patients in the androgen receptor inhibitor groups and 140 (41%) of 344 patients in the placebo groups, compared with 878 (44%) of 2015 patients in the androgen receptor inhibitor groups and 321 (30%) of 1073 patients in the placebo groups among patients younger than 80 years. The most common grade 3-4 adverse events were hypertension (168 [8%] of 2015 patients aged <80 years and 51 [8%] of 672 patients aged ≥80 years in the androgen receptor inhibitor groups vs 53 [5%] of 1073 patients aged <80 years and 22 [6%] of 344 patients aged ≥80 years in the placebo groups) and fracture (61 [3%] and 36 [5%] in the androgen receptor inhibitor groups vs 15 [1%] and 11 [3%] in the placebo groups). INTERPRETATION: The findings of this pooled analysis support the use of androgen receptor inhibitors in older men with non-metastatic castration-resistant prostate cancer. Incorporating geriatric assessment tools in the care of older adults with non-metastatic castration-resistant prostate cancer might help clinicians to offer individualised treatment to each patient. FUNDING: None.

FDA Approval Summary: Olaparib Monotherapy or in Combination with Bevacizumab for the Maintenance Treatment of Patients with Advanced Ovarian Cancer.

On December 19, 2018, the U.S. Food and Drug Administration (FDA) granted approval to olaparib monotherapy for first-line maintenance treatment of BRCA-mutated (BRCAm) advanced ovarian cancer and, on May 8, 2020, expanded the indication of olaparib to include its use in combination with bevacizumab for first-line maintenance treatment of homologous recombination deficient (HRD)-positive advanced ovarian cancer. Both these approvals were based on randomized, double-blind, placebo-controlled trials. Approval for olaparib monotherapy was based on the SOLO-1 trial, comparing the efficacy of olaparib versus placebo in patients with BRCAm advanced ovarian, fallopian tube, or primary peritoneal cancer after surgical cytoreduction and first-line platinum-based chemotherapy. Two companion diagnostic (CDx) tests were approved with this indication: BRACAnalysis CDx, for germline BRCA1/2 alterations, and FoundationOne CDx, for BRCA1/2 alterations in tissue specimens. Approval for olaparib in combination with bevacizumab was based on the results of the PAOLA-1 trial that compared olaparib with bevacizumab versus placebo plus bevacizumab in patients with advanced high-grade epithelial ovarian cancer, fallopian tube, or primary peritoneal cancer after first-line platinum-based chemotherapy and bevacizumab. Myriad myChoice CDx was designated as a companion diagnostic device for use of olaparib plus bevacizumab combination for ovarian cancer associated with HRD-positive status. Both trials demonstrated clinically meaningful improvements in progression-free survival and favorable benefit-risk profiles for the indicated populations. This article summarizes the FDA thought process and data supporting the approval of olaparib as monotherapy and in combination with bevacizumab for maintenance therapy in this setting. IMPLICATIONS FOR PRACTICE: These approvals represent the first poly (ADP-ribose) polymerase inhibitor, alone or in combination with bevacizumab, approved in first-line maintenance treatment of women with advanced ovarian cancer after cytoreductive surgery and chemotherapy. In patients with BRCA-mutated tumors, olaparib monotherapy demonstrated a 70% reduction in the risk of disease progression or death compared with placebo, and olaparib in combination with bevacizumab demonstrated a 67% reduction in the risk of disease progression or death compared with bevacizumab alone in homologous recombination deficient-positive tumors. These approvals represent a major advance for the treatment of women with advanced ovarian cancer who are in complete or partial response after their initial platinum-based chemotherapy.

Development of Treatments for Localized Prostate Cancer in Patients Eligible for Active Surveillance: U.S. Food and Drug Administration Oncology Center of Excellence Public Workshop.

PURPOSE: The following is a summary of discussion at a United States FDA (Food and Drug Administration) public workshop reviewing potential trial designs and end points to develop therapies to treat localized prostate cancer. MATERIALS AND METHODS: The workshop focused on the challenge that drug and device development to treat localized prostate cancer has been limited by the large trial sizes and lengthy timelines required to demonstrate an improvement in overall or metastasis-free survival and by the lack of agreed on alternative end points. Additionally, evolving treatment paradigms in the management of localized prostate cancer include the widespread use of active surveillance of patients with low and some intermediate risk prostate cancer, and the availability of advances in imaging and genomics. RESULTS: The workshop addressed issues related to trial design in this setting. Attendees discussed several potential novel end points such as a delay of morbidity due to radiation or prostatectomy and pathological end points such as Gleason Grade Group upgrade. CONCLUSIONS: The workshop provided an open forum for multiple stakeholder engagement to advance the development of effective treatment options for men with localized prostate cancer.

