Camidanlumab tesirine in patients with relapsed or refractory lymphoma: a phase 1, open-label, multicentre, dose-escalation, dose-expansion study.

BACKGROUND: Novel approaches are required to improve outcomes in relapsed or refractory classical Hodgkin lymphoma and non-Hodgkin lymphoma. We aimed to evaluate camidanlumab tesirine, an anti-CD25 antibody-drug conjugate, in this patient population. METHODS: This was a phase 1, dose-escalation (part 1), dose-expansion (part 2), multicentre trial done in 12 hospital sites (seven in the USA and five in the UK). Adults (≥18 years old) with pathologically confirmed relapsed or refractory classical Hodgkin lymphoma or non-Hodgkin lymphoma, an Eastern Cooperative Oncology Group performance status 0-2, who had no therapies available to them with established clinical benefit for their disease stage were enrolled. Camidanlumab tesirine was administered intravenously (3-150 µg/kg) once every 3 weeks. Primary objectives were to assess dose-limiting toxicity, determine maximum tolerated dose and recommended expansion dose(s), and assess safety of camidanlumab tesirine. Safety was assessed in all treated patients; antitumour activity was assessed in patients with one or more valid baseline and post-baseline disease assessment and in those who had disease progression or died after first study-drug dose. This trial was registered with ClinicalTrials.gov, NCT02432235. FINDINGS: Between Oct 5, 2015, and Jun 30, 2019, 133 patients were enrolled (77 [58%] had classical Hodgkin lymphoma and 56 (42%) had non-Hodgkin lymphoma). Median follow-up was 9·2 months (IQR 4·2-14·3). Eight dose-limiting toxicities were reported in five (6%) of 86 patients who were evaluable; the maximum tolerated dose was not reached. The recommended doses for expansion were 30 µg/kg and 45 µg/kg for patients with classical Hodgkin lymphoma and 80 µg/kg for patients with T-cell non-Hodgkin lymphomas. No recommended doses for expansion were defined for B-cell non-Hodgkin lymphomas. Grade 3 or worse treatment-emergent adverse events (reported by ≥10% of the 133 patients) included increased γ-glutamyltransferase (20 [15%] patients), maculopapular rash (16 [12%]), and anaemia (15 [11%]); 74 (56%) patients had serious treatment-emergent adverse events, most commonly pyrexia (16 [12%]). One (1%) fatal treatment-emergent adverse event and two (2%) deaths outside the reporting period were considered at least possibly study-drug related. Antitumoural activity was seen in classical Hodgkin and non-Hodgkin lymphomas; notably in all patients with classical Hodgkin lymphoma, the overall response was 71% (95% CI 60-81). INTERPRETATION: These results warrant evaluation of camidanlumab tesirine as a potential treatment option for relapsed or refractory lymphoma, particularly in patients with classical Hodgkin lymphoma. FUNDING: ADC Therapeutics.

Loncastuximab tesirine in relapsed or refractory diffuse large B-cell lymphoma (LOTIS-2): a multicentre, open-label, single-arm, phase 2 trial.

BACKGROUND: Patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL) who do not respond to or who have progressive disease after salvage therapies have a poor prognosis. Loncastuximab tesirine is a CD19-directed antibody-drug conjugate with encouraging phase 1 single-agent antitumour activity and acceptable safety in non-Hodgkin lymphoma. We aimed to evaluate the antitumour activity and safety of loncastuximab tesirine in patients with relapsed or refractory DLBCL. METHODS: We did a multicentre (28 hospital sites in the USA, UK, Italy, and Switzerland), open-label, single-arm, phase 2 trial (LOTIS-2) in patients aged 18 years or older with relapsed or refractory DLBCL after two or more multiagent systemic treatments, who had measurable disease and Eastern Cooperative Oncology Group performance status 0-2. Eligible patients received loncastuximab tesirine intravenously on day 1 of each 21-day cycle, at 150 µg/kg for two cycles, then 75 µg/kg thereafter, for up to 1 year or until disease relapse or progression, unacceptable toxicity, death, major protocol deviation, pregnancy, or patient, investigator, or sponsor decision. The primary endpoint was overall response rate assessed by central review. Primary antitumour activity and safety analyses were done in the as-treated population (patients who received at least one dose of loncastuximab tesirine), when all responding patients had at least 6 months of follow-up after initial documented response. Enrolment is complete. This trial is registered with ClinicalTrials.gov, NCT03589469. FINDINGS: Between Aug 1, 2018, and Sept 24, 2019, 184 patients were assessed for eligibility and 145 (79%) were enrolled and received at least one dose of loncastuximab tesirine, including patients with high-risk characteristics for poor prognosis, such as double-hit, triple-hit, transformed, or primary refractory DLBCL. 70 of 145 patients had complete or partial response (overall response rate 48·3% [95% CI 39·9-56·7]); 35 had complete response and 35 had partial response. The most common grade 3 or higher treatment-emergent adverse events were neutropenia (37 [26%] of 145 patients), thrombocytopenia (26 [18%]), and increased gamma-glutamyltransferase (24 [17%]). Serious adverse events were reported in 57 (39%) of 145 patients. Treatment-emergent adverse events with a fatal outcome occurred in eight (6%) of 145 patients; none were considered related to loncastuximab tesirine. INTERPRETATION: Loncastuximab tesirine has substantial single-agent antitumour activity and produces durable responses with an acceptable safety profile, potentially offering a new therapeutic option for heavily pretreated patients with relapsed or refractory DLBCL. FUNDING: ADC Therapeutics.

