Round Table Discussion on Optimal Clinical Trial Design in Precursor Multiple Myeloma.

SUMMARY: While the current approach to precursor hematologic conditions is to "watch and wait," this may change with the development of therapies that are safe and extend survival or delay the onset of symptomatic disease. The goal of future therapies in precursor hematologic conditions is to improve survival and prevent or delay the development of symptomatic disease while maximizing safety. Clinical trial considerations in this field include identifying an appropriate at-risk population, safety assessments, dose selection, primary and secondary trial endpoints including surrogate endpoints, control arms, and quality-of-life metrics, all of which may enable more precise benefit-risk assessment.

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: Pirtobrutinib for Relapsed or Refractory Mantle Cell Lymphoma.

In January 2023, the FDA granted accelerated approval to pirtobrutinib for the treatment of adult patients with relapsed or refractory mantle cell lymphoma (MCL) after at least two lines of systemic therapy, including a Bruton tyrosine kinase (BTK) inhibitor. Approval was based on BRUIN, a single-arm study of pirtobrutinib monotherapy in patients with B-cell malignancies. Efficacy was based on independent review committee-assessed overall response rate (ORR) supported by durability of response in 120 patients with relapsed or refractory MCL who had received a prior BTK inhibitor and received the approved pirtobrutinib dosage of 200 mg once daily. The ORR was 50% [95% confidence interval (CI), 41-59], and the complete response rate was 13% (95% CI, 7-20), with an estimated median duration of response of 8.3 months. The most common nonhematologic adverse reactions were fatigue, musculoskeletal pain, diarrhea, edema, dyspnea, pneumonia, and bruising. Warnings and Precautions in labeling include infection, hemorrhage, cytopenias, atrial arrhythmias, and second primary malignancies. Postmarketing studies were required to evaluate longer-term safety of pirtobrutinib and to verify the clinical benefit of pirtobrutinib. This article summarizes key aspects of the regulatory review, including the indication statement, efficacy and safety considerations, and postmarketing requirements.

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.

Eligibility criteria and enrollment of a diverse racial and ethnic population in multiple myeloma clinical trials.

The narrow eligibility criteria may contribute to the underrepresentation of racial and ethnic subgroups in cancer clinical trials. We conducted a retrospective pooled analysis of multicenter global clinical trials submitted to the US Food and Drug Administration between 2006 and 2019 to support the approval of the use of multiple myeloma (MM) therapies that analyze the rates and reasons for trial ineligibility based on race and ethnicity in MM clinical trials. Race and ethnicity were coded per Office of Management and Budget standards. Patients flagged as having screen failures were identified as ineligible. Ineligibility rates were calculated as the percentage of patients who were ineligible compared with the screened population within the respective racial and ethnic subgroups. Trial eligibility criteria were grouped into specific categories to analyze the reasons for trial ineligibility. Black patients (24%) and other (23%) race subgroups had higher ineligibility rates than White patients (17%). The Asian race had the lowest ineligibility rate (12%) among all racial subgroups. Failure to meet the hematologic laboratory criteria (19%) and treatment-related criteria (17%) were the most common reasons for ineligibility among Black patients and were more common in Black patients than in other races. Failure to meet disease-related criteria was the most common reason for ineligibility among White (28%) and Asian (29%) participants. Our analysis indicates that specific eligibility criteria may contribute to enrollment disparities for racial and ethnic subgroups in MM clinical trials. However, the small number of screened patients in the underrepresented racial and ethnic subgroups limits definitive conclusions.

FDA Analysis of Ineligibility for Acute Myeloid Leukemia Clinical Trials by Race and Ethnicity.

BACKGROUND: Patients of certain racial and ethnic groups have been underrepresented in clinical trials for treatment of malignancy. One potential barrier to participation is entry requirements that lead to patients in various racial and ethnic groups not meeting eligibility criteria for studies (ie, "screen failure"). The objective of this study was to analyze the rates and reasons for trial ineligibility by race and ethnicity in trials of acute myeloid leukemia (AML) submitted to the U.S. Food and Drug Administration (FDA) between 2016 and 2019. MATERIALS AND METHODS: Multicenter, global clinical trials submitted to the FDA to support AML drugs and biologics. We examined the rate of ineligibility among participants screened for studies of AML therapies submitted to the FDA from 2016 to 2019. Data were extracted from 13 trials used in approval evaluations, including race, screen status, and reason for ineligibility. RESULTS: Overall, patients in historically underrepresented racial and ethnic groups were less likely to meet entry criteria for studies compared to White patients, with 26.7% of White patients, 29.4% of Black patients, and 35.9% of Asian patients not meeting entry criteria. Lack of relevant disease mutation was the reason for ineligibility more frequently among Black and Asian patients. The findings were limited by the small number of underrepresented patients screened for participation. CONCLUSION: Our results suggest that entry requirements for studies may put underrepresented patients at a disadvantage, leading to less eligible patients and thus lower participation in clinical trials.

