Repotrectinib in ROS1 Fusion-Positive Non-Small-Cell Lung Cancer.

BACKGROUND: The early-generation ROS1 tyrosine kinase inhibitors (TKIs) that are approved for the treatment of ROS1 fusion-positive non-small-cell lung cancer (NSCLC) have antitumor activity, but resistance develops in tumors, and intracranial activity is suboptimal. Repotrectinib is a next-generation ROS1 TKI with preclinical activity against ROS1 fusion-positive cancers, including those with resistance mutations such as ROS1 G2032R. METHODS: In this registrational phase 1-2 trial, we assessed the efficacy and safety of repotrectinib in patients with advanced solid tumors, including ROS1 fusion-positive NSCLC. The primary efficacy end point in the phase 2 trial was confirmed objective response; efficacy analyses included patients from phase 1 and phase 2. Duration of response, progression-free survival, and safety were secondary end points in phase 2. RESULTS: On the basis of results from the phase 1 trial, the recommended phase 2 dose of repotrectinib was 160 mg daily for 14 days, followed by 160 mg twice daily. Response occurred in 56 of the 71 patients (79%; 95% confidence interval [CI], 68 to 88) with ROS1 fusion-positive NSCLC who had not previously received a ROS1 TKI; the median duration of response was 34.1 months (95% CI, 25.6 to could not be estimated), and median progression-free survival was 35.7 months (95% CI, 27.4 to could not be estimated). Response occurred in 21 of the 56 patients (38%; 95% CI, 25 to 52) with ROS1 fusion-positive NSCLC who had previously received one ROS1 TKI and had never received chemotherapy; the median duration of response was 14.8 months (95% CI, 7.6 to could not be estimated), and median progression-free survival was 9.0 months (95% CI, 6.8 to 19.6). Ten of the 17 patients (59%; 95% CI, 33 to 82) with the ROS1 G2032R mutation had a response. A total of 426 patients received the phase 2 dose; the most common treatment-related adverse events were dizziness (in 58% of the patients), dysgeusia (in 50%), and paresthesia (in 30%), and 3% discontinued repotrectinib owing to treatment-related adverse events. CONCLUSIONS: Repotrectinib had durable clinical activity in patients with ROS1 fusion-positive NSCLC, regardless of whether they had previously received a ROS1 TKI. Adverse events were mainly of low grade and compatible with long-term administration. (Funded by Turning Point Therapeutics, a wholly owned subsidiary of Bristol Myers Squibb; TRIDENT-1 ClinicalTrials.gov number, NCT03093116.).

First-Line Selpercatinib or Chemotherapy and Pembrolizumab in RET Fusion-Positive NSCLC.

BACKGROUND: Selpercatinib, a highly selective potent and brain-penetrant RET inhibitor, was shown to have efficacy in patients with advanced RET fusion-positive non-small-cell lung cancer (NSCLC) in a nonrandomized phase 1-2 study. METHODS: In a randomized phase 3 trial, we evaluated the efficacy and safety of first-line selpercatinib as compared with control treatment that consisted of platinum-based chemotherapy with or without pembrolizumab at the investigator's discretion. The primary end point was progression-free survival assessed by blinded independent central review in both the intention-to-treat-pembrolizumab population (i.e., patients whose physicians had planned to treat them with pembrolizumab in the event that they were assigned to the control group) and the overall intention-to-treat population. Crossover from the control group to the selpercatinib group was allowed if disease progression as assessed by blinded independent central review occurred during receipt of control treatment. RESULTS: In total, 212 patients underwent randomization in the intention-to-treat-pembrolizumab population. At the time of the preplanned interim efficacy analysis, median progression-free survival was 24.8 months (95% confidence interval [CI], 16.9 to not estimable) with selpercatinib and 11.2 months (95% CI, 8.8 to 16.8) with control treatment (hazard ratio for progression or death, 0.46; 95% CI, 0.31 to 0.70; P<0.001). The percentage of patients with an objective response was 84% (95% CI, 76 to 90) with selpercatinib and 65% (95% CI, 54 to 75) with control treatment. The cause-specific hazard ratio for the time to progression affecting the central nervous system was 0.28 (95% CI, 0.12 to 0.68). Efficacy results in the overall intention-to-treat population (261 patients) were similar to those in the intention-to-treat-pembrolizumab population. The adverse events that occurred with selpercatinib and control treatment were consistent with those previously reported. CONCLUSIONS: Treatment with selpercatinib led to significantly longer progression-free survival than platinum-based chemotherapy with or without pembrolizumab among patients with advanced RET fusion-positive NSCLC. (Funded by Eli Lilly and others; ClinicalTrials.gov number, NCT04194944.).

