On August 26, 2011, crizotinib received accelerated approval for the treatment of patients with locally advanced or metastatic non‐small cell lung cancer (NSCLC) that is ALK‐positive as detected by a ...test approved by the U.S. Food and Drug Administration (FDA). Approval was based on two single‐arm trials demonstrating objective response rates (ORRs) of 50% and 61% and median response durations of 42 and 48 weeks. On November 20, 2013, crizotinib received regular approval based on confirmation of clinical benefit in study A8081007, a randomized trial in 347 patients with ALK‐positive advanced NSCLC who had previously received one platinum‐containing regimen. Patients were assigned (1:1) to receive crizotinib 250 mg orally twice daily or standard of care (docetaxel or pemetrexed). The primary endpoint was progression‐free survival (PFS) determined by independent radiology review; secondary endpoints were ORR and overall survival (OS). PFS was significantly longer in the crizotinib arm, with median PFS of 7.7 and 3.0 months in the crizotinib and chemotherapy arms, respectively, and a 46% absolute increase in ORR but no difference in OS between treatment arms at the interim analysis. The most common adverse drug reactions (>25%) in crizotinib‐treated patients were vision disorders, nausea, diarrhea, vomiting, constipation, edema, elevated transaminases, and fatigue. The most serious toxicities of crizotinib were hepatotoxicity, interstitial lung disease or pneumonitis, and QT‐interval prolongation. Crizotinib's rapid clinical development program (6 years from identification of ALK rearrangements in a subset of NSCLC to full FDA approval) is a model of efficient drug development in this new era of molecularly targeted oncology therapy.
This paper outlines the U.S. Food and Drug Administration review of A8081007, a randomized trial comparing crizotinib and the standard of care (docetaxel or pemetrexed) in 347 patients with ALK‐positive advanced non‐small cell lung cancer who had previously received one platinum‐containing regimen. This trial was submitted to confirm the clinical benefit of crizotinib and to support conversion to regular approval.
Abstract The PI3K/Akt/mTOR pathway is a prototypic survival pathway that is constitutively activated in many types of cancer. Mechanisms for pathway activation include loss of tumor suppressor PTEN ...function, amplification or mutation of PI3K, amplification or mutation of Akt, activation of growth factor receptors, and exposure to carcinogens. Once activated, signaling through Akt can be propagated to a diverse array of substrates, including mTOR, a key regulator of protein translation. This pathway is an attractive therapeutic target in cancer because it serves as a convergence point for many growth stimuli, and through its downstream substrates, controls cellular processes that contribute to the initiation and maintenance of cancer. Moreover, activation of the Akt/mTOR pathway confers resistance to many types of cancer therapy, and is a poor prognostic factor for many types of cancers. This review will provide an update on the clinical progress of various agents that target the pathway, such as the Akt inhibitors perifosine and PX-866 and mTOR inhibitors (rapamycin, CCI-779, RAD-001) and discuss strategies to combine these pathway inhibitors with conventional chemotherapy, radiotherapy, as well as newer targeted agents. We will also discuss how the complex regulation of the PI3K/Akt/mTOR pathway poses practical issues concerning the design of clinical trials, potential toxicities and criteria for patient selection.
Tagraxofusp-erzs (Elzonris, Stemline) is a cytotoxin that targets CD123-expressing cells. On December 21, 2018, FDA approved tagraxofusp-erzs for the treatment of blastic plasmacytoid dendritic cell ...neoplasms (BPDCN) in adult and pediatric patients 2 years and older. Approval was based on the response rate in a single-arm trial, Study STML-401-0114; the pivotal cohort included 13 patients with treatment-naïve BPDCN who received tagraxofusp-erzs monotherapy. The complete response or clinical complete response (CR/CRc) rate in the pivotal cohort was 54% (95% CI: 25%-81%), and the median duration of CR/CRc was not reached with a median follow-up of 11.5 months (range: 0.2-12.7). In a separate exploratory cohort, a CR/CRc was achieved by 2 (13%) patients with R/R BPDCN. Safety was assessed in 94 patients with myeloid neoplasms treated with tagraxofusp-erzs at the approved dose and schedule. The major toxicity was capillary leak syndrome (CLS), which occurred in 55% of patients and was fatal in 2%. Hepatotoxicity and hypersensitivity reactions were reported in 88% and 46% of patients, respectively. Other common (≥30%) adverse reactions were nausea, fatigue, peripheral edema, pyrexia, and weight increase. A high proportion of patients (85%) developed neutralizing antidrug antibodies. Tagraxofusp-erzs is the first FDA-approved treatment for BPDCN.
