Male Patients on Rilanocept Can Safely Conceive
Yes, males on rilanocept can conceive without needing to discontinue therapy, as there is no evidence of paternal medication transfer affecting offspring outcomes with biologic therapies, and the general principle from rheumatology guidelines supports continuation of immunosuppressive biologics in men attempting conception.
Evidence-Based Rationale
Biologic Therapies and Male Fertility
The American College of Rheumatology strongly recommends continuation of biologic agents including TNF inhibitors and IL-1 antagonists in men planning to father a pregnancy, as these large molecular weight proteins do not transfer in clinically significant amounts through seminal fluid 1.
Rilanocept is an IL-1 trap (fusion protein) with a molecular weight of approximately 251 kDa, making it far too large to cross into seminal fluid in meaningful concentrations, similar to other biologic agents 2, 3.
No reports exist of post-conception teratogenesis attributable to biologic medications taken by men with rheumatic or autoinflammatory diseases 1.
Specific Guidance for Rilanocept Context
Rilanocept is FDA-approved for CAPS (familial cold autoinflammatory syndrome and Muckle-Wells syndrome) and has demonstrated excellent safety and efficacy in controlling IL-1β-driven inflammation 4.
Discontinuing rilanocept poses significant risk to the male patient, as untreated CAPS can lead to severe complications including secondary AA amyloidosis (25% risk in Muckle-Wells syndrome), chronic inflammation, and organ damage 5.
The risk-benefit analysis strongly favors continuation: the theoretical (and unproven) risk to offspring is vastly outweighed by the documented harm of uncontrolled autoinflammatory disease 6, 5.
Medications That DO Require Discontinuation in Males
For context, only two medication classes require discontinuation before conception in males:
- Cyclophosphamide must be stopped 3 months before attempting conception due to mutagenic effects on sperm DNA 1.
- Thalidomide must be stopped at least 1 month before conception as it is detectable in seminal fluid and highly teratogenic 1.
Clinical Algorithm for Male Patients on Rilanocept
Reassure the patient that rilanocept continuation is safe when attempting conception 1.
Emphasize the importance of disease control - uncontrolled CAPS inflammation poses greater risk than medication exposure 5.
Ensure the female partner is not exposed to rilanocept (though this is not a concern as it is not transferred through intercourse) 1.
Monitor for adequate disease control with symptom scores and inflammatory markers (CRP, SAA) to prevent amyloidosis risk 4.
If conception does not occur after 12 months of attempting, consider standard fertility evaluation including semen analysis, but do not attribute infertility to rilanocept without evidence 7.
Critical Pitfalls to Avoid
Do not confuse maternal and paternal medication safety profiles - many medications contraindicated in pregnant women (like mycophenolate) are safe for men attempting conception 8.
Do not discontinue rilanocept based on theoretical concerns - there is no evidence of harm, and disease flare carries documented serious risks including amyloidosis and organ damage 5.
Do not delay conception counseling - patients should receive fertility guidance before starting any immunosuppressive therapy, but rilanocept does not require preconception discontinuation 1.