Improving Collection and Analysis of Overall Survival Data.

Advances in anticancer therapies have provided crucial benefits for millions of patients who are living long and fulfilling lives. While these successes should be celebrated, there is certainly room to continue improving cancer care. Increased long-term survival presents additional challenges for determining whether new therapies further extend patients' lives through clinical trials, commonly known as the gold standard endpoint of overall survival (OS). As a result, there is an increasing reliance on earlier efficacy endpoints , which may or may not correlate with OS, to continue the timely pace of translating innovation into novel therapies available for patients. Even when not powered as an efficacy endpoint, OS remains a critical indication of safety for regulatory decisions and is a key aspect of the U.S. Food and Drug Administration's Project Endpoint. Unfortunately, in the pursuit of earlier endpoints, many registrational clinical trials lack adequate planning, collection, and analysis of OS data, which complicates interpretation of a net clinical benefit or harm. This article shares best practices, proposes novel statistical methodologies, and provides detailed recommendations to improve the rigor of using OS data to inform benefit-risk assessments, including incorporating the following in clinical trials intending to demonstrate the safety and effectiveness of a cancer therapy: prospective collection of OS data, establishment of fit-for-purpose definitions of OS detriment, and prespecification of analysis plans for using OS data to evaluate for potential harm. These improvements hold promise to help regulators, patients and providers better understand the benefits and risks of novel therapies.

Impact of Increasing PD-L1 Levels on Outcomes to PD-1/PD-L1 Inhibition in Patients With NSCLC: A Pooled Analysis of 11 Prospective Clinical Trials.

BACKGROUND: Programmed death ligand 1 (PD-L1) expression is recognized as a key biomarker in the treatment of non-small cell lung cancer (NSCLC) with anti-PD(L)1 inhibitors. Previous work has highlighted that outcomes in patients with NSCLC treated with anti-PD(L)1 inhibitors generally improve with increasing PD-L1 expression. The objectives of these analyses are to quantitate the effect of PD-L1 expression on outcomes, to characterize the potentially nonlinear relationship between PD-L1 expression and outcomes, and to assess potential differences in these relationships across subgroups. PATIENTS AND METHODS: We performed a retrospective, pooled analysis of 11 clinical trials submitted to the US FDA between 2015 and 2022 that included patients with advanced NSCLC treated with anti-programmed death 1 or anti-PD-L1 immune checkpoint inhibitor (ICI) monotherapy in the first-line (1L) or second-line (2L) treatment setting. The clinical outcomes explored were overall survival (OS), progression-free survival (PFS), and objective response rate (ORR). RESULTS: The primary analysis population included 3806 patients with advanced NSCLC, of which 2040 were treated in 1L and 1766 in 2L. For patients with a PD-L1 score of 100% in the 1L setting, the hazard ratio versus a patient with 1% PD-L1 was 0.55 (95% CI, 0.43 to 0.70) for OS and 0.50 (95% CI, 0.41 to 0.61) for PFS. For patients with a PD-L1 score of 100% in the 2L setting, the hazard ratio versus a patient with 0% PD-L1 was 0.55 (95% CI, 0.43 to 0.71) for OS and 0.51 (95% CI, 0.41 to 0.63) for PFS. Subgroup analyses suggested that this relationship may vary by subgroup, particularly by region. CONCLUSIONS: These analyses suggest PD-L1 expression has an appreciable impact on clinical outcomes for patients with NSCLC treated with ICI. As the impact of PD-L1 expression on outcomes may vary across regions, it is critical that future trials are multiregional and enroll a diverse patient population.

FDA Approval Summary: Ivosidenib in Combination with Azacitidine for Treatment of Patients with Newly Diagnosed Acute Myeloid Leukemia with an IDH1 Mutation.