The Impact of Improved Treatments on Survival of Adult U.S. Leukemia Patients: 1990-2018.

INTRODUCTION: Molecularly targeted therapies such as tyrosine kinase inhibitors (TKI) are effective treatments for B-cell receptor (BCR)-ABL-bearing leukemias. We evaluated the impact of TKIs on historical chronic myeloid leukemia (CML) mortality trends compared with acute lymphoblastic leukemia (ALL) and chronic lymphoblastic leukemia (CLL). METHODS: Because mortality trends reflect combined effects of leukemia incidence and survival, we also evaluated the contribution of incidence and survival trends to mortality trends by subtypes. We used data from 13 U.S. (SEER) registries (1992-2017) among U.S. adults. We utilized histology codes to identify cases of CML, ALL, and CLL and death certificate data to calculate mortality. We used Joinpoint to characterize incidence (1992-2017) and mortality (1992-2018) trends by subtype and diagnosis year. RESULTS: For CML, mortality rates started declining in 1998 at an average rate of 12% annually. Imatinib was approved by the FDA for treating CML and ALL in 2001, leading to clear benefits for patients with CML. Five-year CML survival increased dramatically over time, especially between 1996 to 2011, 2.3% per year on average. ALL incidence increased 1.5% annually from 1992 to 2017. ALL mortality decreased 0.6% annually during 1992 to 2012 and then stopped declining. CLL incidence fluctuated during 1992 to 2017 while mortality decreased 1.1% annually during 1992 to 2011 and at a faster rate of 3.6% per year from 2011. Five-year survival increased 0.7% per year on average during 1992 to 2016. CONCLUSIONS: Survival benefit from TKIs and other novel therapies for treating leukemia subtypes has been demonstrated in clinical trials. IMPACT: Our study highlights the impact of molecularly targeted therapies at the population level.

Minimal Residual Disease Data in Hematologic Malignancy Drug Applications and Labeling: An FDA Perspective.

Minimal residual disease (MRD) is increasingly used as a prognostic biomarker, a measure of clinical efficacy, and a guide for treatment decisions in various hematologic malignancies. We sought to characterize MRD data in registrational trials in hematologic malignancies submitted to the U.S. Food and Drug Administration (FDA) with the ultimate goal of expanding the utility of MRD data in future drug applications. We descriptively analyzed MRD data collected in registrational trials, including the type of MRD endpoint, assay, disease compartment(s) assessed, and the acceptance of MRD data in the U.S. prescribing information (USPI). Of 196 drug applications submitted between January 2014 and February 2021, 55 (28%) included MRD data. Of the 55 applications, MRD data was proposed by the Applicant for inclusion in the USPI in 41 (75%) applications but was included in only 24 (59%). Despite an increasing number of applications that proposed to include MRD data in the USPI, the acceptance rate decreased over time. Although MRD data have the potential to expedite drug development, our analysis identified challenges and specific areas for improvement, including assay validation, standardization of collection methods to optimize performance, and considerations in trial design and statistical methodology.

Use of Single-Arm Trials for US Food and Drug Administration Drug Approval in Oncology, 2002-2021.

Importance: Single-arm trials have allowed for transformative therapies to be made available to patients expeditiously. However, using single-arm trials to support drug approval presents several challenges that must be carefully considered. Observations: Between January 1, 2002, and December 31, 2021, the US Food and Drug Administration granted 176 new malignant hematology and oncology indications based on single-arm trials, including 116 accelerated approvals (AAs) and 60 traditional approvals. Overall, 87 approvals (49%) were for new molecular entities or original biologics and 89 (51%) were supplemental indications. Response rate (RR) was the most common end point used to support approval in these single-arm trials (173 of 176 [98%]). Of the 116 AAs based on single-arm trials, 45 (38%) fulfilled their postmarketing requirement to verify clinical benefit, 61 (52%) are pending verification of benefit, and 10 (9%) were withdrawn from the market as of December 31, 2021. Most (56 of 61 [92%]) AAs based on single-arm trials pending verification of benefit occurred during the previous 5 years and have ongoing confirmatory trials as of December 2021. Conclusions and Relevance: Single-arm trials have been a common development strategy to support regulatory approval as early-stage expansion cohorts with promising durable RRs have become more prevalent. In the appropriate context, single-arm trials using durable RRs can allow patients expedited access to novel therapies and will continue to serve a role in advancing drug development in oncology. However, single-arm trials have a smaller noncomparative safety data set, inability to use time-to-event end points, and other limitations that require careful consideration within the context of the disease and available therapies. The randomized clinical trial remains the preferred approach in clinical investigation.

