Best answer: (A) Subcutaneous pembrolizumab (790 mg/9,600 units every 6 weeks) provides the longest labeled dosing interval among the subcutaneous anti–PD-1 options, making it a well-suited regimen for patients who need to minimize treatment-related travel and clinical visits.

Rationale: Choice (A) best aligns with this particular patient’s stated preference to minimize scheduled travel. Among the listed regimens, subcutaneous pembrolizumab 790 mg/9,600 units every 6 weeks has the longest labeled dosing interval. Subcutaneous nivolumab 1,200 mg/20,000 units is administered every 4 weeks. Thus, the pembrolizumab schedule would require fewer planned treatment visits during a 12-month adjuvant course, which may be particularly relevant for a long-haul truck driver who lives far from the treatment center. Both injections are administered over several minutes, so the principal logistical distinction in this case is the dosing interval rather than the duration of each visit.^1,2

This conclusion is patient-specific and does not indicate that subcutaneous pembrolizumab is universally preferable. Subcutaneous nivolumab every 4 weeks remains an appropriate and practical option. Another patient might prefer more frequent in-person contact, have better insurance or formulary access to nivolumab, or receive treatment at a center where nivolumab is more readily available. Dosing frequency should therefore be considered alongside efficacy, toxicity, access, institutional workflow, and individual patient preferences.

The pivotal phase III 3475A-D77 trial demonstrated pharmacokinetic noninferiority of subcutaneous pembrolizumab administered every 6 weeks compared with intravenous pembrolizumab administered every 6 weeks.³ Similarly, CheckMate 67T demonstrated that subcutaneous nivolumab every 4 weeks met its prespecified pharmacokinetic noninferiority criteria compared with intravenous nivolumab.⁴ These studies support the respective subcutaneous formulations but did not directly compare pembrolizumab with nivolumab or establish the superiority of one subcutaneous anti–PD-1 agent over the other.

Pembrolizumab and nivolumab are both NCCN guideline-recommended adjuvant anti–PD-1 treatment options following complete resection of stage III melanoma, and both subcutaneous products have FDA-labeled indications for adjuvant melanoma treatment.⁶ Accordingly, the selection between them should be individualized rather than based solely on the number of treatment visits.

The patient’s wife, who is a nurse, asks whether the injection could be administered at home or at a clinic closer to their residence. The oncologist explains that both products must be administered by a healthcare professional and are not labeled for patient or caregiver self-administration at home. Treatment at a local clinic might be possible if that site can obtain and administer the medication, provide appropriate monitoring, secure payer authorization, and coordinate care with the treating oncology team.

Best answer: (C) Pembrolizumab and nivolumab have comparable safety and irAE profiles regardless of IV or SC administration; for patients with BRAF V600E mutations, targeted therapy with dabrafenib/trametinib represents an equally effective adjuvant alternative that completely avoids immune-mediated toxicities.

Rationale: Pembrolizumab and nivolumab are both anti-PD-1 monoclonal antibodies with comparable mechanisms of action and similar immune-related adverse event (irAE) profiles. Neither agent has demonstrated a clearly superior safety profile over the other in the adjuvant setting. The subcutaneous formulations preserve the same irAE rates as their IV counterparts; the route of administration does not meaningfully alter the risk of immune-mediated toxicity (though mild injection site reactions are slightly more common with SC delivery).^1,2

For this patient with a strong family history of autoimmune disease and BRAF V600E-mutant melanoma, the most important counseling point is that adjuvant dabrafenib/trametinib is also an effective alternative that avoids the approximately 15% risk of lifelong endocrine dysfunction and other irAEs associated with anti-PD-1 therapy.⁶

NCCN guidelines note that there is no good evidence basis for selecting between adjuvant BRAF/MEK inhibitors versus immune checkpoint inhibitors, as both have similar efficacy.⁵

Side effects from immune checkpoint inhibitor therapy tend to be longer lasting than those from BRAF/MEK inhibitor therapy, persisting after discontinuation of treatment.⁸

If the patient still prefers immunotherapy, either subcutaneous pembrolizumab or nivolumab would be appropriate. Given her proximity to the cancer center, the dosing interval (Q3W vs Q4W vs Q6W) is less of a differentiating factor.