On May 25, 2022, FDA approved a supplemental application for ivosidenib (Tibsovo; Servier) extending the indication in patients with newly diagnosed IDH1-mutated acute myeloid leukemia (AML) in older adults or those with comorbidities to include the combination with azacitidine. The efficacy of ivosidenib in combination with azacitidine was evaluated in Study AG120-C-009, a phase 3, multicenter, double-blind, randomized (1:1), controlled study of ivosidenib or matched placebo in combination with azacitidine in adults with previously untreated AML with an IDH1 mutation who were 75 years or older or had comorbidities that precluded use of intensive induction chemotherapy. Efficacy was established on the basis of improved event-free survival and overall survival on the ivosidenib + azacitidine arm [HR, 0.35; 95% confidence interval (CI), 0.17-0.72; P = 0.0038, and HR, 0.44; 95% CI, 0.27-0.73; P = 0.0010], respectively. Furthermore, the rate and duration of complete remission (CR) were improved with ivosidenib versus placebo [CR 47% versus 15%, two-sided P < 0.0001; median duration of CR not estimable (NE; 95% CI, 13.0-NE) months versus 11.2 (95% CI, 3.2-NE) months. The safety profile of ivosidenib in combination with azacitidine was consistent with that of ivosidenib monotherapy, with important adverse reactions including differentiation syndrome (15%) and QT interval prolongation (20%).

SAM: Self-adapting mixture prior to dynamically borrow information from historical data in clinical trials.

Mixture priors provide an intuitive way to incorporate historical data while accounting for potential prior-data conflict by combining an informative prior with a noninformative prior. However, prespecifying the mixing weight for each component remains a crucial challenge. Ideally, the mixing weight should reflect the degree of prior-data conflict, which is often unknown beforehand, posing a significant obstacle to the application and acceptance of mixture priors. To address this challenge, we introduce self-adapting mixture (SAM) priors that determine the mixing weight using likelihood ratio test statistics or Bayes factors. SAM priors are data-driven and self-adapting, favoring the informative (noninformative) prior component when there is little (substantial) evidence of prior-data conflict. Consequently, SAM priors achieve dynamic information borrowing. We demonstrate that SAM priors exhibit desirable properties in both finite and large samples and achieve information-borrowing consistency. Moreover, SAM priors are easy to compute, data-driven, and calibration-free, mitigating the risk of data dredging. Numerical studies show that SAM priors outperform existing methods in adopting prior-data conflicts effectively. We developed R package "SAMprior" and web application that are freely available at CRAN and www.trialdesign.org to facilitate the use of SAM priors.

Improving Dose-Optimization Processes Used in Oncology Drug Development to Minimize Toxicity and Maximize Benefit to Patients.

This review highlights strategies to integrate dose optimization into premarketing drug development and discusses the underlying statistical principles. Poor dose optimization can have negative consequences for patients, most commonly because of toxicity, including poor quality of life, reduced effectiveness because of inability of patients to stay on current therapy or receive subsequent therapy because of toxicities, and difficulty in developing combination regimens. We reviewed US Food and Drug Administration initial approvals (2019-2021) of small molecules and antibody-drug conjugates for oncologic indications to determine the proportion with a recommended dosage at the maximum tolerated dose or the maximal administered dose, to characterize the use of randomized evaluations of multiple dosages in dose selection, to describe the frequency of dose modifications at the recommended dosage, and to identify case examples that highlight key principles for premarket dose optimization during drug development. Herein, we highlight major principles for dose optimization and review examples of recent US Food and Drug Administration approvals that illustrate how investigation of dose- and exposure-response relationships and use of randomized dose trials can support dose optimization. Although there has been some progress, dose optimization through randomized dose evaluation in oncology trials is not routinely conducted. Dose optimization is essential to ensure that patients receive therapies which maximize efficacy while minimizing toxicity.

FDA Approval Summary: Revised Indication and Dosing Regimen for Ponatinib Based on the Results of the OPTIC Trial.

