Is there a role for metronomic induction (and maintenance) therapy in elderly patients with acute myeloid leukemia? A literature review

Efficacy and Safety of Metronomic Chemotherapy Versus Palliative Hydroxyurea in Unfit Acute Myeloid Leukemia Patients: A Multicenter, Open-Label Randomized Controlled Trial

Background:

Management of unfit AML patients is a therapeutic challenge. Most hematologists tend to avoid aggressive treatment leaving patients with a choice of best supportive care. We hypothesized that metronomic chemotherapy could be an alternative treatment for unfit AML patients.

Methods:

A multi-center randomized controlled trial was conducted in seven university-affiliated hospitals in Thailand. Unfit AML patients were recruited and followed up from December 2014 to December 2017. Patients were randomly assigned to receive either metronomic chemotherapy or palliative hydroxyurea. Overall survival rates were compared using Cox’s proportional hazard survival analysis.

Results:

A total of 81 eligible patients were randomly allocated and included for ITT analysis. The OS rate was higher in group receiving metronomic chemotherapy than in group receiving palliative treatment at 6 and 12 months with borderline significance (6 months HR 0.60; 95%CI 0.36, 1.02; p-value 0.060; 12 months: HR 0.66; 95%CI 0.41, 1.08; p-value 0.097).

Conclusion:

Metronomic chemotherapy could prolong survival time of unfit AML patients, especially in the first 12 months after diagnosis without increasing treatment-associated adverse events.

Prolonged administration of low-dose cytarabine and thioguanine in elderly patients with acute myeloid leukaemia (AML) achieves high complete remission rates and prolonged survival

The prognosis of AML in elderly patients is poor and research into novel therapeutic approaches is urgently needed. This study examined the use of low-dose chemotherapy with cytarabine and thioguanine administered in repetitive cycles in 62 elderly patients with newly diagnosed or relapsed/refractory AML. The overall response rate was 58% in the total cohort. Response rates (CR/CRi) were significantly higher in patients with newly diagnosed AML (74%) compared to patients with relapsed/refractory disease (25%, p = .0004). Kaplan-Meier estimate of overall survival was 289 days (95% CI; 183-395 days) with a relapse rate of 65.7%. The induction mortality rate was 16.1% with treatment successfully undertaken in the outpatient setting. Similar clinical outcomes were observed in a retrospective analysis of a second cohort of 25 AML patients treated at a different site. These results support the use of a sustained low intensity chemotherapy approach as a therapeutic option for elderly patients with AML.

Metronomic therapy in pediatric oncology: A snapshot

Metronomic chemotherapy transitioned from the bench to bedside in the early 2000s and since then has carved a niche for itself in pediatric oncology. It has been used solely or in combination with other modalities such as radiotherapy, maximum tolerated dose chemotherapy, and targeted agents in adjuvant, palliative, as well as maintenance settings. No wonder, the resulting medical literature is extremely heterogeneous. In this review, the authors review and synthesize the published literature in pediatric metronomics giving a glimpse of its history, varied applications, and evolution of this genre of chemotherapy in pediatric cancers. Limitations, future prospects, and grey areas are also highlighted.

Treatment patterns and comparative analysis of non-intensive regimens in elderly acute myeloid leukemia patients-a real-world experience from India

