A biomarker signature to predict complete response to itacitinib and corticosteroids in acute graft-versus-host disease.

A broad proteomic analysis was conducted to identify and evaluate candidate biomarkers potentially predictive of response to treatment with an oral selective Janus kinase 1 (JAK1) inhibitor, itacitinib, in acute graft-versus-host disease (GVHD). Plasma samples from 25 participants (identification cohort; NCT02614612) were used to identify novel biomarkers that were tested in a validation cohort from a placebo-controlled, randomised trial (n = 210; NCT03139604). The identification cohort received corticosteroids plus 200 or 300 mg itacitinib once daily. The validation cohort received corticosteroids plus 200 mg itacitinib once daily or placebo. A broad proteomic analysis was conducted using a proximity extension assay. Baseline and longitudinal comparisons were performed with unpaired t-test and one-way analysis of variance used to evaluate biomarker level changes. Seven candidate biomarkers were identified. Monocyte-chemotactic protein (MCP)3, pro-calcitonin/calcitonin (ProCALCA/CALCA), together with a previously identified prognostic acute GVHD biomarker, regenerating islet-derived protein (REG)3A, stratified complete responders from non-responders (participants with progressive disease) to itacitinib, but not placebo, potentially representing predictive biomarkers of itacitinib in acute GVHD. ProCALCA/CALCA, suppressor of tumorigenicity (ST)2, and tumour necrosis factor receptor (TNFR)1 were significantly reduced over time by itacitinib in responders, potentially representing response-to-treatment biomarkers. Novel biomarkers have the potential to identify patients with acute GVHD that may respond to itacitinib plus corticosteroid treatment (NCT02614612; NCT03139604).

Efficacy and safety of itacitinib versus placebo in combination with corticosteroids for initial treatment of acute graft-versus-host disease (GRAVITAS-301): a randomised, multicentre, double-blind, phase 3 trial.

BACKGROUND: Acute graft-versus-host disease (GVHD) is a common and life-threatening complication of allogeneic haematopoietic stem cell transplantation (HSCT); there is an urgent unmet need for effective therapies. We aimed to evaluate the Janus kinase 1 inhibitor itacitinib versus placebo, both in combination with corticosteroids, for initial treatment of acute GVHD. METHODS: GRAVITAS-301 was an international, double-blind, adaptive (group sequential design) phase 3 study conducted at 129 hospitals and community practices in 19 countries. Eligible patients were aged 18 years or older, had previously received allogeneic HSCT for a haematological malignancy, developed grades II-IV acute GVHD, and received up to 2 days of systemic corticosteroids. Patients were stratified by clinical standard-risk or high-risk acute GVHD and randomly assigned (1:1), via a centralised interactive voice response system, to receive either oral itacitinib (200 mg) or placebo once daily, both in addition to corticosteroids. The primary endpoint was overall response rate (ORR) at day 28 (defined as the proportion of patients with complete response, very good partial response, or partial response 28 days after the start of treatment). For sample size determination, an absolute improvement in ORR at day 28 over standard therapy of 16% was considered clinically meaningful. Efficacy analyses were performed in the intention-to-treat population; safety analyses included patients who received at least one dose of study drug. GRAVITAS-301 is registered with ClinicalTrials.gov (NCT03139604) and is complete. FINDINGS: Between July 19, 2017, and Oct 3, 2019, 439 patients were randomly assigned to receive either itacitinib plus corticosteroids (n=219; itacitinib group) or placebo plus corticosteroids (n=220; placebo group). 173 (39%) patients were female and 390 (89%) were White. At baseline, 107 (24%) of 439 patients (itacitinib 51 [23%] of 219; placebo 56 [25%] of 220) had clinical high-risk acute GVHD. The ORR at day 28 was 74% (95% CI 67·6-79·7; 162 of 219; complete response 53% [116 of 219]) for itacitinib and 66% (59·7-72·6; 146 of 220; complete response, 40% [89 of 220]) for placebo (odds ratio for ORR 1·45, 95% CI 0·96-2·20; two-sided p=0·078). Grade 3 or worse adverse events occurred in 185 (86%) of 215 itacitinib recipients and 178 (82%) of 216 placebo recipients, and most commonly included thrombocytopenia or platelet count decreased (78 [36%] vs 68 [31%]), neutropenia or neutrophil count decreased (49 [23%] vs 45 [21%]), anaemia (42 [20%] vs 26 [12%]), and hyperglycaemia (26 [12%] vs 28 [13%]). Treatment-related deaths occurred in three of 215 patients (1%) in the itacitinib group and four of 216 (2%) in the placebo group. INTERPRETATION: The observed improvement in ORR at day 28 with the addition of itacitinib versus placebo to corticosteroids did not reach the prespecified significance level. Further studies might provide additional insight into the utility of selective JAK1 inhibition for the treatment of acute GVHD. FUNDING: Incyte.