Final results of a phase 1 study of loncastuximab tesirine in relapsed/refractory B-cell non-Hodgkin lymphoma.

The prognosis for patients with relapsed or refractory (R/R) B-cell non-Hodgkin lymphoma (B-NHL) remains poor, with a need for alternatives to current salvage therapies. Loncastuximab tesirine (ADCT-402) is an antibody-drug conjugate comprising a humanized anti-CD19 monoclonal antibody conjugated to a pyrrolobenzodiazepine dimer toxin. Presented here are final results of a phase 1 dose-escalation and dose-expansion study in patients with R/R B-NHL. Objectives were to determine the maximum tolerated dose (MTD) and recommended dose(s) for expansion and evaluate safety, clinical activity, pharmacokinetics, and immunogenicity of loncastuximab tesirine. Overall, 183 patients received loncastuximab tesirine, with 3 + 3 dose escalation at 15 to 200 µg/kg and dose expansion at 120 and 150 µg/kg. Dose-limiting toxicities (all hematologic) were reported in 4 patients. The MTD was not reached, although cumulative toxicity was higher at 200 µg/kg. Hematologic treatment-emergent adverse events were most common, followed by fatigue, nausea, edema, and liver enzyme abnormalities. Overall response rate (ORR) in evaluable patients was 45.6%, including 26.7% complete responses (CRs). ORRs in patients with diffuse large B-cell lymphoma (DLBCL), mantle cell lymphoma, and follicular lymphoma were 42.3%, 46.7%, and 78.6%, respectively. Median duration of response in all patients was 5.4 months and not reached in patients with DLBCL (doses ≥120 µg/kg) who achieved a CR. Loncastuximab tesirine had good stability in serum, notable antitumor activity, and an acceptable safety profile, warranting continued study in B-NHL. The recommended dose for phase 2 was determined as 150 µg/kg every 3 weeks for 2 doses followed by 75 µg/kg every 3 weeks. This trial was registered at www.clinicaltrials.gov as #NCT02669017.

Camidanlumab tesirine, an antibody-drug conjugate, in relapsed/refractory CD25-positive acute myeloid leukemia or acute lymphoblastic leukemia: A phase I study.

There is a significant need for improved therapeutics in older patients with acute leukemia. Camidanlumab tesirine is an antibody-drug conjugate against CD25, an antigen expressed in several malignancies, including acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). This open-label, dose-escalation and -expansion study (NCT02588092) assessed the safety, activity, pharmacokinetics (PK), and immunogenicity of camidanlumab tesirine in patients with relapsed/refractory ALL/AML. A total of 35 patients (34 AML and 1 ALL) were enrolled and received camidanlumab tesirine intravenously at 3-92 µg/kg once every three weeks (Q3W, n = 26) or 30 or 37.5 µg/kg every week (QW, n = 9). One dose-limiting toxicity of maculopapular rash occurred in the 30 µg/kg QW group; the maximum tolerated dose was not reached. No additional safety concerns or adverse events (AEs) of interest were identified. The most common (>10 % of patients) Grade ≥3 treatment-emergent AEs were febrile neutropenia (25.7 %), lymphopenia, neutropenia, thrombocytopenia or fatigue (all 14.3 %), pneumonia, increased gamma-glutamyltransferase, and hypophosphatemia (each 11.4 %). No signal for serious immune-related AEs such as Guillain-Barré syndrome/polyradiculopathy was observed and there was no evidence of immunogenicity. PK showed rapid clearance with apparent half-life <2 days for conjugated and total antibody, suggesting that Q3W dosing may be insufficient for therapeutic efficacy, and prompting exploration of a QW schedule. Two patients achieved complete responses with incomplete hematologic recovery; one each at 30 and 37.5 µg/kg QW. The trial was terminated during dose escalation due to programmatic reasons other than safety. Hence, recommended dose was not determined.

