The intravenous amivantamab regimen has faced adoption challenges due to practical burdens on patients and clinics, including long infusion times, infusion reactions, and scheduling difficulties. The shift to a subcutaneous formulation is a critical step to overcome these non-clinical barriers.

Beyond clinical efficacy, patient experience is a key differentiator. Patients strongly prefer single-administration ("one and done") gene therapies over treatments requiring regular injections. This is due to the cumulative stress, cost, and logistical burden of lifelong, recurring treatments, which directly informs therapeutic modality choice.

Despite superior efficacy and a manageable side effect profile, Gedatolisib's requirement for weekly IV infusions is its primary drawback. If it were an oral drug, it would be universally adopted for post-CDK4/6 inhibitor breast cancer treatment, as its clinical benefits are otherwise compelling.

Despite proven benefits, side effects from adjuvant CDK4/6 inhibitors like abemaciclib create significant adherence challenges. The speaker notes that in practice, almost no patient completes the full multi-year course at the starting dose. Even in a supportive study, 20% of patients discontinued therapy within six months, highlighting a critical gap between trial efficacy and real-world tolerability.

Second-generation PI3K inhibitor enovalisib has a 7% discontinuation rate compared to 25% for its predecessor, alpelisib. This is due to a better toxicity profile (e.g., 6% vs. 33% high-grade hyperglycemia) and improved proactive side effect management by clinicians.

Patient adherence with new drugs like ADCs often hinges on managing side effects in the first two cycles. This period requires significant "hand-holding," proactive follow-ups, and empathy to manage the patient experience, ensure compliance, and maintain quality of life before treatment becomes routine.

The perception that pills are less intense than infusions is a misconception. Patients on oral PARP inhibitors require constant monitoring for side effects like fatigue, nausea, and hematologic toxicities, especially in the first three months.

While its IV administration is a hurdle, the pan-PI3K/mTOR inhibitor gedotolisib is clinically compelling because of its distinct safety profile. It causes significantly less hyperglycemia and diarrhea compared to oral PI3K inhibitors like alpelisib, making it an attractive option for patients where those specific toxicities are a major concern.

The AKT inhibitor capivasertib has a unique and complex dosing schedule (twice daily, four days on, three days off). This necessitates providing patients, especially the elderly, with specific tools like dosing diaries to prevent confusion and ensure adherence.