Background
To review and summarize all U.S. Food and Drug Administration (FDA) approvals of programmed death (PD)‐1 and PD‐ligand 1 blocking antibodies (collectively referred to as PD‐L1 inhibitors) ...over a 6‐year period and corresponding companion/complementary diagnostic assays.
Materials and Methods
To determine the indications and pivotal trials eligible for inclusion, approval letters and package inserts available on Drugs@FDA were evaluated for approved PD‐L1 inhibitors to identify all new indications granted from the first approval of a PD‐L1 inhibitor on September 4, 2014, through September 3, 2020. The corresponding FDA drug and device reviews from the marketing applications for the approved indications were identified through FDA internal records. Two reviewers independently extracted information for the endpoints, efficacy data, basis for approval, type of regulatory approval, and corresponding in vitro diagnostic device test. The results were organized by organ system and tumor type.
Results
Of 70 Biologic Licensing Application or supplement approvals that resulted in new indications, 32 (46%) were granted based on response rate (ORR) and durability of response, 26 (37%) on overall survival, 9 (13%) on progression‐free survival, 2 (3%) on recurrence‐free survival, and 1 (1%) on complete response rate. Most ORR‐based approvals were granted under the accelerated approval provisions and were supported with prolonged duration of response. Overall, 21% of approvals were granted with a companion diagnostic. Efficacy results according to tumor type are discussed.
Conclusion
PD‐L1 inhibitors are an effective anticancer therapy in a subset of patients. This class of drugs has provided new treatment options for patients with unmet need across a wide variety of cancer types. Yet, the modest response rates in several tumor types signal a lack of understanding of the biology of these diseases. Further preclinical and clinical investigation may be required to identify a more appropriate patient population, particularly as drug development continues and additional treatment alternatives become available.
Implications for Practice
The number of PD‐L1 inhibitors in drug development and the associated companion and complementary diagnostics have led to regulatory challenges and questions regarding generalizability of trial results. The interchangeability of PD‐L1 immunohistochemical assays between PD‐1/PD‐L1 drugs is unclear. Furthermore, robust responses in some patients with low levels of PD‐L1 expression have limited the use of PD‐L1 as a predictive biomarker across all cancers, particularly in the setting of diseases with few alternative treatment options. This review summarizes the biomarker thresholds and assays approved as complementary and companion diagnostics and provides regulatory perspective on the role of biomarkers in oncology drug development.
This review provides a regulatory overview on the U.S. FDA approvals of PD‐1 and PD‐L1 inhibitors and highlights complementary and companion diagnostics within the context of each disease and indication.
On April 29, 2014, the FDA granted accelerated approval to ceritinib (ZYKADIA; Novartis Pharmaceuticals Corporation), a breakthrough therapy-designated drug, for the treatment of patients with ...anaplastic lymphoma kinase (ALK)-positive, metastatic non-small cell lung cancer (NSCLC) who have progressed on or are intolerant to crizotinib. The approval was based on a single-arm multicenter trial enrolling 163 patients with metastatic ALK-positive NSCLC who had disease progression on (91%) or intolerance to crizotinib. Patients received ceritinib at a starting dose of 750 mg orally once daily. The objective response rate (ORR) by a blinded independent review committee was 44% (95% CI, 36-52), and the median duration of response (DOR) was 7.1 months. The ORR by investigator assessment was similar. Safety was evaluated in 255 patients. The most common adverse reactions and laboratory abnormalities included diarrhea (86%), nausea (80%), increased alanine transaminase (80%), increased aspartate transaminase (75%), vomiting (60%), increased glucose (49%), and increased lipase (28%). Although 74% of patients required at least one dose reduction or interruption due to adverse reactions, the discontinuation rate due to adverse reactions was low (10%). With this safety profile, the benefit-risk analysis was considered favorable because of the clinically meaningful ORR and DOR.