On December 18, 2020, US Food and Drug Administration (FDA) approved a supplemental application for ponatinib extending the indication in patients with chronic-phase chronic myeloid leukemia (CP-CML) to patients with resistance or intolerance of at least 2 prior kinase inhibitors. Ponatinib was initially approved in December 2012 but was briefly voluntarily withdrawn due to serious safety concerns including the risk of arterial occlusive events (AOE). It returned to the market in December 2013 with an indication limited to patients with T315I mutation or for whom no other tyrosine kinase inhibitor (TKI) therapy was indicated with revised warnings and precautions. A post-marketing requirement was issued to identify the optimal safe and effective dose for CP-CML. Thus, the OPTIC trial was performed, which randomized patients to 1 of 3 doses, 45 mg, 30 mg, or 15 mg, with a dose reduction to 15 mg on achievement of MR2 (BCR-ABLIS ≤1%). Patients enrolled were treated with at least 2 prior TKIs or had a T315I mutation. Patients with a history of clinically significant, uncontrolled, or active cardiovascular disease were excluded. Efficacy was established on an interim analysis based on the rate of MR2 at 12 months in the modified intent-to-treat population of 261 patients, with 88, 86, and 87 patients in the 45, 30, and 15 mg cohorts, respectively. With a median follow-up of 28 months, the rate of achievement of MR2 at 12 months was 42%, 28%, and 24% in the respective cohorts. The safety profile was consistent with that observed in prior evaluations of ponatinib with notable adverse reactions including pancreatitis, hypertension, hyperlipidemia, liver dysfunction, and AOE. Of patients treated at the 45/15 mg dose, AOEs were seen in 13%, with a higher rate being observed in patients age 65 or older compared to younger patients. A readjudication of AOEs seen on the prior pivotal phase 2 study resulted in a rate of 26%. Overall, the results supported a modification of the recommended dose for patients with CP-CML to 45 mg until the achievement of MR2 followed by a reduction to 15 mg. The expansion of the indication to patients with exposure to 2 prior TKIs was approved given data showing that ponatinib could be successfully used for the treatment of this population with appropriate monitoring and screening for risk factors.

FDA Approval Summary: Decitabine and Cedazuridine Tablets for Myelodysplastic Syndromes.

On July 7, 2020, the Food and Drug Administration approved Inqovi (Otsuka Pharmaceutical Co.), an oral fixed-dose combination tablet comprising 35 mg decitabine, a hypomethylating agent, and 100 mg cedazuridine, a cytidine deaminase inhibitor (abbreviated DEC-C) for treatment of adult patients with myelodysplastic syndromes (MDS). Evidence of effectiveness of DEC-C was established in phase III ASTX727-02 (N = 133) in adults with MDS. The study involved a two-sequence crossover comparing DEC-C and intravenous (IV) decitabine 20 mg/m2 once daily for the first 5 days of each 28-day cycle in the first 2 cycles. From cycle 3 onward, patients received DEC-C. Five-day cumulative area under the curve (5-d AUC) of decitabine for DEC-C was similar to that of IV decitabine, with geometric mean ratio 0.99 (90% confidence interval: 0.93-1.06). Clinical benefit was supported by study ASTX727-02 and the similarly designed phase II study ASTX727-01-B (n = 80), with complete remission (CR) of 21% and 18% and median duration of CR 7.5 and 8.7 months, respectively. Adverse reactions were consistent with IV decitabine. Postmarketing assessments were issued to address the effect of cedazuridine on QT prolongation, food effect, moderate and severe hepatic impairment, and severe renal impairment on the pharmacokinetics and safety of DEC-C.

FDA Approval Summary: Ruxolitinib for Treatment of Chronic Graft-Versus-Host Disease after Failure of One or Two Lines of Systemic Therapy.

On September 22, 2021, the Food and Drug Administration approved ruxolitinib for the treatment of chronic graft-versus-host disease (cGVHD) after the failure of one or two lines of systemic therapy in adult and pediatric patients 12 years and older. Approval was based on Study INCB 18424-365 (REACH-3; CINC424D2301; NCT03112603), a randomized, open-label, multicenter trial of ruxolitinib in comparison to best available therapy (BAT) for the treatment of corticosteroid-refractory cGVHD occurring after the allogeneic hematopoietic stem cell transplantation. A total of 329 patients were randomized 1:1 to receive either ruxolitinib 10 mg twice daily (n = 165) or BAT (n = 164). BAT was selected by the investigator prior to randomization. The overall response rate through Cycle 7 Day 1 was 70% (95% CI, 63-77) in the ruxolitinib arm, and 57% (95% CI, 49-65) in the BAT arm. The median duration of response, calculated from first response to progression, death, or initiation of new systemic therapies for cGVHD, was 4.2 months (95% CI, 3.2-6.7) for the ruxolitinib arm and 2.1 months (95% CI, 1.6-3.2) for the BAT arm; and the median time from first response to death or initiation of new systemic therapies for cGVHD was 25 months (95% CI, 16.8-not estimable) for the ruxolitinib arm and 5.6 months (95% CI, 4.1-7.8) for the BAT arm. Common adverse reactions included anemia, thrombocytopenia, and infections. Given the observed response rate with durability, the clinical benefit of ruxolitinib appears to outweigh the risks of treatment for cGVHD after the failure of one or two lines of systemic therapy.

