Exhibit 99.1

Calle La Colonia N° 150,

Urb. El Vivero - Santiago de Surco

Telf: 317-6000

Lima, November 2, 2026

Sirs

Superintendencia del Mercado De Valores – SMV

Lima.-

Pursuant to the provisions of Article 30 of the Consolidated Text of the Securities Market Law and the Regulations on Material Events and Reserved Information approved by SMV Resolution No. 005-2014-SMV/01, we hereby report the following:

Today, we have become aware of the response submitted by MSRA S.A.C. (the valuation entity designated to determine the minimum price per share to be considered by Inversiones Aspi S.A. in the Public Tender Offer for the voting shares issued by Cementos Pacasmayo S.A.A.) to the Superintendence of the Securities Market (the “SMV”) in order to address the additional observations made by the SMV through Official Letter No. 5490-2026-SMV/11.1 (File No. 2026017300) dated October 29, 2026, regarding the valuation report prepared by MSRA S.A.C. within the framework of the PTO.

Attached as an Annex to this communication is a copy of the aforementioned response submitted by MSRA S.A.C. to the SMV.

Without further business, we remain yours truly.

Sincerely,

CEMENTOS PACASMAYO S.A.A.

José Félix Villafuerte Mendoza

Representante Bursátil

ANNEX 1:

Mr.César Figueroa Benites

Acting General Intendant

General Intendency of Conduct Supervision Superintendence of the Securities Market Av.

Paseo de la República N° 3617, San Isidro Lima.-

Lima, October 30, 2026

Ref.: Official Letter N° 5490-2026-SMV/11.1 - File N° 2026017300Subject: Absolution of the reiterated observations regarding requirements 2.2, 2.9, and 3.1 of Official Letter N° 5332-2026-SMV/11.1

Dear Sir:

We address you on behalf of MSRA S.A.C. (hereinafter, MSRA), in response to the reference Official Letter, notified on October 29, 2026, through which it is required to complete the answers to requirements 2.2, 2.9, and 3.1 of Official Letter N° 5332-2026-SMV/11.1, addressed via brief dated October 22, 2026 (hereinafter, the Brief), regarding the Valuation Report of the common shares of Cementos Pacasmayo S.A.A. (hereinafter, CPAC or the Company) submitted on October 14, 2026 (hereinafter, the Report).

Below, we address each observation following the numbering of the Official Letter. The tables come from the valuation model that supports the Report. Unless otherwise indicated, figures are expressed in thousands of soles (S/ thousands). None of the addressed points modifies the minimum price determined in the Report (S/ 8.93 per common share as of October 14, 2026), which corresponds to the consideration value methodology.

Observation 1 (requirement 2.2)

CPAC produces and markets cement, ready-mix concrete, pavements, mortars, precast products, quicklime, and other construction materials; cement is its main line, accounting for 82% of consolidated net sales in 2025 (Report, section 5.1). In the model, the projected volume corresponds to shipments of cement, concrete, and precast products, grouped in thousands of MT, which generate 97% of projected revenues (Report, section 10.4.3.1); in this response, “CPAC’s volume” refers to this aggregate. This volume depends on the national demand for cement and CPAC’s market share therein. The assumption of growth at the private investment rate (elasticity close to 1) is based on three fundamentals: (a) national cement demand is mostly expenditure that national accounts register as private investment; (b) in the historical series, cement demand varies in a proportion close to that of private investment; and (c) CPAC’s market share has been relatively stable, so it is projected at its current level.

a) Cement demand is part of private investment Of the national cement dispatch, 72% goes to self-construction, 14% to formal private works, and 14% to public works (Report, sections 6.1.1 and 8.2.3); that is, 86% corresponds to private works. In the national accounts prepared by INEI, housing construction—including self-construction by households—and private buildings and works are registered as private gross fixed investment; the BCRP publishes this series, which is the one used in the Report (Annex 16.5.1.4). Therefore, the expenditure driving cement demand is mostly a component of private investment. Although private investment also includes machinery and equipment, which do not demand cement, the evidence in literal (b) shows that cement volume varies in a proportion close to that of private investment.

b) Historical evidence: elasticity close to 1 Table 1 compares the annual variation of local cement dispatch, according to the INEI series, with that of real private investment. The 2020-2022 period is excluded, as it was distorted by the halt of works in 2020 and the subsequent rebound.

Table 1. Local cement dispatch and real private investment (Annual variation %)

(Sources: INEI, table 2.7.02 “Local dispatches by company” (in metric tons; information by cemnt producing companies); BCRP, real gross private fixed investment (Report, Annex 16.5.1.4). Elaboration: MSRA).

The regression of cement variation against private investment variation yields:

Table 1.1 Regression: ∆% cement = a+b x ∆% private investment (11 observations)

The estimated elasticity (0.97) is close to 1 and is not statistically different from 1. There is, therefore, no statistical evidence to justify applying an elasticity different from 1; projecting the volume with the private investment rate is the specification supported by the evidence.

c) Relatively stable market share for CPAC With an elasticity close to 1 and a stable share, CPAC’s volume grows at a rate similar to that of national demand. Between 2012 and 2025, CPAC’s share in local cement dispatch remained between 18.0% and 24.2%, with an average of 20.5%; in 2025 it was 21.0% and in the twelve months ended March 31, 2026, it was 21.0%. It is projected to remain stable because: (i) land transportation costs segment the market by zones; (ii) CPAC has the capacity to meet demand; and (iii) CPAC’s greater exposure to El Niño is already captured in the scenarios applied to private investment (Annes 16.5.1.2).

