First-in-Human Phase I Trial Combining Biologically Guided Radioimmunotherapy (RIT) Using a 90Y-Anti-CD25 Monoclonal Antibody (Mab) with CT-guided Total Marrow and Lymphoid Irradiation (TMLI) in Relapsed and Refractory (R/R) Acute Leukemia

PURPOSE/OBJECTIVE(S)

Patients with R/R acute leukemia after allogeneic hematopoietic cell transplant (alloHCT) have a dismal prognosis with 3-year survival rates of < 20%. To improve outcomes, innovative targeted forms of organ sparing radiotherapy, such as tumor-specific RIT and TMLI, are needed to dose escalate with acceptable toxicities, especially in patients ≥ age 60 years who cannot tolerate total body irradiation (TBI) / myeloablative regimens and who have a poor prognosis. CD25 is an ideal RIT target given its expression in acute leukemias, association with poor prognosis, and expression by leukemia stem cells. In this phase I trial (NCT05139004) we hypothesized that combining dose escalated 90Y-anti-CD25 RIT with fixed dose TMLI 12 Gy, fludarabine (flu), and melphalan (mel) in patients with R/R disease is safe and associated with acceptable toxicities.

MATERIALS/METHODS

The primary objective of this trial is to determine the maximum tolerated dose and recommended phase 2 dose of 90Y-anti-CD25 Mab (Day -15) with 12 Gy TMLI (1.5 Gy twice a day, days -8 to -5), flu (30 mg/m2/d days -5 to -2), and mel (100 mg/m2, day -2) in patients ≥ 60 years old or with a HCT-comorbidity index ≥ 2 and with R/R AML, ALL or myelodysplastic syndrome (MDS) scheduled to undergo alloHCT from a matched donor. TMLI mean organ dose constraints for kidney, lung and liver were 4 Gy. Planned dose levels of 90Y-anti-CD25 were 0.3, 0.4, and 0.5 mCi/kg. 111In-anti-CD25 (5 mCi) was co-infused followed by serial nuclear scans to assess dosimetry and biodistribution.

RESULTS

To date 5 patients (ages 31-74) with R/R AML have been treated. Marrow and circulating blasts ranged from 10-36% and 9-44%, respectively. For the 3 patients at 0.3 mCi/kg, follow-up ranged from 89-191+ days. 90Y/111In-anti-CD25 nuclear scans demonstrated persistent uptake in bone out to 144 hours, which was associated with a decline in circulating blasts. After combined RIT and TMLI, mean doses (Gy) to lungs ranged from 5.7-6.5, to kidneys from 7.5-8.2 and to liver from 7.2-11.6. No dose-limiting toxicities (DLT) were observed. All 3 patients achieved CR on day +30 bone marrow biopsies and 2 remained in CR on day +90 biopsies. Two patients have recently been treated at the 0.4 mCi/kg dose level. The results of patients treated at the higher dose levels will be provided.

CONCLUSION

Dose escalation by adding 90Y-anti-CD25 RIT at 0.3 mCi/kg to 12 Gy TMLI was safe, including in older patients, with no dose-limiting toxicities, mean critical organ doses lower than conventional myeloablative TBI, and encouraging response rates. The toxicity profile and dose estimates at 0.3 mCi/kg predict that the planned higher dose levels will also be feasible with acceptable toxicities. RIT and TMLI are complementary and when combined address the limitations of each modality. Combining these targeted therapies may be a superior strategy to intensify dose to leukemia compared to dose escalation of either modality alone.

Barriers of healthcare professionals in utilizing the service of drugs and poison information Centre: A cross-sectional study

Background

Health care professionals (HCPs) have been using drugs and poison information centre (DIC) less frequently in recent years. The purpose of this study was to identify the barriers that inhibit HCPs from using the DIC service in a tertiary care hospital, as well as the factors that assist HCPs in using DIC more effectively.

Methods

A cross-sectional study was conducted among HCPs in Sri Ramachandra Institute of Higher Education and Research, Chennai. HCPs were given a semi-structured questionnaire that was developed and validated by a subject expert, a public health expert, and a clinical psychologist, and their barriers and facilitators in accessing drug information services were recorded.

Findings

A total of 405 HCPs responded to the survey. Among the identified barriers, the top 3 were: HCPs found it easier to use mobile internet (31%) and the department's reference library (25%) instead of contacting DIC for any drug/poison information. In addition, 17% of HCPs stated that they were too busy. The factors that may assist HCPs utilize DIC more effectively were more awareness is required to demonstrate the functionalities of DIC (24%), and a mobile application is required (23%).

Conclusion

Today's HCPs have easy access to a variety of drug information resources, and many prefer to do their own drug/poison research. As current generation HCPs find it more convenient to use mobile internet than contacting DIC, the creation of a mobile application for drug information service may enhance the number of questions from HCPs.

Slow versus fast enteral feed advancement in very low birth weight infants: a randomized control trial

OBJECTIVE

To evaluate the tolerance of rapid advancement of enteral feeds in VLBW babies.

SETTING

Tertiary teaching hospital.

DESIGN

Randomized controlled trial.

METHODS

All stable neonates with birth weight less than 1250 grams were included in the study. The primary outcome variable was the time taken to achieve full enteral feeds (defined as 180 ml/kg/day). The secondary outcome variables were incidence of Necrotizing enterocolitis (NNEC) and incidence of apnea. At 48 hours, the infants were randomized into the slow advancement group (enteral feeds advanced by increments of 15 ml/kg/day) or fast advancement group (enteral feeds advanced by increments of 30 ml/kg/day). The monitoring during feeding included daily weight record, two hourly abdominal girth charting, gastric aspirates, apnea, time taken to reach full enteral feedings and for NNEC.

RESULTS

There were 53 infants who were enrolled for the study (27 in the fast advancement group and 26 in the slow advancement group). In the fast advancement group, 20 percent completed the trial; whereas 14 (53.8 percent;) in the slow advancement group completed the study. The two groups were comparable for birth weights, gestational age, sex, intrauterine growth status, Apgar and CRIB scores. The infants in the fast group reached full enteral intake of 180 ml/kg/day significantly earlier (10 +/- 1.8 days) than in the slow group (14.8 +/- 1.5 days). The two groups were comparable for episodes of feed intolerance, apnea, NNEC. Infants in the fast group regained birth weight significantly earlier (median 18 days) than in the slow advancement group (median 23 days).

CONCLUSIONS

Stable VLBW neonates can tolerate rapid advancements of enteral feeding without increased risk of adverse effects.