FDA Approval Summary: Oral Azacitidine for Continued Treatment of Adults with Acute Myeloid Leukemia Unable to Complete Intensive Curative Therapy.

On September 1, 2020, the FDA granted approval for oral azacitidine (Onureg, CC-486) for continued treatment of adult patients with acute myeloid leukemia (AML) who achieved complete remission (CR) or complete remission with incomplete blood count recovery (CRi) following intensive induction chemotherapy and who are not able to complete intensive curative therapy. Approval was based on improvement in overall survival using CC-486 300 mg daily in a 2 weeks on/2 weeks off schedule in comparison with placebo (HR, 0.69; 95% confidence interval, 0.55-0.86; P = 0.0009) in the randomized trial CC-486-AML-001 (QUAZAR) in adults ≥ 55 years old with AML in CR/CRi who did not complete standard intensive induction and postremission therapy. Of note, the study was not designed to test CC-486 as maintenance after standard postremission therapy or as an alternative to standard postremission therapy. Gastrointestinal toxicities, fatigue, and pneumonia were more common in patients treated with CC-486 compared with placebo. Additional studies are needed to establish safe dosing for patients with hepatic impairment. The pharmacokinetic parameters, recommended dose, and recommended schedule of CC-486 differ substantially from those of other azacitidine formulations; therefore, inappropriate substitutions between formulations pose a considerable risk for harm.

FDA Approval Summary: Belumosudil for Adult and Pediatric Patients 12 Years and Older with Chronic GvHD after Two or More Prior Lines of Systemic Therapy.

On July 16, 2021, the FDA approved belumosudil, a kinase inhibitor, for adult and pediatric patients 12 years and older with chronic GvHD (cGvHD) after failure of at least two prior lines of systemic therapy. Approval was based on the results of Study KD025-213, which included 65 patients with cGvHD treated with belumosudil 200 mg daily in an open-label, single-arm cohort. Efficacy was determined by the overall response rate (ORR) through Cycle 7 Day 1, which included complete response (CR) or partial response (PR) according to the 2014 NIH consensus criteria, and durability of response. The ORR through Cycle 7 Day 1 was 75% [95% confidence interval (CI), 63-85]; 6% of patients achieved a CR, and 69% achieved a PR. The median duration of response was 1.9 months (95% CI, 1.2-2.9), and 62% (95% CI, 46-74) of responding patients remained alive without new systemic therapy for at least 12 months from response. The common adverse reactions were infections, asthenia, nausea, diarrhea, dyspnea, cough, edema, hemorrhage, abdominal pain, musculoskeletal pain, headache, phosphate decreased, gamma-glutamyl transferase increased, lymphocytes decreased, and hypertension. Additional study is warranted to confirm safety with long-term use.

Response Rate, Event-Free Survival, and Overall Survival in Newly Diagnosed Acute Myeloid Leukemia: US Food and Drug Administration Trial-Level and Patient-Level Analyses.

