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.

Chemotherapy-induced peripheral neuropathy: Current status and progress.

As there are increasing numbers of cancer survivors, more attention is being paid to the long term unwanted effects patients may experience as a result of their treatment and the impact these side effects can have on their quality of life. Chemotherapy-induced peripheral neuropathy (CIPN) is one of the most common long-term toxicities from chemotherapy. In this review we will briefly review the clinical presentation, evaluation and management of chemotherapy-induced peripheral neuropathy, with a focus on CIPN related to platinum and taxane agents. We will then discuss current clinical models of peripheral neuropathy and ongoing research to better understand CIPN and develop potential treatment options.

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.

Advancing Clinical Trial Design for Non-Muscle Invasive Bladder Cancer.

BACKGROUND: Despite recent drug development for non-muscle invasive bladder cancer (NMIBC), few therapies have been approved by the US Food and Drug Administration (FDA), and there remains an unmet clinical need. Bacillus Calmette-Guerin (BCG) supply issues underscore the importance of developing safe and effective drugs for NMIBC. OBJECTIVE: On November 18-19, 2021, the FDA held a public virtual workshop to discuss NMIBC research needs and potential trial designs for future development of effective therapies. METHODS: Representatives from various disciplines including urologists, oncologists, pathologists, statisticians, basic and translational scientists, and the patient advocacy community participated. The workshop format included invited lectures, panel discussions, and opportunity for audience discussion and comment. RESULTS: In a pre-workshop survey, 92% of urologists surveyed considered the development of alternatives to BCG as a high drug development priority for BCG-naïve high-risk patients. Key topics discussed included definitions of disease states; trial design for BCG-naïve NMIBC, BCG-unresponsive carcinoma in situ, and BCG-unresponsive papillary carcinoma; strengths and limitations of single-arm trial designs; assessing patient-reported outcomes; and considerations for assessing avoidance of cystectomy as an efficacy measure. CONCLUSIONS: The workshop discussed several important opportunities for trial design refinement in NMIBC. FDA encourages sponsors to meet with the appropriate review division to discuss trial design proposals for NMIBC early in drug development.

Modernizing Clinical Trial Eligibility Criteria: Recommendations of the ASCO-Friends of Cancer Research Washout Period and Concomitant Medication Work Group.

PURPOSE: Washout periods and concomitant medication exclusions are common in cancer clinical trial protocols. These exclusion criteria are often applied inconsistently and without evidence to justify their use. The authors sought to determine how washout period and concomitant medication allowances can be broadened to speed trial enrollment and improve the generalizability of trial data to a larger oncology practice population without compromising the safety of trial participants. EXPERIMENTAL DESIGN: A multistakeholder working group was convened to define problems associated with excessively long washout periods and exclusion of patients due to concomitant medications. The group performed a literature search and evaluated study data from the Pancreatic Cancer Action Network (PanCAN), Emory University School of Medicine (Atlanta, GA), and the FDA to understand recent approaches to these eligibility criteria. The group convened to develop consensus recommendations for broadened eligibility criteria. RESULTS: The data analysis found that exclusion criteria based on washout periods and concomitant medications are frequently inconsistent and lack scientific rationale. Scientific rationale for appropriate eligibility criteria are presented in the article; for washout periods, rationale is presented by treatment type. CONCLUSIONS: Arbitrary or blanket washout and concomitant medication exclusions should be eliminated. Where there is evidence to support them, clinically relevant washout periods and concomitant medication-related eligibility criteria may be included.See related commentary by Giantonio, p. 2369.

An FDA Review of Drug Development in Nonmetastatic Castration-resistant Prostate Cancer.

The FDA has approved three androgen receptor inhibitors-enzalutamide, apalutamide, and darolutamide-for the treatment of patients with nonmetastatic castration-resistant prostate cancer (nmCRPC). These approvals were all based on randomized, double blind, placebo-controlled trials demonstrating large improvements in metastasis-free survival (MFS) and internally consistent evidence of benefit seen across secondary endpoints. In this article, we summarize the FDA regulatory history of MFS and we describe the design, conduct, and results of the three pivotal trials supporting these important treatment options for patients with nmCRPC.

Regulatory Considerations for Contribution of Effect of Drugs Used in Combination Regimens: Renal Cell Cancer Case Studies.

The development and review of combination drug regimens in oncology may present unique challenges to investigators and regulators. For regulatory approval of combination regimens, it is necessary to demonstrate the contribution of effect of each monotherapy to the overall combination. Alternative approaches to traditional designs may be needed to accelerate oncology drug development, for example, when combinations are substantially superior to available therapy, to reduce exposure to less effective therapies, and for drugs that are inactive as single agents and that in combination potentiate activity of another drug. These approaches include demonstration of activity in smaller randomized trials and/or monotherapy trials conducted in a similar disease setting. This article will discuss alternative approaches used in the development of approved drugs in combination, based on examples of recent approvals of combination regimens in renal cell carcinoma.