Bruton’s tyrosine kinase (BTK) is a critical downstream signaling element from the B-cell receptor (BCR) that has been effectively inhibited in B-cell cancers by irreversible, covalent inhibitors including ibrutinib and acalabrutinib. All FDA-approved covalent BTK inhibitors rely on binding to the cysteine 481 (C481) amino acid within the active site of BTK, thus rendering it inert. While covalent BTK inhibitors have been very successful in multiple B-cell malignancies, improving both overall survival and progression-free survival relative to chemoimmunotherapy in phase 3 trials, they can be limited by intolerance and disease progression. Pirtobrutinib is a novel, highly selective, and non-covalent BTK inhibitor that binds independently of C481, and in a recent, first-in-human phase 1/2 clinical trial was shown to be extremely well tolerated and lead to remissions in relapsed/refractory patients with multiple B-cell malignancies. Here, we review the pharmacologic rationale for pursuing non-covalent BTK inhibitors, the clinical need for such inhibitors, existing safety, and resistance mechanism data for pirtobrutinib, and the forthcoming clinical trials that seek to define the clinical utility of pirtobrutinib, which has the potential to fulfill multiple areas of unmet clinical need for patients with B-cell malignancies.

PURPOSE: Adult T-cell leukemia/lymphoma (ATLL) is an aggressive disease caused by the human T-cell leukemia virus type 1. Real-world data of ATLL in Latin America are lacking. PATIENTS AND METHODS: We analyzed patients with ATLL (acute, lymphomatous, chronic, and smoldering) encountered in 11 Latin American countries between 1995 and 2019. Treatment response was assessed according to the 2009 consensus report. Survival curves were estimated using the Kaplan-Meier method and log-rank test. RESULTS: We identified 253 patients; 226 (lymphomatous: n = 122, acute: n = 73, chronic: n = 26, and smoldering: n = 5) had sufficient data for analysis (median age 57 years). Most patients with ATLL were from Peru (63%), Chile (17%), Argentina (8%), and Colombia (7%). Hypercalcemia was positively associated with acute type (57% v lymphomatous 27%, P = .014). The median survival times (months) were 4.3, 7.9, 21.1, and not reached for acute, lymphomatous, chronic, and smoldering forms, with 4-year survival rates of 8%, 22%, 40%, and 80%, respectively. First-line zidovudine (AZT)-interferon alfa (IFN) resulted in an overall response rate of 63% (complete response [CR] 24%) for acute. First-line chemotherapy yielded an overall response rate of 41% (CR 29%) for lymphomatous. CR rate was 42% for etoposide, cyclophosphamide, vincristine, doxorubicin, and prednisone versus 12% for cyclophosphamide, vincristine, doxorubicin, and prednisone–like regimen ( P < .001). Progression-free survival at 1 year for acute type patients treated with AZT-IFN was 67%, whereas 2-year progression-free survival in lymphomatous type patients who achieved CR after chemotherapy was 77%. CONCLUSION: This study confirms Latin American ATLL presents at a younger age and has a high incidence of lymphomatous type, low incidence of indolent subtypes, and worse survival rates as compared with Japanese patients. In aggressive ATLL, chemotherapy remains the preferred choice for lymphomatous favoring etoposide-based regimen (etoposide, cyclophosphamide, vincristine, doxorubicin, and prednisone), whereas AZT-IFN remains a good first-line option for acute subtype.

The aim of this study was to describe clinical and survival characteristics of transplant-eligible multiple myeloma (MM) patients in Latin America (LA), with a special focus on differences between public and private healthcare facilities. We included 1293 patients diagnosed between 2010 and 2018. A great disparity in outcomes and survival between both groups was observed. Late diagnosis and low access to adequate frontline therapy and ASCT in public institutions probably explain these differences. Patients treated with novel drug induction protocols, followed by autologous stem cell transplantation (ASCT) and maintenance, have similar overall survival compared to that published internationally.

Existe escasa información sobre su epidemiologia y clínica en Latinoamérica. Recientemente se publicó un interesante reporte de 852 pacientes en el que participaron 23 instituciones de Argentina, Perú, Chile, México y Brasil⁴, un gran esfuerzo de Hungria et al en esta materia.

PURPOSE: Waldenstrom Macroglobulinemia (WM) is a rare lymphoma with distinct clinical features, and data from Latin American patients are lacking. Therefore, we aim to investigate the clinical, therapy, and outcome patterns of WM in Latin America. METHODS: We retrospectively analyzed patients with WM diagnosed between 1991 and 2019 from 24 centers in seven Latin American countries. The study outcomes were overall survival (OS) and progression-free survival (PFS). RESULTS: We identified 159 cases (median age 67 years, male 62%). Most patients (95%) were symptomatic at diagnosis. The International Prognostic Scoring System for WM (IPSSWM) at diagnosis was available in 141 (89%) patients (high-risk 40%, intermediate-risk 37%, and low-risk 23%). Twenty-seven (17%) patients were tested for MYD88^L265P, with 89% (n = 24 of 27) carrying the mutation. First-line and second-line therapies were administered to 142 (89%) and 53 (33%) patients, respectively. Chemoimmunotherapy was the most commonly used first-line (66%) and second-line (45%) approach; only 18 (11%) patients received ibrutinib. With a median follow-up of 69 months, the 5-year OS rate was 81%. In treated patients, the 5-year OS and PFS rates were 78% and 59%, respectively. High-risk IPSSWM at treatment initiation was an independent risk factor for OS (adjusted hazard ratio: 4.73, 95% CI, 1.67 to 13.41, P = .003) and PFS (adjusted hazard ratio: 2.43, 95% CI, 1.31 to 4.50, P = .005). CONCLUSION: In Latin America, the management of WM is heterogeneous, with limited access to molecular testing and novel agents. However, outcomes were similar to those reported internationally. We validated the IPSSWM score as a prognostic factor for OS and PFS. There is an unmet need to improve access to recommended diagnostic approaches and therapies in Latin America.

Background: There is an increased risk of second primary malignancies (SMPs) in patients with multiple myeloma (MM). This multinational ‘real-world’ retrospective study analyzed the characteristics and outcomes of MM patients that developed SPMs. Results: 165 patients were analyzed: 62.4% males; 8.5% with a prior cancer; 113 with solid SPMs, mainly ≥stage 2; and 52 with hematological SPM (hemato-SPM), mainly MDS/AML. Patients with hemato-SPM were younger (p = 0.05) and more frequently had a prior AutoHCT (p = 0.012). The time to SPM was shorter in the older (>65 years) and more heavily pretreated patients. One hundred patients were actively treated at the time of SPM detection. Treatment was discontinued in 52, substituted with another anti-MM therapy in 15, and continued in 33 patients. Treatment discontinuation was predominant in the patients diagnosed with hemato-SPM (76%). The median OS following SPM detection was 8.5 months, and the main cause of death was SPM. A poor ECOG status predicted a shorter OS (PS 3 vs. 0, HR = 5.74, 2.32–14.21, p < 0.001), whereas a normal hemoglobin level (HR = 0.43, 0.19–0.95, p = 0.037) predicted longer OS. Conclusions: With the continuing improvement in OS, a higher proportion of MM patients might develop SPM. The OS following SPM diagnosis is poor; hence, frequent surveillance and early detection are imperative to improve outcomes.