Overall survival (OS) of patients with TRK fusion–positive cancer receiving larotrectinib versus standard of care (SoC): A matching-adjusted indirect comparison (MAIC) using real-world data (RWD)

6579

Background: Larotrectinib trials in Tropomyosin Receptor Kinase (TRK) fusion cancer population were single arm trials and therefore limited comparative effectiveness data with larotrectinib are available.MAIC is typically used to balance population characteristics to facilitate cross-study comparisons. The objective of this study was to use MAIC to compare efficacy of the highly specific TRK inhibitor larotrectinib vs. SoC. Methods: Individual patient data from larotrectinib trials (NCT02122913, NCT02637687, NCT02576431) were compared with published aggregate SoC data from patients with locally advanced/metastatic TRK fusion cancer identified in the Flatiron Health/Foundation Medicine clinico-genomic database (Demetri et al. Ann Oncol. 2021). Prior to matching, eligible patients were ≥18 years and had to have received ≤4 lines of prior therapy (LoPT). Patients were matched on available common baseline characteristics (Table). Overall survival was the only endpoint assessed and was defined as time from locally advanced/metastatic disease diagnosis to death. The analyses included: 1) a log-rank test of equality to test whether the two groups were similar before larotrectinib initiation; and 2) estimation of treatment effect of larotrectinib vs. SoC. Hazard ratios (HRs) were used to compare the 2 groups. MAIC assumes that all observed and unobserved prognostic factors are adjusted for in the analysis. Results: 85 larotrectinib patients and 28 SoC patients were included. After matching, log-rank testing suggested no difference between the 2 groups (P=0.26), and larotrectinib was associated with a 78% lower risk of death (adjusted HR: 0.22 [95% confidence interval: 0.09, 0.54]; P=0.001), compared to SoC. Conclusions: This analysis suggests longer overall survival with larotrectinib, compared to SoC, in adult patients with TRK fusion cancer. The current analysis was limited to the prognostic variables available in the RWD. Further data are warranted to confirm those results. [Table: see text]

Long-term control and safety of larotrectinib in a cohort of adult and pediatric patients with tropomyosin receptor kinase (TRK) fusion primary central nervous system (CNS) tumors

2010

Background: Neurotrophic tyrosine receptor kinase ( NTRK) gene fusions are known oncogenic drivers in a variety of tumor types. Larotrectinib is a highly selective, CNS-active TRK inhibitor that demonstrated an objective response rate (ORR) of 30% and a 24-week disease control rate (DCR) of 73% across 33 evaluable adult and pediatric patients with TRK fusion primary CNS tumors, as of July 2020 (Doz et al, Neuro Oncol 2021). We report updated data on an expanded dataset of patients. Methods: Patients with TRK fusion primary CNS tumors in two clinical trials (NCT02637687, NCT02576431) were included. Larotrectinib was administered at 100 mg twice daily (BID) in adults and 100 mg/m2 (max 100 mg) BID in pediatric patients. Response was investigator-assessed. Results: As of July 2021, 38 adult and pediatric patients with TRK fusion primary CNS tumors were identified: high-grade glioma (HGG; n =23), low-grade glioma (LGG; n =9), and other (n =6; includes glioneuronal, neuroepithelial, diffuse leptomeningeal, neuroblastoma, recurrent small round blue cell, and not otherwise specified). Median age at enrollment was 10.8 years (range 1.3–79.0; 28 [74%] patients < 18 years old). The gene fusions involved NTRK2 (n = 28), NTRK1 (n = 6), and NTRK3 (n = 4). Sixteen (42%) patients received one prior line of systemic therapy and 16 (42%) received ≥2 prior lines. The ORR for 37 evaluable patients was 30% (95% confidence interval [CI] 16–47): three complete responses, eight partial responses, 21 stable disease (16 patients ≥24 weeks), and five progressive disease. The 24-week DCR was 73% (95% CI 56–86) for all patients, 68% (95% CI 45–86) for patients with HGG, and 89% (95% CI 52–100) for patients with LGG. Twenty-five of 31 patients (81%) with measurable disease at baseline had tumor shrinkage. Median time to response was 1.9 months. Median duration of response (DoR) was not reached; median follow-up was 25.6 months. The 12-month DoR rate was 64%. Median progression-free survival (PFS) was 16.5 months (95% CI 6.7–not estimable); median follow-up was 27.4 months. Median overall survival (OS) was not reached; median follow-up was 26.7 months. The 24-month OS rate was 65%. Treatment duration ranged from 0.1+ to 38.7+ months. Twenty-two patients (58%) progressed on treatment and three continued treatment post-progression for ≥4 weeks. Treatment-related adverse events (TRAEs) were reported in 21 patients (55%); the majority of these patients (18/21 [86%]) reported Grade 1 or 2 TRAEs. No Grade 3 or higher treatment-related neurological adverse events were reported. There were no treatment discontinuations due to TRAEs. Conclusions: Larotrectinib achieved a high DCR, rapid and durable responses, and a manageable safety profile in patients with TRK fusion primary CNS tumors. These results support testing for NTRK gene fusions in patients with CNS tumors. Clinical trial information: NCT02637687, NCT02576431.

Updated efficacy and safety of larotrectinib in patients with tropomyosin receptor kinase (TRK) fusion lung cancer

9024

Background: Neurotrophic tyrosine receptor kinase ( NTRK) gene fusions have been identified as oncogenic drivers in a variety of tumor types, including lung cancer. Larotrectinib is a highly selective, central nervous system (CNS)-active TRK inhibitor that demonstrated an objective response rate (ORR) of 73% across 15 investigator-assessed patients (pts) with lung cancer (Drilon et al, JCO Precis Oncol 2022). We report data on an expanded cohort of pts with TRK fusion lung cancer treated with larotrectinib. Methods: Pts with TRK fusion lung cancer enrolled in two larotrectinib clinical trials (NCT02576431 and NCT02122913) were included for this analysis. Larotrectinib was administered at 100 mg twice daily. Response was assessed by independent review committee (IRC) per RECIST v1.1. Results: As of July 20, 2021, a total of 26 pts with TRK fusion lung cancer (24 non-small cell lung cancer, 1 atypical carcinoid, 1 neuroendocrine) were enrolled, including 10 pts with CNS metastases at baseline. Median age was 51.5 years (range 25.0–76.0). The gene fusions involved NTRK1 (n =21; 81%) or NTRK3 (n =5; 19%). Pts received a median of 2 prior lines of systemic therapies with 19 (73%) receiving ≥2. Among 23 pts evaluable per IRC, the ORR was 83% (95% confidence interval [CI] 61–95): two complete responses, 17 partial responses (PR), and four stable disease (SD). The median time to response was 1.8 months. Among 10 evaluable pts with baseline CNS metastases, the ORR was 80% (95% CI 44–97): eight PR and two SD. Median duration of response (DoR) and progression-free survival (PFS) were not reached; median follow-up was 12.9 and 14.6 months, respectively. The 24-month rates for DoR and PFS were 72% and 67%, respectively. Median follow-up for overall survival (OS) was 12.9 months. The 24-month and 36-month rates for OS were both 72%. For the 10 evaluable pts with CNS metastases, the 12-month DoR, PFS, and OS rates were 26%, 22%, and 78%, respectively. Duration of treatment for all pts evaluable per IRC ranged from 2.1 to 52.7+ months. At data cut-off, six pts had progressed, with all six continuing treatment post-progression for ≥4 weeks. Treatment-related adverse events (TRAEs) were predominantly Grade 1–2. Grade 3–4 TRAEs were reported in five pts (increased alanine aminotransferase, increased aspartate aminotransferase, hypersensitivity, myalgia, and increased weight). There were no treatment discontinuations due to TRAEs. Conclusions: In this larger dataset, larotrectinib demonstrated rapid and durable responses, extended survival, and a favorable long-term safety profile in pts with advanced lung cancer harboring NTRK gene fusions, including in pts with CNS metastases. These results support testing for NTRK gene fusions in pts with lung cancer. Clinical trial information: NCT02576431, NCT02122913.