Exploration of baseline patient-reported side effect bother from cancer therapy.

BACKGROUND: Patient reports of expected treatment side effects are increasingly collected as part of the assessment of patient experience in clinical trials. A global side effect item that is patient-reported has the potential to inform overall tolerability. Therefore, the aim of this study was to examine the completion and distribution of such a global single-item measure of side effect burden in five cancer clinical trials. METHODS: Data from five trials from internal Food and Drug Administration databases that included the Functional Assessment of Cancer Therapy-General single-item measure of overall side effect burden (i.e. impact on degree of bother) were analyzed. Completion rates for the side effect bother item, items adjacent to this item, and two non-adjacent items on the Functional Assessment of Cancer Therapy-General that are related to health-related quality of life were calculated at the baseline assessment and at the 3-month assessment. To evaluate the distribution, the percentage of patients reporting high levels (quite a bit or very much bother) of side effect bother at baseline and 3 months was assessed. RESULTS: Completion rates for all items were at least 80% regardless of time point or trial population. However, in three of the five trials, completion rates for the side effect bother item were lower at baseline compared to adjacent and non-adjacent items. This difference was not observed at 3 months. Up to 9.4% of patients reported high levels of side effect bother at baseline. CONCLUSION: Patients may enter trials already reporting some bother from side effects. This can make interpretation of results with respect to the investigational agent under study challenging. Patients may skip an item evaluating side effect bother at baseline, suggesting some difficulty with interpretation of what is being asked. Further study of the wording and utility of a baseline side effect bother assessment is warranted.

FDA Approval Summary: Atezolizumab or Pembrolizumab for the Treatment of Patients with Advanced Urothelial Carcinoma Ineligible for Cisplatin-Containing Chemotherapy.

The U.S. Food and Drug Administration (FDA) granted accelerated approval to atezolizumab and pembrolizumab in April and May 2017, respectively, for the treatment of patients with locally advanced or metastatic urothelial carcinoma who are not eligible for cisplatin-containing chemotherapy. These approvals were based on efficacy and safety data demonstrated in the two single-arm trials, IMvigor210 (atezolizumab) and KEYNOTE-052 (pembrolizumab). The primary endpoint, confirmed objective response rate, was 23.5% (95% confidence interval [CI]: 16.2%-32.2%) in patients receiving atezolizumab and 28.6% (95% CI: 24.1%-33.5%) in patients receiving pembrolizumab. The median duration of response was not reached in either study and responses were seen regardless of PD-L1 status. The safety profiles of both drugs were generally consistent with approved agents targeting PD-1/PD-L1. Two ongoing trials (IMvigor130 and KEYNOTE-361) are verifying benefit of these drugs. Based on concerning preliminary reports from these trials, FDA revised the indications for both agents in cisplatin-ineligible patients. Both drugs are now indicated for patients not eligible for any platinum-containing chemotherapy or not eligible for cisplatin-containing chemotherapy and whose tumors/infiltrating immune cells express a high level of PD-L1. The indications for atezolizumab and pembrolizumab in patients who have received prior platinum-based therapy have not been changed. This article summarizes the FDA thought process and data supporting the accelerated approval of both agents and the subsequent revision of the indications. IMPLICATIONS FOR PRACTICE: The accelerated approvals of atezolizumab and pembrolizumab for cisplatin-ineligible patients with advanced urothelial carcinoma represent the first approved therapies for this patient population. These approvals were based on single-arm trials demonstrating reasonable objective response rates and favorable durations of response with an acceptable toxicity profile compared with available non-cisplatin-containing chemotherapy regimens. However, based on concerning preliminary reports from two ongoing phase III trials, the FDA revised the indication for both agents in cisplatin-ineligible patients. Both are now indicated either for patients not eligible for any platinum-containing chemotherapy or not eligible for cisplatin-containing chemotherapy and whose tumors have high expression of PD-L1.

Hepatotoxicity of immune checkpoint inhibitors: An evolving picture of risk associated with a vital class of immunotherapy agents.