Author Correction: HER kinase inhibition in patients with HER2- and HER3-mutant cancers.

The 'Competing interests' statement of this Article has been updated; please see the accompanying Amendment. The original Article has not been corrected online.

Zurletrectinib is a next-generation TRK inhibitor with strong intracranial activity against NTRK fusion-positive tumours with on-target resistance to first-generation agents.

BACKGROUND: While NTRK fusion-positive cancers can be exquisitely sensitive to first-generation TRK inhibitors, resistance inevitably occurs, mediated in many cases by acquired NTRK mutations. Next-generation inhibitors (e.g., selitrectinib, repotrectinib) maintain activity against these TRK mutant tumors; however, there are no next-generation TRK inhibitors approved by the FDA and select trials have stopped treating patients. Thus, the identification of novel, potent and specific next-generation TRK inhibitors is a high priority. METHODS: In silico modeling and in vitro kinase assays were performed on TRK wild type (WT) and TRK mutant kinases. Cell viability and clonogenic assays as well as western blots were performed on human primary and murine engineered NTRK fusion-positive TRK WT and mutant cell models. Finally, zurletrectinib was tested in vivo in human xenografts and murine orthotopic glioma models harboring TRK-resistant mutations. RESULTS: In vitro kinase and in cell-based assays showed that zurletrectinib, while displaying similar potency against TRKA, TRKB, and TRKC WT kinases, was more active than other FDA approved or clinically tested 1st- (larotrectinib) and next-generation (selitrectinib and repotrectinib) TRK inhibitors against most TRK inhibitor resistance mutations (13 out of 18). Similarly, zurletrectinib inhibited tumor growth in vivo in sub-cute xenograft models derived from NTRK fusion-positive cells at a dose 30 times lower when compared to selitrectinib. Computational modeling suggests this stronger activity to be the consequence of augmented binding affinity of zurletrectinib for TRK kinases. When compared to selitrectinib and repotrectinib, zurletrectinib showed increased brain penetration in rats 0.5 and 2 h following a single oral administration. Consistently, zurletrectinib significantly improved the survival of mice harboring orthotopic NTRK fusion-positive, TRK-mutant gliomas (median survival = 41.5, 66.5, and 104 days for selitrectinib, repotrectinib, and zurletrectinib respectively; P < 0.05). CONCLUSION: Our data identifies zurletrectinib as a novel, highly potent next-generation TRK inhibitor with stronger in vivo brain penetration and intracranial activity than other next-generation agents.

HER kinase inhibition in patients with HER2- and HER3-mutant cancers.

Somatic mutations of ERBB2 and ERBB3 (which encode HER2 and HER3, respectively) are found in a wide range of cancers. Preclinical modelling suggests that a subset of these mutations lead to constitutive HER2 activation, but most remain biologically uncharacterized. Here we define the biological and therapeutic importance of known oncogenic HER2 and HER3 mutations and variants of unknown biological importance by conducting a multi-histology, genomically selected, 'basket' trial using the pan-HER kinase inhibitor neratinib (SUMMIT; clinicaltrials.gov identifier NCT01953926). Efficacy in HER2-mutant cancers varied as a function of both tumour type and mutant allele to a degree not predicted by preclinical models, with the greatest activity seen in breast, cervical and biliary cancers and with tumours that contain kinase domain missense mutations. This study demonstrates how a molecularly driven clinical trial can be used to refine our biological understanding of both characterized and new genomic alterations with potential broad applicability for advancing the paradigm of genome-driven oncology.

Efficacy and safety of NTRK inhibitors in patients with NTRK fusion-positive lung and thyroid cancers.

Neurotrophic tyrosine receptor kinase (NTRK) gene fusions are implicated in various cancers, including those of the lung and thyroid. The prevalence of NTRK fusions is 0.1 to 0.3% in non-small cell lung cancer (NSCLC) and as high as 26% in pediatric papillary thyroid carcinoma. Detection methods include immunohistochemistry, fluorescence in situ hybridization, reverse transcription polymerase chain reaction, and next-generation sequencing. Management of NTRK fusion-positive lung cancer primarily involves targeted therapies, notably the tyrosine receptor kinase (TRK) inhibitors larotrectinib and entrectinib. Both agents demonstrate high response rates and durable disease control, particularly in metastatic adenocarcinoma of the lung. They are preferred as first-line treatments because of their efficacy over immunotherapy. Possible adverse events include dizziness, weight gain, neuropathy-like pain, and liver enzyme elevation. Larotrectinib and entrectinib also produce robust and durable responses in NTRK fusion-positive thyroid cancer that is refractory to radioactive iodine. Second-generation TRK inhibitors that have been designed to overcome acquired resistance are under investigation.

Decision-making as discovery: Vetting clinical research in a leading precision oncology service.

