Pirtobrutinib in relapsed or refractory B-cell malignancies (BRUIN): a phase 1/2 study.

BACKGROUND: Covalent Bruton's tyrosine kinase (BTK) inhibitors are efficacious in multiple B-cell malignancies, but patients discontinue these agents due to resistance and intolerance. We evaluated the safety and efficacy of pirtobrutinib (working name; formerly known as LOXO-305), a highly selective, reversible BTK inhibitor, in these patients. METHODS: Patients with previously treated B-cell malignancies were enrolled in a first-in-human, multicentre, open-label, phase 1/2 trial of the BTK inhibitor pirtobrutinib. The primary endpoint was the maximum tolerated dose (phase 1) and overall response rate (ORR; phase 2). This trial is registered with ClinicalTrials.gov, NCT03740529. FINDINGS: 323 patients were treated with pirtobrutinib across seven dose levels (25 mg, 50 mg, 100 mg, 150 mg, 200 mg, 250 mg, and 300 mg once per day) with linear dose-proportional exposures. No dose-limiting toxicities were observed and the maximum tolerated dose was not reached. The recommended phase 2 dose was 200 mg daily. Adverse events in at least 10% of 323 patients were fatigue (65 [20%]), diarrhoea (55 [17%]), and contusion (42 [13%]). The most common adverse event of grade 3 or higher was neutropenia (32 [10%]). There was no correlation between pirtobrutinib exposure and the frequency of grade 3 treatment-related adverse events. Grade 3 atrial fibrillation or flutter was not observed, and grade 3 haemorrhage was observed in one patient in the setting of mechanical trauma. Five (1%) patients discontinued treatment due to a treatment-related adverse event. In 121 efficacy evaluable patients with chronic lymphocytic leukaemia (CLL) or small lymphocytic lymphoma (SLL) treated with a previous covalent BTK inhibitor (median previous lines of treatment 4), the ORR with pirtobrutinib was 62% (95% CI 53-71). The ORR was similar in CLL patients with previous covalent BTK inhibitor resistance (53 [67%] of 79), covalent BTK inhibitor intolerance (22 [52%] of 42), BTK C481-mutant (17 [71%] of 24) and BTK wild-type (43 [66%] of 65) disease. In 52 efficacy evaluable patients with mantle cell lymphoma (MCL) previously treated with covalent BTK inhibitors, the ORR was 52% (95% CI 38-66). Of 117 patients with CLL, SLL, or MCL who responded, all but eight remain progression-free to date. INTERPRETATION: Pirtobrutinib was safe and active in multiple B-cell malignancies, including patients previously treated with covalent BTK inhibitors. Pirtobrutinib might address a growing unmet need for alternative therapies for these patients. FUNDING: Loxo Oncology.

Treatment-free interval as an additional measure of efficacy in a large UK dataset of transplant ineligible myeloma patients.

Treatment of transplant-ineligible (TNE) newly diagnosed multiple myeloma (NDMM) requires a balance between disease control and maintaining quality of life (QoL). Patients value treatment-free remission periods in this incurable condition, as they are associated with better QoL. We set out to study clinical outcomes of consecutive TNE NDMM patients in routine care treated in Thames Valley Cancer Network between 2009 and 2017. The primary outcome was the evaluation of the treatment-free interval (TFI) after 1st and subsequent lines of therapy in the total cohort and in individual subgroups, according to age (≤75 vs. >75 years), and co-morbidities using Charlson Co-morbidity Index (CCI): mild: 0-2 vs. moderate: 3-4 vs. severe: ≥5). Secondary outcomes include response rates, overall survival (OS) and progression-free survival (PFS) between subgroups: according to age and according to co-morbidities. In a total cohort of 292 patients, median TFI (IQR) was longest after first-line therapy 6.9 months (1.4-16.9), reducing after second line therapy to 1.8 months (.7-6.9), and after third line therapy to 0.6 months (0.2-1.5). Median TFI followed the same trend across the different subgroups, by age (≤75, >75 years) and by CCI (0-2, 3-4, ≥5). Overall response rate (ORR) to first line therapy for total cohort was 67%, with responses categorised as complete response (CR): 21%, very good partial response: 16%, partial response: 30%, stable disease: 18%, and progressive disease: 8%. ORR in individual subgroups by age were (≤75: 70% vs. >75: 63%), and by CCI (0-2: 65% vs. 3-4: 71% vs. ≥5: 77%). Median OS and PFS for the total cohort were (30.2 months, 95% CI: 23.8-36.9), and (9 months, 95% CI: 7.9-9.8), respectively. Patients aged >75 years showed a significant reduction in OS and PFS compared to those ≤75 years of age: OS (49.0 vs. 22.4 months, p<0.0001, HR: 2.08, 95% CI: 1.5-2.8), PFS (9.7 vs. 8.0 months, p<0.01, HR: 1.47, 95% CI: 1.1-1.9). Median OS was significantly reduced with worsening co-morbidities: (CCI 0-2: 52.4 months vs. CCI 3-4: 33.0 months vs. CCI ≥5: 24.0 months, p = 0.01, HR: 1.43, 95% CI: 1.1-1.9). Median PFS was significantly reduced in the severely co-morbid subgroup (CCI 0-2: 9.4 months vs. CCI 3-4: 9.6 months vs. CCI ≥5: 7.1 months, p = 0.025, HR: 1.3, 95% CI: 1.0-1.6). This study demonstrated that first line therapy in the TNE NDMM setting resulted in the longest TFI which was modest at a median of 6.9 months, and decreased significantly following subsequent lines of therapy and across the different subgroups by age and by co-morbidities. Therapy objective should be to maximise the benefit of first line treatment. We envisage that the recent shift towards a continuous therapeutic approach will benefit TNE patients in view of improved survival data demonstrated by a number phase 3 trials. When continuous therapy is not appropriate due to patient choice or toxicities, an efficacious (not limited to thalidomide and bortezomib) but tolerable first line FDT strategy, which can maximise TFI and maintain a good QoL, remains a reasonable alternative approach.

Management and controversies of classical Hodgkin lymphoma in pregnancy.

The goal of managing classical Hodgkin lymphoma (cHL) in pregnancy is to obtain good long-term outcomes for both the mother and fetus. Given the excellent outcomes outside of pregnancy, the goal of treatment should remain curative. There remains a tension and debate regarding the timing of chemotherapy, the curative nature of such treatment and the timing of delivery. Moreover, the aim during pregnancy should be to minimize fetal toxicity and optimize perinatal outcomes. The management of cHL within pregnancy was covered within the excellent recent British Committee for Standards in Haematology guidelines, but with necessary brevity. By reviewing the literature over the last 30 years, herein we discuss the options for management during each trimester. Critical organogenesis occurs between 2 and 8 weeks post-conception; during which time the immature fetus is vulnerable to cytotoxic exposure. We discuss the evidence for using ABVD (doxorubicin, bleomycin, vinblastine and dacarbazine) and single agent vinblastine in the first trimester. cHL presenting in pregnancy raises complex and difficult ethical dilemmas that can cause anxiety for patients, families and physicians. Decision-making must be multi-disciplinary and holistic, taking into account the patient's wishes, psycho-social and religious beliefs and personal circumstances. Clear communication between the haemato-oncologist, medical obstetrician, nurse specialists, midwives and neonatologists is paramount to a successful outcome.