Indirect assessment of tumor-infiltrating lymphocyte activity in serum for predicting outcome in patients with glioblastoma treated with immunotherapy in the recurrent setting

2059

Background: Glioblastoma (GBM) is an aggressive brain tumor and despite efforts in developing new effective therapies, patient survival remains low. There is increasing interest in using immune checkpoint inhibitors (ICIs) for GBM, however the immunosuppressive (cold tumor) characteristics of GBM limit the efficacy of ICIs. Consequently, there is a need to identify patients with active tumor-infiltrating lymphocytes (hot tumor). Several studies have shown that brain extracellular matrix such as type IV collagen has a dynamic composition with protease-induced alterations. In this study, we evaluated the clinical utility of a non-invasive biomarker of granzyme B degraded type IV collagen (C4G) reflecting tumor-infiltrating lymphocyte activity and of matrix metalloproteinase (MMP) degraded type IV collagen (C4M) in GBM patients treated with nivolumab (anti-PD-1) and bevacizumab (anti-VEGF) in the recurrent setting. Methods: C4G and C4M were measured in serum from 22 controls and 39 GBM patients previously treated with surgery, radiotherapy and chemotherapy in the primary setting. After GBM recurrence, 18 patients underwent salvage resection (arm A) however 21 patients had no possibility for resection (arm B). All patients were treated with nivolumab and bevacizumab (NCT03890952 phase II study). Baseline GBM samples were taken before the second-line treatment. The association between C4G levels and outcome was evaluated by Cox regression analysis for overall survival (OS) and odds ratio (OR) calculations for complete response (CR) rate after dichotomizing patients into low vs high levels of C4G (median cutpoint). Results: C4G (p = 0.004), but not C4M (p = 0.166), was significantly elevated in serum from GBM patients compared to controls. Moreover, patients with high C4G levels had a significantly increased likelihood of experiencing CR (OR=6.68, p<0.0001). Furthermore, patients with high C4G experienced improved OS compared to low C4G (HR=0.39), and this remained significant after adjusting for other significant risk factors (treatment arm and MGMT methylation) by multivariate analysis (HR=0.44) (table). Conclusions: A non-invasive biomarker reflecting tumor-infiltrating lymphocyte activity (C4G) has the potential to identify GBM patients responding to nivolumab and bevacizumab in the recurrent setting. In the future, this may provide a non-invasive biomarker tool for stratifying patients with GBM for ICI trials. Clinical trial information: NCT03890952. [Table: see text]

Long-term efficacy and safety of larotrectinib in patients with TRK fusion-positive lung cancer

9109

Background: Neurotrophic tyrosine receptor kinase ( NTRK) gene fusions have been identified as oncogenic drivers in a diverse array of tumor types including lung cancer. Larotrectinib is a first-in-class, highly selective, central nervous system (CNS)-active tropomyosin receptor kinase (TRK) inhibitor approved for the treatment of adult and pediatric patients (pts) with TRK fusion cancer, with an objective response rate (ORR) of 78% across multiple non-CNS cancers (McDermott et al, ESMO 2020). Here, we report the updated data on pts with lung cancer treated with larotrectinib. Methods: Pts with lung cancer harboring a NTRK gene fusion enrolled in two clinical trials (NCT02576431 and NCT02122913) were identified for this analysis. Larotrectinib 100 mg PO BID was administered on a continuous 28-day schedule until disease progression, withdrawal, or unacceptable toxicity. Response was assessed by the investigator per RECIST v1.1. Results: As of July 20, 2020, a total of 20 pts with TRK fusion-positive lung cancer (19 with non-small cell lung cancer and 1 with small cell lung cancer) were enrolled. Median age was 48.5 years (range 25.0–76.0). The gene fusions involved NTRK1 (n = 16; 80%) or NTRK3 (n = 4; 20%). Pts were heavily pre-treated with a median of 3 systemic therapies (range 0–6). Among 15 evaluable pts, the confirmed ORR was 73% (95% CI 45–92): 1 complete response, 10 partial responses (PR), 3 stable disease (SD) and 1 progressive disease (PD). The median time to response was 1.8 months. Among 8 evaluable pts with baseline measurable and non-measurable CNS metastases, the ORR was 63% (95% CI 25–91): 5 PR, 2 SD, and 1 PD. In all evaluable pts, the 12-month rates for duration of response and progression-free survival were 81% and 65%, respectively. Median overall survival was 40.7 months (95% CI 17.2 to not estimable) at a median follow-up of 16.2 months. Duration of treatment ranged from 0.03+ to 51.55+ months. Adverse events (AEs) were predominantly Grade 1–2. Treatment-related AEs were reported in 16 pts, of which 2 experienced Grade 3 events (myalgia, hypersensitivity, weight increase). There were no treatment discontinuations due to AEs. Conclusions: These data confirm that larotrectinib is highly active with rapid and durable responses, extended survival benefit, and a favorable long-term safety profile in pts with advanced lung cancer harboring NTRK gene fusions, including in pts with CNS metastases. These results underscore the importance of screening for NTRK gene fusions in pts with lung cancer. Clinical trial information: NCT02576431 and NCT02122913.

Intra-patient comparison from larotrectinib clinical trials in TRK fusion cancer: An expanded dataset