A phase 1 trial of itacitinib, a selective JAK1 inhibitor, in patients with acute graft-versus-host disease.

Acute graft-versus-host disease (aGVHD) following allogeneic hematopoietic cell transplantation (HCT) is a primary cause of nonrelapse mortality and a major barrier to successful transplant outcomes. Itacitinib is a Janus kinase (JAK)1-selective inhibitor that has demonstrated efficacy in preclinical models of aGVHD. We report results from the first registered study of a JAK inhibitor in patients with aGVHD. This was an open-label phase 1 study enrolling patients aged ≥18 years with first HCT from any source who developed grade IIB to IVD aGVHD. Patients with steroid-naive or steroid-refractory aGVHD were randomized 1:1 to itacitinib 200 mg or 300 mg once daily plus corticosteroids. The primary endpoint was safety and tolerability; day 28 overall response rate (ORR) was the main secondary endpoint. Twenty-nine patients (200 mg, n = 14; 300 mg, n = 15) received ≥1 dose of itacitinib and were included in safety and efficacy assessments. One dose-limiting toxicity was reported (grade 3 thrombocytopenia attributed to GVHD progression in a patient receiving 300 mg itacitinib with preexisting thrombocytopenia). The most common nonhematologic treatment-emergent adverse event was diarrhea (48.3%, n = 14); anemia occurred in 11 patients (38%). ORR on day 28 for all patients in the 200-mg and 300-mg groups was 78.6% and 66.7%, respectively. Day 28 ORR was 75.0% for patients with treatment-naive aGVHD and 70.6% in those with steroid-refractory aGVHD. All patients receiving itacitinib decreased corticosteroid use over time. In summary, itacitinib was well tolerated and demonstrated encouraging efficacy in patients with steroid-naive or steroid-refractory aGVHD, warranting continued clinical investigations. This trial was registered at www.clinicaltrials.gov as #NCT02614612.

Ruxolitinib for the treatment of steroid-refractory acute GVHD (REACH1): a multicenter, open-label phase 2 trial.

Patients who develop steroid-refractory acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic cell transplantation have poor prognosis, highlighting an unmet therapeutic need. In this open-label phase 2 study (ClinicalTrials.gov identifier: NCT02953678), patients aged at least 12 years with grades II to IV steroid-refractory aGVHD were eligible to receive ruxolitinib orally, starting at 5 mg twice daily plus corticosteroids, until treatment failure, unacceptable toxicity, or death. The primary end point was overall response rate (ORR) at day 28; the key secondary end point was duration of response (DOR) at 6 months. As of 2 July 2018, 71 patients received at least 1 dose of ruxolitinib. Forty-eight of those patients (67.6%) had grade III/IV aGVHD at enrollment. At day 28, 39 patients (54.9%; 95% confidence interval, 42.7%-66.8%) had an overall response, including 19 (26.8%) with complete responses. Best ORR at any time was 73.2% (complete response, 56.3%). Responses were observed across skin (61.1%), upper (45.5%) and lower (46.0%) gastrointestinal tract, and liver (26.7%). Median DOR was 345 days. Overall survival estimate at 6 months was 51.0%. At day 28, 24 (55.8%) of 43 patients receiving ruxolitinib and corticosteroids had a 50% or greater corticosteroid dose reduction from baseline. The most common treatment-emergent adverse events were anemia (64.8%), thrombocytopenia (62.0%), hypokalemia (49.3%), neutropenia (47.9%), and peripheral edema (45.1%). Ruxolitinib produced durable responses and encouraging survival compared with historical data in patients with steroid-refractory aGVHD who otherwise have dismal outcomes. The safety profile was consistent with expectations for ruxolitinib and this patient population.