Immune checkpoint inhibitors (ICIs) block CTLA-4, PD-1 and PD-L1, or other molecules that control antitumour activities of lymphocytes. These products are associated with a broad array of immune-related toxicities affecting a variety of organs, including the liver. ICI-associated immune-mediated hepatitis (IMH) ranges in severity between mild and life-threatening and is marked by findings that bear both similarities as well as differences with idiopathic autoimmune hepatitis. Hepatotoxic events are often detected in clinical trials of ICIs that are powered for efficacy. Risk levels for ICI-induced liver injury may be impacted by the specific checkpoint molecule targeted for treatment, the ICI dose levels, and the presence of a pre-existing autoimmune diathesis, chronic infection or tumour cells which infiltrate the liver parenchyma. When patients develop liver injury during ICI treatment, a prompt assessment of the cause of injury, in conjunction with the application of measures to optimally manage the adverse event, should be made. Strategies to manage the risk of IMH include the performance of pretreatment liver tests with regular monitoring during and after ICI treatment and patient education. Using Common Terminology Criteria for Adverse Events developed at the National Cancer Institute to measure the severity level of liver injury, recommended actions may include continued ICI treatment with close patient monitoring, ICI treatment suspension or discontinuation and/or administration of corticosteroids or, when necessary, a non-steroidal immunosuppressive agent. The elucidation of reliable predictors of tumour-specific ICI treatment responses, as well as an increased susceptibility for clinically serious immune-related adverse events, would help optimize treatment decisions for individual patients.

FDA Approval Summary: Atezolizumab for the Treatment of Patients with Progressive Advanced Urothelial Carcinoma after Platinum-Containing Chemotherapy.

Until recently in the United States, no products were approved for second-line treatment of advanced urothelial carcinoma. On May 18, 2016, the U.S. Food and Drug Administration approved atezolizumab for the treatment of patients with locally advanced or metastatic urothelial carcinoma whose disease progressed during or following platinum-containing chemotherapy or within 12 months of neoadjuvant or adjuvant treatment with platinum-containing chemotherapy. Atezolizumab is a programmed death-ligand 1 (PD-L1) blocking antibody and represents the first approved product directed against PD-L1. This accelerated approval was based on results of a single-arm trial in 310 patients with locally advanced or metastatic urothelial carcinoma who had disease progression after prior platinum-containing chemotherapy. Patients received atezolizumab 1,200 mg intravenously every 3 weeks until disease progression or unacceptable toxicity. Key efficacy measures were objective response rate (ORR), as assessed by Independent Review per RECIST 1.1, and duration of response (DoR). With a median follow-up of 14.4 months, confirmed ORR was 14.8% (95% CI: 11.1, 19.3) in all treated patients. Median DoR was not reached and response durations ranged from 2.1+ to 13.8+ months. Of the 46 responders, 37 patients had an ongoing response for ≥ 6 months. The most common adverse reactions (≥20%) were fatigue, decreased appetite, nausea, urinary tract infection, pyrexia, and constipation. Infection and immune-related adverse events also occurred, including pneumonitis, hepatitis, colitis, endocrine disorders, and rashes. Overall, the benefit-risk assessment was favorable to support accelerated approval. The observed clinical benefits need to be verified in confirmatory trial(s). IMPLICATIONS FOR PRACTICE: This accelerated approval of atezolizumab for second-line use in advanced urothelial carcinoma provides patients with an effective, novel treatment option for the management of their disease. This represents the first immunotherapy approved in this disease setting.

FDA Approval Summary: Nivolumab for the Treatment of Metastatic Non-Small Cell Lung Cancer With Progression On or After Platinum-Based Chemotherapy.

UNLABELLED: : On October 9, 2015, the U.S. Food and Drug Administration expanded the nivolumab metastatic non-small cell lung cancer (NSCLC) indication to include patients with nonsquamous NSCLC after a 3.25-month review timeline. Approval was based on demonstration of an improvement in overall survival (OS) in an international, multicenter, open-label, randomized trial comparing nivolumab to docetaxel in patients with metastatic nonsquamous NSCLC with progression on or after platinum-based chemotherapy. The CheckMate 057 trial enrolled 582 patients who were randomized (1:1) to receive nivolumab or docetaxel. Nivolumab demonstrated improved OS compared with docetaxel at the prespecified interim analysis with a hazard ratio (HR) of 0.73 (p = .0015), and a median OS of 12.2 months (95% CI: 9.7-15.0 months) in patients treated with nivolumab compared with 9.4 months (95% CI: 8.0-10.7 months) in patients treated with docetaxel. A statistically significant improvement in objective response rate (ORR) was also observed, with an ORR of 19% (95% CI: 15%-24%) in the nivolumab arm and 12% (95% CI: 9%-17%) in the docetaxel arm. The median duration of response was 17 months in the nivolumab arm and 6 months in the docetaxel arm. Progression-free survival was not statistically different between arms. A prespecified retrospective subgroup analysis suggested that patients with programmed cell death ligand 1-negative tumors treated with nivolumab had similar OS to those treated with docetaxel. The toxicity profile of nivolumab was consistent with the known immune-mediated adverse event profile except for 1 case of grade 5 limbic encephalitis, which led to a postmarketing requirement study to better characterize immune-mediated encephalitis. IMPLICATIONS FOR PRACTICE: Based on the results from the CheckMate 057 clinical trial, nivolumab represents a new treatment option for patients requiring second-line treatment for metastatic non-small cell lung cancer. The role of nivolumab in patients with sensitizing epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) alterations is less clear. Until dedicated studies are performed to better characterize the role and sequence of programmed cell death 1 (PD-1) therapy, patients with EGFR or ALK alterations should have progressed on appropriate targeted therapy before initiating PD-1 inhibitor therapy. Some patients whose tumors lack programmed cell death ligand 1 (PD-L1) expression also appear to have durable responses. The U.S. Food and Drug Administration granted approval to Dako's PD-L1 test, PD-L1 IHC 28-8 pharmDx, which the applicant claimed as a nonessential complementary diagnostic for nivolumab use.