Based on fieldwork carried out at the Early Drug Development Service of a world-leading cancer institution, our study sheds lights on decision-making processes at the stage where decisions are made about which clinical trial to pursue and thus which experimental drugs will feed the growing pipeline of molecularly guided therapies and therapeutic strategies available to treating physicians. The paper shows how such collective decision-making practices by a translational research unit employ formal tools and ad hoc valuation strategies that interweave technical-scientific matters of concern with patient-oriented clinical ones, as part of the institutional assetization of biomedical knowledge production. In the process, decision-making practices in part define the conditions of possibility for the provision of care in what is increasingly becoming a 'clinic of variants.' They do so by reconfiguring on an evolving basis the socio-material ecosystem through which precision oncology is enacted as a rapidly evolving assemblage of patients, physicians, research and support staff, protocols, molecular markers, drugs and administrative components.

Larotrectinib efficacy and safety in adult patients with tropomyosin receptor kinase fusion sarcomas.

BACKGROUND: Larotrectinib, a first-in-class, highly selective tropomyosin receptor kinase (TRK) inhibitor, has demonstrated efficacy in adult and pediatric patients with various solid tumors harboring NTRK gene fusions. This subset analysis focuses on the efficacy and safety of larotrectinib in an expanded cohort of adult patients with TRK fusion sarcomas. METHODS: Patients (≥18 years old) with sarcomas harboring NTRK gene fusions were identified from three clinical trials. Patients received larotrectinib 100 mg orally twice daily. Response was investigator-assessed per RECIST v1.1. Data cutoff was July 20, 2021. RESULTS: At the data cutoff, 36 adult patients with TRK fusion sarcomas had initiated larotrectinib therapy: two (6%) patients had bone sarcomas, four (11%) had gastrointestinal stromal tumors, and 30 (83%) had soft tissue sarcomas. All patients were evaluable for response and demonstrated an objective response rate of 58% (95% confidence interval, 41-74). Patients responded well to larotrectinib regardless of number of prior lines of therapy. Adverse events (AEs) were mostly grade 1/2. Grade 3 treatment-emergent AEs (TEAEs) occurred in 15 (42%) patients. There were no grade 4 TEAEs. Two grade 5 TEAEs were reported, neither of which were considered related to larotrectinib. Four (11%) patients permanently discontinued treatment due to TEAEs. CONCLUSIONS: Larotrectinib demonstrated robust and durable responses, extended survival benefit, and a favorable safety profile in adult patients with TRK fusion sarcomas with longer follow-up. These results continue to demonstrate that testing for NTRK gene fusions should be incorporated into the clinical management of adult patients with various types of sarcomas. PLAIN LANGUAGE SUMMARY: Tropomyosin receptor kinase (TRK) fusion proteins result from translocations involving the NTRK gene and cause cancer in a range of tumor types. Larotrectinib is an agent that specifically targets TRK fusion proteins and is approved for the treatment of patients with TRK fusion cancer. This study looked at how well larotrectinib worked in adult patients with sarcomas caused by TRK fusion proteins. Over half of patients had a durable response to larotrectinib, with no unexpected side effects. These results show that larotrectinib is safe and effective in adult patients with TRK fusion sarcomas.

Efficacy of Selpercatinib in RET-Altered Thyroid Cancers.

BACKGROUND: RET mutations occur in 70% of medullary thyroid cancers, and RET fusions occur rarely in other thyroid cancers. In patients with RET-altered thyroid cancers, the efficacy and safety of selective RET inhibition are unknown. METHODS: We enrolled patients with RET-mutant medullary thyroid cancer with or without previous vandetanib or cabozantinib treatment, as well as those with previously treated RET fusion-positive thyroid cancer, in a phase 1-2 trial of selpercatinib. The primary end point was an objective response (a complete or partial response), as determined by an independent review committee. Secondary end points included the duration of response, progression-free survival, and safety. RESULTS: In the first 55 consecutively enrolled patients with RET-mutant medullary thyroid cancer who had previously received vandetanib, cabozantinib, or both, the percentage who had a response was 69% (95% confidence interval [CI], 55 to 81), and 1-year progression-free survival was 82% (95% CI, 69 to 90). In 88 patients with RET-mutant medullary thyroid cancer who had not previously received vandetanib or cabozantinib, the percentage who had a response was 73% (95% CI, 62 to 82), and 1-year progression-free survival was 92% (95% CI, 82 to 97). In 19 patients with previously treated RET fusion-positive thyroid cancer, the percentage who had a response was 79% (95% CI, 54 to 94), and 1-year progression-free survival was 64% (95% CI, 37 to 82). The most common adverse events of grade 3 or higher were hypertension (in 21% of the patients), increased alanine aminotransferase level (in 11%), increased aspartate aminotransferase level (in 9%), hyponatremia (in 8%), and diarrhea (in 6%). Of all 531 patients treated, 12 (2%) discontinued selpercatinib owing to drug-related adverse events. CONCLUSIONS: In this phase 1-2 trial, selpercatinib showed durable efficacy with mainly low-grade toxic effects in patients with medullary thyroid cancer with and without previous vandetanib or cabozantinib treatment. (Funded by Loxo Oncology and others; LIBRETTO-001 ClinicalTrials.gov number, NCT03157128.).

