H3B-8800-G0001-101: A first in human phase I study of a splicing modulator in patients with advanced myeloid malignancies

TPS7075

Background: Dysregulated mRNA splicing is important in tumorigenesis and in resistance to cancer therapy. Somatic heterozygous mutations in core spliceosome genes (e.g. SF3B1, SRSF2, U2AF1) have been reported at high frequencies in patients with myelodysplastic syndromes (MDS), acute myeloid leukemia (AML), and chronic myelomonocytic leukemia (CMML). These mutations confer a change of function resulting in aberrant mRNA splicing that, in preclinical models, results in defects in hematopoietic cell development and myelodysplasia. Recurrent mutations in the spliceosome of patients with malignancies suggests importance in disease pathogenesis. Cells bearing splicing mutations depend on wild-type spliceosome function, suggesting the spliceosome as a therapeutic target. In vitro data indicate preferential induction of apoptosis (measured by caspase 3/7 activation) in SF3B1-mutant cells following treatment with the SF3B1 modulator H3B-8800. H3B-8800 inhibits growth in human AML cell lines, including those with mutations in U2AF1, SRSF2 or SF3B1. Oral administration of H3B-8800 modulates splicing and induces antitumor activity in xenograft leukemia models expressing mutant core spliceosome components. Methods: This study explores the safety of H3B-8800 in patients with myeloid cancers. Dose escalation (Cohort A) follows a 3+3 design with a starting dose of 1 mg daily for 5 consecutive days every 14 days in a 28 day cycle. Cohort A is open to patients with MDS, AML or CMML, irrespective of spliceosome mutations. In parallel to dose escalation, up to 6 patients with mutations of interest may be enrolled at doses determined to be safe in Cohort A (Cohort B). After determining the recommended phase 2 dose, 4 expansion cohorts will enroll patients with: (1) International Prognostic Scoring System (IPSS) low/int-1 risk MDS with SF3B1 mutations, (2) IPSS low/intermediate risk-1 MDS with mutations in SRSF2, U2AF1, or ZRSR2, (3) high/intermediate risk-2 MDS or AML, and (4) CMML; 3 and 4 having mutations in SF3B1, SRSF2, U2AF1, or ZRSR2. The first cohort enrolled 3 patients and the trial is currently enrolling patients at the second dose level. Clinical trial information: NCT02841540.

Late complications following clavicular fractures and their operative management

We describe our experience of the operative treatment of sequelae from high-energy injuries of the clavicle. Surgery was performed on 17 patients who often had more than one indication. This included the following: painful non-union (nine patients), neurogenic thoracic outlet syndrome (TOS), hypertrophic non-union three patients, hypertrophic malunion five patients, bony spike two patients), vascular TOS (two patients) and brachial plexus neuroma (one patient). At clinical review, functional outcome was assessed by using a Constant score, a visual analogue pain score, return to work status and by patient subjective satisfaction rating. We performed 11 decompressions with callus excision, three simple neurolysis, eight fixations for non-union, one osteotomy and three excisions of bone spikes. Two patients required a further decompression procedure; one patient developed deep sepsis requiring sequestrectomy and two patients required removal of metalwork. At mean follow-up of 49 months the average Constant score was 64 (range 27-93). The mean pain score was 4. Ten patients returned to work at an average of 8 months. Five patients were completely asymptomatic, eight reported occasional paraesthesiae and three had significant cold intolerance. Patient satisfaction scores were 14% very satisfied, 50% satisfied, 14% unsatisfied and 22% very unsatisfied. High-energy clavicle injuries can cause significant morbidity due to non-union and TOS. Refractory symptoms can be improved by operative intervention with satisfactory functional outcome. However, the majority of patients experience some degree of residual symptoms.

SAPHO syndrome: 20-year follow-up

Considerable attention has been paid in the past 10 years to the radiological spectrum of disease entities belonging to the SAPHO syndrome. We report an unusual case presenting with an extra-axial (femoral) lesion, prior to description of this syndrome, which was radiologically and histologically mistaken for a parosteal osteosarcoma. Nineteen years later, a further lesion developed in the scapula together with the typical sternoclavicular manifestations, at which stage the correct diagnosis of SAPHO syndrome was established.

The incidence of gastroesophageal reflux in preterm infants

We observed an increased incidence of gastroesophageal reflux (GER) in a group of preterm infants. Seventy-five infants (birth weight 1117 +/- 242 gm, gestational age 30 +/- 3 weeks) were tested within 1 week before hospital discharge (37 to 38 weeks postconceptional age). All of the infants had a two-channel pneumocardiogram and a 1-hour esophageal pH study (Tuttle test). Home monitors were used for all infants after hospital discharge and their use was maintained until standard discontinuation criteria were achieved. The Tuttle test was abnormal in 47 (63%) of the infants. Of the 47 infants with GER, 22 (47%) had evidence of obstructive apnea during the periods of reflux and 32 (68%) had an abnormal PCG result. Thirty-eight (81%) of the infants with GER had episodes of either obstructive or central apnea. The diagnosis of GER is important in premature infants because of the high association with recurrent or obstructive apnea.

Development of insulin sensitivity in rat aorta after chronic propranolol treatment

Spontaneously hypertensive rats and normotensive Kyoto Wistar controls were divided into 3 groups of 10 animals each and treated with phenoxybenzamine (5 mg/kg once daily), propranolol (25 mg/kg twice daily) or saline (once daily). After 5 weeks the in vitro incorporation of D-[U-14C]-glucose into aortic lipids and glycogen was measured in the presence and absence of insulin (1 mU/ml). In both normotensive and hypertensive rats treated with propranolol 14C-incorporation into triglycerides was reduced. Furthermore, insulin significantly stimulated 14C-incorporation into triglycerides, phospholipids and glycogen in propranolol-treated hypertensive rats. This effect was not statistically significant (0.05 less than p less than 0.1) in propranolol-treated normotensives. Phenoxybenzamine treatment did not significantly modify aortic lipogenesis or glycogen synthesis from glucose. Chronic propranolol treatment of spontaneously hypertensive rats resulted in aortic tissue becoming sensitized to insulin. Possible mechanisms and explanations for this are discussed.