Table 1.2 Local cement dispatches and CPAC participation, 2012 – march 2026

Market share = CPAC local dispatch / Total local dispatch. Average, minimum, and maximum calculated using the full years 2012–2025; standard deviation of 2.1 pp. Figures for 2026 are preliminary. Source: INEI, Table 2.7.02 “Local cement dispatch by company” (data from cement-producing companies). Elaboration: MSRA. The table measures only local cement dispatch; the model volume (3,045 thousand MT in 2025; Report, section 10.4.3.1) also includes concrete and precast products.

Therefore, CPAC’s volume grows at the private investment rate because cement demand varies in a proportion close to that variable (elasticity of 0.97, not different from 1) and CPAC’s share in that demand has remained stable.

Observation 2 (Requirement 2.9)

The 2036 D&A is calculated by asset category and by year of commissioning (cohort), with three components: (i) existing assets as of 12.31.2025, which maintain their 2025 annual charge until their net carrying amount is fully depreciated; (ii) CapEx from 2026 onward, on a straight-line basis with a half-year convention in the year of addition and in the final year of useful life; and (iii) the 2035 capacity expansion. Table 3 summarizes the result, Tables 3.1 through 3.4 detail the calculation of each component, and Table 3.5 presents the valuation effect of the revision indicated in note (a).

Table 3. Breakdown of 2036 D&A (S/ thousands)

PPE: Property, plant, and equipment, excluding right-of-use assets. Sums may differ due to rounding. Source: DCF valuation model, tabs “N09_PPE” and “N10_Intangibles”. Elaboration: MSRA.

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(a) In the 2036 column of the intangible assets tab of the original model submitted, two amortization formulas for existing assets referenced the 2026 column instead of 2025: the limited-life intangible, fully amortized in 2028, recorded a credit of S/ 2,454 thousand instead of zero, and exploration costs recorded a charge of S/ 114 thousand instead of S/ 76 thousand. Consequently, in the submitted model, 2036 intangible amortization was S/ 4,993 thousand and 2036 D&A was S/ 91,132 thousand (S/ 2,416 thousand lower than the figures in this table). The valuation impact is detailed in Table 3.5.

Table 3.1. Existing Assets as of 12.31.2025: 2036 Charge (S/ thousands)

Annual charge (B): 2025 charge for each category. The charge continues until net book value is fully amortized; the final year captures the remaining balance (e.g., machinery: 805,723−8×95,891=38,595 in 2034). (b) 2026 charge = annualized 1Q-2026 amortization net of amortization from 2026 additions. Source: DCF valuation model. Elaboration: MSRA.

Table 3.2. CapEx from 2026 Onward: 2036 Depreciation by Cohort (S/ thousands)

2036 depreciation of each cohort = addition × annual rate × fraction. Fraction: 50% in the addition year and in the year useful life is reached; 100% in intermediate years; 0% thereafter. Examples: Buildings, 2026 cohort: 42,411×2.632%×100%=1,116; 2036 cohort: 43,796×2.632%×50%=576. Transport, 2027 cohort: reaches 9 years in 2036 →3,833×11.11%×50%=213; the 2026 cohort is already fully depreciated. Computing: the 2026–2028 cohorts are already fully depreciated; the 2029 cohort reaches 7 years in 2036 (50%). Additions = direct additions + transfers from construction in progress, allocated among categories based on the 2021–2025 transfer proportion; machinery excludes the 2035 expansion. Useful lives fall within CPAC’s accounting policy ranges (Brief, Table 10). Source: DCF valuation model, tab “N09_PPE”. Elaboration: MSRA.

Table 3.3. 2035 Expansion and Assets Amortized by Units of Production (S/ thousands)

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Rates for mine development, quarry closure, and exploration: 2021–2025 average of annual amortization divided by the opening balance of each category, which replicates CPAC’s units-of-production method (Note 2 to its financial statements). Rates rounded to one decimal place; the calculation uses the model’s exact rate. 2036 exploration additions are amortized for half a year, and mine development and quarry closure for a full year, following the model convention for these categories (difference under S/ 70 thousand). Source: DCF valuation model, tabs “N09_PPE” and “N10_Intangibles”. Elaboration: MSRA.

Table 3.4. Computer Software Applications: 2036 Amortization by Cohort (S/ thousands)

5-year useful life (20% rate), with a half year in the addition year and in the fifth year. The total of S/ 6,409 thousand corresponds exclusively to software applications acquired from 2026 onward. Source: DCF valuation model, tab “N10_Intangibles”. Elaboration: MSRA.

Table 3.5. Valuation Effect of Intangibles Amortization Revision on DCF Value (S/ thousands)

Observation 3 (Requirement 3.1)

1. Calculation Method: Each realization factor is determined in three steps:

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Table 4. Liquidity Levels and Realization Haircuts in Liquidation

2. Inventories: 56% Factor

Table 5. Inventories: Factor Calculation by Component (S/ thousands)

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3. Other Property, Plant, and Equipment: 62% Factor

Table 6. Other Property, Plant, and Equipment: Factor Calculation by Component (S/ thousands)

Without further business, we remain at your disposal for any further clarification.

Sincerely,

Johan Cieza De Los Santos

Legal Representative

MSRA S.A.C.