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 model for predicting effect of treatment on progression-free survival using MRD as a surrogate end point in CLL.

Our objective was to evaluate minimal residual disease (MRD) at the end of induction treatment with chemoimmunotherapy as a surrogate end point for progression-free survival (PFS) in chronic lymphocytic leukemia (CLL) based on 3 randomized, phase 3 clinical trials (ClinicalTrials.gov identifiers NCT00281918, NCT00769522, and NCT02053610). MRD was measured in peripheral blood (PB) from treatment-naïve patients in the CLL8, CLL10, and CLL11 clinical trials, and quantified by 4-color flow cytometry or allele-specific oligonucleotide real-time quantitative polymerase chain reaction. A meta-regression model was developed to predict treatment effect on PFS using treatment effect on PB-MRD. PB-MRD levels were measured in 393, 337, and 474 patients from CLL8, CLL10, and CLL11, respectively. The model demonstrated a statistically significant relationship between treatment effect on PB-MRD and treatment effect on PFS. As the difference between treatment arms in PB-MRD response rates increased, a reduction in the risk of progression or death was observed; for each unit increase in the (log) ratio of MRD- rates between arms, the log of the PFS hazard ratio decreased by -0.188 (95% confidence interval, -0.321 to -0.055; P = .008). External model validation on the REACH trial and sensitivity analyses confirm the robustness and applicability of the surrogacy model. Our surrogacy model supports use of PB-MRD as a primary end point in randomized clinical trials of chemoimmunotherapy in CLL. Additional CLL trial data are required to establish a more precise quantitative relationship between MRD and PFS, and to support general applicability of MRD surrogacy for PFS across diverse patient characteristics, treatment regimens, and different treatment mechanisms of action.

Phase I multidose-escalation study of the anti-CD19 maytansinoid immunoconjugate SAR3419 administered by intravenous infusion every 3 weeks to patients with relapsed/refractory B-cell lymphoma.

PURPOSE: We determine the maximum-tolerated dose (MTD), pharmacokinetics, safety, and preliminary efficacy of SAR3419, an antibody-drug conjugate targeting CD19, in a first-in-man phase I clinical trial in patients with relapsed lymphoma. PATIENTS AND METHODS: Patients with relapsed CD19+ B-cell lymphoma were treated with escalating doses of SAR3419 given by intravenous infusion once every 21 days. RESULTS: Thirty-nine patients were treated on seven dose levels ranging from 10 to 270 mg/m(2). The median number of prior treatment regimens was four (range, 1 to 9), and 11 patients had prior autologous or allogeneic stem-cell transplantation. The dose-limiting toxicities were reversible severe blurred vision associated with microcystic epithelial corneal changes reported in six patients and neuropathy in one patient. The MTD was 160 mg/m(2) once every 21 days. Hematologic and hepatic toxicities were predominantly grade 1 or 2 in severity. A total of 35 patients have completed at least two cycles of treatment and were evaluable for tumor response. Twenty-six patients (74%) demonstrated reduction in their tumor size; six of those patients achieved partial or complete remissions. Seven (47%) of 15 patients with rituximab-refractory disease demonstrated reduction in their tumor sizes. The pharmacokinetic profile of SAR3419 is characterized by linear kinetics, low clearance from 0.2 to 0.6 L/d/m(2), and an elimination half-life in the range of 3 to 7 days. CONCLUSION: Using an every 3-week-schedule of SAR3419 for six cycles, the MTD is 160 mg/m(2). SAR3419 can be safely administered to patients with relapsed B-cell lymphoma and demonstrates promising clinical activity, including patients who were refractory to rituximab.

Phase I studies of AVE9633, an anti-CD33 antibody-maytansinoid conjugate, in adult patients with relapsed/refractory acute myeloid leukemia.

The efficacy of anti-CD33 immunoconjugates had been previously demonstrated for gemtuzumab-ozogamicin. AVE9633 is an anti-CD33-maytansine conjugate created by ImmunoGen Inc. Phase I trials of AVE9633 were performed in patients with AML to evaluate tolerability, pharmacokinetics and pharmacodynamics. Three phase I studies of AVE9633 were performed in 54 patients with refractory/relapsed AML, evaluating drug infusion on day 1 of a 21-day cycle (Day 1 study), day 1 and 8 (Day 1/8 study) and day 1, 4 and 7 (Day 1/4/7 study) of a 28-day cycle. Toxicity was mainly allergic reaction during infusion (3 grade 3 bronchospasms). DLT was reached for the D1-D7 schedule at 150 mg/sqm (1 keratitis, 1 liver toxicity), and the MTD was set at 130 mg/sqm for this schedule. In the two other phases I, the DLT was not reached. In the Day 1/8 study, CD33 on peripheral blasts was saturated and down-modulated for doses of 75 mg/m(2) × 2 or higher, which was correlated with WBC kinetics and plasma levels of AVE9633. Decrease of DM4/CD33 ratio on the blasts surface between day 1 and 8 was the rational for evaluating day 1/4/7 schedule. This induced relatively constant DM4/CD33 levels over the first 8 days, however no activity was noted. One CRp, one PR and biological activity in five other patients were observed in this study. The Day 1 and Day 1/4/7 studies were early discontinued because of drug inactivity at doses significantly higher than CD33 -saturating doses. No myelossuppression was observed at any trial of AVE9633. The pharmacokinetics/pharmacodynamics data obtained in these studies will provide very useful information for the design of the next generation of immunoconjugates.