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.

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.

FDA Approval Summary: Amivantamab for the Treatment of Patients with Non-Small Cell Lung Cancer with EGFR Exon 20 Insertion Mutations.

The FDA granted accelerated approval for amivantamab-vmjw (hereafter referred to as amivantamab), a bispecific antibody directed against EGFR and mesenchymal-epithelial transition receptor, on May 21, 2021, for the treatment of adult patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) with EGFR exon 20 insertion mutations whose disease has progressed on or after platinum-based chemotherapy. Approval was based on results of an ongoing, multicenter, nonrandomized, open-label, multicohort clinical trial (CHRYSALIS, NCT02609776), demonstrating a substantial overall response rate (ORR) and durable responses, with an ORR of 40% [95% confidence interval (CI): 29-51] and a median response duration of 11.1 months (95% CI: 6.9-not evaluable). Guardant360 CDx was contemporaneously approved as a companion diagnostic for this indication to identify EGFR exon 20 insertion mutations in plasma specimens. The most notable safety finding was the high incidence (66%) of infusion-related reactions, which is addressed in both the Dosage and Administration and Warnings and Precautions sections of the product label. Other common adverse reactions (occurring in ≥20% of patients) were rash, paronychia, musculoskeletal pain, dyspnea, nausea and vomiting, fatigue, edema, stomatitis, cough, and constipation. The approval of amivantamab was the first approval of a targeted therapy for patients with advanced NSCLC harboring EGFR exon 20 insertion mutations.

Regulatory implications of ctDNA in immuno-oncology for solid tumors.

In the era of precision oncology, use of circulating tumor DNA (ctDNA) is emerging as a minimally invasive approach for the diagnosis and management of patients with cancer and as an enrichment tool in clinical trials. In recent years, the US Food and Drug Administration has approved multiple ctDNA-based companion diagnostic assays for the safe and effective use of targeted therapies and ctDNA-based assays are also being developed for use with immuno-oncology-based therapies. For early-stage solid tumor cancers, ctDNA may be particularly important to detect molecular residual disease (MRD) to support early implementation of adjuvant or escalated therapy to prevent development of metastatic disease. Clinical trials are also increasingly using ctDNA MRD for patient selection and stratification, with an ultimate goal of improving trial efficiency through use of an enriched patient population. Standardization and harmonization of ctDNA assays and methodologies, along with further clinical validation of ctDNA as a prognostic and predictive biomarker, are necessary before ctDNA may be considered as an efficacy-response biomarker to support regulatory decision making.

FDA Approval Summary: Mobocertinib for Metastatic Non-Small Cell Lung Cancer with EGFR Exon 20 Insertion Mutations.

On September 15, 2021, the FDA granted accelerated approval to mobocertinib (Exkivity, Takeda Pharmaceuticals USA, Inc.) for the treatment of adult patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) with EGFR exon 20 insertion mutations, as detected by an FDA-approved test, whose disease has progressed on or after platinum-based chemotherapy. The approval was based on data from Study AP32788-15-101 (NCT02716116), an international, non-randomized, multi-cohort clinical trial that included patients with locally advanced or metastatic NSCLC with EGFR exon 20 insertion mutations. The overall response rate in 114 patients whose disease had progressed on or after platinum-based chemotherapy was 28% [95% confidence interval (CI), 20%-37%] with a median duration of response of 17.5 months (95% CI, 7.4-20.3). The most common adverse reactions (>20%) were diarrhea, rash, nausea, stomatitis, vomiting, decreased appetite, paronychia, fatigue, dry skin, and musculoskeletal pain. Product labeling includes a Boxed Warning for QTc prolongation and torsades de pointes. This is the first approval of an oral targeted therapy for patients with advanced EGFR exon 20 insertion mutation-positive NSCLC.

Proceedings From the ASCO/College of American Pathologists Immune Checkpoint Inhibitor Predictive Biomarker Summit.