Bone-targeting agents in prostate cancer.

Bone metastases are present in the vast majority of men with advanced prostate cancer, representing the main cause for morbidity and mortality. Recurrent or metastatic disease is managed initially with androgen deprivation but the majority of the patients eventually will progress to castration-resistant prostate cancer, with patients developing bone metastases in most of the cases. Survival and growth of the metastatic prostate cancer cells is dependent on a complex microenvironment (onco-niche) that includes the osteoblasts, the osteoclasts, the endothelium, and the stroma. This review summarizes agents that target the pathways involved in this complex interaction between prostate cancer and bone microenvironment and aim to transform lethal metastatic prostate cancer into a chronic disease.

Optimal sequencing of docetaxel and abiraterone in men with metastatic castration-resistant prostate cancer.

BACKGROUND: Recent advances have yielded multiple new life-prolonging treatments for men with metastatic castration-resistant prostate cancer (mCRPC) including chemotherapy, next-generation hormonal therapy, immunotherapy, and radiopharmaceutical products. However, the optimal sequencing of these agents to maximize clinical benefit remains unclear. Recent data from the CHAARTED and STAMPEDE studies suggest that early use of docetaxel in men with metastatic hormone-sensitive prostate cancer (mHSPC) significantly improves survival, but whether early compared with delayed use of chemotherapy also provides a survival advantage in mCRPC is unknown. METHODS: A retrospective analysis of consecutive mCRPC patients treated at Johns Hopkins is reported. Patients included were treated with sequential docetaxel and abiraterone, in either order. The combined progression-free survival (combined PFS: PFS1 + PFS2) of abiraterone-to-docetaxel is compared to the reverse sequence, where PFS1 and PFS2 represent progression-free survival on the first and second agents respectively. Overall survival (OS) from the start of the first therapy to death is compared between groups. Baseline characteristics are reported prior to the start of the first agent in the sequence. Propensity score-weighted multivariable models and Kaplan-Meier analysis are used for evaluation of the primary and secondary outcomes. RESULTS: Fifty-eight patients who began treatment for mCRPC between January 2011 (the year of abiraterone's FDA-approval) and February 2015 were identified: 26 were in the docetaxel-to-abiraterone group and 32 were in the abiraterone-to-docetaxel group. Patients in the abiraterone-to-docetaxel group had more Gleason 8-10 tumors, greater metastatic burden in bone, and higher median PSAs than those in the docetaxel-to-abiraterone group. Propensity score-weighted univariate analyses for combined PFS (HR 0.82; 95%CI 0.50-1.33; P = 0.41) and OS (HR 0.79; 95%CI 0.50-1.25; P = 0.31) do not identify any significant differences based on treatment sequence. Propensity score-weighted multivariate analyses for combined PFS (HR 0.91; 95%CI 0.52-1.60; P = 0.74) and OS (HR 0.98; 95%CI 0.59-1.63; P = 0.95) also do not identify any significant differences between groups. CONCLUSIONS: We do not observe differences in clinical outcomes based on alternative sequencing of abiraterone and docetaxel in men with mCRPC. Treatment sequencing should be determined by patient and disease characteristics, comorbidities and end-organ function, ability to tolerate side effects, and patient preferences. Studies evaluating biomarkers to inform optimal treatment sequencing in men with mCRPC are urgently needed.

Clinical activity of enzalutamide versus docetaxel in men with castration-resistant prostate cancer progressing after abiraterone.

