The Phase 2 TRAIT study suggests starting adjuvant abemaciclib at a lower dose and escalating over several weeks significantly reduces early discontinuations due to side effects like diarrhea. This strategy helps more patients get through the initial high-toxicity period and remain on the effective dose for the full two-year course.
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After observing deep, MRD-negative responses at their starting dose, Colonia Therapeutics unconventionally tested a lower dose level. This counter-intuitive strategy aims to identify the minimum effective dose, which is crucial for maximizing the safety profile (the therapeutic window) and improving commercial viability through lower manufacturing costs.
Due to fedratinib's significant GI side effect profile and the logistical difficulty of measuring thiamine levels, clinicians should proactively provide patients with thiamine supplements, anti-emetics, and anti-diarrheal therapies. Instructing patients to take the drug with food can also help mitigate GI toxicity.
The failure of an adjuvant trial for the TKI pazopanib was likely caused by a protocol change that reduced the dose to manage transaminitis. While well-intentioned to improve tolerability and adherence, the lower dose was sub-therapeutic. This serves as a critical lesson that managing side effects by compromising dose can nullify a drug's potential efficacy.
Experts favor adjuvant abemaciclib for eligible patients because of longer follow-up after treatment completion. The continuously separating survival curves in the MonarchE trial suggest abemaciclib may eradicate micrometastatic disease, unlike prior trials where curves converged post-treatment, implying only delayed growth.
A modified three-step-up dosing schedule for epcoritamab drastically reduced cytokine release syndrome (CRS) rates to 26%, with no severe events. This safety profile supports fully outpatient administration, making this highly effective regimen accessible to community practices without immediate hospital access.
The enzalutamide arms saw discontinuation rates of 20-25% due to adverse events. This high rate reflects a different risk calculation for patients who feel healthy and are asymptomatic. Unlike in advanced disease where patients tolerate more toxicity, this population has a very low threshold for side effects, making early intervention a significant trade-off.
Despite showing massive weight loss, new obesity drugs from Eli Lilly and others have high discontinuation rates due to side effects. This suggests the industry's singular focus on efficacy may be hitting diminishing returns, opening a new competitive front based on better patient tolerance and adherence.
Data from the MONARCH-E and NATALY trials show that the benefit of adjuvant CDK4/6 inhibitors like abemaciclib and ribociclib persists and even increases after patients complete their 2-3 year treatment course. This sustained "carryover effect" suggests a lasting impact on disease biology rather than just temporary suppression.
Clinical trial data shows that despite specific toxicities, antibody-drug conjugates (ADCs) can be better tolerated overall than standard chemotherapy. For example, trials for both sacituzumab govitecan and dato-DXd reported fewer patients discontinuing treatment in the ADC arm compared to the chemotherapy arm.
Using a second CDK4/6 inhibitor after progression on a first showed disappointing results in trials like post-MONARCH. However, the EMBER-3 trial's success, combining abemaciclib with the novel SERD imlunestrant, demonstrated robust efficacy. This suggests the choice of endocrine partner is the critical factor for making this sequencing strategy viable.