Efficacy of Selpercatinib in RET Fusion-Positive Non-Small-Cell Lung Cancer.

BACKGROUND: RET fusions are oncogenic drivers in 1 to 2% of non-small-cell lung cancers (NSCLCs). In patients with RET fusion-positive NSCLC, the efficacy and safety of selective RET inhibition are unknown. METHODS: We enrolled patients with advanced RET fusion-positive NSCLC who had previously received platinum-based chemotherapy and those who were previously untreated separately in a phase 1-2 trial of selpercatinib. The primary end point was an objective response (a complete or partial response) as determined by an independent review committee. Secondary end points included the duration of response, progression-free survival, and safety. RESULTS: In the first 105 consecutively enrolled patients with RET fusion-positive NSCLC who had previously received at least platinum-based chemotherapy, the percentage with an objective response was 64% (95% confidence interval [CI], 54 to 73). The median duration of response was 17.5 months (95% CI, 12.0 to could not be evaluated), and 63% of the responses were ongoing at a median follow-up of 12.1 months. Among 39 previously untreated patients, the percentage with an objective response was 85% (95% CI, 70 to 94), and 90% of the responses were ongoing at 6 months. Among 11 patients with measurable central nervous system metastasis at enrollment, the percentage with an objective intracranial response was 91% (95% CI, 59 to 100). The most common adverse events of grade 3 or higher were hypertension (in 14% of the patients), an increased alanine aminotransferase level (in 12%), an increased aspartate aminotransferase level (in 10%), hyponatremia (in 6%), and lymphopenia (in 6%). A total of 12 of 531 patients (2%) discontinued selpercatinib because of a drug-related adverse event. CONCLUSIONS: Selpercatinib had durable efficacy, including intracranial activity, with mainly low-grade toxic effects in patients with RET fusion-positive NSCLC who had previously received platinum-based chemotherapy and those who were previously untreated. (Funded by Loxo Oncology and others; LIBRETTO-001 ClinicalTrials.gov number, NCT03157128.).

Tumour-agnostic efficacy and safety of selpercatinib in patients with RET fusion-positive solid tumours other than lung or thyroid tumours (LIBRETTO-001): a phase 1/2, open-label, basket trial.

BACKGROUND: Selpercatinib is a first-in-class, highly selective RET kinase inhibitor with CNS activity that has shown efficacy in RET fusion-positive lung and thyroid cancers. RET fusions occur rarely in other tumour types. We aimed to investigate the efficacy and safety of selpercatinib in a diverse group of patients with RET fusion-positive non-lung or thyroid advanced solid tumours (ie, a tumour-agnostic population). METHODS: LIBRETTO-001 is an ongoing phase 1/2, single-group, open-label, basket trial of selpercatinib in patients aged 18 years and older (or ≥12 years, where permitted by regulatory authorities) with RET-altered cancers. The trial is being conducted at 89 sites in 16 countries; the tumour-agnostic population was enrolled at 30 sites (outpatient and inpatient medical facilities) across eight countries. A prespecified interim analysis of LIBRETTO-001 was planned to investigate the efficacy and safety of selpercatinib in a tumour-agnostic population of patients with RET fusion-positive advanced solid tumours; the data cutoff date was Sept 24, 2021. Eligible patients had disease progression on or after previous systemic therapies or no satisfactory therapeutic options and an Eastern Cooperative Oncology Group performance status of 0-2. Selpercatinib was orally administered in a continuous 28-day cycle. Patients enrolled in the phase 1 dose-escalation portion received between 20 mg once daily or 20-240 mg twice daily; the phase 2 recommended dose was 160 mg twice daily. The primary endpoint was the objective response rate as determined by the independent review committee. The efficacy-evaluable tumour-agnostic population was defined as patients with RET fusion-positive cancer, other than non-small-cell lung cancer and thyroid cancer, who had at least 6 months of follow-up from the first study dose at the time of data cutoff (all responders at the time of data cutoff were followed up for at least 6 months from the onset of response unless they progressed or died earlier). Safety was analysed in the tumour-agnostic population of patients who had been enrolled and received selpercatinib on or before the data cutoff date. This study is registered with ClinicalTrials.gov (NCT03157128) and is still recruiting participants. FINDINGS: Between Dec 4, 2017, and Aug 4, 2021, 45 patients with RET fusion-positive tumour-agnostic cancers were enrolled from the phase 1 dose-escalation and phase 2 dose-expansion cohorts of the trial. 43 (96%) of 45 patients received a starting dose of selpercatinib at the recommended dose of 160 mg twice daily. Of the two patients who did not, one received a dose of 160 mg twice daily via intra-patient dose escalation (as allowed per protocol for patients enrolled in the phase 1 portion of the study at lower doses) and the other patient's starting dose of 120 mg twice daily was never escalated. Of the 41 efficacy-evaluable patients, the objective response rate as per the independent review committee was 43·9% (95% CI 28·5-60·3; 18 of 41 patients). The most common grade 3 or worse treatment-emergent adverse events were hypertension (ten [22%] of 45 patients), increased alanine aminotransferase (seven [16%]), and increased aspartate aminotransferase (six [13%]). Treatment-emergent serious adverse events occurred in 18 (40%) of 45 patients. No treatment-related deaths occurred. INTERPRETATION: Selpercatinib showed clinically meaningful activity in the RET fusion-positive tumour-agnostic population, with a safety profile consistent with that observed in other indications. Comprehensive genomic testing that includes RET fusions will be crucial for identifying patients who might benefit from selpercatinib. FUNDING: Loxo Oncology.