BACKGROUND: The optimal sequencing of the multiple active agents now available for metastatic castration-resistant prostate cancer (mCRPC) is unclear. Prior reports have suggested diminished responses to sequential lines of androgen receptor (AR)-targeted therapies, but it is unknown whether subsequent taxane-based chemotherapy may be more effective than sequential AR-targeting treatment. We sought to evaluate the clinical activity of enzalutamide versus docetaxel in men with mCRPC who progressed on abiraterone. METHODS: We performed a single-institution retrospective analysis of consecutive mCRPC patients who had progressed on abiraterone therapy and subsequently received either enzalutamide (n=30) or docetaxel (n=31). We evaluated clinical outcomes including prostate-specific antigen decline of >30% (PSA30) or >50% (PSA50), PSA-progression-free survival (PSA-PFS), and clinical/radiographic PFS. We performed multivariable modeling to control for baseline and on-treatment differences between groups. RESULTS: Compared to subjects who received enzalutamide post-abiraterone, subjects who received docetaxel post-abiraterone had more bone metastases, more visceral metastases, higher baseline PSA, and had more frequent PSA tests while on-treatment. There were no significant differences in PSA30 (41% for enzalutamide vs. 53% for docetaxel) or PSA50 (34% vs. 40%) response rates between the two groups; there remained no difference after stratifying by presence/absence of prior response to abiraterone. Median PSA-PFS was 4.1 versus 4.1 months for the enzalutamide and docetaxel cohorts, respectively (HR 1.35, 95% CI, 0.53-3.66, P=0.502). Median PFS was 4.7 versus 4.4 months, respectively (HR 1.44, 95% CI, 0.77-2.71, P=0.257). PSA-PFS and PFS did not differ after stratifying by prior response to abiraterone. In multivariable analyses, there were no significant differences in PSA-PFS or PFS between the two groups. CONCLUSIONS: Treatment with either enzalutamide or docetaxel produced modest PSA responses and PFS intervals in this abiraterone-pretreated mCRPC population. In this retrospective study with small sample size, no significant differences in outcomes were observed between groups. Therefore, either enzalutamide or docetaxel may be a reasonable option in men who have progressed on abiraterone.

Cytoreductive nephrectomy in the era of immune checkpoint inhibitors: a US Food and Drug Administration pooled analysis.

BACKGROUND: This pooled analysis of patient-level data from trials evaluated the clinical outcomes of patients with metastatic renal cell carcinoma with or without cytoreductive nephrectomy before a combination of immune checkpoint inhibitor and antiangiogenic therapy. METHODS: Data from 5 trials of immune checkpoint inhibitors plus antiangiogenic therapy were pooled. Only patients with stage 4 disease at initial diagnosis were included to ensure that nephrectomy was performed for cytoreductive purposes and not to previously treat an earlier stage of disease. The effect of cytoreductive nephrectomy before immune checkpoint inhibitor therapy on outcomes was evaluated using the Kaplan-Meier method and a Cox proportional hazards regression model, adjusted for age, sex, risk group, performance status, and the presence of sarcomatoid differentiation. RESULTS: A total of 981 patients were included. The estimated median progression-free survival with and without nephrectomy was 15 and 11 months, respectively; the adjusted hazard ratio was 0.71 (95% confidence interval = 0.59 to 0.85). The estimated median overall survival with and without nephrectomy was 46 and 28 months, respectively; the adjusted hazard ratio was 0.63 (95% confidence interval = 0.51 to 0.77). Objective response was 60% of patients with vs 46% of patients without cytoreductive nephrectomy. CONCLUSIONS: Patients with metastatic renal cell carcinoma who undergo cytoreductive nephrectomy before immune checkpoint inhibitor plus antiangiogenic therapy had improved outcomes compared with patients without cytoreductive nephrectomy. Selection factors for cytoreductive nephrectomy may be prognostic and could not be fully controlled for in this retrospective analysis. Prospective determination of and stratification by prior cytoreductive nephrectomy may be considered when designing clinical trials to assess the impact of this factor on prognosis.

FDA Approval Summary: Enfortumab Vedotin plus Pembrolizumab for Cisplatin-Ineligible Locally Advanced or Metastatic Urothelial Carcinoma.