3114

Background: Larotrectinib is a highly selective, CNS-active tropomyosin receptor kinase (TRK) inhibitor that demonstrated rapid and durable responses in three phase I/II single-arm studies of patients (pts) with TRK fusion cancer. In single-arm studies the growth modulation index (GMI) can be used to provide a comparative analysis. GMI is an intra-patient comparison that uses pts as their own control by comparing progression-free survival (PFS) on current therapy to time to progression or treatment failure (TTP) on the most recent prior therapy; namely the ratio of PFS/TTP (EMA Guidelines. Guideline on the Evaluation of Anticancer Medicinal Products in Man, EMA/CHMP/205/95 Rev.5). A GMI ratio ≥1.33 has been used as a threshold of meaningful clinical activity. In a previous analysis of 122 pts with TRK fusion cancer treated with larotrectinib, 84 pts (69%) had a GMI ≥1.33. Conversely, 38 pts (31%) had a GMI < 1.33, but of these, 9 pts were ongoing treatment and censored for PFS as of July 2019 (Italiano et al, ESMO 2020). Here, we report the GMI of this initial group with a longer follow-up as well as an expanded dataset to more accurately assess the treatment effect of larotrectinib in pts with TRK fusion cancer previously treated with ≥1 line of therapy. Methods: Pts with TRK fusion cancer from three clinical trials on larotrectinib treatment with ≥1 prior line of systemic therapy were eligible for retrospective GMI analysis. TTP on the prior line of therapy was investigator-assessed. PFS on larotrectinib was determined by independent review committee per RECIST v1.1. Pts who had not progressed were censored as of date of last visit. Kaplan–Meier (KM) analyses were used to estimate median GMI, in addition to median PFS and TTP. The data cut-off was July 2020. Results: With an extended follow up of the original 122 pts, 90 (74%) pts had a GMI ≥1.33, including 6 of the 9 pts who were previously censored with a GMI < 1.33 and ongoing treatment; 6 pts (5%) had a GMI ≥1 to < 1.33 and 26 (21%) had a GMI < 1. The KM estimated median GMI increased from 7.6 (95% CI 5.7–88.0) to 9.5 (95% CI 5.7–17.4). In the expanded dataset of 140 pts, 103 pts (74%) had GMI ≥1.33, 7 (5%) had a GMI ≥1 to < 1.33 and 30 (21%) had a GMI < 1. Six of the 37 pts with a GMI < 1.33 were censored and still ongoing treatment. The KM estimated median GMI was 8.9 (95% CI 6.2–17.4). Among pts who had received 1, 2, or ≥3 prior lines of therapy, 74%, 65%, and 80%, respectively, had GMI of ≥1.33. Median TTP on the prior therapy was 3.0 months (95% CI 2.1–3.5) and median PFS on larotrectinib was 33.0 months (95% CI 16.6–34.9). Conclusions: With a longer follow-up, nearly three-quarters of pts with TRK fusion cancer treated with larotrectinib had a prolonged PFS compared to their most recent prior therapy. These results further validate the use of larotrectinib in treating patients with TRK fusion cancer. Clinical trial information: NCT02576431, NCT02122913, NCT02637687.

Long-term efficacy and safety of larotrectinib in an integrated dataset of patients with TRK fusion cancer

3108

Background: Neurotrophic tyrosine receptor kinase ( NTRK) gene fusions encode tropomyosin receptor kinase (TRK) fusion proteins, which are oncogenic drivers in various tumor types. Larotrectinib is a first-in-class, highly selective, CNS-active TRK inhibitor approved to treat adult and pediatric patients with TRK fusion cancer. Larotrectinib demonstrated an objective response rate (ORR) of 78% and a median progression-free survival (PFS) of 36.8 months in an integrated analysis of 175 patients with non-primary CNS TRK fusion cancer (McDermott et al, ESMO 2020). We report updated efficacy and safety data with longer follow-up in an expanded dataset. Methods: Data were pooled from three clinical trials of patients with non-primary CNS TRK fusion cancer treated with larotrectinib. Larotrectinib was administered until disease progression, withdrawal, or unacceptable toxicity. Response was assessed by investigators using RECIST v1.1. Data cutoff: July 20, 2020. Results: As of data cutoff, 218 patients were treated with larotrectinib, of which 206 were evaluable for efficacy. There were 21 different tumor types, the most common being soft tissue sarcoma (STS [46%], including infantile fibrosarcoma [20%] and other STS [26%]), thyroid (13%), salivary gland (11%), lung (9%), and colorectal (5%). The median age was 38.0 years (range 0.1–84.0). Patients were heavily pretreated with 45% having received 2 or more prior lines of systemic therapy; 27% had 0 prior lines of systemic therapy. The ORR was 75% (95% CI 68–81): 45 (22%) complete response, 109 (53%) partial response (PR), 33 (16%) stable disease (SD), and 13 (6%) progressive disease (PD). Nineteen patients had brain metastases at baseline, with 15 evaluable for efficacy. The ORR for patients with brain metastases was 73% (95% CI 45–92): 11 PR, 2 SD, and 2 PD. Among all evaluable patients, the median time to response was 1.8 months (range 0.9–9.1). With a median follow up of 22.3 months, the median duration of response was 49.3 months (95% CI 27.3–not estimable). Treatment duration ranged from 0.03+ to 60.4+ months. Median PFS was 35.4 months (95% CI 23.4–55.7) with a median follow up of 20.3 months. At a median follow-up of 22.3 months, median overall survival (OS) was not reached and 36-month OS was 77% (95% CI 69–84). Treatment-related adverse events (TRAEs) were mainly Grade 1–2, with 18% having Grade 3–4 TRAEs. Only 2% of patients discontinued due to TRAEs. Conclusions: These results highlight the importance of testing for NTRK gene fusions in patients with cancer because the majority of patients with TRK fusion cancer treated with larotrectinib had long-term clinical benefit. The safety profile continued to be favorable and no new safety signals were identified. Clinical trial information: NCT02576431, NCT02122913, NCT02637687.

Quality of life of adults and children with TRK fusion cancer treated with larotrectinib compared to the general population

3614

Background: NTRK gene fusions occur in diverse tumor types in adults and children. The selective TRK inhibitor, larotrectinib, has shown high response rates, durable disease control, and a favorable safety profile in patients (pts) with TRK fusion cancer. We report an expanded quality of life (QoL) analysis for pts treated with larotrectinib. Methods: QoL data were collected in two trials of larotrectinib in pts with TRK fusion cancer using EORTC QLQ-C30 (adults) and PedsQL (children) questionnaires, and were analyzed descriptively and longitudinally. EORTC QLQ-C30 global health scores (GHS) and PedsQL total scores range from 0 to 100, with higher scores indicating better QoL. We calculated the proportion of pts with normal/above and below normal QoL scores compared to values in the literature for the US general population. Results: By July 2019, 126 pts with TRK fusion cancer (74 adults, 24 children ≥2 yrs, and 28 infants <2 yrs) had received larotrectinib and completed baseline (BL) and ≥1 post-BL questionnaire. Most pts had clinically meaningful QoL improvements that reached or exceeded the minimally important difference (Table); a positive change from BL was also seen in infants: mean best change of 12.0 (SD 13.8). Of 52 adults with BL EORTC QLQ-C30 GHS at or above the population norm, 51 remained in this category on treatment and 1 moved into the below normal category. Of 22 adults with BL scores below the population norm, 20 moved into the normal/above normal category. All 9 children aged ≥2 yrs with BL PedsQL scores at or above the population norm remained in this category on treatment. Of 15 children with BL scores below the population norm, 10 moved into the normal/above normal category. Sustained QoL improvements (change from BL ≥0) occurred by 2 months of treatment in 69% of adults and 75% of children. Median duration of sustained improvement in EORTC QLQ-C30 GHS and PedsQL total score was 12.0 months (range 1.7–20.3) and not estimable (range 1.1–23.0), respectively. Conclusions: Adults and children with TRK fusion cancer treated with larotrectinib had rapid, clinically meaningful, and sustained improvements in QoL. Clinical trial information: NCT02576431, NCT02637687 . [Table: see text]

Activity and safety of larotrectinib in adult patients with TRK fusion cancer: An expanded data set