FDA Approval Summary: Belantamab Mafodotin for Patients with Relapsed or Refractory Multiple Myeloma.

On August 5, 2020, the FDA granted accelerated approval to belantamab mafodotin-blmf (BLENREP; GlaxoSmithKline) for the treatment of adult patients with relapsed or refractory multiple myeloma who have received at least four prior therapies including an anti-CD38 monoclonal antibody, a proteasome inhibitor, and an immunomodulatory agent. Substantial evidence of effectiveness was obtained from the phase II, multicenter DREAMM-2 trial. Patients received belantamab mafodotin 2.5 or 3.4 mg/kg intravenously once every 3 weeks until disease progression or unacceptable toxicity. The trial demonstrated an overall response rate of 31% in the 2.5 mg/kg cohort and 34% in the 3.4 mg/kg cohort. Keratopathy was the most frequent adverse event, occurring in 71% and 77% of patients, respectively. Other ocular toxicities included changes in visual acuity, blurred vision, and dry eye. The U.S. prescribing information for belantamab mafodotin includes a boxed warning for ocular toxicity, and belantamab mafodotin is available only through a restricted program under a Risk Evaluation and Mitigation Strategy. This article summarizes the data and the FDA review process supporting accelerated approval of belantamab mafodotin 2.5 mg/kg intravenously once every 3 weeks. This approval may be contingent upon verification and description of clinical benefit in confirmatory trial(s).

FDA approval summary: Crizotinib for pediatric and young adult patients with relapsed or refractory systemic anaplastic large cell lymphoma.

In January 2021, the U.S. Food and Drug Administration (FDA) approved crizotinib for pediatric patients 1 year and older and young adults with relapsed or refractory systemic anaplastic large cell lymphoma (sALCL). This is the first approval for pediatric sALCL. Approval was based on a single-arm trial of crizotinib monotherapy that included 26 patients, aged 1-20 years, with previously treated sALCL. Efficacy was based on centrally assessed objective response rate (88%) and duration of response. Herein, we highlight unique aspects of the regulatory review, including extension of the indication to young adults, postmarketing safety, and dose optimization strategies.

Exploring racial disparities in treatment patterns and outcomes for patients with multiple myeloma using real world data.

This retrospective observational study evaluated racial disparities among Black and White patients with multiple myeloma (MM). We included patients from a longitudinal de-identified EHR-derived database who had ≥2 visits recorded on or after 1/1/2011, documented treatment, and race listed as White or Black. Black patients (n = 1172) were more likely female (54.8%/42.9%) and younger (<65 years, 40.8%/30.8%) than White patients (n = 4637). Unadjusted median real-world overall survival (rwOS) indexed to first-line of therapy (LOT) was 64.6 months (95% CI: 57.8-74.0) for Blacks and 54.5 months (95% CI: 50.9-56.2) for Whites. Adjusted rwOS estimates (for sex, age at index date, and practice type) to either first- (aHR = 0.94; 95% CI: 0.84-1.06) or second-LOT (aHR = 0.90; 95% CI: 0.77-1.05) were similar. Unadjusted derived response rate (dRR) during first-LOT was 84.8% (95% CI: 80.7-88.1) for Blacks and 86.9% (95% CI: 85.0-88.5) for Whites (odds ratio [OR] = 0.78 [95% CI: 0.57-1.10]); in second-LOT, 67.2% (95% CI: 58.4-75.0) for Blacks and 72.4% (95% CI: 68.1-76.3) for Whites (OR = 0.72 [95% CI: 0.46-1.13]). High representation of Black patients enabled this robust analysis, albeit with limitations inherent to the observational data source, the retrospective design, and the analytic use of newly derived endpoints requiring further validation.

Reaching beyond maximum grade: progress and future directions for modernising the assessment and reporting of adverse events in haematological malignancies.