Immune biomarkers and response to checkpoint inhibition of BRAFV600 and BRAF non-V600 altered lung cancers.

BACKGROUND: While 2-4% of lung cancers possess alterations in BRAF, little is known about the immune responsiveness of these tumours. METHODS: Clinical and genomic data were collected from 5945 patients with lung cancers whose tumours underwent next-generation sequencing between 2015 and 2018. Patients were followed through 2020. RESULTS: In total, 127 patients with metastatic BRAF-altered lung cancers were identified: 29 tumours had Class I mutations, 59 had Class II/III alterations, and 39 had variants of unknown significance (VUS). Tumour mutation burden was higher in Class II/III than Class I-altered tumours (8.8 mutations/Mb versus 4.9, P < 0.001), but this difference was diminished when stratified by smoking status. The overall response rate to immune checkpoint inhibitors (ICI) was 9% in Class I-altered tumours and 26% in Class II/III (P = 0.25), with median time on treatment of 1.9 months in both groups. Among patients with Class I-III-altered tumours, 36-month HR for death in those who ever versus never received ICI was 1.82 (1.17-6.11). Nine patients were on ICI for >2 years (two with Class I mutations, two with Class II/III alterations, and five with VUS). CONCLUSIONS: A subset of patients with BRAF-altered lung cancers achieved durable disease control on ICI. However, collectively no significant clinical benefit was seen.

NTRK1 Fusions identified by non-invasive plasma next-generation sequencing (NGS) across 9 cancer types.

BACKGROUND: Activating fusions of the NTRK1, NTRK2 and NTRK3 genes are drivers of carcinogenesis and proliferation across a broad range of tumour types in both adult and paediatric patients. Recently, the FDA granted tumour-agnostic approvals of TRK inhibitors, larotrectinib and entrectinib, based on significant and durable responses in multiple primary tumour types. Unfortunately, testing rates in clinical practice remain quite low. Adding plasma next-generation sequencing of circulating tumour DNA (ctDNA) to tissue-based testing increases the detection rate of oncogenic drivers and demonstrates high concordance with tissue genotyping. However, the clinical potential of ctDNA analysis to identify NTRK fusion-positive tumours has been largely unexplored. METHODS: We retrospectively reviewed a ctDNA database in advanced stage solid tumours for NTRK1 fusions. RESULTS: NTRK1 fusion events, with nine unique fusion partners, were identified in 37 patients. Of the cases for which clinical data were available, 44% had tissue testing for NTRK1 fusions; the NTRK1 fusion detected by ctDNA was confirmed in tissue in 88% of cases. Here, we report for the first time that minimally-invasive plasma NGS can detect NTRK fusions with a high positive predictive value. CONCLUSION: Plasma ctDNA represents a rapid, non-invasive screening method for this rare genomic target that may improve identification of patients who can benefit from TRK-targeted therapy and potentially identify subsequent on- and off-target resistance mechanisms.

Larotrectinib Treatment for Patients With TRK Fusion-Positive Salivary Gland Cancers.