Best answer: (E) Subcutaneous formulations of either pembrolizumab or nivolumab provide equal adjuvant efficacy while eliminating the need for invasive vascular access or port placement in patients with compromised peripheral IV access.

Rationale: This patient has very high-risk disease (stage IIID) where the absolute benefit of adjuvant anti-PD-1 therapy is greatest, making observation a less favorable option.⁷ The subcutaneous formulations of both pembrolizumab and nivolumab eliminate the need for IV access entirely, avoiding the morbidity and infection risk of port placement in a patient with bilateral upper extremity lymphedema.
Both SC options are equally valid from an efficacy standpoint. The choice between them may be guided by practical considerations:

• Subcutaneous pembrolizumab Q6W requires fewer total visits (~8 over 12 months) and has a shorter injection time (~2 minutes for the Q6W dose).¹
• Subcutaneous nivolumab Q4W requires ~12 visits but offers the flexibility of a Q2W schedule if more frequent monitoring is desired for this very high-risk patient.²

For a patient with stage IIID disease, some clinicians may prefer the Q4W or Q2W nivolumab schedule to allow more frequent clinical assessments during the early months of therapy, when the risk of both recurrence and irAEs is highest. Conversely, if the patient values fewer visits, the Q6W pembrolizumab schedule is equally appropriate.

The key teaching point is that subcutaneous formulations now provide a practical solution for patients who would otherwise require invasive vascular access devices, removing a significant barrier to receiving guideline-recommended adjuvant therapy.

Best answer: (A) Switching directly from IV to subcutaneous nivolumab is supported by product labeling as an intra-drug route change, whereas switching to subcutaneous pembrolizumab represents a change in the therapeutic agent that warrants a separate clinical discussion.

Rationale: The FDA label for Opdivo Qvantig explicitly states that adult patients currently receiving IV nivolumab as a single agent may switch to subcutaneous Opdivo Qvantig at their next scheduled dose.¹ This is a straightforward route-of-administration switch within the same drug. Similarly, the Keytruda Qlex label supports switching between IV and SC pembrolizumab.²

However, switching from nivolumab to pembrolizumab (or vice versa) represents a change in the therapeutic agent itself, not merely the route of administration. While nivolumab and pembrolizumab are both anti-PD-1 antibodies with similar mechanisms and are considered interchangeable by some experts, the pivotal adjuvant trials studied each agent independently, and the FDA approvals are drug-specific. A switch between agents mid-treatment should involve a clinical discussion about the rationale, and the decision should be documented.

In this case, the most straightforward approach is to switch from IV nivolumab to SC nivolumab (Opdivo Qvantig) 1,200 mg Q4W, maintaining the same drug and dosing interval while eliminating the need for IV infusion. If the patient strongly prefers the Q6W schedule, a discussion about switching to SC pembrolizumab Q6W is reasonable, acknowledging that this is a drug change rather than a simple formulation switch.

Best answer: (D) Neither pembrolizumab nor nivolumab requires renal dose adjustment, but subcutaneous pembrolizumab requires a substantially smaller injection volume (4.8 mL Q6W vs. 20 mL Q4W for nivolumab), which may guide patient comfort and preference.

Rationale: Anti-PD-1 antibodies are large monoclonal antibodies that are not renally cleared, and neither pembrolizumab nor nivolumab requires dose adjustment for renal impairment. This patient’s CKD stage 3b (eGFR 48) does not affect the choice between agents or necessitate dose modification.
Regarding injection volume, there is a notable difference between the two SC formulations:

• Keytruda Qlex Q6W: 4.8 mL injected over ~2 minutes (or 2.4 mL Q3W over ~1 minute)¹
• Opdivo Qvantig Q4W: 20 mL injected over 3–5 minutes (1,200 mg/20,000 units)²

The substantially smaller injection volume of SC pembrolizumab may be relevant for patients concerned about injection site discomfort or those with limited subcutaneous tissue. In clinical studies, injection site reactions with both formulations were predominantly grade 1–2 and self-limiting. However, the smaller volume of pembrolizumab SC (4.8 mL vs 20 mL) is a practical differentiator that may influence patient preference and comfort.