PURPOSE: To explore trial-level and patient-level associations between response (complete remission [CR] and CR + CR with incomplete hematologic [CRi] or platelet [CRp] recovery), event-free survival (EFS), and overall survival (OS) in newly diagnosed acute myeloid leukemia (AML) trials of intensive chemotherapy. METHODS: We identified data from eight randomized, active-controlled trials of intensive chemotherapy submitted to the US Food and Drug Administration for treatment of newly diagnosed AML (N = 4,482). Associations between trial-level odds ratios (ORs) for CR and CR + CRi or CRp, and hazard ratios (HRs) for EFS and OS were analyzed using weighted linear regression models. We performed patient-level responder analyses to compare OS by response using pooled data from all studies. RESULTS: In trial-level analyses, association between HR for OS and OR for CR was moderate (R2 = 0.49; 95% CI, 0.05 to 0.86), as was the association with OR for CR + CRi or CRp (R2 = 0.48; 95% CI, 0.05 to 0.99). For OS versus EFS, a strong association was observed (R2 = 0.87; 95% CI, 0.47 to 0.98) when EFS definitions were harmonized across trials using raw data. In the patient-level responder analyses, patients who achieved CR had better OS compared with CRi or CRp responders (0.73; 95% CI, 0.64 to 0.84) and nonresponders (HR, 0.33; 95% CI, 0.31 to 0.37). CONCLUSION: On a trial level, there is a moderate association between OS and CR rate. A strong association between EFS and OS was observed. However, CIs were wide, and results became moderate using alternative definitions for EFS. Patient-level analyses showed CR responders have better OS compared with CRi or CRp responders and nonresponders. A therapy in newly diagnosed AML with benefit in EFS or substantial benefit in CR rate would be likely to have an OS effect.

FDA Approval Summary: Atezolizumab and Durvalumab in Combination with Platinum-Based Chemotherapy in Extensive Stage Small Cell Lung Cancer.

The U.S. Food and Drug Administration (FDA) granted approval to atezolizumab and durvalumab in March of 2019 and 2020, respectively, for use in combination with chemotherapy for first-line treatment of patients with extensive stage small cell lung cancer. These approvals were based on data from two randomized controlled trials, IMpower133 (atezolizumab) and CASPIAN (durvalumab). Both trials demonstrated an improvement in overall survival (OS) with anti-programmed death ligand 1 antibodies when added to platinum-based chemotherapy as compared with chemotherapy alone. In IMpower133, patients receiving atezolizumab with etoposide and carboplatin demonstrated improved OS (hazard ratio [HR], 0.70; 95% confidence interval [CI], 0.54-0.91; p = .0069), with median OS of 12.3 months compared with 10.3 months in patients receiving etoposide and carboplatin. In CASPIAN, patients receiving durvalumab with etoposide and either cisplatin or carboplatin also demonstrated improved OS (HR, 0.73; 95% CI, 0.59-0.91; p = .0047) with median OS of 13.0 months compared with 10.3 months in patients receiving etoposide and either cisplatin or carboplatin. The safety profiles of both drugs were generally consistent with known toxicities of immune-checkpoint inhibitor therapies. This review summarizes the FDA perspective and data supporting the approval of these two agents. IMPLICATIONS FOR PRACTICE: Effective therapeutic options for small cell lung cancer (SCLC) are limited, and there has been modest improvement in the overall survival (OS) of patients with SCLC over the past 3 decades. The approvals of atezolizumab and of durvalumab in combination with chemotherapy for first-line treatment of patients with extensive stage SCLC represent the first approved therapies with OS benefit for this patient population since the approval of etoposide in combination with other approved chemotherapeutic agents. Additionally, the efficacy results from IMpower133 and CASPIAN lay the groundwork for possible further evaluation in other treatment settings in this disease.

US Food and Drug Administration review of statistical analysis of patient-reported outcomes in lung cancer clinical trials approved between January, 2008, and December, 2017.

With the advent of patient-focused drug development, the US Food and Drug Administration (FDA) has redoubled its efforts to review patient-reported outcome (PRO) data in cancer trials submitted as part of a drug's marketing application. This Review aims to characterise the statistical analysis of PRO data from pivotal lung cancer trials submitted to support FDA drug approval between January, 2008, and December, 2017. For each trial and PRO instrument identified, we evaluated prespecified PRO concepts, statistical analysis, missing data and sensitivity analysis, instrument completion, and clinical relevance. Of the 37 pivotal lung cancer trials used to support FDA drug approval, 25 (68%) trials included PRO measures. The most common prespecified PRO concepts were cough, dyspnoea, and chest pain. At the trial level, the most common statistical analyses were descriptive (24 trials [96%]), followed by time-to-event analyses (19 trials [76%]), longitudinal analyses (12 trials [48%]), and basic inferential tests or general linear models (10 trials [40%]). Our findings indicate a wide variation in the analytic techniques and data presentation methods used, with very few trials reporting clear PRO research objectives and sensitivity analyses for PRO results. Our work further supports the need for focused research objectives to justify and to guide the analytic strategy of PROs to facilitate the interpretation of patient experience.