BACKGROUND: Larotrectinib is a first-in-class, highly selective, and central nervous system-active tropomyosin receptor kinase (TRK) inhibitor approved for the treatment of adult and pediatric patients with TRK fusion cancer. We report the efficacy and safety of larotrectinib in patients with TRK fusion-positive salivary gland cancers. PATIENTS AND METHODS: Patients with TRK fusion-positive salivary gland cancer treated with larotrectinib were identified from two clinical trials (NCT02122913 and NCT02576431). Patients received larotrectinib 100 mg twice daily (BID) except for one patient who received 150 mg BID in the phase I trial. The primary endpoint was objective response rate (ORR) as assessed by the investigator using Response Evaluation Criteria in Solid Tumors version 1.1. RESULTS: At the data cut-off (July 20, 2020), 24 patients with TRK fusion-positive salivary gland cancer had been treated. The most common histologies were secretory carcinoma (54%), adenocarcinoma (25%), and mucoepidermoid carcinoma (13%). All 24 patients had an ETV6-NTRK3 gene fusion. The ORR was 92% (95% confidence interval, 73-99). Best overall response was complete response in three (13%) patients, partial response in 19 (79%), and progressive disease in two (8%). The rate of progression-free survival at 24 months was 78% (median follow-up 30.9 months). Most treatment-related adverse events (AEs) were grade 1-2, and no patients discontinued treatment due to AEs. CONCLUSION: Larotrectinib demonstrated robust and durable efficacy in patients with TRK fusion-positive salivary gland tumors of various histologies, and a favorable safety profile. These findings support NTRK gene fusion testing in patients with advanced salivary gland cancers. CLINICALTRIALS.GOV NUMBERS: NCT02122913 and NCT02576431.

Phase I study of lurbinectedin in combination with weekly paclitaxel with or without bevacizumab in patients with advanced solid tumors.

Lurbinectedin and paclitaxel showed synergism in preclinical studies and have non-completely overlapping toxicity profiles. This phase I trial evaluated a combination of paclitaxel and lurbinectedin with/without bevacizumab in advanced tumors. This trial was divided into Group A, which evaluated weekly paclitaxel (60 or 80 mg) plus lurbinectedin (3.0-5.0 mg flat dose [FD] or 2.2 mg/m2) every 3 weeks in advanced solid tumors; and Group B, which evaluated bevacizumab (BEV, 15 mg/kg) added to the recommended dose (RD) defined in Group A in advanced epithelial ovarian or non-small cell lung cancer (NSCLC). 67 patients (A, n = 55; B, n = 12) were treated. The RD was paclitaxel 80 mg/m2 on Day (D)1,D8 plus lurbinectedin 2.2 mg/m2 on D1. At this RD, myelotoxicity was reversible and manageable, and most non-hematological toxicities were mild/moderate. Adding BEV did not notably change tolerability. Twenty-five confirmed responses were observed: 20/51 evaluable patients in Group A (overall response rate [ORR] = 39% at all dose levels and at the RD), and 5/10 evaluable patients in Group B (ORR = 50%). Most responders had breast (n = 7/12 patients), small cell lung (SCLC) (n = 5/7), epithelial ovarian (n = 3/9) and endometrial cancer (n = 3/11) in Group A, and epithelial ovarian (n = 3/4) and NSCLC (n = 2/6) in Group B. Clinical benefit rate was 61% in Group A (58% at the RD), and 90% in Group B. No major pharmacokinetic drug-drug interactions were observed. Paclitaxel/lurbinectedin and paclitaxel/lurbinectedin/BEV are feasible combinations. Further development is warranted of paclitaxel/lurbinectedin in SCLC, breast, and endometrial cancer, and of paclitaxel/lurbinectedin/BEV in epithelial ovarian cancer.

Rationale and design of ON-TRK: a novel prospective non-interventional study in patients with TRK fusion cancer treated with larotrectinib.

BACKGROUND: Tropomyosin receptor kinase (TRK) fusion proteins resulting from neurotrophic tyrosine receptor kinase (NTRK) gene fusions are rare primary oncogenic drivers in a wide array of tumors. Larotrectinib is a first-in-class, highly selective, central nervous system-active TRK inhibitor approved by the US Food and Drug Administration (FDA), European Medicines Agency (EMA), and over 40 countries for the treatment of TRK fusion solid tumors in adult and pediatric patients. Due to the rarity of TRK fusion cancer, larotrectinib was granted accelerated approval based on a relatively small number of patients enrolled in three early phase trials. ON-TRK aims to evaluate the safety profile of larotrectinib in a broader population and over extended time periods. METHODS: ON-TRK is a prospective, non-interventional, open-label, multicenter, multi-cohort, post-approval study in adult and pediatric patients with locally advanced or metastatic TRK fusion cancer treated with larotrectinib that will describe the safety and effectiveness of larotrectinib in real-world practice conditions. Adult patients will be grouped by tumor type and followed for at least 2 years. Patients < 18 years old will be enrolled under a 'pediatric' cohort regardless of tumor type and will be followed for 5 years to evaluate the risk of potential long-term adverse effects of larotrectinib on their growth and development. The effectiveness of larotrectinib in the overall study population as well as in patient subgroups will also be evaluated. Procedures avoided in patients with infantile fibrosarcoma (e.g., amputation) and the number of patients who were able to undergo surgery with a curative intent (excluding amputation) because of the use of larotrectinib will be described. Larotrectinib treatment patterns in real-world practice, including dosing and duration of treatment, will be described. DISCUSSION: The FDA Accelerated Approval Program allows for earlier approval of and patient access to drugs that treat serious conditions and fill an unmet medical need. This study is designed to fulfill post-approval requirements set by the FDA as well as post-marketing requirements set forth by local regulatory bodies and is part of the risk management plan for the EMA. STUDY REGISTRATION: This study is registered at ClinicalTrials.gov ( NCT04142437 ). PROTOCOL VERSION: v2.5, 25 March 2021.