On April 3, 2023, the FDA granted accelerated approval to enfortumab vedotin-ejfv (EV) plus pembrolizumab for treatment of patients with locally advanced or metastatic urothelial carcinoma who are ineligible for cisplatin-containing chemotherapy. Substantial evidence of effectiveness was obtained from EV-103/KEYNOTE-869 (NCT03288545), a multicohort study. Across cohorts, a total of 121 patients received EV 1.25 mg/kg (maximum of 125 mg) intravenously on days 1 and 8 of a 21-day cycle plus pembrolizumab 200 mg intravenously on day 1 of each 21-day cycle until disease progression or unacceptable toxicity. The major efficacy outcome measures were objective response rate (ORR) and duration of response (DoR), determined by blinded independent central review using RECIST v1.1. The confirmed ORR in 121 patients was 68% (95% confidence interval, 59-76), including 12% with complete responses. The median DoR for the 82 responders was 22 months (range: 1+ to 46+). The safety profile of the combination comprised adverse reactions expected to occur with the corresponding monotherapies, but with overall increased frequency of adverse reactions, including skin toxicity, pneumonitis, and peripheral neuropathy. The article summarizes the data and the FDA thought process supporting accelerated approval of EV + pembrolizumab, as well as additional exploratory analyses conducted by the FDA.

Efficacy of Poly(ADP-ribose) Polymerase Inhibitors by Individual Genes in Homologous Recombination Repair Gene-Mutated Metastatic Castration-Resistant Prostate Cancer: A US Food and Drug Administration Pooled Analysis.

PURPOSE: We performed a pooled analysis of multiple trials of poly(ADP-ribose) polymerase inhibitors (PARPi) in metastatic castration-resistant prostate cancer (mCRPC) to investigate the efficacy of PARPi in each individual homologous recombination repair (HRR) mutated (m) gene. PATIENTS AND METHODS: We pooled patient-level data from trials of PARPi in mCRPC that reported mutation status in individual HRR genes. Any HRR gene with available data across all the randomized trials of PARPi in first-line mCRPC was selected. The hazard ratios (HRs; 95% CI) for radiographic progression-free survival (rPFS; by blinded independent review) and overall survival (OS) of a PARPi plus an androgen receptor pathway inhibitor (ARPI) relative to placebo plus an ARPI in the pool of three randomized trials in first-line mCRPC were calculated using Kaplan-Meier estimates and a Cox proportional hazards model. RESULTS: In ATMm (N = 268), rPFS HR was 1.05 (0.74 to 1.49) and OS HR was 1.18 (0.82 to 1.71). In BRCA1m (N = 64), rPFS HR was 0.51 (0.23 to 1.1) and OS HR was 0.74 (0.34 to 1.61). In BRCA2m (N = 422), rPFS HR was 0.31 (0.23 to 0.42) and OS HR was 0.66 (0.49 to 0.89). In CDK12m (N = 164), rPFS HR was 0.50 (0.32 to 0.80) and OS HR was 0.63 (0.39 to 0.99). In CHEK2m (N = 172), rPFS HR was 1.06 (0.67 to 1.66) and OS HR was 1.53 (0.95 to 2.46). In PALB2m (N = 41) rPFS HR was 0.52 (0.23 to 1.17) and OS HR was 0.78 (0.34 to 1.8). CONCLUSION: In this pooled analysis, benefit from PARPi appeared greatest for patients with BRCA1m, BRCA2m, CDK12m, and PALB2m. Given limitations of this exploratory analysis, the apparent lack of benefit from PARPi in patients with CHEK2m or ATMm should be further explored in future clinical trials.

A Pooled Analysis of Treatment-Free Survival in Advanced Renal Cell Carcinoma.

PURPOSE: A clinically meaningful attribute of some immune-oncology (IO) regimens is potential durable clinical benefit during a treatment-free interval. We characterize treatment-free survival (TFS) with and without ongoing toxicity in trials of frontline IO-VEGF tyrosine kinase inhibitor (TKI) combinations in patients with advanced renal cell carcinoma (aRCC). PATIENTS AND METHODS: Individual patient data were pooled by treatment arm from randomized trials submitted to the FDA evaluating IO-TKI combination in treatment-naïve aRCC with at least 30 months of median follow-up. OS, TFS, TFS with and without toxicity, and time to all protocol therapy cessation were assessed. TFS was estimated by 30-month restricted mean times defined as area between Kaplan-Meier curves for two time-to-event endpoints originating at randomization: time to all protocol therapy cessation and time to subsequent systemic therapy initiation or death. RESULTS: Three trials met criteria for analysis; 1183 pts received IO-TKI versus 1184 on control arms received TKI alone (sunitinib [SUN]). IO-TKI and SUN groups spent 9% (2.7 months [95% confidence interval (CI): 1.8, 3.5]) and 10% (2.9 months [95% CI: 2.1, 3.8]) of the 30-mo period alive and treatment-free, respectively. Mean TFS without grade ≥3 toxicity was 1.7 and 2.3 months in IO-TKI and SUN groups, respectively. CONCLUSIONS AND RELEVANCE: In this post hoc partitioned survival analysis, TFS and TFS without toxicity appeared similar in the IO-TKI group compared to the SUN group. These findings may reflect continuation of TKI until progression per protocol design in all trials and discontinuation of IO after 2 years in 2 trials.