PURPOSE: Immune checkpoint inhibition (ICI) therapy represents one of the great advances in the field of oncology, highlighted by the Nobel Prize in 2018. Multiple predictive biomarkers for ICI benefit have been proposed. These include assessment of programmed death ligand-1 expression by immunohistochemistry, and determination of mutational genotype (microsatellite instability or mismatch repair deficiency or tumor mutational burden) as a reflection of neoantigen expression. However, deployment of these assays has been challenging for oncologists and pathologists alike. METHODS: To address these issues, ASCO and the College of American Pathologists convened a virtual Predictive Factor Summit from September 14 to 15, 2021. Representatives from the academic community, US Food and Drug Administration, Centers for Medicare and Medicaid Services, National Institutes of Health, health insurance organizations, pharmaceutical companies, in vitro diagnostics manufacturers, and patient advocate organizations presented state-of-the-art predictive factors for ICI, associated problems, and possible solutions. RESULTS: The Summit provided an overview of the challenges and opportunities for improvement in assay execution, interpretation, and clinical applications of programmed death ligand-1, microsatellite instability-high or mismatch repair deficient, and tumor mutational burden-high for ICI therapies, as well as issues related to regulation, reimbursement, and next-generation ICI biomarker development. CONCLUSION: The Summit concluded with a plan to generate a joint ASCO/College of American Pathologists strategy for consideration of future research in each of these areas to improve tumor biomarker tests for ICI therapy.

Changes in Circulating Tumor DNA Reflect Clinical Benefit Across Multiple Studies of Patients With Non-Small-Cell Lung Cancer Treated With Immune Checkpoint Inhibitors.

PURPOSE: As immune checkpoint inhibitors (ICI) become increasingly used in frontline settings, identifying early indicators of response is needed. Recent studies suggest a role for circulating tumor DNA (ctDNA) in monitoring response to ICI, but uncertainty exists in the generalizability of these studies. Here, the role of ctDNA for monitoring response to ICI is assessed through a standardized approach by assessing clinical trial data from five independent studies. PATIENTS AND METHODS: Patient-level clinical and ctDNA data were pooled and harmonized from 200 patients across five independent clinical trials investigating the treatment of patients with non-small-cell lung cancer with programmed cell death-1 (PD-1)/programmed death ligand-1 (PD-L1)-directed monotherapy or in combination with chemotherapy. CtDNA levels were measured using different ctDNA assays across the studies. Maximum variant allele frequencies were calculated using all somatic tumor-derived variants in each unique patient sample to correlate ctDNA changes with overall survival (OS) and progression-free survival (PFS). RESULTS: We observed strong associations between reductions in ctDNA levels from on-treatment liquid biopsies with improved OS (OS; hazard ratio, 2.28; 95% CI, 1.62 to 3.20; P < .001) and PFS (PFS; hazard ratio 1.76; 95% CI, 1.31 to 2.36; P < .001). Changes in the maximum variant allele frequencies ctDNA values showed strong association across different outcomes. CONCLUSION: In this pooled analysis of five independent clinical trials, consistent and robust associations between reductions in ctDNA and outcomes were found across multiple end points assessed in patients with non-small-cell lung cancer treated with an ICI. Additional tumor types, stages, and drug classes should be included in future analyses to further validate this. CtDNA may serve as an important tool in clinical development and an early indicator of treatment benefit.

FDA Approval Summary: Abemaciclib With Endocrine Therapy for High-Risk Early Breast Cancer.

PURPOSE: The US Food and Drug Administration approved abemaciclib in combination with endocrine therapy (ET) for the adjuvant treatment of adult patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative, node-positive, early breast cancer (EBC) at high risk of recurrence and a Ki-67 score ≥ 20%. PATIENTS AND METHODS: The approval was based on monarchE, a phase III, open-label, 2-cohort, multicenter trial of patients with EBC randomly assigned to receive abemaciclib plus ET (n = 2,808) or ET alone (n = 2,829). Abemaciclib was given at 150 mg orally twice daily for 2 years. RESULTS: Invasive disease-free survival (IDFS) in the intent-to-treat population was statistically significant at the second IDFS interim analysis (IA; March 2020; hazard ratio [HR; 95% CI], 0.747 [0.598 to 0.932]; P = .0096); however, only 12.5% of patients had completed adjuvant therapy, and the HR for overall survival (OS) was > 1. A prespecified, controlled analysis of IDFS in patients with Ki-67 ≥ 20% in cohort 1 was statistically significant at the final IDFS analysis (July 2020; HR [95% CI], 0.643 [0.475 to 0.872]; P = .0042). At the first OS IA (April 2021), the majority of patients had completed adjuvant therapy, IDFS remained consistent, and potential detriment in OS was not observed for this subgroup (HR [95% CI], 0.767 [0.511 to 1.152]). The HR for OS in the intent-to-treat population at OS IA remained > 1 (HR [95% CI], 1.091 [0.818 to 1.455]). More patients in the abemaciclib plus ET arm experienced treatment emergent adverse events (all grades 98.4% v 88.8%, grade 3 ≥ 49.7% v 16.3%). CONCLUSION: The approval of abemaciclib in adjuvant EBC was limited to patients with high risk of recurrence and Ki-67 ≥ 20%, given their favorable benefit:risk with a statistically significant IDFS advantage and no observed detriment on survival.

