Fludarabine, cyclophosphamide and rituximab plus granulocyte macrophage colony-stimulating factor as frontline treatment for patients with chronic lymphocytic leukemia

A novel method to investigate drug resistance in the chronic lymphocytic leukemia (CLL) microenvironment: Analysis of CLL Cellular Environment and Response (ACCER)

Microenvironments such as lymph nodes allow chronic lymphocytic leukemia (CLL) cells to survive and become drug resistant. There are limited methods to study the to study the contribution of the stromal microenvironment. We have adapted a solid tumor microenvironment cell culture system that provides elements of the CLL microenvironment called Analysis of CLL Cellular Environment and Response (ACCER). We optimized the cell number for patient's primary CLL cells and HS-5 human bone marrow stromal cell line that will give sufficient cell number and viability with the ACCER. We then determined the amount of collagen type 1 to give the best extracellular matrix to seed CLL cells to the membrane. Finally, we determined that ACCER provide CLL cell protection against cell death following treatment with fludarabine and ibrutinib compared to co-culture conditions. This describes novel microenvironment model to investigate factors that promote drug resistance in CLL.

Secondary primary malignancies after treatment with chemo-immunotherapy in treatment-naïve patients with CLL: a systematic literature review

OBJECTIVES

In chronic lymphocytic leukemia (CLL), therapy-related cytotoxicity and the resulting immunodeficiency are thought to contribute to the development of secondary primary malignancies (SPM). Here we analyzed clinical trial data on the occurrence of SPM following chemo-immunotherapy (CIT) regimens in treatment-naïve CLL patients.

METHODS

A systematic literature search was conducted covering multiple databases between 2003-2019. Data from relevant clinical trials on the proportion of patients with SPMs were extracted. Then the number of SPM patients/person-years was calculated by taking into account the trials' follow-up time. Finally, a random-effects meta-analysis to pool the rates from individual studies was performed.

RESULTS

We identified 22 studies reporting SPM data available for analysis. Random-effects meta-analysis estimated that the number of SPM patients/1000 person-years was 24 (95%CI: 19-29). Results from trials with cancer-specific data indicated 19 (95%CI: 14-26) solid and 9 (95%CI: 6-12) hematological SPM patients/1000 person-years. These estimations did not change significantly when sub-groups were analysed by CIT regimens.

CONCLUSION

Although pooling data with the intention to analyze adverse event rates is challenging, our study concluded that in case of CIT regimens, SPM should be considered an important adverse outcome. Different regimens showed similar trends; however, other clinical and demographic factors have a profound impact in this respect.

Sargramostim (rhu GM-CSF) as Cancer Therapy (Systematic Review) and An Immunomodulator. A Drug Before Its Time?

BACKGROUND

Sargramostim [recombinant human granulocyte-macrophage colony-stimulating factor (rhu GM-CSF)] was approved by US FDA in 1991 to accelerate bone marrow recovery in diverse settings of bone marrow failure and is designated on the list of FDA Essential Medicines, Medical Countermeasures, and Critical Inputs. Other important biological activities including accelerating tissue repair and modulating host immunity to infection and cancer via the innate and adaptive immune systems are reported in pre-clinical models but incompletely studied in humans.

OBJECTIVE

Assess safety and efficacy of sargramostim in cancer and other diverse experimental and clinical settings.

METHODS AND RESULTS

We systematically reviewed PubMed, Cochrane and TRIP databases for clinical data on sargramostim in cancer. In a variety of settings, sargramostim after exposure to bone marrow-suppressing agents accelerated hematologic recovery resulting in fewer infections, less therapy-related toxicity and sometimes improved survival. As an immune modulator, sargramostim also enhanced anti-cancer responses in solid cancers when combined with conventional therapies, for example with immune checkpoint inhibitors and monoclonal antibodies.

CONCLUSIONS

Sargramostim accelerates hematologic recovery in diverse clinical settings and enhances anti-cancer responses with a favorable safety profile. Uses other than in hematologic recovery are less-well studied; more data are needed on immune-enhancing benefits. We envision significantly expanded use of sargramostim in varied immune settings. Sargramostim has the potential to reverse the immune suppression associated with sepsis, trauma, acute respiratory distress syndrome (ARDS) and COVID-19. Further, sargramostim therapy has been promising in the adjuvant setting with vaccines and for anti-microbial-resistant infections and treating autoimmune pulmonary alveolar proteinosis and gastrointestinal, peripheral arterial and neuro-inflammatory diseases. It also may be useful as an adjuvant in anti-cancer immunotherapy.

Fludarabine, cyclophosphamide, and multiple-dose rituximab as frontline therapy for chronic lymphocytic leukemia

BACKGROUND

Fludarabine, cyclophosphamide, and rituximab (FCR) result in durable responses in patients with previously untreated chronic lymphocytic leukemia (CLL). Previous reports have suggested that in patients with relapsed CLL, a dose-intensified rituximab regimen increases response rates in comparison with standard-dose rituximab. It is unknown whether rituximab intensification of the FCR regimen will result in improved response rates and patient outcomes in patients with previously untreated CLL.

METHODS

A single-arm study was conducted to evaluate the safety and efficacy of a modified FCR regimen with multiple-dose rituximab (FCR3) in 65 patients with previously untreated CLL. The results were compared with those for a historical cohort treated with FCR.

