Discovery of an Orally Bioavailable and Selective PKMYT1 Inhibitor, RP-6306

PKMYT1 is a regulator of CDK1 phosphorylation and is a compelling therapeutic target for the treatment of certain types of DNA damage response cancers due to its established synthetic lethal relationship with CCNE1 amplification. To date, no selective inhibitors have been reported for this kinase that would allow for investigation of the pharmacological role of PKMYT1. To address this need compound 1 was identified as a weak PKMYT1 inhibitor. Introduction of a dimethylphenol increased potency on PKMYT1. These dimethylphenol analogs were found to exist as atropisomers that could be separated and profiled as single enantiomers. Structure-based drug design enabled optimization of cell-based potency. Parallel optimization of ADME properties led to the identification of potent and selective inhibitors of PKMYT1. RP-6306 inhibits CCNE1-amplified tumor cell growth in several preclinical xenograft models. The first-in-class clinical candidate RP-6306 is currently being evaluated in Phase 1 clinical trials for treatment of various solid tumors.

Oral Lorazepam is not Superior to Placebo for Lowering Stress in Children Before Digestive Endoscopy: A Double-Blind, Randomized, Controlled Trial

BACKGROUND

Digestive endoscopies must be performed within a safe and comfortable environment. We have previously shown that the quality of intravenous sedation is influenced by preoperative stress.

AIM

Our primary objective was to compare the effects of oral lorazepam and placebo on the salivary cortisol response of children undergoing a digestive endoscopy. Secondary objectives were the assessment of procedural pain and comfort as well as the occurrence of adverse events.

METHODS

Participants were randomized and received either lorazepam, placebo, or no premedication. Saliva was collected upon arrival at the hospital and 1 h following randomization. The sedation protocol included midazolam and fentanyl ± ketamine. Procedural pain was evaluated with the Nurse Assessed Patient Comfort Score (NAPCOMS). Patients completed a postoperative questionnaire. The primary outcome was defined as the proportion of children having a cortisol decrease ≥ 15 nmol/L.

RESULTS

101 participants (54 females) were included. The rate of children having a cortisol decrease ≥ 15 nmol/L was 27.3%, 35.3%, and 19.4% for lorazepam, placebo, and no premedication, respectively (p = 0.356). The median (IQR) NAPCOMS pain score was 3.0 (0-6) for lorazepam, 4.4 (0-6) for placebo, and 3.4 (3-4) for no premedication (p = 0.428). With lorazepam, 75.9% of children reported experiencing a comfortable procedure, compared with 41.9% taking placebo and 34.5% with no premedication (p = 0.013). Transient tachycardia was the most frequent intraoperative adverse event, particularly with lorazepam (62.5%, p = 0.029).

CONCLUSIONS

Oral lorazepam had no effect on patients' preoperative stress, as measured by salivary cortisol, but was associated with a higher rate of comfortable procedures.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov, Identifier NCT03180632.