Overview of Oncology and Hematology Drug Approvals at US Food and Drug Administration Between 2008 and 2016.

BACKGROUND: We previously conducted an overview of oncology products reviewed by the Office of Oncology Drug Products in the Center for Drug Evaluation and Research at the US Food and Drug Administration for marketing approval and the regulatory actions taken during July 2005 to December 2007. There is a need to understand if the changes in the laws, regulations, and the organization that occurred after 2007 had any impact on the regulatory drug approvals. We present a detailed overview of hematology and oncology products reviewed by Office of Oncology Drug Products and Office of Hematology and Oncology Drug Products. METHODS: We identified all oncology-hematology applications that were submitted to the US Food and Drug Administration from January 1, 2008 through December 31, 2016, and reviewed the approval actions taken. RESULTS: During the study period, the Office of Hematology and Oncology Products approved 239 applications that supported 260 new indications. Of the 239 applications approved, 141 were approved via priority review and 98 were approved via standard review. Fifty-three of these applications were granted accelerated approval, 29 were converted from accelerated approval to regular approval, and 157 received regular approval. Since its promulgation in 2013, breakthrough designation status has been granted to 25.7% of applications. A variety of endpoints were used to support these approvals. CONCLUSION: During the study period, despite changes in the regulations and organization, the Office of Hematology and Oncology Products consistently utilized regulatory mechanisms that expedite the development and approval of promising oncology and hematology drug products resulting in the approval of 260 new indications.

FDA Supplemental Approval: Blinatumomab for Treatment of Relapsed and Refractory Precursor B-Cell Acute Lymphoblastic Leukemia.

On July 11, 2017, the Food and Drug Administration granted approval for blinatumomab for the treatment of relapsed or refractory (R/R) precursor B-cell acute lymphoblastic leukemia (ALL). Blinatumomab is a bispecific CD19-directed CD3 T-cell engager. The basis for the approval included results from two clinical trials, TOWER and ALCANTARA. TOWER, a randomized trial comparing overall survival in patients with Philadelphia chromosome (Ph)-negative R/R ALL receiving blinatumomab versus standard-of-care (SOC) chemotherapy, demonstrated a hazard ratio of 0.71 favoring blinatumomab (p = .012; median survival, 7.7 months with blinatumomab and 4.0 months with SOC chemotherapy). Complete remission (CR) rates were 34% for patients receiving blinatumomab and 16% for those receiving SOC. Adverse events were consistent with those observed in prior trials, with cytokine release syndrome and some neurologic events, including tremor, encephalopathy, peripheral neuropathy, and depression, observed more frequently in the blinatumomab arm, whereas neutropenia and infection were less common among patients receiving blinatumomab. Depression emerged as a rare but potentially severe neurologic event associated with blinatumomab. In ALCANTARA, a single-arm trial of blinatumomab in patients with Ph-positive R/R ALL, the CR rate was 31%, and adverse events were similar to those observed previously in Ph-negative R/R ALL. These results support conversion from accelerated to regular approval of blinatumomab for R/R ALL and broadening of the intended population to include both Ph-positive and Ph-negative precursor B-cell R/R ALL. IMPLICATIONS FOR PRACTICE: In TOWER, a randomized trial in patients with relapsed or refractory Philadelphia chromosome (Ph)-negative precursor B-cell acute lymphoblastic leukemia (ALL), treatment with blinatumomab showed superiority over conventional chemotherapy for complete remission (CR) rate (34% vs. 16%) and survival (3.7-month improvement in median; hazard ratio, 0.71). In ALCANTARA, a single-arm trial of blinatumomab for treatment of relapsed or refractory Ph-positive precursor B-cell ALL, the CR rate was 31%. Blinatumomab is now approved for treatment of relapsed or refractory precursor B-cell ALL that is Ph positive or Ph negative.