Ruxolitinib for the treatment of patients with steroid-refractory GVHD: an introduction to the REACH trials.

For patients with hematologic malignancies and disorders, allogeneic hematopoietic stem cell transplantation offers a potentially curative treatment option. Many patients develop graft-versus-host disease (GVHD), a serious complication and leading cause of nonrelapse mortality. Corticosteroids are the standard first-line treatment for GVHD; however, patients often become steroid-refractory or remain corticosteroid-dependent. New second-line treatment options are needed to improve patient outcomes. Here we review the role of JAK1 and JAK2 in acute and chronic GVHD. We also describe the study designs of the Phase II REACH1 (NCT02953678) and the Phase III REACH2 (NCT02913261) and REACH3 (NCT03112603) clinical trials that are currently recruiting patients to evaluate the JAK1/JAK2 inhibitor ruxolitinib in patients with corticosteroid-refractory acute or chronic GVHD.

Exploration of serum metabolomic profiles and outcomes in women with metastatic breast cancer: a pilot study.

BACKGROUND: Metabolomics, a global study of metabolites and small molecules, is a novel expanding field. In this pilot study, metabolomics has been applied to serum samples from women with metastatic breast cancer to explore outcomes and response to treatment. PATIENTS AND METHODS: Pre-treatment and serial on-treatment serum samples were available from an international clinical trial in which 579 women with metastatic breast cancer were randomized to paclitaxel plus either a targeted anti-HER2 treatment (lapatinib) or placebo. Serum metabolomic profiles were obtained using 600 MHz nuclear magnetic resonance spectroscopy. Profiles were compared with time to progression, overall survival and treatment toxicity. RESULTS: Pre- and on-treatment serum samples were assessed for over 500 patients. Unbiased metabolomic profiles in the biologically unselected overall trial population did not correlate with outcome or toxicity. In a subgroup of patients with HER2-positive disease treated with paclitaxel plus lapatinib, metabolomic profiles from patients in the upper and lower thirds of the dataset showed significant differences for time to progression (N = 22, predictive accuracy = 89.6%) and overall survival (N = 16, predictive accuracy = 78.0%). CONCLUSIONS: In metastatic breast cancer, metabolomics may play a role in sub selecting patients with HER2 positive disease with greater sensitivity to paclitaxel plus lapatinib.

A phase II study of lapatinib and bevacizumab as treatment for HER2-overexpressing metastatic breast cancer.

Preclinical data have demonstrated that the combination of antihuman epidermal growth factor receptor-2 (anti-HER2) and antivascular endothelial growth factor (anti-VEGF)--targeted agents has antitumor activity; these data indicate certain patients with HER2-overexpressing breast cancer may derive clinical benefit from this combination. The purpose of this single-arm phase II study was to determine the efficacy and safety of the dual-targeting combination of lapatinib and bevacizumab. Women with HER2-overexpressing advanced breast cancer received 1,500 mg oral lapatinib daily plus 10 mg/kg IV bevacizumab every 2 weeks. The primary endpoint was progression-free survival (PFS) at week 12; secondary endpoints included overall tumor response rate (ORR), clinical benefit rate (CBR), duration of response, time-to-response, PFS, and safety. Circulating tumor cells (CTC) and circulating endothelial cells (CEC) were measured at baseline and during study treatment as potential response markers. Fifty-two patients with stage IV disease were enrolled. The 12-week investigator-assessed PFS rate was 69.2% (95% confidence interval [CI]: 54.9, 81.3). Median PFS was 24.7 weeks (95% CI: 20.4, 35.1), and the CBR was 30.8% (95% CI: 18.7, 45.1). Of 45 patients with measurable disease, 6 were determined to have a partial response per Response Evaluation Criteria in Solid Tumors (ORR: 13.3%; 95% CI: 5.1, 26.8). The most common adverse events (AEs) included diarrhea, rash, and fatigue; most of these were either grade 1 or 2. Clinical responses were correlated with decreases in CTC and CEC. Lapatinib plus bevacizumab was active in patients with HER2-overexpressing breast cancer. The AE profile of the combination was consistent with the known profiles for these agents.