3610

Background: The highly selective TRK inhibitor larotrectinib is approved for the treatment of adult and pediatric cancers that harbor NTRK gene fusions; it achieves a 79% overall response rate (ORR) in this population (Hong et al., Lancet Oncol, 2020). The activity of larotrectinib in adults alone was further characterized in this update with a larger series of patients and more mature durability data. Methods: Adults (aged ≥18 y) with TRK fusion cancer treated in three larotrectinib clinical trials (NCT02122913, NCT02576431, and NCT02637687) were analyzed. Larotrectinib was administered 100 mg BID until disease progression, withdrawal, or unacceptable toxicity. ORR was investigator-assessed (RECIST v1.1). Compared to previously presented data on 74 patients, this expanded data set includes an additional 42 patients (data cutoff: July 15, 2019). Results: 116 adults (median age: 56 y, range 19–84 y; 53% female) with TRK fusion cancer were treated. Tumor types included thyroid cancer (22%), salivary gland cancer (19%), soft tissue sarcoma (16%), lung cancer (12%), colon cancer (7%), melanoma (5%), breast cancer (5%), GIST (3%), and 9 other types (≤2% each). NTRK fusions involved NTRK1 (43%), NTRK2 (3%), and NTRK3 (54%). 78% of patients had received prior systemic therapy (with 68% of those receiving ≥2 prior therapies). The ORR was 71% (95% CI 62–79): 10% complete response, 60% partial response (2% pending confirmation), 16% stable disease, 9% progressive disease, 3% not determined. In patients with brain metastases, the ORR was 71% (95% CI 42–92; 10 of 14 patients, all partial responses). Median duration of response for the overall data set (n = 116) was 35.2 mo (95% CI 21.6–not estimable [NE]). Median progression-free survival was 25.8 mo (95% CI 15.2–NE). Median overall survival was not reached (range 0.5+ to 51.6+ mo) at a median follow-up of 15.8 mo. Duration of treatment ranged from 0.10 to 51.6+ mo. 12% of patients had dose reductions. One patient (1%) discontinued due to a larotrectinib-related adverse event (AE). AEs were mostly grade 1–2; no new unexpected AEs were reported. Conclusions: In an expanded data set of adults with TRK fusion cancer, larotrectinib demonstrated robust and durable tumor-agnostic efficacy and favorable safety, supporting NTRK gene fusion testing in patients with solid tumors of any type. Clinical trial information: NTC02122913, NCT02576431, NCT02637687 .

Growth modulation index (GMI) as a comparative efficacy measure of larotrectinib versus prior systemic treatments for TRK fusion cancer patients

e15638

Background: Larotrectinib is a highly selective TRK inhibitor that demonstrated high response rates and durable disease control in three phase I/II single-arm studies of patients (pts) with TRK fusion cancer. While single-arm studies are often used for rare cancer populations, they do not provide comparative data. GMI utilizes pts as their own control and can be used in this setting. GMI is the ratio of progression-free survival (PFS) on the current therapy to time to progression (TTP) on the most recent prior line of therapy. A GMI ≥1.33 has been used as a threshold of meaningful clinical activity. We report GMI for TRK fusion cancer pts treated with larotrectinib. Methods: Data were pooled from 3 clinical trials of pts with TRK fusion cancer treated with larotrectinib. A retrospective, exploratory analysis of GMI was conducted in pts who had been on larotrectinib and followed up for ≥6 mos or pts who discontinued early, and had ≥1 prior line of systemic treatment for locally advanced or metastatic disease. TTP on the prior line of therapy was investigator assessed. PFS on larotrectinib was determined by independent review committee per RECIST 1.1. Pts who had not progressed were not censored from the analysis. Results: As of July 15, 2019, 122 pts were eligible for analysis. Fifteen different tumor types were represented, the most common being soft tissue sarcoma in 26 pts (21%), infantile fibrosarcoma in 22 (18%), and thyroid in 21 (17%). Median GMI was 3.35 (range 0.00–337.00; Table); In metastatic pts (n = 81), the proportion with a GMI ≥1.33 was higher in pts with a complete or partial response vs non-responders (88% vs 42%). In the whole analysis set (N = 122), median TTP on prior line of treatment was 2.7 mos (95% CI 2.0–3.1) and median PFS on larotrectinib was 33.4 mos (95% CI 13.8–NE; HR 0.20 [95% CI 0.14–0.29]). In metastatic pts (n = 81), median TTP on prior line of treatment was 2.3 mos (95% CI 1.9–3.0) and median PFS on larotrectinib was 23.4 mos (95% CI 10.9–NE; HR 0.24 [95% CI 0.16–0.36]). Conclusions: Greater than two-thirds of pts with TRK fusion cancer treated with larotrectinib had a GMI ≥1.33, demonstrating a clinically meaningful improvement in PFS compared to TTP on their prior treatment. Clinical trial information: NCT02122913, NCT02576431, NCT02637687.

Tisotumab Vedotin in Previously Treated Recurrent or Metastatic Cervical Cancer

PURPOSE

Tissue factor (TF) is a potential target in cervical cancer, as it is frequently highly expressed and associated with poor prognosis. Tisotumab vedotin, a first-in-class investigational antibody-drug conjugate targeting TF, has demonstrated encouraging activity in solid tumors. Here we report data from the cervical cancer cohort of innovaTV 201 phase I/II study (NCT02001623).

PATIENTS AND METHODS

Patients with recurrent or metastatic cervical cancer received tisotumab vedotin 2.0 mg/kg every 3 weeks until progressive disease, unacceptable toxicity, or consent withdrawal. The primary objective was safety and tolerability. Secondary objectives included antitumor activity.

RESULTS

Of the 55 patients, 51% had received ≥2 prior lines of treatment in the recurrent or metastatic setting; 67% had prior bevacizumab + doublet chemotherapy. Fifty-one percent of patients had squamous cell carcinoma. The most common grade 3/4 treatment-emergent adverse events (AEs) were anemia (11%), fatigue (9%), and vomiting (7%). No grade 5 treatment-related AEs occurred. Investigator-assessed confirmed objective response rate (ORR) was 24% [95% confidence interval (CI): 13%-37%]. Median duration of response (DOR) was 4.2 months (range: 1.0+-9.7); four patients responded for >8 months. The 6-month progression-free survival (PFS) rate was 29% (95% CI: 17%-43%). Independent review outcomes were comparable, with confirmed ORR of 22% (95% CI: 12%-35%), median DOR of 6.0 months (range: 1.0+-9.7), and 6-month PFS rate of 40% (95% CI: 24%-55%). Tissue factor expression was confirmed in most patients; no significant association with response was observed.

CONCLUSIONS

Tisotumab vedotin demonstrated a manageable safety profile and encouraging antitumor activity in patients with previously treated recurrent or metastatic cervical cancer.

