This is a randomized, double-blind, placebo-controlled, multi-center

Phase 2a dose-ranging study to evaluate the efficacy, safety, and

tolerability of HT-001 for the treatment of EGFRI-induced skin

toxicity. The study will include adult patients (18 years of age)

receiving initial or repeat EGFRI therapy.

The study will be conducted in parallel in 2 cohorts: Part 1 (only at

selected PK sites), an open-label cohort consisting of 12 patients to

measure PK of HT-001 (2% aprepitant); and Part 2 (all sites), a

randomized, parallel arm study comparing 3 dose strengths of

HT-001 (0.5%, 1%, or 2% aprepitant) to placebo (HT-001 vehicle).

Patients in the randomized cohorts will be randomly assigned to 1 of

the 4 treatment arms in a 2:2:2:1 ratio

All patients in both open-label and blinded cohorts will apply the

study drug once a day to each area affected with cutaneous toxicity

up to 30% body surface area (BSA) involvement, inclusive of skin,

scalp, and nails.

Patients initiating EGFRI therapy will be monitored by their

oncologist for development of cutaneous toxicities and will be

referred for Screening/Baseline (V1), at which point they will be

enrolled in either the open-label cohort (Part 1) for application of

HT-001 (2% aprepitant) for 6 weeks or randomized to HT-001

(0.5%, 1.0%, or 2.0% aprepitant) or placebo (HT-001 vehicle) for

6 weeks (Part 2). Patients in the randomized, double-blind cohort

(Part 2 only) will be stratified across severity scores of acneiform

rash to allow for subgroup analysis for safety and efficacy per

severity. All affected BSA with EGFRI-related cutaneous toxicity

disorders will be treated. Patients from each arm will be monitored

for treatment failures requiring rescue medication. BSA for each

patient will be recorded at each visit and when dosing areas change,

as well as total dose applied, and any changes to application area will

be monitored.