Testing methods to diagnose TRK fusion cancer - a plain language summary and patient perspective.

WHAT IS THIS SUMMARY ABOUT?: This is a plain language summary of a 2022 study published in Cancer Genetics. This study describes the different tests used to detect a rare type of cancer called TRK (tropomyosin receptor kinase) fusion cancer in people taking part in three clinical trials testing the medication larotrectinib. Larotrectinib targets TRK fusion proteins, abnormal proteins that result from abnormal NTRK (neurotrophic tyrosine receptor kinase) gene fusions. People who were shown to have solid tumors containing TRK fusion proteins were able to participate in clinical trials that evaluated larotrectinib. WHAT WERE THE RESULTS?: Different testing methods were used to identify participants with TRK fusion cancer. Which test was used depended on different factors such as how commonly NTRK gene fusions are found in a specific cancer type, and the cost and accessibility of the test. Participants with different types of cancer were included in the study, which allowed researchers to identify which TRK fusion proteins were found across various types of tumor. WHAT DO THE RESULTS MEAN?: The results of this study provide a guidance for healthcare professionals on the methods used for testing to identify patients that have TRK fusion cancer. By characterizing the types of testing done across cancer types, patients and their caregivers can gain an understanding of the importance of testing. This plain language summary also includes insights and perspectives from a person affected by TRK fusion cancer, and from patient advocates. Clinical Trial Registration: NCT02122913 (ClinicalTrials.gov) Clinical Trial Registration: NCT02637687 (ClinicalTrials.gov) Clinical Trial Registration: NCT02576431 (ClinicalTrials.gov).

LIBRETTO-432, a phase III study of adjuvant selpercatinib or placebo in stage IB-IIIA RET fusion-positive non-small-cell lung cancer.

Selpercatinib, a first-in-class, highly selective and potent central nervous system-active RET kinase inhibitor demonstrated clinically meaningful activity with manageable toxicity in pretreated and treatment-naive advanced/metastatic RET fusion-positive non-small-cell lung cancer (NSCLC). LIBRETTO-432 is a global, randomized, double-blind, phase III trial evaluating selpercatinib versus placebo in stage IB-IIIA, RET fusion-positive NSCLC, previously treated with definitive surgery or radiation; participants must have undergone available anti-cancer therapy (including chemotherapy or durvalumab) or not be suitable for it, per investigator's discretion. The primary end point is investigator-assessed event-free survival (EFS) in the primary analysis population (stage II-IIIA RET fusion-positive NSCLC). Key secondary end points include EFS in the overall population, overall survival, and time to distant disease recurrence in the central nervous system.

Selpercatinib is approved in multiple countries for the treatment of advanced or metastatic RET-altered lung cancers. Selpercatinib has shown promising efficacy and safety results in patients with advanced/metastatic RET fusion-positive NSCLC. This is a summary of the LIBRETTO-432 study which compares selpercatinib with placebo in patients with earlier stages (stage IB-IIIA) of RET fusion-positive NSCLC, who have already undergone surgery or radiotherapy and applicable adjuvant chemotherapy. This study is active and currently recruiting new participants. This trial will evaluate how long people live without evidence of cancer recurrence, both during and after treatment. Side effects will also be evaluated in this study. Clinical Trial Registration: NCT04819100 (ClinicalTrials.gov).

Therapeutic Potential of Afatinib in NRG1 Fusion-Driven Solid Tumors: A Case Series.