FDA Approval Summary: Olaparib in Combination With Abiraterone for Treatment of Patients With BRCA-Mutated Metastatic Castration-Resistant Prostate Cancer.

PURPOSE: This article summarizes the US Food and Drug Administration (FDA) review of the data leading to approval of olaparib plus abiraterone for the treatment of patients with deleterious or suspected deleterious BRCA-mutated (BRCAm) metastatic castration-resistant prostate cancer (mCRPC), as determined by an FDA-approved companion diagnostic test. PATIENTS AND METHODS: Approval was based on the results from PROpel, a double-blind trial that randomly assigned 796 patients with mCRPC to abiraterone plus prednisone or prednisolone with either olaparib or placebo. The primary end point was radiographic progression-free survival (rPFS) per investigator assessment. RESULTS: There was a statistically significant improvement in rPFS for olaparib plus abiraterone versus placebo plus abiraterone, with a median rPFS of 25 versus 17 months and a hazard ratio (HR) of 0.66 (95% CI, 0.54 to 0.81) in the intention-to-treat population. In an exploratory analysis of the subgroup of 85 patients with BRCAm mCRPC, the HR for rPFS was 0.24 (95% CI, 0.12 to 0.45) and the HR for overall survival (OS) was 0.30 (95% CI, 0.15 to 0.59). In an exploratory analysis of the subgroup of 711 patients without an identified BRCA mutation, the HR for rPFS was 0.77 (95% CI, 0.63 to 0.96) and the HR for OS was 0.92 (95% CI, 0.74 to 1.14). Adding olaparib to abiraterone resulted in increased toxicity, including anemia requiring transfusion in 18% of patients. CONCLUSION: In patients with mCRPC, efficacy of the combination of olaparib plus abiraterone was primarily attributed to the treatment effect in the BRCAm subgroup, the indicated population for the approval. For patients without BRCAm, the FDA determined that the modest rPFS improvement, combined with clinically significant toxicities, did not demonstrate a favorable risk/benefit assessment.

US Food and Drug Administration Approval Summary: Talazoparib in Combination With Enzalutamide for Treatment of Patients With Homologous Recombination Repair Gene-Mutated Metastatic Castration-Resistant Prostate Cancer.

PURPOSE: The US Food and Drug Administration (FDA) approved talazoparib with enzalutamide for first-line treatment of patients with homologous recombination repair (HRR) gene-mutated metastatic castration-resistant prostate cancer (mCRPC). PATIENTS AND METHODS: The approval was based on the HRR gene-mutated (HRRm) population of TALAPRO-2, a randomized, double-blind trial that randomly assigned 1,035 patients with mCRPC to receive enzalutamide with either talazoparib or placebo. Two cohorts enrolled sequentially: an all-comer population (Cohort 1), followed by an HRRm-only population (Cohort 2). The independent primary end points were radiographic progression-free survival (rPFS) per blinded independent central review (BICR) in Cohort 1 (all-comers) and in the combined HRRm population (all HRRm patients from Cohorts 1 and 2). Overall survival (OS) was a key secondary end point. RESULTS: A statistically significant improvement in rPFS by BICR was demonstrated in both the all-comers cohort and the combined HRRm population, with hazard ratio (HR) of 0.63 (95% CI, 0.51 to 0.78; P < .0001) and 0.45 (95% CI, 0.33 to 0.61; P < .0001), respectively. In an exploratory analysis of the 155 patients with BRCA-mutated (BRCAm) mCRPC, rPFS HR was 0.20 (95% CI, 0.11 to 0.36). In the non-HRRm/unknown stratum of Cohort 1 (n = 636), the rPFS HR was 0.70 (95% CI, 0.54 to 0.89). OS was immature. CONCLUSION: Despite a statistically significant rPFS improvement in the all-comer cohort, FDA did not consider the magnitude of rPFS clinically meaningful in the context of the broad indication, combination treatment, and safety profile. Approval was therefore limited to patients with HRRm mCRPC, for whom there was a statistically significant and clinically meaningful improvement in rPFS and favorable OS results. This represents the first approval for the first-line treatment of patients with HRRm mCRPC.