Results from a first-in-man, open label, safety and tolerability trial of CAN04 (nidanilimab), a fully humanized monoclonal antibody against the novel antitumor target, IL1RAP, in patients with solid tumor malignancies

2504

Background: Interleukin 1 receptor Accessory protein, IL1RAP, is expressed in several solid tumors, both on cancer cells and tumor-associated inflammatory cells. CAN04 is a first-in-class fully humanized monoclonal antibody targeting IL1RAP blocking IL-1 alpha and beta signaling and triggering antibody dependent cellular cytotoxicity. Methods: The primary objective was to assess safety and tolerability of weekly CAN04 in order to define the Recommended Phase 2 Dose (RP2D). Patients (pts) with relapsed or refractory non-small cell lung cancer (NSCLC), pancreatic ductal adenocarcinoma (PDAC), breast or colorectal cancer were included using a 3+3 dose escalation design. Key eligibility criteria were ECOG ≤1, normal organ function and no bleeding disorder/coagulopathy. Tumor responses were evaluated according to irRC every 8 weeks. PK and biomarkers were analyzed in serum. Results: 22 pts were enrolled across 5 cohorts (1-10 mg/kg). Demography: mean age 62 yrs (39-81); gender 14 M and 8 F; median number of prior lines of therapy 3 (range 1-11). AEs occurred mainly following the first dose and the most common AEs were: infusion related reaction (IRR) (41%), pyrexia (27%), fatigue (23%), chills (23%) and nausea (23%). AE grade 3 or 4: one IRR, one neutropenia/leukopenia and one hypokalemia, all of them grade 3. Serum CRP and IL-6 were reduced after two weeks of treatment. There were linear increases of AUC and Cmax (1-10 mg/kg) and CAN04 exposure at 10mg/kg was above levels associated with signs of efficacy in preclinical models. In pts receiving at least one dose of CAN04, 9/20 (45%) had SD by irRC (7/20 had SD by RECIST 1.1) at 8 weeks follow up. Two pts, one with NSCLC and one with PDAC, had SD for 6 and 4 months (latter still on therapy). Conclusions: CAN04 demonstrated a manageable safety profile and a RP2D of 10 mg/kg has been established. The dose expansion phase of the trial will evaluate CAN04 as monotherapy as well as in combination with relevant chemotherapy regimens in NSCLC and PDAC in separate arms. Clinical trial information: NCT03267316.

Larotrectinib efficacy and safety in adult TRK fusion cancer patients

3122

Background: A broad range of pediatric and adult malignancies harbor TRK fusions involving the NTRK1, NTRK2, and NTRK3 genes. The highly-selective TRK inhibitor, larotrectinib, has previously shown a high overall response rate (ORR) and a favorable safety profile in patients (pts) with TRK fusion cancer. To better delineate efficacy in adults, as pediatric pts have a particularly high ORR, here we report updated efficacy and safety data from the adult subset of pts with TRK fusion cancer treated with larotrectinib. Methods: Adult pts (aged 18 or older) with TRK fusion cancer detected by local testing in 2 larotrectinib clinical trials (NCT02122913 and NCT02576431) were analyzed. Larotrectinib was administered 100 mg PO BID until disease progression, withdrawal, or unacceptable toxicity. Disease status was assessed by both investigator (INV) and independent assessment (IRC) using RECIST v1.1. Results: As of July 30, 2018, 83 adults (median age: 57 y, range 20–80 y) with TRK fusion cancer had been treated. Cancer types included salivary gland (23%) and thyroid cancer (19%), soft tissue sarcoma (14%), lung cancer (13%), colon cancer and melanoma (7% each), GIST (5%), and bone sarcoma, cholangiocarcinoma, and appendiceal, breast, and pancreas cancer (≤2% each). TRK fusions involved NTRK1 (40%), NTRK2 (2%), and NTRK3 (57%). 77% of pts had received prior systemic therapy (median lines: 2, range 0–10). In 74 pts evaluable per INV, the ORR was 76% with 9% CR, 57% confirmed PR, 9% PR pending confirmation, 12% SD, 11% PD, and 1% not determined; 9 pts were non-evaluable (NE) due to lack of post-baseline assessment. In 65 pts evaluable per IRC, the ORR was 68% with 17% CR, 51% PR, 15% SD, 12% PD, and 5% NE. With a median follow up of 17.2 and 17.5 mo per INV and IRC, respectively, the median duration of response had not been reached (ranges identical: 1.9+ to 38.7+ months). At data cutoff, 63% remained on treatment; 30% had discontinued due to disease progression. Adverse events were mostly grade 1–2. Conclusions: Larotrectinib demonstrated robust tumor-agnostic efficacy and a favorable safety profile in adult pts with TRK fusion cancer. These results support testing for TRK fusion cancer in pts with advanced solid tumors, regardless of site of primary diagnosis. Clinical trial information: NCT02122913 and NCT02576431.

Efficacy and safety of dabrafenib (D) and trametinib (T) in patients (pts) with BRAF V600E–mutated biliary tract cancer (BTC): A cohort of the ROAR basket trial

187

Background: BTCs are rare, aggressive malignancies with poor prognoses. Treatment options and outcomes after first-line therapy are not well defined. Median progression-free survival (PFS) in second-line BTC is < 5 mo. Combined BRAF + MEK inhibition is efficacious in BRAF V600–mutated anaplastic thyroid cancer, melanoma, and lung cancer, but less so in BRAF V600E-mutated colorectal cancer. Activating BRAF V600E mutations have been reported in 0% to 20% of BTCs; thus, D (BRAF inhibitor) + T (MEK inhibitor) was evaluated as a treatment for pts with BRAF V600E–mutated BTC in the ROAR basket trial. Methods: In this phase II, open-label trial, pts with BRAF V600E mutations in 9 rare tumor types, including BTC, received D (150 mg BID) + T (2 mg QD) until unacceptable toxicity, disease progression, or death. Eligible pts had advanced or metastatic cancer and had been treated with ≥ 1 prior systemic therapy. The primary endpoint was investigator-assessed overall response rate (ORR). Secondary endpoints included duration of response (DOR), PFS, overall survival (OS), biomarker correlates, and safety. Results: Thirty-three pts with BTC had enrolled at data cutoff (January 3, 2018). BRAF V600E mutations were centrally confirmed in 30 of 33 pts with BTC (91%). Median age was 58 y, and 78% had received ≥ 2 prior lines of systemic therapy. 32 of 33 pts with BTC were evaluable. Investigator-assessed ORR was 41% (13/32; 95% CI, 24%-59%), with 6 of 13 responses ongoing at data cutoff, 7 of 13 pts (54%) had a DOR ≥ 6 mo. Median PFS was 7.2 mo (95% CI, 4.6-10.1 mo), and median OS was 11.3 mo (95% CI, 7.3-17.6 mo). Grade 3/4 adverse events in ≥ 3 pts were increased γ-glutamyltransferase (n = 3 [9%]) and decreased white blood cell count (n = 3 pts [9%]). Biomarker analyses demonstrate a heterogeneous genetic landscape, and suggest a higher baseline expression of MAPK pathway genes in the pts who did not respond to D + T. Conclusions: D + T demonstrated promising efficacy in pts with BTC, with a favorable safety profile. These pts should be considered for BRAF mutation analysis, and D + T should be considered for pts with BRAF V600E-mutated BTC. Clinical trial information: NCT02034110.