FDA Approval Summary: Capmatinib and Tepotinib for the Treatment of Metastatic NSCLC Harboring MET Exon 14 Skipping Mutations or Alterations.

The FDA approved capmatinib and tepotinib on May 6, 2020, and February 3, 2021, respectively. Capmatinib is indicated for patients with metastatic non-small cell lung cancer (mNSCLC) whose tumors have a mutation leading to mesenchymal-epithelial transition (MET) exon 14 skipping as detected by an FDA-approved test. Tepotinib is indicated for mNSCLC harboring MET exon 14 skipping alterations. The approvals were based on trials GEOMETRY mono-1 (capmatinib) and VISION (tepotinib). In GEOMETRY mono-1, overall response rate (ORR) per Blinded Independent Review Committee (BIRC) was 68% [95% confidence interval (CI), 48-84] with median duration of response (DoR) 12.6 months (95% CI, 5.5-25.3) in 28 treatment-naïve patients and 41% (95% CI: 29, 53) with median DoR 9.7 months (95% CI, 5.5-13) in 69 previously treated patients with NSCLC with mutations leading to MET exon 14 skipping. In VISION, ORR per BIRC was 43% (95% CI: 32, 56) with median DoR 10.8 months (95% CI, 6.9-not estimable) in 69 treatment-naïve patients and 43% (95% CI, 33-55) with median DoR 11.1 months (95% CI, 9.5-18.5) in 83 previously-treated patients with NSCLC harboring MET exon 14 alterations. These are the first two therapies to be FDA approved specifically for patients with metastatic NSCLC with MET exon 14 skipping.

U.S. FDA Drug Approvals for Gynecological Malignancies: A Decade in Review.

Over the last decade, there has been tremendous progress in the treatment of patients with gynecologic cancers with a changing therapy landscape. This summary provides an overview of U.S. Food and Drug Administration (FDA) approvals for gynecologic cancers from 2010 to 2020, totaling 17 new indications. For each of the approved indications, endpoints, trial design, results, and regulatory considerations are outlined. Among these 17 indications, six received accelerated approval (AA) and 11 received regular approval (RA). As of September 2021, of the six AA, three have subsequently demonstrated clinical benefit resulting in conversion to RA and the remaining three have ongoing clinical trials that have not yet reported results. Approval decisions for these 17 indications were supported by primary efficacy endpoints of progression-free survival (n = 10), objective response rate (n = 6), and overall survival (n = 1) and showed a favorable benefit-risk profile. Among the 17 indications, 15 received priority review and three applications participated in one or more novel Oncology Center of Excellence initiatives, including Real Time Oncology Review, Assessment Aid, and Project Orbis. Current FDA thinking on drug development opportunities and regulatory initiatives currently under way will be discussed.

U.S. FDA Drug Approvals for Breast Cancer: A Decade in Review.

Over the last decade, the treatment of patients with breast cancer has been greatly impacted by the approval of multiple drugs and indications. This summary describes 30 FDA approvals of treatments for breast cancer from 2010 to 2020. The trial design endpoints, results, and regulatory considerations are described for each approved indication. Of the 30 indications, 23 (76.6%) received regular and 7 (23.3%) received accelerated approval. Twenty-six approvals were granted in metastatic breast cancer (MBC) and four in early breast cancer. Approval decisions for the 26 MBC indications were initially supported by progression-free survival (PFS) in 21 (80.8%), overall survival (OS) or a combination of OS and PFS in two (7.7%), and objective response rate (ORR) in three (11.5%). The four approvals in early breast cancer utilized pathologic complete response (pCR) in one (25%) and invasive disease-free survival (iDFS) in three (75%) trials. Among the 30 indications, 22 received priority review, seven were granted Breakthrough Therapy Designation, and 10 applications participated in one or more pilot Oncology Center of Excellence regulatory review initiatives, including Real Time Oncology Review, Assessment Aid, and Project Orbis. FDA initiatives to advance breast cancer drug development are also described.

FDA Approval Summary: Pembrolizumab for the Treatment of Tumor Mutational Burden-High Solid Tumors.