Loncastuximab tesirine, an anti-CD19 antibody-drug conjugate, in relapsed/refractory B-cell acute lymphoblastic leukemia.

Relapsed or refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL) remains a therapeutic challenge. Loncastuximab tesirine is an antibody-drug conjugate against CD19, an antigen expressed in many B-cell malignancies. This open-label, single-arm, dose-escalation, dose-expansion study assessed the safety, tolerability, pharmacokinetics (PKs), immunogenicity, and preliminary clinical activity of loncastuximab tesirine in adults with R/R B-ALL. A total of 35 patients were enrolled, with a median age of 55 years (range, 20-80) and a median of 3 prior therapies (range, 1-15). All patients received at least 1 IV infusion of loncastuximab tesirine at 15 to 150 µg/kg once every 3 weeks (Q3W; n = 30) or 50 µg/kg IV weekly (n = 5). Common treatment-emergent adverse events (TEAEs) were nausea (42.9%), febrile neutropenia (37.1%), and reversible liver test abnormalities. Grade ≥3 TEAEs were reported in 85.7% patients, most commonly febrile neutropenia and other hematologic abnormalities and reversible liver test abnormalities. There were no treatment-related deaths. Four patients (11.4%) had grade 2 infusion-related reactions, and 1 patient (150 µg/kg Q3W) had a dose-limiting toxicity of hyperbilirubinemia that resolved within 6 days without further action. The maximum tolerated dose was not reached. Three patients achieved complete responses, 1 each at 30, 120, and 150 µg/kg Q3W. PK studies showed marked interpatient variability, with target-mediated drug disposition seeming to contribute to time- and dose-dependent disposition. No clinically relevant anti-drug-antibody formation occurred. The trial was terminated in the dose-escalation phase because of slow accrual. This trial was registered at www.clinicaltrials.gov as NCT02669264.

A Phase I Study of ADCT-402 (Loncastuximab Tesirine), a Novel Pyrrolobenzodiazepine-Based Antibody-Drug Conjugate, in Relapsed/Refractory B-Cell Non-Hodgkin Lymphoma.

PURPOSE: ADCT-402 (loncastuximab tesirine) is an antibody-drug conjugate comprising a CD19-targeting antibody and pyrrolobenzodiazepine dimers. A first-in-human study evaluated the safety and preliminary clinical activity of loncastuximab tesirine in patients with B-cell non-Hodgkin lymphoma (NHL). PATIENTS AND METHODS: A multicenter, phase I, dose-escalation and dose-expansion study enrolled patients ages ≥18 years with relapsed/refractory (R/R) B-cell NHL. Patients received loncastuximab tesirine every 3 weeks at doses assigned by a 3+3 dose-escalation design. Dose escalation was used to assess the safety and tolerability of loncastuximab tesirine to determine the dose for expansion. Secondary objectives evaluated clinical activity, characterized the pharmacokinetic profile, and evaluated antidrug antibodies. RESULTS: During dose escalation, 88 patients with R/R B-cell NHL were treated with loncastuximab tesirine at doses 15 to 200 µg/kg. Treatment-emergent adverse events (TEAEs) were experienced by 87/88 (98.9%) patients. Most common TEAEs (≥20% of patients) were hematologic abnormalities, fatigue, edema, liver test abnormalities, nausea, rash, and dyspnea. Grade ≥3 TEAEs (≥5% of patients) included hematologic abnormalities, liver test abnormalities, fatigue, and dyspnea. Overall response rate at doses ≥120 µg/kg was 59.4% (41 of 69 patients; 40.6% complete response; 18.8% partial response). Median duration of response, progression-free survival, and overall survival (all doses) were 4.8, 5.5, and 11.6 months, respectively. Drug exposure increased with increasing dose, showing moderate accumulation with multiple doses ≥150 µg/kg. There was no evidence of immunogenicity. CONCLUSIONS: Loncastuximab tesirine had promising activity with acceptable safety in this dose-escalation study. A phase II study with initial dosing at 150 µg/kg has been initiated based on these results.

Approaches and limitations of phosphatidylinositol-3-kinase pathway activation status as a predictive biomarker in the clinical development of targeted therapy.