A U.S. Food and Drug Administration-pooled Analysis of Frontline Combination Treatment Survival Benefits by Risk Groups in Metastatic Renal Cell Carcinoma.

BACKGROUND: While frontline immuno-oncology/tyrosine kinase inhibitor (IO/TKI) combination therapy has established a benefit in metastatic renal cell carcinoma (mRCC), this may differ by International Metastatic RCC Database Consortium (IMDC) risk grouping. Looking at individual trials, we noted an apparently smaller magnitude of benefit for favorable-risk disease. OBJECTIVE: We aimed to assess treatment benefit by risk groupings, especially in favorable-risk, augmenting patient numbers via a pooled analysis. DESIGN, SETTING, AND PARTICIPANTS: We pooled four frontline mRCC trials of IO/TKI combinations including 3,098 patients (839 favorable-risk) with approvals from 2019 to 2021. INTERVENTION: All trials used IO/TKI combinations as the treatment option and sunitinib as the control. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We analyzed progression-free survival (PFS) and overall survival (OS) by IMDC groupings. To specifically address the favorable-risk group, we combined all others into an intermediate/poor-risk group. RESULTS AND LIMITATIONS: In this exploratory analysis adjusted for baseline covariates, IO/TKI combinations have yet to demonstrate an OS benefit in favorable-risk (hazard ratio [HR] 1.24; 95% confidence interval [CI]: 0.86, 1.78) despite demonstrating an OS benefit in the intermediate/poor-risk group (HR 0.64; 95% CI: 0.55, 0.75). In contrast, IO/TKI demonstrated a PFS benefit for both the favorable-risk (HR 0.63; 95% CI: 0.50, 0.79) and the intermediate/poor-risk (HR 0.52; 95% CI: 0.45, 0.60) group. For objective response rate, a smaller difference was observed between the combination and sunitinib arms in favorable-risk (68.2% vs 49.9%) versus intermediate/poor-risk (59.9% vs 36.5%) groups, while the difference in complete response rate was larger for favorable-risk (15.3% vs 6.0%) versus intermediate/poor-risk (9.1% vs 3.4%) groups. CONCLUSIONS: The frontline IO/TKI combination therapy benefit was shown to be greater in the intermediate/poor-risk group than in the favorable-risk group. The OS benefit observed with IO/TKI for mRCC has yet to be demonstrated for favorable-risk patients; longer follow-up is needed. PATIENT SUMMARY: Patients with intermediate/poor-risk metastatic renal cell carcinoma derive an overall survival benefit from immuno-oncology/tyrosine kinase inhibitor combinations, while data for favorable-risk remain immature.

FDA Approval Summary: Lutetium Lu 177 Vipivotide Tetraxetan for Patients with Metastatic Castration-Resistant Prostate Cancer.

On March 23, 2022, the FDA approved Pluvicto (lutetium Lu 177 vipivotide tetraxetan, also known as 177Lu-PSMA-617) for the treatment of adult patients with prostate-specific membrane antigen (PSMA)-positive metastatic castration-resistant prostate cancer (mCRPC) who have been treated with androgen receptor pathway inhibition and taxane-based chemotherapy. The recommended 177Lu-PSMA-617 dose is 7.4 gigabecquerels (GBq; 200 mCi) intravenously every 6 weeks for up to six doses, or until disease progression or unacceptable toxicity. The FDA granted traditional approval based on VISION (NCT03511664), which was a randomized (2:1), multicenter, open-label trial that assessed the efficacy and safety of 177Lu-PSMA-617 plus best standard of care (BSoC; n = 551) or BSoC alone (n = 280) in men with progressive, PSMA-positive mCRPC. Patients were required to have received ≥1 androgen receptor pathway inhibitor, and one or two prior taxane-based chemotherapy regimens. There was a statistically significant and clinically meaningful improvement in overall survival (OS), with a median OS of 15.3 months in the 177Lu-PSMA-617 plus BSoC arm and 11.3 months in the BSoC arm, respectively (HR: 0.62; 95% confidence interval: 0.52-0.74; P < 0.001). The most common adverse reactions (≥20%) occurring at a higher incidence in patients receiving 177Lu-PSMA-617 were fatigue, dry mouth, nausea, anemia, decreased appetite, and constipation. The most common laboratory abnormalities that worsened from baseline in ≥30% of patients receiving 177Lu-PSMA-617 were decreased lymphocytes, decreased hemoglobin, decreased leukocytes, decreased platelets, decreased calcium, and decreased sodium. This article summarizes the FDA review of data supporting traditional approval of 177Lu-PSMA-617 for this indication.

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.