The FDA approved pembrolizumab on June 16, 2020, for the treatment of adult and pediatric patients with unresectable or metastatic tumor mutational burden-high [TMB-H; ≥10 mutations/megabase (mut/Mb)] solid tumors, as determined by an FDA-approved test, that have progressed following prior treatment and who have no satisfactory alternative treatment options. FDA granted the approval based on a clinically important overall response rate (29%; 95% confidence interval, 21-39) and duration of response (57% of responses lasting ≥ 12 months) in the subset of patients with TMB-H solid tumors (n = 102) spanning nine different tumor types enrolled in a multicenter single-arm trial (KEYNOTE-158). The efficacy of pembrolizumab was supported by the results of whole-exome sequencing (WES) analyses of TMB in additional patients enrolled across multiple pembrolizumab clinical trials, and a scientific understanding of the effects of PD-1 inhibition. Overall, the adverse event profile of pembrolizumab was similar to the adverse event profile observed in prior trials that supported the approval of pembrolizumab in other indications. This approval of pembrolizumab is the first time that the FDA has approved a cancer treatment for an indication based on TMB, and the fourth based on the presence of a biomarker rather than the primary site of origin.

FDA Approval Summary: Pralsetinib for the Treatment of Lung and Thyroid Cancers With RET Gene Mutations or Fusions.

The FDA granted accelerated approval for pralsetinib on September 4, 2020 for non-small cell lung cancer (NSCLC) and December 1, 2020 for thyroid cancer, for: (i) adult patients with metastatic RET fusion-positive NSCLC, (ii) adult and pediatric patients ≥12 years of age with advanced or metastatic RET-mutant medullary thyroid cancer who require systemic therapy, and (iii) adult and pediatric patients ≥12 years of age with advanced or metastatic RET fusion-positive thyroid cancer who require systemic therapy and who are radioactive iodine refractory (if radioactive iodine is appropriate). Approval was based on the results of a multicenter, open-label, multi-cohort clinical trial (ARROW, NCT03037385), demonstrating substantial overall response rates (ORR) and durable responses in patients with RET-altered tumors. ORRs within the approved patient populations ranged from 57% [95% confidence interval (CI), 46-68] in patients with RET fusion-positive NSCLC previously treated with platinum chemotherapy to 89% (95% CI, 52-100) in patients with RET fusion-positive thyroid cancer, with response duration of at least 6 months in most responders. The product label includes warnings and precautions for pneumonitis, hypertension, hepatotoxicity, hemorrhagic events, tumor lysis syndrome, risk of impaired wound healing, and embryo-fetal toxicity. This article summarizes the major considerations during FDA review leading to the approval of pralsetinib.

FDA Approval Summary: Rucaparib for the Treatment of Patients with Deleterious BRCA-Mutated Metastatic Castrate-Resistant Prostate Cancer.

The U.S. Food and Drug Administration (FDA) granted accelerated approval to rucaparib in May 2020 for the treatment of adult patients with deleterious BRCA mutation (germline and/or somatic)-associated metastatic castrate-resistant prostate cancer (mCRPC) who have been treated with androgen receptor-directed therapy and a taxane. This approval was based on data from the ongoing multicenter, open-label single-arm trial TRITON2. The primary endpoint, confirmed objective response rate, in the 62 patients who met the above criteria, was 44% (95% confidence interval [CI]: 31%-57%). The median duration of response was not estimable (95% CI: 6.4 to not estimable). Fifty-six percent of patients had a response duration of >6 months and 15% >12 months. The safety profile of rucaparib was generally consistent with that of the class of poly-(ADP-ribose) polymerase enzyme inhibitors and other trials of rucaparib in the treatment of ovarian cancer. Deaths due to adverse events (AEs) occurred in 1.7% of patients, and 8% discontinued rucaparib because of an AE. Grade 3-4 AEs occurred in 59% of patients. No patients with prostate cancer developed myelodysplastic syndrome or acute myeloid leukemia. The trial TRITON3 in patients with mCRPC is ongoing and is planned to verify the clinical benefit of rucaparib in mCRPC. This article summarizes the FDA thought process and data supporting this accelerated approval. IMPLICATIONS FOR PRACTICE: The accelerated approval of rucaparib for the treatment of adult patients with deleterious BRCA mutation (germline and/or somatic)-associated metastatic castrate-resistant prostate cancer who have been treated with androgen receptor-directed therapy and a taxane represents the first approved therapy for this selected patient population. This approval was based on a single-arm trial demonstrating a confirmed objective response rate greater than that of available therapy with a favorable duration of response and an acceptable toxicity profile. The ongoing trial TRITON3 is verifying the clinical benefit of this drug.

FDA Approval Summary: Pertuzumab, Trastuzumab, and Hyaluronidase-zzxf Injection for Subcutaneous Use in Patients with HER2-positive Breast Cancer.