Chromosome 17 polysomy without human epidermal growth factor receptor 2 amplification does not predict response to lapatinib plus paclitaxel compared with paclitaxel in metastatic breast cancer.

PURPOSE: It has been suggested that a subgroup of human epidermal growth factor receptor 2 (HER2)-negative breast cancer patients with chromosome 17 (Chr-17) polysomy benefit from HER2-directed therapy. This hypothesis was examined using the data from a phase III trial that randomized patients with HER2-negative or HER2-untested metastatic breast cancer to first-line therapy with paclitaxel along with either lapatinib or placebo. EXPERIMENTAL DESIGN: HER2 expression level by immunohistochemistry, fluorescence in situ hybridization (FISH), and mean HER2 ratio of Chr-17 values were determined centrally using archival tissue. Polysomy means of 2.0 and 2.2 served as thresholds. RESULTS: Of 580 patients on the original trial, 406 were HER2 negative by FISH. Progression-free survival (PFS) data were available for 405 patients, of whom 44 (11%) met the definition of polysomy (Chr-17 >or=2.2, FISH negative for HER2). Median PFS in the polysomy group was 20.9 and 24.4 weeks for paclitaxel plus lapatinib and paclitaxel plus placebo, respectively. In the nonpolysomy group, median PFS was 24.6 and 23.1 weeks for paclitaxel plus lapatinib and paclitaxel plus placebo, respectively. Log-rank testing showed no treatment advantage for either group. Similar results were found using a Chr-17 polysomy cutoff of 2.0. Response rates in the polysomy group were 17% for paclitaxel plus lapatinib and 10% for paclitaxel plus placebo. In the nonpolysomy group, response rates were 32% for paclitaxel plus lapatinib and 25% for paclitaxel plus placebo. Neither comparison was statistically significant. CONCLUSION: This analysis could not confirm the hypothesis that Chr-17 polysomy in HER2-nonamplified patients improved chemotherapy outcome when lapatinib is added as a HER2-targeted treatment.

Prognostic and predictive value of HER2 extracellular domain in metastatic breast cancer treated with lapatinib and paclitaxel in a randomized phase III study.

PURPOSE: The HER2 extracellular domain (ECD) is enzymatically cleaved from the cell membrane. Shed ECD in serum has been studied as both prognostic and predictive markers. Lapatinib is a dual inhibitor of HER2 and epidermal growth factor receptor kinases. We examined the prognostic and predictive role of HER2 ECD in a randomized trial of paclitaxel with placebo or lapatinib in women with HER2-negative or -unknown breast cancer. PATIENTS AND METHODS: Patients (n = 579) with newly diagnosed metastatic breast cancer (MBC) were randomly assigned to paclitaxel with placebo or lapatinib. HER2 status was determined centrally. ECD was centrally measured by enzyme linked immunoassay in available samples at baseline (b; n = 472), week 9, and every 12 weeks thereafter. Results were correlated to overall response rate (ORR) and progression-free survival (PFS). RESULTS: Elevated baseline ECD (bECD) levels (>or= 16 ng/mL) did not predict HER2 tumor status (sensitivity, 62%; specificity, 75%). In HER2-negative tumors, elevated bECD was not correlated with improved efficacy for lapatinib plus paclitaxel versus placebo plus paclitaxel (ORR: odds ratio, 1.6; 95% CI, 0.1 to 3.8; P = .365; PFS: hazard ratio, 0.94; 95% CI, 0.60 to 1.47; P = .797). ECD levels tended to decrease over time when bECD was elevated. ECD conversion from low to high was associated with worse PFS. Converting from high to low was associated with a better PFS. A consistently low ECD level had better PFS than a consistently elevated ECD. All associations were found to be independent of lapatinib. CONCLUSION: HER2 bECD does not predict lapatinib benefit in patients with HER2-negative MBC. Changes in ECD status correlates with patient outcome regardless of treatment given. Measuring HER2 ECD is not currently recommended for predicting benefit to lapatinib.

Estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2 (HER2), and epidermal growth factor receptor expression and benefit from lapatinib in a randomized trial of paclitaxel with lapatinib or placebo as first-line treatment in HER2-negative or unknown metastatic breast cancer.

PURPOSE: Lapatinib is a dual inhibitor of epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) with activity in HER2-amplified metastatic breast cancer (MBC). Its role in non-HER2-amplified MBC remains unclear. EGF30001, a phase III trial of lapatinib and paclitaxel versus paclitaxel and placebo, demonstrated lapatinib does not significantly benefit HER2-negative or HER2-unselected patients with MBC. Published data support interactions between steroid hormone and peptide growth factor signaling. We hypothesized that molecular subgroups may exist within EGF30001 that would benefit from lapatinib. METHODS: A blinded, retrospective biomarker evaluation was performed using immunohistochemistry to semiquantitate estrogen (ER), progesterone (PR), and EGFR expression. HER2 amplification was determined by fluorescent in situ hybridization. Effects of these biomarkers on event-free survival (EFS) were examined in patients with available tissue (n = 493). RESULTS: Lapatinib improved median EFS in HER2-amplified, ER- or PR-positive MBC (n = 36; 5.7 v 4.5 months; P = .351); benefit was greater and statistically significant in HER2-amplified, ER-negative, PR-negative MBC (n = 42; 8.3 v 5.0 months; P = .007). In HER2-negative, ER-positive MBC, median EFS improvement varied by degree of PR expression (H-score): no benefit if PR-strong (n = 133; 9.3 v 7.3 months; P = .373), benefit if PR-weak (n = 50; 7.3 v 2.4 months; P = .026), and potential antagonism if PR-negative (n = 40; 3.7 v 7.2 months; P = .004). No benefit was seen in triple-negative MBC (n = 131; median EFS, 4.6 v 4.8 months; P = .255). EGFR expression was not correlated with benefit from lapatinib. CONCLUSION: Although subgroups are small, these analyses support the hypothesis that semiquantitative determination of hormone receptor status may be a surrogate for EGFR and/or HER2 dependency.

HER-2 gene amplification, HER-2 and epidermal growth factor receptor mRNA and protein expression, and lapatinib efficacy in women with metastatic breast cancer.

PURPOSE: Biomarkers from two randomized phase III trials were analyzed to optimize selection of patients for lapatinib therapy. EXPERIMENTAL DESIGN: In available breast cancer tissue from EGF30001 (paclitaxel +/- lapatinib in HER-2-negative/unknown metastatic breast cancer, n = 579) and EGF100151 (capecitabine +/- lapatinib in HER-2-positive metastatic breast cancer, n = 399), HER-2 gene amplification by fluorescence in situ hybridization (FISH), HER-2 mRNA by reverse transcription-PCR (RT-PCR), HER-2 protein expression by HercepTest immunohistochemistry (IHC), epidermal growth factor receptor (EGFR) mRNA level by RT-PCR, and EGFR protein by IHC were analyzed and compared with clinical outcome. HER-2 was determined by FISH in an academic reference/research laboratory and in a large, high-volume commercial reference laboratory. RESULTS: The HER-2 gene was amplified in 47% (344 of 733) and IHC was 3+ in 35% (279 of 798), with significant correlation (P < 0.01) between FISH and IHC. Positive EGFR immunostaining (IHC 1+, 2+, or 3+) in 28% (213 of 761) correlated with EGFR mRNA levels by RT-PCR (r = 0.59; P < 0.01). HER-2 gene amplification/overexpression was associated with improved clinical outcomes (progression-free survival; P < 0.001) in both trials. A significant improvement in outcome was seen in FISH-positive and IHC 0, 1+, or 2+ patients. HER-2 mRNA expression correlated with HER-2 FISH (r = 0.83) and IHC status (r = 0.72; n = 138). No correlation was found between EGFR expression (IHC or mRNA) and responsiveness to lapatinib regardless of HER-2 status. Although a significant correlation with lapatinib responsiveness was observed among "HER-2-negative" breast cancer patients in the large, high-volume commercial reference laboratory, this was not confirmed in the academic reference/research laboratory. CONCLUSIONS: Women with HER-2-positive metastatic breast cancer benefit from lapatinib, whereas women with HER-2-negative metastatic breast cancer derive no incremental benefit from lapatinib.

