TABLE 5.

Univariate and multivariate analyses of variables affecting PFS.

Independent variable	Cox proportional hazard regression analysis for PFS
		Univariate			Multivariate
		HR	95% CI	p value	HR	95% CI	p value
Time from diagnosis to IRd	≥5 y versus <5 y	0.48	0.29–0.79	0.004	0.32	0.18–0.57	0.0001
Age	≥70 versus <70	0.56	0.34–0.93	0.02	0.6	0.36–1.002	0.05
Best response	≥VGPR versus <VGPR	0.55	0.31–0.99	0.04	0.67	0.36–1.24	0.20
Len‐exposure status	Exposed, non‐refractory to Len non immediately prior to IRd versus Len‐naïve	1.62	0.87–3.03	0.13	2.14	1.07–4.27	0.03
	Refractory to Len non immediately prior to IRd versus Len‐naïve	2.13	1.02–4.42	0.04	3.33	1.46–7.61	0.004
	Exposed, non‐refractory to Len immediately prior to IRd versus Len‐naïve	1.18	0.44–3.19	0.74	2.04	0.69–6.02	0.19
	Refractory to Len immediately prior to IRd versus Len‐naïve	3.59	1.41–9.16	0.007	4.31	1.56–11.94	0.004
Bor‐exposure status	Refractory to Bor versus Bor‐exposed, non‐refractory	2.23	1.13–4.41	0.02	—
	Bor‐naïve versus Bor‐exposed, non‐refractory	1.19	0.53–2.67	0.67	—
Prior lines of therapy	1 versus ≥2	0.59	0.33–1.02	0.07	—
Cytogenetics	HR versus SR	1.33	0.74–2.4	0.33	—
Del17p	del17p versus no del17p	0.97	0.48–1.93	0.93	—
Starting Len dose	25 versus <25 mg	1.29	0.69–2.39	0.4	—
Time interval between the last Len administration and IRd	≥12 versus <12 m	0.98	0.52–1.85	0.97	—
eGFR	>60 versus ≤60 mL/min	0.77	0.43–1.39	0.4	—

Abbreviations: Bor, bortezomib; HR, high risk; Len, lenalidomide; m, months; SR, standard risk; VGPR, very good partial response; y, years.