The efficacy of larotrectinib (LOXO-101), a selective tropomyosin receptor kinase (TRK) inhibitor, in adult and pediatric TRK fusion cancers

LBA2501

Background: Larotrectinib is the first selective small-molecule pan-TRK inhibitor. TRK fusions appear oncogenic independent of tumor lineage, are widely distributed across cancers, and affect all ages. We present an integrated dataset from 3 studies intended to support regulatory approval. Methods: All NTRK fusion pts with RECIST measurable disease enrolled to the adult (NCT02122913, n=8) and pediatric (NCT02637687, n=12) phase I trials and adult/adolescent phase 2 trial (NCT02576431, n=35) were analyzed. TRK fusion status was determined by local testing prior to enrollment. Pts were dosed predominantly at 100mg BID on a continuous 28-day schedule. Primary objective was investigator-assessed overall response rate (ORR) per RECIST v1.1. Secondary endpoints included duration of response (DOR) and safety. Data were cut on 31-JAN-2017. Results: 55 TRK fusion pts (12 peds, 43 adult, range: 4 mo.-76 yrs) were enrolled (median priors=2). Fusions involved NTRK1 (n=25), NTRK2 (n=1), and NTRK3 (n=29), and 14 unique partners. 13 discrete tumor types were treated: salivary (12), sarcoma (10), infantile fibrosarcoma (7), lung (5), thyroid (5), colon (4), melanoma (4), cholangio (2), GIST (2), and other (4). For the 46 pts evaluated to date, the ORR was 78% (95% CI: 64%–89%) with responses in 12 unique tumor types. Responses are ongoing in 29/33 (88%) pts, excluding 3 peds pts whose DOR was censored at attempted curative resection. A median DOR has not been reached as the majority of responders remain on treatment without progression. The longest responder remains on treatment at 23 mos., 8 pts remain in response at >12 mos., and 16 pts at >6 mos. NTRK solvent front mutations were detected in all 4 pts to develop acquired resistance. The most common TEAEs were fatigue (30%), dizziness (28%), and nausea (28%). 5 (11%) pts required dose reductions. Conclusions: Larotrectinib has demonstrated consistent and durable antitumor activity in TRK fusion cancers, across a wide range of ages and tumor types, and was well-tolerated. Larotrectinib could be the first targeted therapy developed in a tissue type-agnostic manner, and the first developed simultaneously in adults and pediatrics. Clinical trial information: NCT02576431, NCT02122913, NCT02637687.

Notch pathway inhibition with LY3039478 in adenoid cystic carcinoma (ACC)

6024

Background: ACCs have high levels of Notch-1 receptor expression and activation. LY3039478 (LY) is an orally bioavailable selective Notch inhibitor (Notch 1-4). Here we report on safety, pharmacokinetics (PK), pharmacodynamics (PD), and anti-tumor activity of LY in patients (pts) with ACC. Methods: Ongoing, multi-part, phase I trial enrolled pts with advanced or metastatic ACC, measurable disease, ECOG ≤1, and baseline tumor tissue. Eligible pts received LY 50 mg three times per week (TIW), on a 28-day cycle until disease progression. Safety assessments were based on CTCAE V4.0. Tumor responses were assessed using RECIST 1.1. Primary objectives are to confirm the recommended phase II dose of LY and document antitumor activity. Secondary objectives are safety and toxicity, PK and progression-free survival (PFS). Exploratory objectives include assessment for PET metabolic responses. Results: 22 pts have been enrolled and received LY 50mg TIW (13 men, 9 women; median age 60, range 41-82). All pts had metastatic disease; median treatment duration was 3 cycles (range 1-10) with 6 pts continuing on treatment. One pt had an unconfirmed partial response. Disease control rate (DCR) was 16/22 (73%), of which 4 pts had stable disease ≥ 6 months. In the overall group (n = 22) median PFS (mPFS) was 5.3 months (95% CI: 2.4, NE). mPFS was 7.7 (95% CI: 4.0, NE) for pts in second line (n = 7), while mPFS was 2.4 (95% CI: 1.1, NE) for pts in third line or more (n = 9). In pts without prior systemic therapy (n = 6) mPFS could not be estimated since 4 of those patients were censored. In preliminary analysis, 14 pts were assessed by PET, with 2 (14%) achieving partial metabolic response. Most frequent related adverse events (all grades) occurring in ≥20% of pts included diarrhea (55%), fatigue (45%), vomiting (36%), decreased appetite (27%), dry mouth (27%), and dry skin (23%). Grade 3/4 related treatment-emergent adverse events observed in more than one pt were diarrhea (n = 3) and squamous cell carcinoma of skin (n = 2). PK was assessed in 17 pts, with peak concentrations occurring approximately 2 hours post-dose. Biomarker and histologic analyses of pre and post treatment biopsies will be presented. Conclusions: LY showed activity (73% DCR) in ACC with a manageable safety profile. Clinical trial information: NCT01695005.

GCT1021-01, a first-in-human, open-label, dose-escalation trial with expansion cohorts to evaluate safety of Axl-specific antibody-drug conjugate (HuMax-Axl-ADC) in patients with solid tumors (NCT02988817)

TPS2605

Background: HuMax-AXL-ADC is an antibody-drug conjugate (ADC) composed of an Axl-specific human monoclonal immunoglobulin G1 (IgG1κ) conjugated via a protease-cleavable valine-citrulline linker to the microtubule disrupting agent monomethyl auristatin E (MMAE). In vivo, HuMax-AXL-ADC demonstrated therapeutic anti-tumor efficacy in patient-derived xenograft models representing a variety of solid cancers, including pancreas, thyroid, lung, esophageal, cervical cancers and malignant melanoma. The non-clinical safety profile and pharmacokinetics (PK) of a once every 3 weeks (1Q3W) dosing schedule were established in cynomolgus monkeys. Methods: The primary objective of this trial is to determine the MTD and to establish the safety profile of HuMax-AXL-ADC in a mixed population of patients with specified solid tumors: ovarian, cervical, endometrial, thyroid cancer, NSCLC, and malignant melanoma. The trial consists of two parts, a phase I dose escalation part and a phase IIa expansion part. The dose escalation part explores two different dosing regimens: the first investigates doses from 0.3 up to 2.8 mg/kg to be administered 1Q3W. The second investigates doses in the range of 0.45 to 1.4 mg/kg to be administered weekly for 3 weeks followed by one treatment-free week (3Q4W dosing schedule). The second arm has a delayed start to inform a safe starting dose: when at least 8 patients have been evaluated for dose limiting toxicities, the 1.5 mg/kg cohort of the 1Q3W arm has been declared safe, and the predicted PK parameters of the starting dose in the 3Q4W arm are below pre-defined limits, the 3Q4W arm will be initiated. The 1Q3W arm follows a modified Bayesian Continuous Reassessment Method including escalation with overdose control in up to 41 patients on up to 7 main and 4 intermediate dose levels while the 3Q4W arm is run as a standard 3+3 trial design on up to 5-6 dose levels. In the phase IIa expansion part, further safety and biological activity data will be generated in selected indications using cohorts of 22 patients (11+11 patients in each cohort applying the Simon’s two-stage design). Clinical trial information: NCT 02988817.

The efficacy of larotrectinib (LOXO-101), a selective tropomyosin receptor kinase (TRK) inhibitor, in adult and pediatric TRK fusion cancers

LBA2501

The full, final text of this abstract will be available at abstracts.asco.org at 7:30 AM (EDT) on Saturday, June 3, 2017, and in the Annual Meeting Proceedings online supplement to the June 20, 2017, issue of the Journal of Clinical Oncology. Onsite at the Meeting, this abstract will be printed in the Saturday edition of ASCO Daily News.