On August 5, 2016, the U.S. Food and Drug Administration granted accelerated approval to pembrolizumab (KEYTRUDA injection, Merck Sharp & Dohme Corp., Kenilworth, NJ) for treatment of patients with ...recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) with disease progression on or after platinum‐containing chemotherapy. Approval was based on the objective response rate (ORR) and duration of response (DoR) in a cohort of patients in a nonrandomized multi‐cohort trial (KEYNOTE‐012) that included 174 patients with recurrent or metastatic HNSCC who had disease progression on or after platinum‐containing chemotherapy. Patients received either intravenous pembrolizumab 10 mg/kg every 2 weeks or 200 mg every 3 weeks. ORR was determined by independent review according to Response Evaluation Criteria in Solid Tumors 1.1. ORR was 16% (95% confidence interval 11, 22) with a complete response rate of 5%. DoR ranged from 2.4+ months to 27.7+ months. Twenty‐three of 28 responding patients (82%) had response durations of ≥6 months. Safety was evaluated in 192 patients with HNSCC receiving at least one dose of pembrolizumab. Frequent (≥2%) serious adverse reactions were pneumonia, dyspnea, confusional state, vomiting, pleural effusion, and respiratory failure. Clinically significant immune‐mediated adverse reactions included pneumonitis, colitis, hepatitis, adrenal insufficiency, diabetes mellitus, skin toxicity, myositis, and thyroid disorders. The benefit‐risk profile of pembrolizumab was considered acceptable in this patient population. As a condition of accelerated approval, Merck is required to conduct a confirmatory trial; this trial, KEYNOTE‐040, is ongoing.
Implications for Practice
This accelerated approval expands the U.S. Food and Drug Administration‐approved indications for pembrolizumab, providing health care providers with new information regarding pembrolizumab for the treatment of patients with recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) with disease progression on or after platinum‐containing chemotherapy. Pembrolizumab is the first drug to receive approval for treatment of patients with HNSCC since cetuximab was approved for this indication in 2006.
This article summarizes the evidence for the impact of BRAF mutations on treatment outcome of anti‐EGFR monoclonal antibodies. Based on a review of literature, eight meta‐analyses were included in this study, which consistently show that patients with BRAF mutations have a lack of treatment benefit of anti‐EGFR monoclonal antibodies. Considering the quality and quantity of available evidence, current guidelines may be revised.
Based on anecdotal cases of clinically important decreases in tumor size following initial evidence of disease progression when treating patients with anti-PD-1 therapies, investigators have ...conducted clinical trials in patients with metastatic non-small lung cancer (mNSCLC) receiving anti-PD-1 therapy allowing for treatment past RECIST-defined disease progression (TPP). We describe the findings of a pooled analysis of three clinical trials submitted to the US Food and Drug administration (FDA) where treatment of patients with mNSCLC permitted TPP in terms of reduction in the sum of target lesions following initial RECIST-defined progression. We identified patients who received TPP and the characteristics and post-TPP change in tumor burden. All patients had advanced or mNSCLC and had previously received a platinum-based doublet regimen. In total, 535 patients were treated with anti-PD-1 therapy in three clinical trials of which 121 patients (23%) received TPP. Among all 535 patients treated with anti-PD-1 therapy, the partial response (PR) rate (≥30% reduction in the size of target lesions compared to baseline) following TPP was 1.9% (10 of 535) or 8.3% (10 of 121) in the TPP subgroup. Patients who responded to TPP were more likely to have responded to the initial course of anti-PD-1 therapy, prior to progression. The subgroup of patients who received TPP appeared to have similar baseline characteristics and response to initial treatment compared to the overall population. This suggests that a treatment strategy that includes TPP may not benefit the overall population. The risks of TPP should be weighed against the low likelihood of a PR and the potential for changing to a different therapy with a higher likelihood of benefit.
The Lung Master Protocol (Lung-MAP, S1400) is a groundbreaking clinical trial designed to advance the efficient development of targeted therapies for squamous cell carcinoma (SCC) of the lung. There ...are no approved targeted therapies specific to advanced lung SCC, although The Cancer Genome Atlas project and similar studies have detected a significant number of somatic gene mutations/amplifications in lung SCC, some of which are targetable by investigational agents. However, the frequency of these changes is low (5%-20%), making recruitment and study conduct challenging in the traditional clinical trial setting. Here, we describe our approach to development of a biomarker-driven phase II/II multisubstudy "Master Protocol," using a common platform (next-generation DNA sequencing) to identify actionable molecular abnormalities, followed by randomization to the relevant targeted therapy versus standard of care.
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