Second- and third-generation tyrosine kinase inhibitors for Philadelphia-positive adult acute lymphoblastic leukemia relapsing post allogeneic stem cell transplantation-a registry study on behalf of the EBMT Acute Leukemia Working Party

Second- and third-generation tyrosine kinase inhibitors (TKI) play an important role in the treatment of Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph + ALL). However, data on feasibility and efficacy of using these drugs for persisting or relapsed Ph + ALL after allogeneic stem cell transplantation (alloSCT) are scarce. Based on the EBMT Acute Leukemia Working Party registry, we evaluated the use of second-/third-generation TKI in 140 patients with Ph + ALL, suffering from measurable residual disease (MRD, n = 6), molecular relapse (MRel, n = 23), or hematological relapse (HRel, n = 111) following alloSCT. Treatment included dasatinib in 104, nilotinib in 18, or ponatinib in 18 patients. Forty-nine patients received TKI monotherapy, while 91 received additional treatment. Toxicity of second-/third-generation TKI post alloSCT was comparable to pretransplant use and could be managed with dose reduction or temporary discontinuation. Response rates were 71% (overall) and 61% (following TKI monotherapy). For the entire cohort, 2- and 5-year overall survival (OS) was 49% and 33%, respectively. OS was comparable among patients treated for persisting MRD/MRel and HRel. Among patients treated with TKI monotherapy, 2- and 5-year OS was 38% and 33%, respectively. The data underscore that second-/third-generation TKI are important compounds for the management of active Ph + ALL post alloSCT.

Effect of Prophylactic Post-transplant Ponatinib Administration on Outcomes in Patients With Philadelphia Chromosome-positive Acute Lymphoblastic Leukemia

BACKGROUND

The objective of the present retrospective study was to evaluate the effect of ponatinib administration as maintenance therapy on the outcomes after allogeneic hematopoietic stem cell transplantation in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia.

PATIENTS AND METHODS

We retrospectively analyzed the data from 34 consecutive patients treated at our institution from January 2008 to June 2019. We had administered post-transplant tyrosine kinase inhibitors preemptively before December 2017. Thereafter, we had initiated the prophylactic use of post-transplant ponatinib. The initial ponatinib dose was 15 mg/d. Ponatinib plasma trough levels were measured using the liquid chromatography-tandem mass spectrometry method 8 days after the first administration and subsequently.

RESULTS

Nine patients received ponatinib maintenance. The 2-year overall survival and leukemia-free survival in the ponatinib maintenance group tended to be better than that in the non-ponatinib group (100% vs. 70.5%, P = .10; and 100% vs. 50.8%, P = .02, respectively). In the first 7 of the 9 consecutive patients, the median plasma concentration after ponatinib administration (15 mg/d) was 15.6 ng/mL (range, 4.8-23.3 ng/mL). Although the treatment schedule for 1 patient was altered because of adverse effects (elevation of serum amylase and neutropenia), ponatinib administration was continued for all the patients, except for 1 patient with molecular relapse. One patient developed a transient elevation of serum lipase. No patient presented with any arterial occlusive events.

CONCLUSION

Our results have indicated that the strategy of ponatinib maintenance after allogeneic hematopoietic stem cell transplantation is safe, efficacious, and promising.

Ponatinib therapy in recurrent Philadelphia chromosome-positive central nervous system leukemia with T315I mutation after Allo-HSCT