Remarkable improvements in outcomes for many haematological malignancies have been driven primarily by a proliferation of novel therapeutics over the past two decades. Targeted agents, immune and cellular therapies, and combination regimens have adverse event profiles distinct from conventional finite cytotoxic chemotherapies. In 2018, a Commission comprising patient advocates, clinicians, clinical investigators, regulators, biostatisticians, and pharmacists representing a broad range of academic and clinical cancer expertise examined issues of adverse event evaluation in the context of both newer and existing therapies for haematological cancers. The Commission proposed immediate actions and long-term solutions in the current processes in adverse event assessment, patient-reported outcomes in haematological malignancies, toxicities in cellular therapies, long-term toxicity and survivorship in haematological malignancies, issues in regulatory approval from an international perspective, and toxicity reporting in haematological malignancies and the real-world setting. In this follow-up report, the Commission describes progress that has been made in these areas since the initial report.

Analysis of racial and ethnic disparities in multiple myeloma US FDA drug approval trials.

African Americans (AAs) have a higher incidence of multiple myeloma (MM) than White patients. Mortality is also higher in AAs compared with White patients. AAs more commonly have immunoglobulin H translocations t(11;14) and t(14;16) compared with White patients. We sought to characterize the demographic representation in MM clinical trials and evaluate outcomes based on race and ethnicity. We conducted a pooled analysis of all trials submitted to the US Food and Drug Administration (FDA) to support approval of a MM therapeutic between 2006 and 2019. Demographic characteristics were analyzed descriptively. An age-adjusted stratified Cox regression model was used to evaluate the relationship between time-to-event outcomes and race and ethnicity. Nineteen global trials comprising 10 157 patients were pooled. White, Asian, and Black patients comprised 84%, 7%, and 4% of the dataset, respectively; Hispanic patients comprised 4%. The age-adjusted overall survival hazard ratio (HR) for Black compared with White patients was 0.89 (95% confidence interval [CI], 0.75-1.05). The age-adjusted HR for US Black vs US White patients was 0.82 (95% CI, 0.66-1.02). For rest-of-world (RoW) Black vs RoW White patients, the HR was 1.31 (95% CI, 0.97-1.77). Black and Hispanic patients were underrepresented in the trials supporting FDA approval of MM drugs. Black patients were primarily enrolled in the United States. Outcomes in US patients were more favorable compared with those in patients in the RoW. Given the higher incidence of MM in AAs and the different disease characteristics, efforts should be made to improve representation of AAs in MM clinical trials.

Need for aligning the definition and reporting of cytokine release syndrome (CRS) in immuno-oncology clinical trials.

As cancer immunotherapies continue to expand across all areas of oncology, it is imperative to establish a standardized approach for defining and capturing clinically important toxicities, such as cytokine release syndrome (CRS). In this paper, we provide considerations for categorizing the variety of adverse events that may accompany CRS and for recognizing that presentations of CRS may differ among various immunotherapies (e.g., monoclonal antibodies, CAR T cell therapies and T cell engagers, which can include bispecific antibodies and other constructs). The goals of this paper are to ensure accurate and consistent identification of CRS in patients receiving immunotherapies in clinical studies to aid in reporting; enable more precise evaluation of the therapeutic risk-benefit profile and cross-study analyses; support evidence-based monitoring and management of important toxicities related to cancer immunotherapies; and improve patient care and outcomes. These efforts will become more important as the number and variety of molecular targets for immunotherapies broaden and as therapies with novel mechanisms continue to be developed.

Perspectives on Drug Development in Multiple Myeloma-Looking Forward to 2025.

The multiple myeloma treatment landscape has evolved considerably over the last 20 years with the development of multiple therapies with novel mechanisms of action and new combination regimens. However, the recent failure of several large phase III trials, coupled with an increased understanding of the mutational landscape of multiple myeloma has provided opportunities to explore optimal strategies for future multiple myeloma drug development. The Office of Oncologic Diseases at the FDA held an educational symposium, "Drug Development in MM-Project 2025," in November 2019. The symposium brought together select U.S.-based academic thought leaders in the field of multiple myeloma to explore issues relevant to regulatory science in the field, including considerations for trial design, combination strategies, control arms, and precision medicine. This article summarizes the highlights of this educational symposium held at the FDA, including discussions on the future development of novel drugs and drug combinations and biomarker-directed therapies for patients with multiple myeloma.