Information when patients participate in a phase I trial: A systematic review

85

Background: While phase I trials are essential for the development of new anticancer drugs, there is a limited chance of benefitting for cancer patients participating in such trials. The information dialogue is therefore of substantial importance for providing a foundation to make a decision, and the support from relatives of potential value for the patient. This systematic review investigated patients’ prerequisites for deciding to participate in a phase I trial by summarizing the existing knowledge regarding patients’ decision-making when entering a phase I trial, and patients’ and their relatives’ perception of the information prior to enrollment. Methods: The review is based on the principles of Preferred Reporting Items for Systematic Reviews. A comprehensive systematic search was performed using the PubMed, Embase and PsycInfo databases and supplemented by a search for unpublished literature. Results: We identified 36 studies for inclusion in this review. When patients are offered participation in a phase I trial, information procedures as well as the patients’ individual approach influence the decision-making and the perception of the information provided. Across the studies exploring patients’ perception of information, there was a limited understanding of trial purpose and unrealistic expectations of benefit. The relatives’ perception of information remains unexplored. Evaluation of the included studies demonstrated a comprehensive risk of bias in the majority of studies. Conclusions: The information dialogue between physician and the patient concerning participation in a phase I trial seems to benefit from exact information taking account of the perspectives for each individual patient as well as the need for further discussion of trial. While relatives intuitively function as resources for patients entering a phase I trial, this topic is still not investigated.

First-in-class, first-in-human phase I trial of KPT-330, a selective inhibitor of nuclear export (SINE) in patients (pts) with advanced solid tumors

2505

Background: In cancers, the majority of tumor suppressor proteins (TSP) are transported out of the nucleus exclusively by Exportin 1 (XPO1/CRM1), rendering these TSPs non-functional. KPT-330 is a potent inhibitor of XPO1, and forces the nuclear retention and activation of > 10 TSPs resulting in tumor cell death in vitro, in murine preclinical models and in dogs with spontaneous lymphomas. Methods: KPT-330 was administered orally for 10 doses in a 28-day cycle. Detailed pharmacokinetic (PK) and pharmacodynamic (PDn) analyses and serial tumor biopsies were performed. Response evaluation was done every 2 cycles (RECIST 1.1). All pts entering the study had documented progressive disease. Results: 23 pts (10 males; median age 62 yrs; ECOG PS 0/1: 5/18) received KPT-330 across 6 dose levels (3 to 30 mg/m2). There has been no dose limiting toxicity. Nine drug related grade 3/4 adverse events (AEs) post cycle 1 were reported in 6 pts (neutropenia, thrombocytopenia, hyponatremia, increased ALT, fatigue, vomiting [n=2], nausea [n=2]). The most common grade 1/2 AEs were nausea (78%), fatigue (74%) and anorexia (74%). PK analysis demonstrated a fairly proportional increase in Cmax and AUC with increasing dose, with no accumulation and without affecting half-life or clearance of KPT-330. At 30 mg/m2, AUC0-last. (4375 ng*h/mL) was comparable to the anti tumor exposure observed in mice and dogs. Tmax (~3 hrs) and T1/2 (6-7 hrs) were consistent across doses. Significant increase (2-20x) in XPO1 mRNA levels (PDn marker) in circulating leukocytes was observed at all doses, with higher doses demonstrating higher levels of XPO1 mRNA induction. Analysis of tumor biopsies confirmed nuclear localization of TSPs (e.g. p53, FOXO3A, IκB) and apoptosis of cancer cells following KPT-330 administration. RECIST response was evaluable in 13 pts. Stable disease (SD) was noted in 9 pts, with 3 (colon, endocervical & endometrial stromal tumors) remaining with SD at 6+ months (dose levels 3 & 6 mg/m2), as well as one minor response (colon). Conclusions: KPT-330 treatment is generally well tolerated, with favorable PK and PDn properties. Preliminary signals of clinical antitumor activity were observed. Clinical trial information: NCT01607905.

Phase I study of anti-PlGF monoclonal antibody (mAb) RO5323441 (RO) and anti-VEGF mab bevacizumab (BV) in patients with recurrent glioblastoma (GBM)

2092

Background: BV inhibits VEGF and is approved for progressive GBM following prior therapy. The placental growth factor (PlGF) is a member of the VEGF family and PlGF expression has been shown to correlate with tumor stage and survival in several human malignancies. In cancer patients (pts) PlGF is up-regulated upon treatment with VEGF inhibitors. RO is a humanized IgG1 mAb directed against PlGF that has demonstrated antitumor activity in an orthotopic GBM model. Single agent RO was previously tested in advanced solid tumors. Methods: Eligibility criteria included histologically confirmed GBM with documented radiographic progression upon front line therapy, ≥18 years of age, KPS ≥70, adequate bone marrow reserve and organ function. Prior treatment with VEGF/PLGF targeted therapies was not permitted. Three to six pts were enrolled per dose level (DL), the MTD defined as the dose with DLTs ≤ 1/6 pts during 28-days of cycle 1, using CTCAE v4. Results: A total of 22 pts (16m/6f) have been enrolled in 3 DLs: RO 625mg (4 pts), 1250mg (6), and 2500mg (12) IV every 2 weeks (q2w), each in combination with BV 10mg/kg IV q2w. Median age: 58 years (range 37-72). RO serum concentrations increased proportionally, while serum exposures of BV were similar between all DLs. Two pts experienced a DLT: Meningitis G3 (1250 mg) and cerebral infarction G3 (2500 mg). Most commonly reported adverse events included hypertension (14 pts), headache (11), dysphonia (10), fatigue (6), nasopharyngitis (5), epistaxis (4), constipation (4), nausea (3), and arthralgia (3). Across all DLs tested, the overall response rate by RANO criteria was 22.7%. Conclusions: The tolerability of RO in combination with BV is acceptable; a MTD was not determined. Anti-PlGF treatment does not appear to add on clinical activity observed for single agent BV in recurrent GBM. Clinical trial information: NCT01308684.

A first-in-human trial of RG7116, a glycoengineered monoclonal antibody targeting HER3, in patients with advanced/metastatic tumors of epithelial cell origin expressing HER3 protein

2522

Background: The Human Epidermal Growth Factor Receptor 3 (HER3) is a key heterodimerization partner for other HER family members thereby acting as a downstream signal amplifier. This is a first in human study evaluating the safety of RG7116, a humanized anti-HER3 monoclonal antibody with potent HER3 signal inhibition. Due to a glycoengineered Fc-part this antibody displays enhanced antibody-dependent cellular cytotoxicity as compared to conventional antibodies. Methods: Patients (pts) with advanced or metastatic carcinomas with centrally confirmed HER3 protein expression were included. A “3+3” dose escalation design was performed starting at 100 mg flat dosing in a q2w regimen. In addition to single agent RG7116 (Part A), RG7116 plus cetuximab (Part B) and RG7116 plus erlotinib (Part C) combinations are evaluated. The results of Part A are presented. Results: Twenty-five pts have been enrolled in 6 cohorts (100 to 2000 mg). No DLTs were observed. Pts had a median (range) of 3 (2 to 6) prior chemotherapy lines. Nine infusion-related reactions (IRRs) Gr 1 to 3 occurred in 7 pts. Three drug-related AEs Gr 3 were reported, 1 IRR, 1 GGT increase, and 1 neutropenia. Only 1 patient was tested positive for human anti human antibodies (HAHA). The PK of RG7116 was non-linear from 100 mg up to 400 mg, possibly as a result of target-mediated drug disposition. Both Cmax and AUC showed a greater than doseEproportional increase over the same dose range, accompanied by a decline in total clearance. Dose proportionality was observed from 800 mg onwards. PD effects were observed from the first dose level onwards with HER3 membranous protein down-regulation in skin and from 200 mg onwards in ontreatment tumor samples. Five pts (1 NSCLC, 2 CRC, 1 SCCHN, 1 BC) had a best response of SD. Confirmed SD (>16 weeks) was observed in 2 pts. One BC patient achieved a PR in 18 FDG-PET and significant shrinkage of non-target tumor lesions on CT scan. Conclusions: RG7116 is the first glycoengineered monoclonal anti-HER3 antibody in clinical development. RG7116 monotherapy was well tolerated, and demonstrated preliminary signs of clinical activity. Clinical trial information: NCT01482377.