BACKGROUND: Neuregulin 1 (NRG1) fusions, which activate ErbB signaling, are rare oncogenic drivers in multiple tumor types. Afatinib is a pan-ErbB family inhibitor that may be an effective treatment for NRG1 fusion-driven tumors. PATIENTS AND METHODS: This report summarizes pertinent details, including best tumor response to treatment, for six patients with metastatic NRG1 fusion-positive tumors treated with afatinib. RESULTS: The six cases include four female and two male patients who ranged in age from 34 to 69 years. Five of the cases are patients with lung cancer, including two patients with invasive mucinous adenocarcinoma and three patients with nonmucinous adenocarcinoma. The sixth case is a patient with colorectal cancer. NRG1 fusion partners for the patients with lung cancer were either CD74 or SDC4. The patient with colorectal cancer harbored a novel POMK-NRG1 fusion and a KRAS mutation. Two patients received afatinib as first- or second-line therapy, three patients received the drug as third- to fifth-line therapy, and one patient received afatinib as fifteenth-line therapy. Best response with afatinib was stable disease in two patients (duration up to 16 months when combined with local therapies) and partial response (PR) of >18 months in three patients, including one with ongoing PR after 27 months. The remaining patient had a PR of 5 months with afatinib 40 mg/day, then another 6 months after an increase to 50 mg/day. CONCLUSION: This report reviews previously published metastatic NRG1 fusion-positive tumors treated with afatinib and summarizes six previously unpublished cases. The latter include several with a prolonged response to treatment (>18 months), as well as the first report of efficacy in NRG1 fusion-positive colorectal cancer. This adds to the growing body of evidence suggesting that afatinib can be effective in patients with NRG1 fusion-positive tumors. KEY POINTS: NRG1 fusions activate ErbB signaling and have been identified as oncogenic drivers in multiple solid tumor types. Afatinib is a pan-ErbB family inhibitor authorized for the treatment of advanced non-small cell lung cancer that may be effective in NRG1 fusion-driven tumors. This report summarizes six previously unpublished cases of NRG1 fusion-driven cancers treated with afatinib, including five with metastatic lung cancer and one with metastatic colorectal cancer. Several patients showed a prolonged response of >18 months with afatinib treatment. This case series adds to the evidence suggesting a potential role for afatinib in this area of unmet medical need.

A Phase I, First-in-Human Study of GSK2849330, an Anti-HER3 Monoclonal Antibody, in HER3-Expressing Solid Tumors.

BACKGROUND: GSK2849330, an anti-HER3 monoclonal antibody that blocks HER3/Neuregulin 1 (NRG1) signaling in cancer cells, is engineered for enhanced antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity. This phase I, first-in-human, open-label study assessed the safety, pharmacokinetics (PK), pharmacodynamics, and preliminary activity of GSK2849330 in patients with HER3-expressing advanced solid tumors. PATIENTS AND METHODS: Patients with various tumor types were prospectively selected for HER3 expression by immunohistochemistry; a subset was also screened for NRG1 mRNA expression. In the dose-escalation phase, patients received GSK2849330 1.4-30 mg/kg every 2 weeks, or 3 mg/kg or 30 mg/kg weekly, intravenously (IV). In the dose-expansion phase, patients received 30 mg/kg GSK2849330 IV weekly. RESULTS: Twenty-nine patients with HER3-expressing cancers, of whom two expressed NRG1, received GSK2849330 (dose escalation: n = 18, dose expansion: n = 11). GSK2849330 was well tolerated. No dose-limiting toxicities were observed. The highest dose, of 30 mg/kg weekly, expected to provide full target engagement, was selected for dose expansion. Treatment-emergent adverse events (AEs) were mostly grade 1 or 2. The most common AEs were diarrhea (66%), fatigue (62%), and decreased appetite (31%). Dose-proportional plasma exposures were achieved, with evidence of HER3 inhibition in paired tissue biopsies. Of 29 patients, only 1 confirmed partial response, lasting 19 months, was noted in a patient with CD74-NRG1-rearranged non-small cell lung cancer (NSCLC). CONCLUSION: GSK2849330 demonstrated a favorable safety profile, dose-proportional PK, and evidence of target engagement, but limited antitumor activity in HER3-expressing cancers. The exceptional response seen in a patient with CD74-NRG1-rearranged NSCLC suggests further exploration in NRG1-fusion-positive cancers. IMPLICATIONS FOR PRACTICE: This first-in-human study confirms that GSK2849330 is well tolerated. Importantly, across a variety of HER3-expressing advanced tumors, prospective selection by HER3/NRG1 expression alone was insufficient to identify patients who could benefit from treatment with this antibody-dependent cell-mediated cytotoxicity- and complement-dependent cytotoxicity-enhanced anti-HER3 antibody. The only confirmed durable response achieved was in a patient with CD74-NRG1-rearranged lung cancer. This highlights the potential utility of screening for NRG1 fusions prospectively across tumor types to enrich potential responders to anti-HER3 agents in ongoing trials.