Phase III, double-blind, randomized study comparing lapatinib plus paclitaxel with placebo plus paclitaxel as first-line treatment for metastatic breast cancer.

PURPOSE: Lapatinib, a dual tyrosine kinase inhibitor of epidermal growth factor receptor (EGFR/ErbB1) and human epidermal growth factor receptor 2 (HER-2/ErbB2), is effective against HER-2-positive locally advanced or metastatic breast cancer (MBC). This phase III trial evaluated the efficacy of lapatinib in HER-2-negative and HER-2-uncharacterized MBC. PATIENTS AND METHODS: Women with MBC were randomly assigned to first-line therapy with paclitaxel 175 mg/m(2) every 3 weeks plus lapatinib 1,500 mg/d or placebo. A preplanned retrospective evaluation of HER-2 status was performed using fluorescence in situ hybridization and immunohistochemistry. The primary end point was time to progression (TTP); secondary end points were objective response rate (ORR), clinical benefit rate (CBR), event-free survival (EFS), and overall survival (OS). RESULTS: In the intent-to-treat population (n = 579), there were no significant differences in TTP, EFS, or OS between treatment arms, although differences in ORR and CBR were noted. In 86 HER-2-positive patients (15%), treatment with paclitaxel-lapatinib resulted in statistically significant improvements in TTP, EFS, ORR, and CBR compared with paclitaxel-placebo. No differences between treatment groups were observed for any end point in HER-2-negative patients. The most common adverse events were alopecia, rash, and diarrhea. The incidence of diarrhea and rash was significantly higher in the paclitaxel-lapatinib arm. The rate of cardiac events was low, and no difference was observed between treatment arms. CONCLUSION: Patients with HER-2-negative or HER-2-untested MBC did not benefit from the addition of lapatinib to paclitaxel. However, first-line therapy with paclitaxel-lapatinib significantly improved clinical outcomes in HER-2-positive patients. Prospective evaluation of the efficacy and safety of this combination is ongoing in early and metastatic HER-2-positive breast cancer patients.

Efficacy and safety of lapatinib as first-line therapy for ErbB2-amplified locally advanced or metastatic breast cancer.

PURPOSE: This study (EGF20009) assessed the efficacy and tolerability of two lapatinib administration schedules as first-line monotherapy in women with ErbB2-amplified locally advanced or metastatic breast cancer. PATIENTS AND METHODS: Patients with ErbB2-amplified, locally advanced or metastatic breast cancer previously untreated in the metastatic setting were randomly assigned to one of two lapatinib dose cohorts and received either 1,500 mg once daily or 500 mg twice daily. Clinical response was assessed at weeks 8 and 12 and every 12 weeks thereafter. RESULTS: A total of 138 patients were treated with lapatinib for a median of 17.6 weeks. The overall response rate (complete response [CR] plus partial response [PR]) was 24% in the intent-to-treat population, and 31% of patients derived clinical benefit (CR, PR, or stable disease for >or= 24 weeks). The median time to response was 7.9 weeks, and the progression-free survival rates at 4 and 6 months were 63% and 43%, respectively. The most common lapatinib-related adverse events (AEs) were diarrhea, rash, pruritus, and nausea, and these events were primarily grade 1 or 2. There were no significant differences in clinical activity or the AE profile between the dosing schedules. CONCLUSION: Lapatinib demonstrated clinical activity and was well tolerated as first-line therapy in ErbB2-amplified locally advanced or metastatic breast cancer. This study supports further evaluation of lapatinib in first-line and early-stage ErbB2-overexpressing breast cancer.