Central nervous system leukemia (CNSL) relapse is relatively common among Philadelphia chromosome-positive (Ph+) leukemia patients who undergo allogeneic hematopoietic stem cell transplantation (allo-HSCT). The prognosis of patients is dismal for those with a BCR-ABL T315I mutation, which is resistant to TKIs including second-generation drugs. We assessed ponatinib for nine patients with recurrent Ph+ CNSL and a T315I mutation after allo-HSCT, including five patients with Ph+ acute lymphoblastic leukemia and four with chronic myelogenous leukemia. Five patients experienced isolated CNSL relapse, and four experienced CNSL with hematologic relapse. All patients received ponatinib combined with intrathecal chemotherapy, and four patients with hematologic relapse received systemic chemotherapy and/or donor lymphocyte infusion. All patients achieved a deep molecular response and central nervous system remission (CNSR) at a median time of 1.5 (range: 0.7-3) months after ponatinib treatment. Two patients experienced a second CNSL relapse due to ponatinib reduction, but they achieved CNSR again after an increase to the standard dosage. Six patients developed graft versus host disease. By April 1, 2019, eight patients were alive, and one died of pneumonia. The median time of survival after the first CNSL relapse posttransplantation was 18 (range: 11.2-48.5) months. Our data from a small number of samples suggests that ponatinib is effective for recurrent Ph+ CNSL patients with a BCR-ABL T315I mutation after allo-HSCT and warrants broader clinical evaluation.

[Clinical characteristics of chronic myeloid leukemia with T315I mutation and the efficacy of ponatinib]

OBJECTIVE

To analyze the clinical features of chronic myeloid leukemia (CML) with T315 I mutation (CML-T315I) and compare the effectiveness of different treatments.

METHODS

We retrospectively analyzed the clinical data and outcomes of 19 patients with CML-T315I receiving different treatments. The T315 I mutations in these patients were detected by examination of BCR-ABL kinase domain (KD) mutation by RTQ-PCR and Sanger sequencing. The relapse following the treatments, defined as hematological, cytogenetic and molecular biological recurrences, were analyzed in these patients.

RESULTS

Of the 19 patients with CML-T315I, 14 (73.7%) were in CML-CP stage at the initial diagnosis, and 13 (81.2%) were high-risk patients based on the Sokal scores. All the 19 patients were treated with TKI after the initial diagnosis, and during the treatment, 15 (78.9%) patients were found to have additional chromosomal aberrations, and 10 (52.6%) had multiple mutations; 13 (68.4%) of the patients experienced disease progression (accelerated phase/blast crisis) before the detection of T315I mutation, with a median time of 40 months (5-120 months) from the initial diagnosis to the mutation detection. After detection of the mutation, 12 patients were treated with ponatinib and 7 were managed with the conventional chemotherapy regimen, and their overall survival rates at 3 years were 83.3% and 14.2%, respectively (P < 0.001).

CONCLUSIONS

CML patients resistant to TKI are more likely to have T315I mutations, whose detection rate is significantly higher in the progressive phase than in the chronic phase. These patients often have additional chromosomal aberrations and multiple gene mutations with poor prognoses and a high recurrence rate even after hematopoietic stem cell transplantation. Long-term maintenance therapy with ponatinib may improve the prognosis and prolong the survival time of the patients.

Long-Term Molecular Remission Achieved by Antibody Anti-CD22 and Ponatinib in a Patient Affected by Ph'+ Acute Lymphoblastic Leukemia Relapsed after Second Allogeneic Hematopoietic Stem Cell Transplantation: A Case Report

Ph'+ acute lymphoblastic leukemia (Ph'+-ALL) is an oncohematologic disorder for which allogeneic bone marrow transplantation still offers the only chance of cure. However, relapse is the main reason for treatment failure, also after hematopoietic stem cell transplantation (HSCT). New drugs, such as third generation tyrosine kinase inhibitors (TKIs) and monoclonal antibodies, have expanded the therapeutic landscape, especially in patients who relapsed before HSCT. Very few reports, up to now, have described the use of both classes of these new agents in combination with donor lymphocyte infusions (DLI) in the setting of patients who relapsed after HSCT. We report on a young patient affected by Ph'+-ALL, who relapsed after the second HSCT and who reached molecular remission and long-term disease control by treatment with the anti-CD22 monoclonal antibody inotuzumab ozogamicin, DLI, and the 3rd generation TKI ponatinib.