The central role played by the class I(A) phosphatidylinositol-3-kinase (PI3K) signaling node in human cancer is highlighted in the multiple mechanisms by which these signals become dysregulated. Many studies suggest that constitutive PI3K activation in human cancer contributes to drug resistance, including targeted agents and standard cytotoxic therapy. The combination of activation mechanisms and the multiple downstream cascades that emanate from the PI3K node contributes to the difficulty in measuring PI3K activation as a biomarker. Although many agents suppress the pathway in models, the challenge remains to translate this biology into a patient selection strategy (i.e., identify patients with "PI3K activated" tumors) and subsequently link this biomarker definition to drug responses in patients. The various genetic and epigenetic lesions resulting in pathway activation necessitate combined approaches using genetic, genomic, and protein biomarkers to accurately characterize "PI3K activated" tumors. Such a combined approach to pathway status can be assessed using a statistical stratification of patients in a randomized trial into "pathway on" and "pathway off" subsets to compare the treatment effect in each arm. Instead of considering individual biomarkers for their predictive ability, this strategy proposes the use of a collection of biomarkers to identify a specific "pathway on" patient population predicted to have clinical benefit from a pathway inhibitor. Here, we review the current understanding of the mechanisms of PI3K activation in breast cancer and discuss a pathway-based approach using PI3K as a predictive biomarker in clinical development, which is currently in use in a global phase 3 setting.

Clinical trial experience with temsirolimus in patients with advanced renal cell carcinoma.

Clinical trials have validated the importance of mammalian target of rapamycin (mTOR) as a therapeutic target in patients with advanced renal cell carcinoma (RCC). The TORC1 complex controls translation of key proteins involved in cell proliferation and regulates the expression and stability of hypoxia-inducible factor (HIF)-1alpha. Temsirolimus, the first mTOR inhibitor approved for treatment of advanced RCC, has demonstrated significantly longer overall survival (hazard ratio for death, 0.73; 95% confidence interval, 0.58-0.92, P = .008) and progression-free survival (P <.001) compared with interferon alfa (IFN) for patients with poor prognostic features. Median progression-free survival durations were 3.8 and 1.9 months, respectively, for patients treated with temsirolimus or IFN, and median overall survivals were 10.9 and 7.3 months, respectively. Exploratory analyses indicate that temsirolimus benefits those patients with metastatic RCC and multiple adverse prognostic factors regardless of tumor histology or nephrectomy status. Most adverse events that occur in patients receiving temsirolimus can be managed medically (eg, hyperglycemia, hyperlipidemia) or addressed by supportive measures (eg, stomatitis, rash). Although development of symptomatic pneumonitis is rare, monitoring is recommended. Temsirolimus is now considered an important first-line treatment option for patients with advanced RCC and multiple factors predictive of short survival. Current trials are investigating the use of temsirolimus in sequence or in combination with other targeted agents to further improve outcomes.

Analysis of PTEN and HIF-1alpha and correlation with efficacy in patients with advanced renal cell carcinoma treated with temsirolimus versus interferon-alpha.

BACKGROUND: Exploratory subgroup analyses from the phase 3 global advanced renal cell carcinoma (ARCC) trial were conducted to determine if baseline levels of the tumor molecular markers PTEN and HIF1 alpha correlated with efficacy in patients treated with temsirolimus (Torisel) versus interferon-alpha (IFN). METHODS: Patients in the IFN group received 3 million U (MU) subcutaneously 3x weekly, escalating to 18 MU. Patients in the temsirolimus group received 25 mg intravenously weekly. PTEN and HIF1 alpha baseline levels were measured in archived tumor specimens by immunohistochemistry. RESULTS: There was no correlation between baseline PTEN and HIF1 alpha levels and treatment effect with respect to overall survival (OS), progression-free survival, or objective response rate (ORR) in patients with advanced renal cell carcinoma with poor-risk prognostic factors. CONCLUSIONS: The baseline status of the molecular markers PTEN and HIF1 alpha did not correlate with efficacy in renal cell carcinoma patients treated with temsirolimus versus IFN. Patients demonstrated OS and progression-free survival benefit when treated with temsirolimus regardless of PTEN and HIF1 alpha status. Thus, baseline PTEN and HIF-1 levels may not predict response to temsirolimus. Alternatively, the lack of correlation may be due to the variability in tumor specimens that occurred because of the global nature of the clinical trial. Other markers in the phosphoinositide 3-kinase (PI3K)/Akt pathway may be of utility as predictors of response to temsirolimus in patients with advanced renal cell carcinoma.

Effect of temsirolimus versus interferon-alpha on outcome of patients with advanced renal cell carcinoma of different tumor histologies.