RESULTS

The overall response rate to FCR3 was 97%, with 75% of the patients achieving a complete remission. Minimal residual disease negativity was achieved for 62% of the patients according to flow cytometry. The median time to progression (TTP) was 81 months, and the median overall survival (OS) was not reached, with 58% of the patients still alive at a median survivor follow-up of 9.7 years. Grade 3 or 4 neutropenia, grade 3 or 4 thrombocytopenia, and major infections were observed with 45%, 5%, and 1.9% of the FCR3 courses, respectively. Therapy-related myelodysplastic syndrome (t-MDS) or therapy-related acute myelogenous leukemia (t-AML) developed in 7 patients (11%; P < .01 vs the historical FCR cohort).

CONCLUSIONS

In patients with previously untreated CLL, FCR3 resulted in response rates, TTP, and OS similar to those of a historical cohort of patients treated with FCR. FCR3 was associated with an increased incidence of t-MDS/t-AML.

Combination of GM-CSF With Fludarabine-Containing Regimens in Chronic Lymphocytic Leukemia and Indolent Non-Hodgkin Lymphoma

BACKGROUND

Granulocyte-monocyte colony stimulating factor (GM-CSF) is a hematopoietic cytokine with immunomodulatory activity that has preclinical evidence for enhancement of antitumor immunity when administered in combination with chemotherapy. We evaluated the utility of GM-CSF with chemoimmunotherapy in patients with indolent non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia (CLL) in a pilot study.

PATIENTS AND METHODS

Patients with previously untreated, relapsed, or refractory indolent NHL or CLL were treated with GM-CSF, rituximab, fludarabine, and cyclophosphamide or mitoxantrone for a maximum of 6 cycles.

RESULTS

Sixteen patients were enrolled, including 1 patient who did not receive study therapy. Of the 15 remaining patients, 6 received cyclophosphamide and 9 received mitoxantrone in combination with fludarabine, rituximab, and GM-CSF. The overall response rate for all patients was 87%. Nine patients have subsequently had relapse of their disease, and 6 remained in remission at last study contact. There were no toxic deaths during the study.

CONCLUSION

GM-CSF-based chemoimmunotherapy was well-tolerated and resulted in a high response rate and warrants evaluation in larger studies.

Initial treatment of CLL: integrating biology and functional status

A better understanding of the biology of chronic lymphocytic leukemia (CLL) has led to significant advances in therapeutic strategies for patients with CLL. Chemoimmunotherapy (CIT) has been the standard first-line therapy for CLL. Age and comorbidities can help decide which patients may benefit from a CIT approach. FCR (fludarabine, cyclophosphamide, and rituximab) is the current standard treatment option for younger patients with CLL. For older patients and for patients with renal dysfunction, bendamustine and rituximab may be a better option. For older patients with comorbidities who may not be able to tolerate intensive CIT, the combination treatment of chlorambucil and obinutuzumab or ofatumumab is an option. For patients with del(17p), ibrutinib is the treatment of choice. Several ongoing phase 3 clinical trials with novel therapies will further refine the frontline therapy of CLL.

Pentostatin, cyclophosphamide and rituximab for previously untreated advanced stage, low-grade B-cell lymphomas

We conducted a prospective phase II trial of pentostatin, cyclophosphamide and rituximab as initial therapy for patients with previously untreated advanced stage low-grade or indolent B-cell lymphomas (iNHLs). Of 83 evaluable patients, 91·6% attained an overall response and 86·8% a complete or unconfirmed complete response. The 3-year progression-free survival (PFS) and overall survival rates were 73% and 93%, respectively. The 3-year PFS rate was significantly different for different diagnoses (P = 0·01): 83% [95% confidence interval (CI): 0·72, 0·96] for follicular lymphomas, 73% (95% CI: 0·54, 1·0) for marginal zone lymphomas and 61% (95% CI: 0·46, 0·81) for small lymphocytic lymphomas. The most common adverse events were haematological. Of 509 cycles of chemotherapy administered, grade 3 or 4 neutropenia was reported in 68 cycles (13% of cycles administered) and most frequently occurred during cycles 4-6. This is the first report demonstrating the effectiveness of pentostatin, cyclophosphamide and rituximab in patients with previously untreated iNHLs, including those over 60 years of age.

Second cancers in patients with chronic lymphocytic leukemia who received frontline fludarabine, cyclophosphamide and rituximab therapy: distribution and clinical outcomes

Patients with chronic lymphocytic leukemia (CLL) are known to have an increased incidence of second cancers, but the contribution of commonly used frontline therapies to the incidence of second cancers is unclear. We report on the characteristics, incidence, outcomes and factors associated with second cancers in 234 patients receiving fludarabine, cyclophosphamide and rituximab (FCR) based regimens in the frontline setting. The risk of second cancers was 2.38 times higher than the expected risk in the general population. Ninety-three patients (40%) had other cancers before and 66 patients (28%) after FCR. Rates of therapy related acute myeloid leukemia/myelodysplastic syndrome (t-AML/MDS) (5.1%) and Richter transformation (RT) (9%) were high, while solid tumors were not increased. Overall survival of patients with second cancers after frontline FCR was shorter (median of 4.5 years) compared to patients with and without prior cancers. Second cancer risk after frontline FCR is mainly due to high rates of t-AML/MDS and RT, and as speculated the survival of affected patients is shorter.