Spotlight on ponatinib in the treatment of chronic myeloid leukemia and Philadelphia chromosome-positive acute lymphoblastic leukemia: patient selection and perspectives

Ponatinib, a third-generation tyrosine kinase inhibitor that inhibits BCR/ABL independent of the mutation status, is currently approved for the treatment of patients with chronic myeloid leukemia or acute lymphoblastic leukemia that are either resistant or unable to tolerate another tyrosine kinase inhibitor. Its US Food and Drug Administration approval was based on results from long-term follow-up of the pivotal Phase II PACE trial, which demonstrated deep and durable molecular responses in the treated patients. Despite the remarkable responses, ponatinib has been associated with high frequency of severe vascular events, which led to its withdrawal from the market in 2013. Following analysis of the risk factors of patients who developed vascular side effects, ponatinib was reintroduced in the market 1 year later with specific dose-reduction recommendations and carrying a black box warning. Thus, careful patient selection with identification of patients whose potential benefit from ponatinib exceeds the potential risks associated with its use is crucial. Ongoing and future studies are focusing on earlier detection of mutations, strategies to minimize side effects, and potential expansion of the treatment indications. Clinical trials testing the safety and efficacy of ponatinib as frontline therapy are ongoing.

Ichthyosiform Pityriasis Rubra Pilaris-Like Eruption Secondary to Ponatinib Therapy: Case Report and Literature Review

Tyrosine kinase inhibitors have revolutionized the chemotherapy arena as targeted therapies for a multitude of malignancies. They are more selective than conventional chemotherapy, and often elicit fewer systemic adverse events, however toxicities still exist. Cutaneous toxicities are common and their management presents a novel challenge to physicians and patients. Ponatinib is a third-generation tyrosine kinase inhibitor increasingly reported to cause cutaneous eruption. A 50-year-old woman with a history of chronic myelogenous leukemia presented with a 4-month history of worsening atrophic and ichthyosiform pink plaques involving the axillae, thighs and abdomen; red patches were also observed on the cheeks and forehead. She was started on the third-generation, ponatinib, 5 months earlier because of disease refractory to previous therapies including interferon, imatinib, dasatinib and bosutinib. A skin biopsy revealed perifollicular fibrosis, alternating orthokeratosis and parakeratosis, and a sparse perivascular lymphocytic infiltrate consistent with a pityriasis rubra pilaris-like reaction. Topical tretinoin 0.025% cream was initiated, resulting in resolution within 3 weeks without discontinuation of ponatinib. A review of previous reports identified significant similarities among the ponatinib-induced drug reactions. Here, we highlight not only that cutaneous eruptions occur on ponatinib therapy, but that the dermatologic manifestations are characteristic and unique, and benefit from retinoid therapy, without requiring interruption of vital chemotherapy.

Ponatinib-Induced Graft-versus-Host Disease/Graft-versus-Leukemia Effect in a Patient with Philadelphia-Positive Acute Lymphoblastic Leukemia without the T315I Mutation Relapsing after Allogeneic Transplant

We describe the case of a patient with Philadelphia-positive acute lymphoblastic leukemia treated with dasatinib plus steroids as first-line therapy, who achieved a major molecular response (MMR) before undergoing matched, unrelated donor allogeneic stem cell transplant. Eleven months after the transplant, she experienced molecular relapse. Mutational screening showed negativity for the T315I mutation, The patient underwent a salvage chemotherapy regimen with clofarabine + cyclophosphamide + steroids and ponatinib (clofarabine 70 mg i.v., days 1-5, cyclophosphamide 700 mg i.v., days 1-5, and ponatinib 45 mg p.o., daily starting at day 15). We observed a rapid decrease in minimal residual disease on molecular assessment with an MMR of P190-BCR-ABL/ABL = 0.01% confirmed by bone marrow revaluations at days +23, +59, +108, and +191 after the first day of salvage chemotherapy. After starting ponatinib, the patient experienced skin graft-versus-host disease, suggesting that the efficacy of ponatinib could be related not only to the direct antileukemic effect but also to its ability to promote an indirect graft-versus-leukemia effect. Ponatinib treatment was well tolerated and considered safe with easily manageable side effects.