Phase I/II dose-escalation study of daratumumab in patients with relapsed or refractory multiple myeloma

8512^

Background: Daratumumab (DARA) is a human CD38 monoclonal antibody (mAb) with broad-spectrum killing activity. Preliminary safety and efficacy data from this first-in-human dose-escalation study of DARA in pts with relapsed or refractory (RR) multiple myeloma (MM) have previously been published. Here, we present safety and efficacy data from the finalized part 1 and preliminary safety data from the ongoing part 2 of the study. Methods: Pts ≥18 years requiring systemic therapy and considered RR to at least 2 prior lines of therapy and ineligible for ASCT were enrolled. In part 1, a 3+3 dose-escalation design was applied and DARA was administered over a 9-week period as 2 pre- and 7 full doses. The phase II dose was determined to 8mg/kg and these pts receive DARA weekly for 8 weeks followed by dosing every 2nd week for 16 weeks and every 4th week until disease progression, toxicity or for max. 24 months. Results: Data from 32 pts included in part 1 are presented. In part 2, 7/16 pts have been recruited: all available data will be presented at the meeting. In part 1, the median number of prior treatment lines was 6. PK analysis showed plasma peak levels as expected but relatively rapid clearance at low dose levels. At doses ≥4mg/kg, observed PK values approximated model-predicted values. Efficacy evaluation from part 1 was based on IMWG guidelines. In the ≥4mg/kg groups (n=12), 5 PRs and 3 MRs were observed. 7 of these pts had a 50-100% concomitant reduction in bone marrow plasma cells. Median PFS in the ≥4mg/kg dose groups was not reached (median follow-up at data cut-off was 3.8mths (range: 0-9.6mths). No ADA responses were detected. In part 1, the most common adverse events reported were infusion related (IRE) which occurred predominantly during the first full infusion. 44% of subjects across all dose groups had IREs grade 1-3, of which 2 were grade 3. Six related SAEs (1 anemia, 1 thrombocytopenia, 2 bronchospasm, 1 cytokine release, 1 AST increase) were reported. Conclusions: DARA induced a marked reduction in paraprotein and bone marrow plasma cells at doses ≥4mg/kg in heavily pretreated RR MM pts. In addition, high response rates and encouraging PFS data were observed. This is unprecedented for single-agent mAb treatment of MM. Clinical trial information: NCT00574288.

Using the decline in CA19-9 after the start of chemotherapy to predict survival in patients with inoperable bile duct cancer

287

Background: CA 19-9 has been approved by the FDA as a tumour marker in pancreatic cancer. The prognostic value of CA19-9 in cholangiocarcinoma is unclear.The aim of the study was to determine if an early CA 19-9 response after the first cycle of chemotherapy is predictive of survival in patients with inoperable bile duct cancer.

Methods: CA 19-9 response was defined as a 20% decline in CA 19-9 compared to baseline after four weeks of chemotherapy, in patients with a baseline CA 19-9 level above 1.5 times the upper limit of normal (ULN). Patients were identified retrospectively database at a single institution. Chemotherapy used was gemcitabine day 1 and 15 (1g/m2), oxaliplatin day 1 and 15 (60 mg/m2) and capecitabine (1g/m2 BID) days 1 to 7 and days 15-21 for six cycles. Patients with a baseline CA 19-9 above 1.5 the ULN and at least one CA 19-9 value measured four weeks after the start of chemotherapy were included in the study. Survival in CA 19-9 responders was compared to non-responders by use of the log rank test. A Cox regression analysis was performed using performance status, gender, disease extent and location, need for endoluminal stenting, baseline CA 19-9, and CA 19-9 response as co-variables.

Results: 212 patients were registered from Feb 2004 until Nov 2010. Among these, 170 were treated with chemotherapy for cholangiocarcinoma and 131 had a baseline CA 19-9 value and at least one follow-up CA 19-9. Patients with baseline CA 19-9 less than 1.5 times the ULN (n=45) or inconclusive measurements (n=7) were excluded leaving 79 patients in the study. Fifty per cent of patients had a CA 19-9 response to chemotherapy. The median survival in the CA 19-9 response group was 11.7 months (95%CI: 7.5 – 16.0) vs. 8.2 months (95% CI: 6.4 – 9.8) in the non-response group. CA 19-9 response (HR: 0.535 (95%CI; 0.331-0.866), p=0.01) and disease extent (metastasis vs. no metastasis) (HR: 0.604 (95%CI; 0.369-0.99) p=0.046) were independent predictors of survival in a Cox model.

Conclusions: CA19-9 response is useful as predictor of survival in patients with inoperable cholangiocarcinoma undergoing chemotherapy.

Early death during chemotherapy in patients with small-cell lung cancer: derivation of a prognostic index for toxic death and progression

Based on an increased frequency of early death (death within the first treatment cycle) in our two latest randomized trials of combination chemotherapy in small-cell lung cancer (SCLC), we wanted to identify patients at risk of early non-toxic death (ENTD) and early toxic death (ETD). Data were stored in a database and logistic regression analyses were performed to identify predictive factors for early death. During the first cycle, 118 out of 937 patients (12.6%) died. In 38 patients (4%), the cause of death was sepsis. Significant risk factors were age, performance status (PS), lactate dehydrogenase (LDH) and treatment with epipodophyllotoxins and platinum in the first cycle (EP). Risk factors for ENTD were age, PS and LDH. Extensive stage had a hazard ratio of 1.9 (P = 0.07). Risk factors for ETD were EP, PS and LDH, whereas age and stage were not. For EP, the hazard ratio was as high as 6.7 (P = 0.0001). We introduced a simple prognostic algorithm including performance status, LDH and age. Using a prognostic algorithm to exclude poor-risk patients from trials, we could minimize early death, improve long-term survival and increase the survival differences between different regimens. We suggest that other groups evaluate our algorithm and exclude poor prognosis patients from trials of dose intensification.

Outcome of combination chemotherapy in extensive stage small-cell lung cancer: any treatment related progress?

During the past two decades many different treatment regimens of combination chemotherapy have been applied in extensive stage small-cell lung cancer (SCLC). This study was carried out to identify whether these modifications have resulted in an improved overall survival for extensive stage during the past two decades. In total, 1111 patients with extensive stage SCLC were included in six consecutive randomised trials in our setting from 1973 until 1992. Of these, 526 patients treated in the early period (1973-1981) were compared with 585 patients treated in the late period (1981-1992) with respect to pretreatment prognostic factors, staging, treatment and outcome. No change in the distribution of prognostic factors was detected and the frequency of patients with extensive stage was equal in the two periods, and no difference in overall response rates and survival was observed (P = 0.49). Median survival in the two periods was 208 days and 215 days, respectively. No stage migration or treatment-related improved outcome was observed in extensive disease. We suggest restricting aggressive treatment to patients with favorable prognosis and long-term survival as a realistic aim.