On June 29, 2020, the FDA approved pertuzumab, trastuzumab, and hyaluronidase-zzxf subcutaneous injection (Phesgo) for the treatment of patients with HER2-positive early-stage and metastatic breast cancer. Patients should be selected for therapy based on an FDA-approved companion diagnostic test. Approval was primarily based on the FeDeriCa trial, a randomized, open-label, multicenter comparability study of pertuzumab, trastuzumab, and hyaluronidase-zzxf subcutaneous injection compared with intravenous pertuzumab and intravenous trastuzumab administered in the neoadjuvant and adjuvant settings with chemotherapy for the treatment of patients with early breast cancer. The pharmacokinetic endpoints were, first, to demonstrate that the exposure of subcutaneous pertuzumab was not inferior to that of intravenous pertuzumab, and then to demonstrate that the exposure of subcutaneous trastuzumab was not inferior to that of intravenous trastuzumab. The primary endpoints were met with the observed lower limit of the two-sided 90% confidence intervals above the prespecified noninferiority margins. The most common adverse reactions were alopecia, nausea, diarrhea, anemia, and asthenia. The totality of the evidence demonstrated comparability of the subcutaneous product to intravenous, allowing for extrapolation and approval of all breast cancer indications for which intravenous trastuzumab and pertuzumab are approved.

FDA Approval Summary: Alpelisib Plus Fulvestrant for Patients with HR-positive, HER2-negative, PIK3CA-mutated, Advanced or Metastatic Breast Cancer.

On May 24, 2019, the FDA granted regular approval to alpelisib in combination with fulvestrant for postmenopausal women, and men, with hormone receptor (HR)-positive, HER2-negative, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA)-mutated, advanced or metastatic breast cancer as detected by an FDA-approved test following progression on or after an endocrine-based regimen. Approval was based on the SOLAR-1 study, a randomized, double-blind, placebo-controlled trial of alpelisib plus fulvestrant versus placebo plus fulvestrant. The primary endpoint was investigator-assessed progression-free survival (PFS) per RECIST v1.1 in the cohort of trial participants whose tumors had a PIK3CA mutation. The estimated median PFS by investigator assessment in the alpelisib plus fulvestrant arm was 11 months [95% confidence interval (CI), 7.5-14.5] compared with 5.7 months (95% CI, 3.7-7.4) in the placebo plus fulvestrant arm (HR, 0.65; 95% CI, 0.50-0.85; two-sided P = 0.001). The median overall survival was not yet reached for the alpelisib plus fulvestrant arm (95% CI, 28.1-NE) and was 26.9 months (95% CI, 21.9-NE) for the fulvestrant control arm. No PFS benefit was observed in trial participants whose tumors did not have a PIK3CA mutation (HR, 0.85; 95% CI, 0.58-1.25). The most common adverse reactions, including laboratory abnormalities, on the alpelisib plus fulvestrant arm were increased glucose, increased creatinine, diarrhea, rash, decreased lymphocyte count, increased gamma glutamyl transferase, nausea, increased alanine aminotransferase, fatigue, decreased hemoglobin, increased lipase, decreased appetite, stomatitis, vomiting, decreased weight, decreased calcium, decreased glucose, prolonged activated partial thromboplastin time, and alopecia.

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.

FDA Approval Summary: Selpercatinib for the Treatment of Lung and Thyroid Cancers with RET Gene Mutations or Fusions.

On May 8, 2020, the FDA granted accelerated approval to selpercatinib for (i) adult patients with metastatic RET fusion-positive non-small cell lung cancer (NSCLC), (ii) adult and pediatric patients ≥12 years of age with advanced or metastatic RET-mutant medullary thyroid cancer who require systemic therapy, and (iii) adult and pediatric patients ≥12 years of age with advanced or metastatic RET fusion-positive thyroid cancer who require systemic therapy and who are radioactive iodine refractory (if radioactive iodine is appropriate). Approval was granted on the basis of the clinically important effects on the overall response rate (ORR) with prolonged duration of responses observed in a multicenter, open-label, multicohort clinical trial (LIBRETTO-001, NCT03157128) in patients whose tumors had RET alterations. ORRs within the approved patient populations ranged from 64% [95% confidence interval (CI), 54-73] in prior platinum-treated RET fusion-positive NSCLC to 100% (95% CI, 63-100) in systemic therapy-naïve RET fusion-positive thyroid cancer, with the majority of responders across indications demonstrating responses of at least 6 months. The product label includes warnings and precautions for hepatotoxicity, hypertension, QT interval prolongation, hemorrhagic events, hypersensitivity, risk of impaired wound healing, and embryo-fetal toxicity. This is the first approval of a drug specifically for patients with RET alterations globally.