Purpose Exploratory subgroup analyses from the phase 3 global advanced renal cell carcinoma (ARCC) trial were conducted to assess the influence of tumor histology on outcome of patients treated with temsirolimus (Torisel) or interferon-alpha (IFN). Patients and methods Patients with ARCC including clear cell and other types such as papillary and chromophobe histologies received either IFN (3 million units [MU] subcutaneously three times weekly, escalating to 18 MU) or temsirolimus (25 mg intravenously weekly). Results Approximately 80% of patients had clear cell and 20% of patients had other histologies, the majority of which were papillary. Patients with clear cell and other RCC histologies, treated with temsirolimus, demonstrated comparable median overall and progression-free survival. In contrast, patients with other RCC histologies, treated with IFN, demonstrated shorter median overall and progression-free survival than patients with clear cell RCC. Hazard ratios for death for treatment with temsirolimus versus IFN were less than 1 for patients regardless of tumor histology. For patients treated with temsirolimus, 59% with clear cell and 68% with other RCC histologies experienced tumor reductions. For patients treated with IFN, 35% with clear cell and 14% with other RCC histologies had tumor reductions. However, temsirolimus did not appear to improve the objective response rate compared to IFN. Temsirolimus resulted in a superior clinical benefit rate compared with IFN, regardless of tumor histology. Conclusion Temsirolimus appears to be efficacious in patients with clear cell and non-clear cell histologies and can, therefore, be used for the treatment of all types of RCC.

Gemtuzumab ozogamicin: first clinical experiences in children with relapsed/refractory acute myeloid leukemia treated on compassionate-use basis.

Gemtuzumab ozogamicin (GO; Mylotarg) was developed to treat CD33(+) acute myeloid leukemia (AML). To date, only studies in adults and preliminary data from a phase 1 study in children have been reported. We report data on 15 children with relapsed/refractory CD33(+) AML who were treated with GO monotherapy on compassionate use basis (4-9 mg/m(2) up to 3 courses). Eight children showed a reduction in bone marrow blasts to 5% or less, including 5 in complete remission without full platelet recovery (CRp). Three of the 5 children with CRp received transplants almost directly following the last GO course, without awaiting further platelet regeneration. Hence in these children no clear discrimination between complete remission (CR) and CRp could be made. In 6 of 8 responding patients further treatment was given consisting of stem cell transplantation (SCT). Two patients are still alive, currently 6 and 9 months after SCT. Hematologic toxicity was difficult to assess due to subsequent SCT or leukemia. Side effects, in one patient each included veno-occlusive disease, transient grade 3 hyperbilirubinemia, transient grade 3 transaminase elevation, and grade 3 hypotension during GO administration. No infections or mucositis occurred. This report demonstrates clinical efficacy of GO in a subset of relapsed/refractory pediatric CD33(+) AML patients and suggests that intensive postremission therapy after remission induction by GO may result in durable responses in some patients, although follow-up is still short. Further studies are needed to determine the efficacy and safety of GO in children with AML.

Acute and long-term toxicities associated with gemtuzumab ozogamicin (Mylotarg) therapy of acute myeloid leukemia.

Gemtuzumab ozogamicin (Mylotarg) targets leukemia cells that express CD33 by means of a humanized anti-CD33 monoclonal antibody conjugated to a modified antitumor antibiotic, calicheamicin. The effects of gemtuzumab ozogamicin (given intravenously at a dose of 9 mg/m2 for 2 doses separated by 2 weeks) have been evaluated in 3 phase II studies involving patients (n = 188) with acute myeloid leukemia (AML) in first relapse. Interim analysis has revealed that 30% of patients achieved remission, characterized by < or = 5% blasts in the marrow, neutrophil count > or = 1500/microL, hemoglobin > or = 9 g/dL, and independence from red blood cell and platelet transfusion. Grade 3/4 acute toxicities included nausea or vomiting (11%); elevated serum aminotransferase enzyme (16%) and bilirubin (26%) levels; and infusion-related chills (9%), fever (6%), and hypotension (5%). As predicted with CD33-targeted therapy, most patients had neutropenia (98%) and thrombocytopenia (99%). However, the incidence of grade 3/4 bleeding events (14%) and infection rates (pneumonia, 7%; sepsis, 15%) was low. No patients were reported to have treatment-related cardiotoxicity, cerebellar toxicity, or alopecia. Veno-occlusive disease (VOD) after gemtuzumab ozogamicin treatment (but prior to other therapies) occurred in 2% of patients (4/188), and the VOD-related death rate was < 1% (1/188). Prior hematopoietic stem cell transplant may be a risk factor for VOD (P = 0.002, univariate analysis). Gemtuzumab ozogamicin is a safe and effective treatment in carefully selected patients with AML in first relapse.