Elderly patients with acute myeloid leukemia have a poor prognosis. Data from developing countries is sparse in the literature. In this retrospective study, 402 patients aged ≥ 60 years, diagnosed between Jan 2013 and Dec 2017, were analyzed for treatment patterns and survival. Median age of the whole cohort was 68 years (range 61-84). A total of 213 patients (53.3%) refused care; 188 patients (46.7%) received either BSC, LDAC, or HMA. Survival (in months) was 3.9, 6.4, and 1.2 with LDAC, HMA, and BSC, respectively. One-year survival was 17.2% and 6% with HMA and LDAC, respectively (P = 0.02). Overall response rate (ORR) did not differ between HMA and LDAC group (p = 0.12). HMA cohort had higher complete responses (20.6% vs 7.4%, p = 0.02), stable disease (32.7% vs 13.5%, p = 0.02), and transfusion independence (TI) (46.5% vs 22.2%, p = 0.01). Survival did not differ between the groups if the patients achieved ORR (12.3 vs 9.8 p = 0.2) or TI (11.6 vs 6.4 p = 0.2). Stable disease with HMA led to longer survival (8.1 vs 5.3 p = 0.01). HMAs were more effective than LDAC irrespective of cytogenetic risk category and blasts, of note HMAs improved survival of poor risk patients (5.6 vs 2.9 p = 0.004). HMA treatment (HR = 0.48; 95% 0.29-0.79, p = 0.004) and transfusion independence (HR = 0.2; 95% 0.1-0.3, p = 0.0001) predicted survival in multivariate analysis. Neutropenia and febrile neutropenia were frequent in HMA. Thrombocytopenia was the common adverse event with LDAC. Novel and cost-effective drugs are essential to improve the prognosis of these patients.

Treatment of Langerhans cell histiocytosis with a modified risk-adapted protocol-experience from a tertiary cancer institute in India

BACKGROUND

Involvement of risk-organs (RO+) in Langerhans cell histiocytosis (LCH) and inadequate early response identifies patients at high risk for relapse and mortality requiring intensive salvage therapy including stem cell transplant, adding cost and toxicity. To mitigate this, we used a standard induction, augmented with metronomic etoposide, and prolonged maintenance-similarly augmented for RO+, and retrospectively analyzed its impact.

PROCEDURE

LCH patients from 2009 through 2014 were included. Patients received standard vinblastine and prednisolone therapy weekly till week 25 for RO+. Single site (SS) and multisystem (MS) without risk organ involvement (RO-) received 3-weekly pulses from week 13 till week 25. Maintenance was 3-weekly vinblastine and 5-day prednisolone pulses, daily 6-mercaptopurine (60 mg/m² ) and weekly methotrexate (15 mg/m² ) for 18 and 9 months for RO+ and MSRO-, respectively. RO+ also received oral etoposide (50 mg/m² ) for 21 of every 28-day cycle for the first year.

RESULTS

Fifty consecutive patients were analyzed. Median age was 36 months (4-189 months). SS, MSRO-, and RO+ were 29 (58%), 12 (24%), and nine (18%), respectively. Four were lost to follow-up and excluded from further evaluation. On response evaluation at week 6, 24 (52%) had no active disease (NAD), 17 (37%) had AD-better (where AD is active disease), and one (2%) had AD-worse. In RO+, eight (66.6%) had AD-better and three (25%) had NAD. Forty-five patients had NAD by week 12. Three patients relapsed. With median follow-up of 39 months (8-84), 5-year event free survival was 85.6% (RO- and SS), and 100% for RO+. One patient's death in remission from unrelated causes resulted in overall survival of 97%.

CONCLUSIONS

RO+LCH receiving oral etoposide augmented induction and maintenance had early and durable responses. Prolonging maintenance lowered reactivation rates in RO+ and RO-LCH, resulting in excellent survival.

Potential role of metronomic chemotherapy in the treatment of esophageal and gastroesophageal cancer

Patients with esophagogastric cancer have poor prognoses in spite of the best available therapies. Patients are debilitated and may not tolerate, or may progress, on standard cytotoxic chemotherapy regimens. Metronomic chemotherapy is an attractive treatment option due to its very low reported toxicity, modest efficacy, low cost and ease of administration. Capecitabine is the most common drug used in metronomic scheduling; other drugs include cyclophosphamide and paclitaxel. Dosing of capecitabine can range from 1000 mg orally daily for 4 weeks on and 1 week off to a continuous dosing schedule of 1500 mg orally daily. Reported toxicities, including neutropenia, mucositis and hand-foot syndrome, occur in <10% of patients. As there is a lack of well-conducted, randomized clinical trials evaluating the role of metronomic chemotherapy in esophagogastric cancer, it cannot be recommended as the standard of care; however, it can be considered to be a therapeutic option, especially in elderly patients with relapsed disease for whom other therapeutic options are limited.